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TRANSCRIPT
A STUDY ON THE TAXONOMY OF THE CATFISHES OF KERALA AT THE
SPECIES LEVEL IN A PRELIMINARY FRAME WORK
RESEARCH REPORT
SUBMITTED TO
INDIAN ACADEMY OF SCIENCES, BANGALORE
BY
ANEESHA DEVASSY
SUPERVISED BY
DR. T. C. NARENDRAN
PROFESSOR AND HEAD OF THE DEPARTMENT (RETIRED),
C/O DEPARTMENT OF ZOOLOGY,
UNIVERSITY OF CALICUT
2010
Name of SRF : Aneesha Devassy
Registration Number : LFS 704
Institution where working : Research Scholar, School of Biosciences,
Mahatma Gandhi University, Kottayam
Date of joining the project : April 4, 2010
Date of Completion of the project : June 4, 2010
Name of the Guide : DR. T. C. NARENDRAN, Professor and Head
of the Department (Retired), c/o Department of
Zoology, University of Calicut
Project Title : A study on the taxonomy of the catfishes of
Kerala in a preliminary framework.
Signature of the guide :
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UNIVERSITY OF CALICUT
Dr. T. C. Narendran, Ph.D.,FASc.Professor & Head (Retd.)
C/o Systematic Entomology Laboratory
DEPARTMENT OF ZOOLOGYUNIVERSITY OF CALICUT
Kerala – 673 635, IndiaOffice: 0494 2401144*419
Res.: 0494 2400302E-mail : [email protected]
CERTIFICATE
This is to certify that this research report “A study on the taxonomy of the catfishes of
Kerala at the species level in a preliminary frame work” is an authentic record of work done
by Miss. Aneesha Devassy, Summer Research Fellow, Indian Academy of Sciences, Bangalore,
in the Systematic Entomology Laboratory, Department of Zoology, University of Calicut under
my guidance and supervision.
Dr. T. C. Narendran
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DECLARATION
I hereby declare that this dissertation entitled “A STUDY ON THE
TAXONOMY OF THE CATFISHES OF KERALA AT THE SPECIES LEVEL IN
A PRELIMINARY FRAME WORK” submitted to Indian Academy of Sciences,
Bangalore, has been originally carried out under the guidance and supervision of
Professor Dr. T. C. Narendran at the Systemic Entomology Laboratory, Department of
Zoology, University of Calicut, Calicut.
Aneesha Devassy
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ACKNOWLEDGEMENT
In the submission of this project, I express my
gratitude to:
Above all else, I acknowledge gratefully the
grace of the Almighty, experienced during each step
of this project and in its successful completion.
Sincere gratitude to Indian Academy of Sciences,
Bangalore, for selecting me for the Summer
Research Fellowship that provided me the
opportunity to conduct this study.
This project was carried out under the able and
inspirational guidance of Dr. T. C. Narendran,
Professor and Head of Department (Retired) c/o
Department of Zoology, University of Calicut. I
remain deeply indebted to him, for his constant
encouragement, suggestions, and optimism that
inspired me throughout this project.
My sincere thanks to Dr. N. Ramani, Head of the
Department of Zoology, University of Calicut, for
providing me the necessary facilities in the
Department. I also thank Professor Dr. M. S. Latha,
Director, School of Biosciences, Mahatma Gandhi
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University, Kottayam for permitting me to undertake
this fellowship programme.
My heartfelt gratitude to my research guide Dr.
Linu Mathew, for the invaluable support and
guidance throughout this work.
I am extremely grateful to Dr. K. G.
Padmakumar, Professor and Associate Director
(Aquaculture), Regional Agricultural Research
Station, RARS, Kumarakom, for the invaluable
guidance and help without which this project would
not have reached completion.
I would also like to gratefully acknowledge the
assistance rendered throughout this work by
Mr. Rakesh C. G., SRF, RARS, Kumarakom.
I convey my sincere thanks to Dr. Sr. Karmaly for
all help and encouragement.
I thank Mr. Antony Chirakkal, Mr. Akhil Antony,
Mr. Arun Antony and all other persons for helping me
to collect the fish specimens, live samples. I would
also like to thank Mr. Shaju for the photographic work
involved. I wish to express my sincere thanks to Ms.
Sreedevi S. for her help and support.
I express my affection and deep sense of
gratitude to all my researcher friends Ms. Lakshmi
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Devi Menon, Ms. Veena P., Mr. Santhosh S. Nair, Mr.
Abhilash Peter, and Ms. Sheeba M. for their whole
hearted and sincere cooperation in my work.
Last but not least I express my gratitude to my
family for their constant encouragement and prayer
without which I would not have been able to pursue
the course of my study.
Aneesha Devassy.
“For it is he who gave me unerring
knowledge of what exist, to know the
structure of the world and the activity of
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elements; the beginning and end and
middle of times, the alterations of the
solstices and the changes of the seasons,
the cycles of the year and the
constellations of the stars, the natures of
animals and the tempers of the wild
animal, the powers of the spirits and the
thoughts of the human beings, the
varieties of plants and the virtues of roots;
I learned both what is secret and what is
manifest, foe wisdom, the sashioner of all
things, taught me.”
Wisdom of Solomon 7: 17-22
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Glossary
Adipose fin : A small and fleshy fin, without rays, placed behind the
dorsal fin on the back of some fishes.
Air bladder : A gas filled sac located in the body cavity below the
vertebrae
Anal fin : The unpaired fin on the midline of underside of body, just
behind the vent
Antrorse : Pointing forward
Anus or vent : The opening at the posterior end of the digestive tract.
Barbel : A slender, tactile, whisker like projection extending from
the head of some fishes; they function primarily as a
sensory organ for locating food.
Base : The part where a fin joins body, as in length of dorsal or
anal fin base
Branchial : Pertaining to gills.
Branchiostegal : Slender bones which support the gill membranes.
Caudal fin : The tail fin
Cleithrum : One of the bones of the pectoral girdle, on which the
pectoral fin is hinged.
Cloaca : Terminal part of gut into which the kidneys and
reproductive ducts open; in such cases there is only a single
posterior opening to the body, the cloacal aperture, instead
of separate anus and urogenital opening.
Dorsal fin : The unpaired fin/s on the midline of back.
Gill arches : The bony supports to which the gills are attached.
Gonopodium : Modified anal finrays, elongated and thickened, and
functioning as an organ of transference of spermatophores
to the body of the female.
Isthmus : The fleshy interspace below the head and between the gill
openings.
Lateral line : Line formed along each side of body by a series of pores or
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minute tubes on scales or skin; most species of fish have a
lateral line.
Nape : The upper neck region.
Nostril : On the snout of fishes the opening of the olfactory organ or
organ of smell; in fishes there are usually a pair of nostrils
on each side of head.
Nictitating membrane : Transparent fold of skin forming a third eyelid; when open
lies at inner (anterior) corner of eye or below lower eyelid.
Occipital process : A median bone on the upper surface of the back of the
head; pertaining to the occiput.
Operculum : The gill cover
Osseous : Bony
Pectoral fins : The paired fins attached to the shoulder girdle.
Pelvic fins : The paired fins placed behind or below the pectoral fins;
often also referred to as ‘ventral fins’.
Preopercle : The anterior cheek bones.
Taxonomy : The science of classification at all levels starting with the
individual and arranging or grouping according to
relationships.
Operculum : The gill cover
Ventral fins : Pelvic fins.
Vestigial : Small and imperfectly developed; rudimentary.
Vomer : Bone in mid-palate, often bearing teeth.
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CONTENTS
Introduction - 11
Review of Literature - 15
Aims and Objectives - 17
Materials and Methods - 18
Results - 19
Order Siluriformes - 22
1. Family Bagridae - 27
1. Family Siluridae - 45
1. Family Schilbeidae - 54
1. Family Sisoridae - 61
1. Family Clariidae - 70
2. Family Heteropneustidae - 74
1. Family Ariidae - 78
1. Family Plotosidae - 80
Discussion - 85
Summary - 89
Conclusion - 90
Bibliography - 91
Plates - 95
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INTRODUCTION
Systematics is the science of the diversity of the organisms. It is the scientific
study of the kinds and diversity of organisms and of any and all relationships among
them (Simpson, 1961). Systematics is one of the most essential branches of biology. The
multitude of species occurring in nature are studied, classified and named so that they can
be identified in future.
Each species should have a name unique to itself. Once a name has been given to
a species, it becomes a label by which information concerning that organism is
communicated, stored and retrieved (Narendran, 2000). Systematics attempts to
systematize nature and provides a working conceptual framework enabling us to make
further studies such as biodiversity of fauna and flora, biology of various species
conservation, evolution, distribution, genetics, biotechnology and various other aspects.
Hence studies in systematics is the prime requisite before undertaking any further studies
on the group concerned.
Catfishes are a group of rayfinned fish. They are named so for their prominent
barbels, that resembles a cat’s whiskers. Catfishes range in size and behavior from the
heaviest, the Mekong giant catfish from Southeast Asia and the longest, the Wells catfish
of Eurasia, to detritivores (species that eat dead material on the bottom) and even to a tiny
parasitic species commonly called the ‘Candiru’, Vandellia cirrhosa.
Most catfishes are bottom feeders. In general, they are negatively buoyant, which
means that they will usually sink rather than float due to a reduced gas bladder and a
heavy bony head (Bruton, 1996). They have a variety of body shapes, though most have a
cylindrical body with a flattened ventrum to allow for benthic feeding.
DIAGNOSTIC FEATURES OF CAT FISHES
A great variation exists in the external morphology of catfishes and it is difficult
to give a standard definition of their external appearance. In general the body is naked
although in some families (eg. Callichthyidae; Loricariidae) it is covered with bony
plates.
Head: A flattened head allows for digging through the substrate as well as
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perhaps serving as a hydrofoil. The mouth is in general non-protractile. Most have a
mouth that can expand to a large size and contains no incisiform teeth. Catfish generally
feed through suction or gulping rather than biting and cutting prey (Bruton, 1996).
However some families notably Loricariidae and Astrolepidae, have a sucker mouth that
allows them to fasten themselves to objects in fast moving water. Catfishes also have a
maxilla reduced to a support for barbels; this means that they are unable to protrude their
mouths as other fish such as carp (Bruton, 1996). The eyes are usually small.
Barbels: Catfishes may have up to 4 pairs of barbels: one nasal pair, one or two
maxillary pairs (on each side of mouth), and two pairs of mandibular or mental pairs. In
many families one or more pairs may be missing. The barbels are provided with
numerous taste buds and are used in detecting food. Because their barbels are more
important in detecting food, the eyes on catfishes are generally small.
Bony plates: Catfishes have no scales, their body is often naked. In some species,
the mucus-covered skin is covered skin is used in cutaneous respiration, where the fish
breathes through its skin (Bruton, 1996).
In some catfishes, the skin is covered in bony plates called scutes; some form of
body armor appears in various ways within the order. In Loricariids and in the Asian
genus Sisor, the armor is primarily made up of one or more rows of free dermal plates.
Similar plates are found in large specimens of Lithodoras. These plates may be supported
by vertebral processes, as in Scoloplacids and in Sisor, but the processes never fuse to
plates or form any external armor. By contrast, in the subfamily Doumienaee (family
Amphiliidae) and in Hoplomyzontines (Aspredinidae), the armor is formed solely by
expanded vertebral processes that form plates. Finally the lateral armor of Doradids, Sisor
and Hoplomyzontines consists of hypertrophied lateral line ossicles with dorsal and
ventral lamina.
Fins: The dorsal and pectoral fins are often provided with a leading spine or a
leading soft ray. An adipose fin is often present and in some families it has a spine. The
pelvic fin is medially placed and has an abdominal position. Important variations are also
noted in size, ranging from a few millimeters (eg. Some Scoloplacidae) and a few
centimeters (eg. Helogenidae) upto several meters (eg. Ictaluridae and some
Pimelodidae).
Weberian apparatus: Like other Ostariophysans, the catfishes are characterized
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by the presence of a Weberian apparatus. Their well developed Weberian apparatus and
reduced gas bladder allow for improved hearing as well as sound production (Bruton,
2006).
Order Siluriformes is an unusually well defined order, comprising approximately
30 families (400 genera) and about 2000 species found in its entire range (Jayaram K. C.
2009).
The objective of the present investigation is to undertake studies on the classical
taxonomy of the catfishes of Kerala at species level in a preliminary frame work. Such a
study can give fundamental information for undertaking further detailed study of these
interesting fishes at the molecular level. This faunal diversity will help the researchers in
accessing the name of the species and its distribution.
DISTRIBUTION OF CATFISHES
Catfishes have a wide geographical distribution and are found in South-East Asia,
Eurasia, Central and South America, Africa, Japan and Ausralia. Except for two families
(Ariidae and Plotosidae) with essentially marine species, catfishes are in general primary
freshwater fishes.
HABITAT OF CATFISHES
They are found in freshwater environments of all kinds, though most inhabit
shallow, running water (Bruton, 1996). Representatives of at least 8 families are
hypogean (live underground) with three families that are also troglobitic (Inhabiting
caves) (Langecker, 1993, Hendrickson, 2001). Numerous species from the families
Ariidae and Plotosidae and a few species from Aspredinidae and Bagridae are found in
sea water (Monks, 2006, Schafer, 2005).
IMPORTANCE OF CATFISHES
Catfishes are of considerable commercial importance. Many of the larger species
are farmed or fished for food. Many of the species, particularly the genus Corydoras, are
important in the aquarium hobby.
Catfishes are high in Vitamin D (Vitamin D and healthy bones). Farm raised
catfishes contain low levels of omega-3 fattyacids and a much higher proportion of
omega-6 fatty acids.
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Catfishes rose in inland tanks or channels are considered safe for the environment,
since their waste and disease should be contained and not spread to the wild (Rogers
paul). In Asia many catfish species are important as food. Several ‘Walking Catfish’
(Clariidae) and shark catfish (Pangasidae) species are heavily cultured in Africa and Asia.
There is a large and growing ornamental fish trade, with hundreds of species of
catfishes, such as Corydoras and Plecos being a popular component of many aquaria.
Other catfishes commonly found in aquarium trade are Banjo catfish, Talking catfish and
long whiskered catfish.
ECONOMIC IMPORTANCE
Catfishes have been widely caught and farmed for food for hundreds of years in
Asia, Africa, Europe and North America. Judgments as to the quality and flavor vary,
with some food critics considering catfishes as being excellent food, others dismiss them
as watery and lacking in flavor (Jenny Baker, 1988).
It is easy to farm catfishes in warm climates, leading to inexpensive and safe food
at local grocers.
Catfishes are one of the economically important groups of fresh and brackish
water fishes in the world; in many countries they form a significant part of inland
fisheries; several species have been introduced in fish culture; numerous species are of
interest to the aquarium industry where they represent a substantial portion of the world
trade (Teugels, 1995).
HISTORY OF THE PRESENT STUDY
A proper taxonomy will help to get rid of the taxonomic and nomenclatural chaos
and thereby to facilitate studies of all kinds. An improvement of scientific knowledge is
greatly needed in the taxonomy of catfishes. In almost all regions the identification of
catfishes is very difficult. This poor knowledge is reflected in frequent incorrect or
inadequate identification of the relevant genus and species which results in unreliable or
confusing records in the literature. Only thorough taxonomic research work can improve
the situation. Through this project work, an attempt is made to study the catfishes of
Kerala which are very important food fish economically important to Kerala.
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REVIEW OF LITERATURE
Order Siluriformes is an unusually well defined order, comprising approximately
30 families (400 genera) and about 2000 species found in its entire range (Jayaram K. C.
2009). Many scientists have contributed to the knowledge of the order siluriformes.
A century ago, contributions to the phylogenetic study of the catfishes were
scarce, and dealing only with a few families and with a limited number of taxa within the
families. Teugels reported in 1995 that only few data on catfish phylogeny were known at
that time. Teugels recognized 33 families with 416 genera and 2584 species with a
comment that these numbers were continuously changing.
The catfishes are a monophyletic group. This is supported by molecular evidence
(Sullivan et. al., 2006). Catfishes belong to a super order called the Ostariophysi, which
also includes the Cypriniformes, Characiformes, Gonorynchiformes and Gymnotiformes,
a super order characterized by the Weberian apparatus. Some place Gymnotiformes as a
suborder of Siluriformes, however this is not as widely accepted. Currently, the
Siluriformes are said to be the sister group to the Gymnotiformes; though this has been
debated due to more recent molecular evidence. As of 2007 there are about 36 existing
catfish families, and about 3,023 existing species have been described (Ferraris, 2007).
This makes the catfish order the second or third most diverse vertebrate order; in fact one
out of every 20 vertebrate species is a catfish.
The taxonomy of catfishes is quickly changing. In a 2007 and 2008 paper,
Horabagrus, Phreatobius and Conorhynchos were not classified under any current
catfish families. There is disagreement on the family status of certain groups; for
example, Nelson 2006 lists Auchenoglaniidae and Heteropneustidae as separate families,
while the All Catfish Species Inventory includes them under other families. Also,
FishBase and the Integrated Taxonomic Information System lists Parakysidae as separate
family, while this group is included under Akysidae by both Nelson (2006) and ACSI
(Froese et. al. 2007). Many sources do not list the recently revised family Anchariidae
(Ng 2005). The family Horabagridae including Horabagrus, Pseudotropius and
Platytropius, is also not shown by some authors but presented by others as a true group
(Sullivan, 2006). Thus the actual numbers of families differs between authors. The
species count is in constant flux due to taxonomic work as well as description of new
species.
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The rate of description of new catfishes is at an all time high. Between 2003 and
2005, over100 species have been named, a rate of three times faster than that of the past
century (Ferraris, 2005).
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AIMS AND OBJECTIVES
1. To briefly review the contributions made by scientists all over the world on the
systematics of the order Siluriformes with special reference to contribution on the
catfishes of Kerala.
1. To get an idea of the collection methods of catfishes.
1. To learn to distinguish Clariids from other Siluriformes
1. To learn to identify the various family of the order Siluriformes and various
genera of the families.
1. To get a preliminary training in methods of species description i.e. parameter to
be taken into consideration, drawings, distinguishing between like species etc.
1. To get a training in preparation of dichotomous keys.
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MATERIALS AND METHODS
The present work was to review the taxonomy of the catfishes of Kerala at the
species level in a preliminary framework. Fish samples were collected as live samples
freshly caught from the rivers and as dead samples collected from the available markets.
Live fish sampling was performed in 100 m reach of all study streams. As the
work was carried out in the peak summer season, April and May, 2010 and due to lack of
time the samples isolated were less. Live samples were isolated from Ernakulam and
Kottayam districts from River Periyar and Vembanadu Lake. In each stream the
sampling was made in different habitats such as pools, riffles and runs using fishing nets
such as drag nets, gill nets and scoop nets. After collection, the fishes were kept alive in
plastic containers and transported to the laboratory for further analysis. Species
identification and confirmation were carried out using standard fish taxonomy textbooks
(Talwar and Jhingran 1991; Jayaram 1999). After identification, the fishes were kept in
the aquarium.
The dead samples obtained from the markets were also carried to the laboratory
for further analysis. After identification using standard fish taxonomy textbooks, the
fishes were dropped directly into a solution of dilute formalin 9 to 10 %. This solution is
made by diluting one part of commercial formalin (37% to 41%) with nine or ten parts of
water. A bucket was kept with measured quantity of water and formalin was added.
When the solution was ready the fish was dropped into the bucket and the bucket was
closed with a lid. In the formalin the fin ad rays were fully expanded and this assisted in
identification. The measurements were taken with a stainless steel ruler with
measurements to millimeter.
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RESULTS
The present review work was based on standard fish taxonomy textbooks Talwar
and Jhingran 1991, Jayaram 1999 and Shaji and Easa 2001. From this study it was found
that the catfishes so far reported from Kerala belong to 8 families of the order
Siluriformes. The orders are Plotosidae, Siluridae, Clariidae, Heteropneustidae, Ariidae,
Sisridae, Bagridae and Schilbeidae. A new key is prepared in this work for the families of
catfishes found in Kerala. The various families and genera and species reported from
Kerala are listed below followed by a systematic account. From the study it was found
that Kerala catfishes belong to 8 families, 15 genera and 31 species.
The family Bagridae includes 3 genera and 11 species.
The family Siluridae includes 3 genera and 4 species.
The family Schilbeidae includes 3 genera and 3 species.
The family Sisoridae includes 1 genus with 5 species.
The family Claridae includes 2 genera and 3 species.
Family Heteropneustidae includes 1 genus and 2 species.
Family Ariidae includes 1 genus and 1 species.
Family Plotosidae includes 1 genus and 2 species.
1. Family Bagridae
1. Genus Batasio Blyth, 1860
1. Batasio travancoria Hora & Law
2. Genus Horabagrus Jayaram, 1955
1. Horabagrus brachysoma (Gunther)
2. Horabagrus nigricollaris Pethiyagoda & Kottelat 1994
3. Genus Mystus Scopoli, 1777
1. Mystus armatus (Day)
2. Mystus keletius (Valenciennes)
3. Mystus malabaricus (Jerdon)
4. Mystus montanus (Jerdon)
5. Mystus oculatus (Valenciennes)
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6. Mystus punctatus (Jerdon)
7. Mystus cavasius (Hamilton-Buchanan)
8. Mystus vittatus (Bloch)
2. Family Siluridae
1. Genus Ompok Lacepede, 1803
1. Ompok bimaculatus (Bloch, 1794)
2. Ompok malabaricus (Valenciennes, 1840)
2.Genus Wallago Bleeker, 1851
1.Wallago attu (Bloch & Schneider, 1801)
3.Genus Silurus Linnaeus, 1758
1.Silurus wynaadensis Day, 1873
3.Family Schielbeidae
1.Genus Pseudeutropius Bleeker 1862
1.Pseudeutropius mitchelli Gunther, 1864
2.Genus Proeutropiichthys Hora 1937
1. Proeutropiichthys takree takree (Sykes 1839)
3. Genus Silonia Swainson, 1838
1. Silonia childreni (Sykes)
4. Family Sisoridae
1. Genus Glyptothorax Blyth
1. Glyptothorax anamaliensis Silas, 1951
2. Glyptothorax annandalei Hora, 1923
3. Glyptothorax housei Herre, 1942
4. Glyptothorax lonah (Sykes, 1839)
5. Glyptothorax madraspatanum (Day, 1873)
5. Family Clariidae
1. Genus Clarias Scopoli
1. Clarias dussumieri dussumieri Valenciennes 1840
2. Clarias dussumieri dayi, 1936
2. Genus Horaglanis Menon
1. Horaglanis krishnai Menon, 1950
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6. Family Heteropneustidae
1. Genus Heteropneustes Muller
1. Heteropneustis fossilis (Bloch, 1794)
2. Heteropneustes microps (Gunther, 1864)
7. Family Ariidae
1. Genus Arius Valenciennes
1. Arius arius (Hamilton-Buchanan, 1822)
8. Family Plotosidae
1. Genus Plotosus Lacepede
1. Plotosus canius (Hamilton-Buchanan, 1822)
2. Plotosus lineatus (Thunberg, 1787)
SYSTEMATIC ACCOUNT
Superclass GNATHOSTOMATA
Class ACTINOPTERYGII
Subclass NEOPTERYGII
Division TELEOSTEI
Division TELEOSTEI
Diagnosis: Endoskeleton bony, sometimes cartilaginous. Membrane bones of head well
developed; skull hyostylic; sometimes amphistylic; skull with sutures; endocranium
ossified. Optic nerves forming or not forming a solid chiasma. Maxilla well toothed,
simple. Palato–quadrate not fused with endocranium. Soft fin rays usually segmented
with pterygials; mostly with two paired fins (pectoral and pelvic), one or more medium
dorsal fin, and an anal fin ventrally and a caudal fin posteriorly; fins with spines and/or
soft rays; four pairs of gill arches; fifth pair modified into tooth-bearing lower
pharyngeal. Biting edge of upper jaw usually formed by dermal bones, the premaxillae
and maxillae; latter mobile. No supramaxilla. Gills with outer edges free; their bases
attached to bony arches; a single lateral gill opening on either side of pharynx covered by
operculum or a single ventral gill opening in pharynx. Interoperculum present. Nostrils
relatively high up in head. Heart divided into auricle, ventricle and arterial bulb; arterial
bulb either muscular with numerous valves or thin with a pair of opposite valves.
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Branchial septa reduced. Branchial lamellae with double row of branchial rays. No
intestinal valve. No nictitating membrane. Air-bladder or lung present. Skin with cycloid
or ctenoid scales. No cloaca except in Nerophis aequoreus (L.) (Syngnathidae). No
pterygopodia but some with gonopodium. Ova small; mostly oviparous; a few viviparous.
Lower Devonian to recent.
Catfishes belong to the order Siluriformes in this division. So a key is provided only up to
the order Siluriformes.
KEY TO ORDERS
1. Body cylindrical, much elongated and eel-
shaped.............................................................2
Body rounded not eel-shaped.............................................................................................3
2. Gill openings confluent, a single slit on ventral surface. Dorsal and anal fins
vestigial or
absent.......................................................................................................Synbranchiformes
= Gill openings free, narrow, on arches of head.Dorsal and anal fins, long, continuous
with caudal fins……….................................................................................Anguilliformes
3. Body short, rounded. Bones of upper and lower in the form of a beak having a
cutting edge and covered with a layer of ivory like
substance......................................................
…………………………………………………………..... ……………Tetraodontiformes
=Body fusiform, Bones of upper jaw normal without any modifications above..............
………………………………………………………………………………Siluriformes
Order SILURIFORMES
Skin naked or with bony scutes or plates, never with true scales. Mouth
not protractile, superiorly bordered by premaxillaries and dentaries, which are generally
toothed as are the pterygoids, palatines and vomer; maxillaries much reduced, toothless,
serving as bases of maxillary barbels. Nearly always one to four pairs of barbels. Adipose
fin generally present. Symplectic, subopercular and intermuscular bones, parietals, first
and second pharyngobranchials, epipleural and epineural bones absent. Pharyngeal bones
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with small conical or villiform teeth. Branchiostegal rays 4 to 17. No pseudobranchiae.
Mesopterygoid reduced, preopercle and interopercle relatively small. Anterior vertebrae,
second, third, fourth coossified to form “complex vertebra”; additional posterior vertebral
centra may be frequently fused to or united by exceedingly tight joints with complex
vertebra. Ribs attached to lower surface of long parapophyses. Supracleithrum
complicated; lower part deeply forked for reception of upper limb of cleithrum. First
pectoral, and last dorsal fin rays modified as hard pungent spines or thick rays. Lateral
line may be ramified, with or without short tubular ossicles enclosing the line. Pelvic fin
abdominal in position. Principal caudal fin rays 18 or fewer (most with 17), caudal
skeleton generally have six hypural plates. Air-bladder subdivided, reduced in many
species.
Order Siluriformes is an unusually well defined order, comprising approximately
30 families (400 genera) and about 2000 species found in its entire range. Most are
confined to freshwater but some are marine.
In this short review work, only the families, genera and species reported from
Kerala are dealt with. 8 families, 16 genera and 30 species of catfishes are commonly
found in Kerala. They are discussed below.
KEY TO FAMILIES FOUND IN KERALA
1. Adipose dorsal fin absent
(fig.1)..........................................................................................2
Fig.1
=Adipose dorsal fin present (fig.2) as a smooth short or long low fin (exception
Clupisoma garua (Hamilton –Buchanan), Schilbeidae where it may be absent in
adult.....................................................................................................................................5
24
24
Fig.2
2. Dorsal fin with a spine. Pelvic fins with 15or 16 rays. Anal fin long, confluent
with caudal fin (fig.3) [Body eel like].................................................................
PLOTOSIDAE
Fig. 3
=Dorsal fin without any spine. Pelvic fins with 6 rays. Anal fin free................................3
3. Nasal barbels absent (fig.4). No accessory respiratory organs [Barbels two or
three pairs; Head fairly compressed]
……………………………………..........................SILURIDAE
Fig. 4
= Nasal barbels present. Accessory respiratory organs present on gills or in the body
cavity………………………………………………………………………………………4
4. Dorsal fin long, with 23 to 76 rays. Accessory respiratory organs (air-breathing
labrynthic organ in branchial chamber) on gills present.
25
25
(fig.5).......................................CLARIIDAE
Fig.5
= Dorsal fin short, with six or seven rays. Accessory respiratory organs as tubular air
sacs present in body cavity (fig.6) [Barbels four pairs; Head greatly depressed; long
air-sac serving as a lung extends posteriorly from gill chamber]…………………………..
………………………………………………………………….HETEROPNEUSTIDAE
Fig. 6
5. Nostrils close together (fig.7), with very little inter space between the
two...................6
Fig. 7
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26
= Nostrils wide apart (fig.8), separated with some inter space, between the two................
……………………………………………………………………………………………..7
Fig. 8
6. No nasal barbels present (fig.9). Barbels two to six. Nostrils separated by a valve
[mainly marine and estuarine]........
……………………………………………………..ARIIDAE
Fig. 9
= A pair of distinct nasal barbels present. Nostrils close together, separated by a barbel.
Barbels eight. [Lateral line always present. Gill membranes united with isthmus
(exception Bagarius Hamilton-Buchanan); mostly small forms occurring in mountain
rapids]…………………………………….......................................................SISORIDAE
7. Anal fin short with less than 20 rays (8 to 16) (Fig.10); (exception Horabagrus
Jayaram,
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27
from Kerala with 23 to 28 rays) [Nostrils wide apart; teeth on roof of mouth; Dorsal and
pectoral spines strong]………........................................................................ BAGRIDAE
Fig. 10
8. Anal fin with more than 20 rays (40 to 46) (fig.11). [Chin barbells absent; nasal
barbells usually present (except in genus Silonia which has caniniform teeth; Anal fin
with 40 to 46 rays)]…… …………………………………………………………
SCHILBEIDAE
Fig. 11
1. Family BAGRIDAE
Bagrid catfishes
Generally large sized, more or less elongate fishes, with a compressed body. Teeth
on pre-maxillaries, mandible and vomer. Nostrils widely separated, above angle of
mouth, anterior tubular on tip of snout, posterior nearer eye than tip of snout and with
nasal barbel. Barbels six or eight, generally well developed. Gill openings wide,
extending to above base of pectoral fins, membranes free from each other and also from
isthmus. Rayed dorsal fin short, inserted anteriorly above middle of pectoral fins, with six
to eight rays and spine. Adipose dorsal fin smooth; not confluent with either rayed dorsal
or with caudal. Paired fins inserted horizontally. Pectoral fins with a strong spine,
generally serrated. Anal fin short or moderately long, not confluent with caudal. Caudal
28
28
fin forked or deeply emarginated. Lateral line present, generally complete.
Air bladder large, free in the abdominal cavity, moderately thick walled.
Lateral ethmoid facet for articulation of palatines more ventral than lateral, usually
visible from underside of skull. Palatines rod like. Endopterygoid absent. Ecto-
metaperygoids present, variously developed. Metapterygoid may not be directly
connected to hyomandibular. Vomer large or small, dentigerous. Autopterotics and
autosphenotics provide ventrally articular facet for hyomandibular, but variable. Post-
temporals present, united to skull by ligament. Mesocoracoid in pectoral girdle present.
Vertebrae 34 to 57
HABITAT: Fresh water; shore and bottom water habitat. (Balogun, 2005)
DISTRIBUTION (world wide): Freshwaters of Africa and Asia: ranging from Africa
through Bangladesh, Cambodia, China, East Indies, Formosa, India, Japan, Korea, Laos,
Malaya, Manchuria, Pakistan, SriLnka, Thailand, Vietnam and West Asia.
In India: Orissa, Madhya Pradesh, Assam, North Bengal, Kerala, Uttar Pradesh, Tamil
Nadu, Karnataka, Maharashtra, West Bengal, Manipur, Western Ghats, Eastern ghats.
Number of genus: 4, Batasio Blyth, Horabagrus Jayaram, Mystus Scopoli, Aurichthys
Wu.
2 subfamilies are present in family Bagridae. Members of one subfamily (Bagrinae) is
only reported from Kerala. It includes 4 genera and 12 species. They are discussed here
with their distribution in different parts of Kerala.
Key to subfamily
1. Pelvic fin with seven or eight
rays..........................................................................RITINAE
Pelvic fins with six rays only..............................................................................BAGRINAE
Key to genera of subfamily bagrinae found in kerala
1. Eyes inferior, visible from below ventral surface
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29
(fig.12)................................................. 2
Fig. 12
= Eyes superior, not visible from below ventral surface (fig.13)................................. 3
Fig. 13
2. Anal fin base long with 23 to 28 soft rays (fig14). A dark shoulder spot
present…….......................................................................................................Horabagrus
Fig. 14
30
30
= Anal fin short with 15 or 16 rays (fig.15);
Fig. 15
An interneural shield in between basal bone of dorsal fin and occipital bone present
(fig.16)...................................................................................................................... Aorichthys
Fig. 16
3. Barbels generally short including the maxillary pair and not extending beyond
head; ventral surface of head with sensory pores [Eyes moderate size, with free orbital
rim, not visible from underside of head; pectoral fins shorter, do not extend to pelvic fins]
……………………………………….............................................................. Batasio
= Barbels long, maxillary pair longer than head; ventral surface of head without any
pores [Interneural shield absent]..............................................................................Mystus
1. Genus BATASIO Blyth
Batasio Blyth, 1861, J. Asiat. Soc. Beng., 29: 149. (Type – species, Batasio buchanani
Blyth = Pimelodus batasio Hamilton – Buchanan); Hora and Law 1941, Rec.
Indian Mus., 43(1): 28-42 (Revision)
Macronoides Hora, 1921, Rec. Indian Mus., 22(3): 179 (type –species: Batasio affinis
Blyth = Pimelodus tengana Hamilton-Buchanan).
Diagnosis: Body short but elongated, high and compressed. Abdomen rounded. Head
small, compressed, conical with pores ventrally and on side; Snout rounded or slightly
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31
pointed; Mouth inferior, crescentic, horizontal, not wide with fringed lip; Eyes moderate,
dorsolateral, in middle part of head, not visible from below ventral surface; lips fleshy,
fimbriated; jaws subequal or slightly overhanging; teeth uniformly villiform in broad
continuous bands on jaws and palate; band on lower jaw continuous. Four pairs of
barbels; one on each of maxillary, nasal and two of mandibular, all generally not
extending beyond head posteriorly. Gill membranes notched anteriorly, free from
isthmus.
Rayed dorsal fin short, inserted above three fourth of pectoral fins anteriorly, with
seven or eight rays and a weak spine. Adipose dorsal fin low, of varying length. Pectoral
fins with five to nine soft rays, and a strong spine serrated along inner edge with antrorse
teeth. Pelvic fin with 6 rays. Anal fin short, with 12 to 15 rays. Caudal fin deeply forked
or deeply emarginated. Lateral line complete, with some sensory pores anteriorly.
Number of species: In India – 3 species (Batasio batasio, Batasio tengana and Batasio
travancoria
In Kerala – 1 species (Batasio travancoria)
Habitat: Fresh Water Rivers
Distribution: This genus is endemic to South Asia. India: Assam, North Bengal, And
Kerala, Bangladesh: Northern parts, Thailand and Malaysia.
Remarks: Talwar and Jhingran (1991, p.574) have merged this genus with Rama Bleeker
as a synonym of Batasio in his work (1981, p. 191).
Species found in Kerala
Batasio travancoria Hora & Law
(Plate I - Fig.1)
Batasio travancoria Hora and Law, 1941, Rec, Indian Mus., 43(1):40, pl.2, figs 7, 8 &9
(Type-locality: Perunthenaruvi, tributary of Pampa river at Edakadathy, Kerala);
Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 220, pl. 5, figs 1, 2 &3.
Description: Body elongate and compressed. Head globular, conical and rounded
anteriorly; occipital process long, separated by a considerable distance from basal bone of
dorsal fin; median longitudinal groove on head long and narrow, extending to base of
occipital process. Mouth small and inferior; barbels four pairs. Five large oval pores
behind lower lip, and two rows (of six rows each) of pores between angle of mouth and
gill cover; several pores between nostrils, below eyes and along free border of gill covers.
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32
Dorsal spine weak; adipose fin with a prominent ridge. Caudal fin deeply forked.
Habitat: Freshwater rivers; Demersal. Tropical climate
Distribution: This endemic species is known from Perumthenaruvi in Trivandrum (Hora
&Law, 1941), Cheenkannippuzha, Chalakudy puzha (Shaji et al. 1995; Shaji and Easa,
1999), Neyyar (Easa et al. 2000), Achenkovilar, Chaliyar, also from Pamba, Kallada,
Chittar rivers in the Anaimalai hill range, Kerala.
Local name: Travancore batasio, Malabar batasio.
Remarks: Occurs in hill streams and rivers at base of hills (Menon, A.G.K., 1999). B.
travancoria has only once been imported to the U.S. In captivity, the experience of one
aquarist is that specimens of B. travancoria show little interest in all foods offered and
slowly lose weight over a span of a few months and perish.
2. Genus HORABAGRUS Jayaram
Horabagrus Jayaram, 1955, Bull. Nat. Inst. Sci. India, No. 7, p.261 (type species
Psedobagrus brachysoma Gunther); Jayaram, 1966, Int. Revue ges. Hydrobiol.,
51(3): 447-448 (Review)
Pseudobagrus (nec Bleeker) Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:108.
Diagnosis: Body moderately elongated, compressed at the tail region. Abdomen rounded.
Head large, anteriorly depressed. Snout obtusely rounded. Mouth subterminal, transverse,
wide. Eyes large, inferior, along angle of mouth, visible when viewed from below ventral
surface. Jaws subequal. Lips thin, plain. Teeth uniformly villiform on jaws and palate. 4
pairs of barbels, one on each of maxillary, nasal, and two of mandibular. Gill membranes
free from each other and also from isthmus.
Rayed dorsal fin inserted above half of pectoral fin, with 5-7 rays and a spine.
Adipose dorsal fin low, short of varying length and depth; inserted far behind the dorsal
origin. Pectoral fins with 8 or 9 rays and a spine serrated along inner edge with antrorse
teeth. Pelvic fins with 6 rays. Anal fin long, with 23 to 29 rays. Caudal fin forked or
deeply emarginated. Lateral line complete, simple.
Number of species: In India: 2
In kerala: 2
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33
Habitat: Fresh water rivers.
Distribution: In India: Kerala. The northern limit is Kanara and the Southern limit is
Neyyattinkara near Trivandrum.
Remarks: Economically very important as food and aquarium fishes.
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34
Key to Kerala species of Horabagrus
1. A large saddle shaped black band extending from the humeral region of each side
over the nape, boardered in pale yellow.…………….…………………………........….H.
nigricollaris
= No such saddle shaped band. A large round black spot on shoulder with a light yellow
ring……………………………………………….......…………....……………H. brachysoma
Species found in Kerala
1. Horabagrus brachysoma (Gunther)
(Fig.17, Plate I - Fig.2)
Pseudobagrus brachysoma, Gunther, 1864, Cat. Fishes Br. Mus., 5: 86 (type-locality:
Cochin); Jayaram, 1952, Ann. Mag. Nat. Hist., (12) 5: 982 (Type-locality
revised); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:109.
Pseudobagrus chryseus Day, 1865, Fishes of Malabar: 185, pl. 13, fig. 2 (type-locality:
Kariyannur river, Kerala).
Macrones chryseus: Day, 1877, Fishes of India: 443, pl.99, fig. 3; Day, 1889, Fauna Br.
India, Fishes, 1: 148, fig. 63.
Horabagrus brachysoma: Jayaram, 1966, Int. Revue ges. Hydrobiol., 51 (3): 447, fig.5.
Diagnosis: Occipital process extends to the base of the dorsal fin. Dark yellowish in
colour with dark black blotch at the humeral region characterized by a light yellow ring.
Habitat: Fresh water; brackish. Benthic, primarily occupying low land areas of rivers and
backwaters with mud and sand substrate. Also seen in deep pools in hill streams.
Distribution: This endemic is abundant in the Vemband Lake, Sasthamkotta Lake,
Chalakudypuzha, Kannur, Trichur, Karivannorpuzha and Periyar.
Local name: Gunther’s catfish, Manjaletta (Mal.), Manjakkoori (Mal.)
Remarks: It is a very common catfish in the Kerala backwaters ans sold in live
condition. It attains a size of 45 cm total length and forms and important element of the
local fishery during the rainy season (October to February). It is caught by traps and long
lines.
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35
Fig. 17
2. Horabagrus nigricollaris Pethiyagoda & Kottelat 1994
(Plate I - Fig.3)
Horabagrus brachysoma, 1994, Pethiyagoda and Kottelat by original description.
Diagnosis: Maxillary barbels extend beyond the pectoral fin; median longitudinal groove
on the head not extends to the base of the occipital process. Body grey brown. A saddle
shaped black band edged with white extend from the humeral region to nape. Caudal fin
light yellow.
Habitat: Fresh water rivers.It inhabits hill streams at upper reaches of rivers.
Distribution: Chalakudy River, 24 km upstream of Chalakudy town near Vettilappara,
Kerala. So far it is known only from the type locality (Petiyagoda and Kottelat, 1994;
Shaji and Easa, 1999).
Local name: Periyar Catfish
Remarks: This is a recently described species from Chalakudy River at Vettilappara.
This species come very near Horabagrus brachysoma in general appearance but differs
from it in having 1) A saddle shaped band over the nape (such a band is absent in H.
brachysoma); 2) No ocellus at the humeral region (A black ocellus present at the humeral
region in H. brachysoma).
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36
3. Genus MYSTUS Scopoli, 1777
Mystus Scopoli, 1777, Introductio ad historiam naturalem: 451 (type speces: Bagrus
halepensis Valenciennes =Silurus pelusius Solander); Jayaram, 1959, Proc. First
All India Congr. Zool., (pt.2); 633; Jayaram, 1966, Int. Revue ges. Hydrobiol.,
51(3): 444-448 (Synopsis).
Diagnosis: Body short or moderately elongated and slightly compressed posteriorly.
Abdomen rounded. Head of moderate size, compressed or rather depressed. Snout
rounded or obtuse. Mouth sub terminal, transverse, moderately wide. Eyes moderately
large, supralateral, in anterior part of head not visible from below ventral surface and
with free circular margins. Lips thin. Jaws sub equal. Teeth uniformly villifom in bands
on jaws and palate, that on latter always uninterrupted (exception in M. horai). Four pairs
of barbels, one each of maxillary, nasal and two of mandibular, generally longer than
head. Gill membranes free from each other and also from isthmus. Branchiostegal rays 10
to 12.
Rayed dorsal fin inserted above last quarter of pectoral fins with seven rays and a
spine. Adipose dorsal fin low, of varying length. Pectoral fin with 6 to 10 rays, and a
spine serrated along inner edge with antrorse teeth. Pelvic fin with 6 rays. Anal fin short,
with 9 to 16 rays. Caudal fin forked, bilobed with unequal lobes: lobes may be rounded,
pointed or sometimes prolonged into filamentous extensions. Lateral line complete,
simple. An axillary pore generally present. Adipose dorsal fin is present and the length
varies with species.
Number of species: In India: 19
In Kerala: 8 (Mystus armatus, M. keletius, M. malabaricus, M.montanus, M.
oculatus, M. punctatus, M. cavasius, M. vittatus)
Habitat: Fresh water rivers. A few species enter the seas and estuaries.
Distribution: Syria in West Asia through India, Nepal, Pakistan to Sri Lanka in south,
through Bangladesh, Myanmar, Thailand, Indo China, Malaysia to East Indies and China
in the east.
Remarks: Roberts (1994) in a systematic revision of Asian bagrid catfishes restricted the
genera limits of Mystus sensu sticto to comprise 8 species only characterized by
moderately to very long maxillary barbels, very long adipose fin, total gill rakers on the
first gill arch 11 – 30 and total vertebrae 37-46 (about equally divided between abdominal
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37
and caudal vertebrae). Of the 8 species, Mystus bleekeri, Mustus cavasius and Mystus
rufescens are the only 3 species from Indian area considered as belonging to Mystus
sensu stricto. The remaining 16 species are considered as not belonging to Mystus in the
true sense. Jayaram and Anuradha (1999) have made a revision of the genus from its
entire world range. This restriction as applied by Roberts does not agree when data of the
four criteria: length of the maxillary barbels, length of the adipose fin, total gill rakers on
the first gill arch, and total vertebrae are tabulated; variations are seen. This has been
discussed in the above paper, and the problem requires a further study. It may however be
mentioned that other Bleekerian names as Aspidobagrus, Hemibagrus are available to
accommodate other species if need be.
Key to species of Mystus seen in Kerala
1) Occipital process extending to the basal bone of the dorsal fin……………….….
……….2
=Occipital process not extending to the basal bone of dorsal fin……………………..…..6
2) Adipose dorsal fin inserted immediately after the rayed dorsal fin (fig.17a);
Fig. 17a
[Maxillary barbels reach caudal fin base or beyond. Interorbital width more than 3.0 (2.0
to 3.0) in head length. A dark spot at base of caudal fin (fig.26) No bands on body]...........
............................................................................................................................M. cavasius
=Adipose dorsal fin inserted behind the rayed dorsal fin after a short distance (fig.18).......
…………………………………………………………………………………………….3
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38
Fig. 18
3) Median longitudinal groove reaching base of occipital process (fig.19) [ Median
longitudinal groove on head short, as two frontanelles, Adipose dorsal fin base
longer than anal fin base; A dark spot at the origin of dorsal fin; adipose dorsal fin short;
its base 1.2 times interdorsal distance; branchiostegal rays 11]……...…………………
…………………………………………………………………………………M. oculatus
Fig. 19
= Median longitudinal groove not reaching base of occipital process (Fig.20)…….…4
Fig. 20
4) Body plain without any shoulder spot or coloured bands on either side of lateral
line[Branchiostegal rays 10]………. ……………......…………......……….M.armatus
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39
= A coloured spot on the shoulder; Coloured bands on either side of lateral line. [Occipital
crest smooth. A dark blotch at base of caudal fin (fig.21). Adipose dorsal fin base longer
than anal fin base. Median longitudinal groove extending beyond posterior border of
orbit, and nearly reaching base of occipital process]......……………………...………..5
Fig. 21
5) Bluish shoulder spot; and a silvery line along the side ending in a dark spot at
base of caudal; one or two light bands along sides above lateral line [Eye diameter 3.5 to
4 times in head length; Pectoral fin with 6 soft rays]……………….……………...…M.
montanus
=A dark shoulder spot; body with 3 or 4 longitudinal colour bands(pale blue or dark
brown or black bands) above and below lateral line (fig.22)[ Eye diameter 4.5 to 6 times
in head length; Pectoral fin with 9 soft rays]………………………...............….M. vittatus
Fig. 22
6) Ten black rounded solid spots along lateral line (fig.23)[ Depth of body 7.8 to 8.4
times in standard length]……………………………………. …............………...M.
punctatus
=No such black rounded solid spots…………………………............………………...…7
40
40
Fig. 23
7) Body depth 4 times in standard length; A light band above and below lateral line
(fig. 24),no spot at base of caudal fin; maxillary barbel extend to the middle of pelvic
fin…………………..........................................................................……………M. keletius
Fig. 24
= Body depth 4.5 to 6 times in standard length; A dark band only along the lateral line
ending with a dark blotch at base of caudal fin (fig.25); maxillary barbel extend to the
end of pelvic fin [Eye diameter 3.5 to 4.5 times in head length]…………………….……..
…………………………………………………………………………….M. malabaricus
Fig. 25
Species found in Kerala
1. Mystus armatus (Day)
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41
(Fig.21, Plate II – Fig.4)
Hypselobagrus armatus, Day, 1865, Proc. Zool. Soc. Lond.: 289 (type-locality: Cochin)
Macrones armatus: Day, 1877, Fishes of India: 450, pl. 101, fig. 3; Day, 1989, Fauna Br.
India, Fishes, 1: 161
Mystus (Mystus) armatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:84.
Mystus armatus: Jayaram, 1977, Rec. zool. Surv. India Occ. Pap., (8): 28, fig. 23B.
Diagnosis: Occipital process exends to the basal bone of the dorsal fin. Median
longitudinal groove on the head as one or two frontelles not extending to the base of
occipital process. Maxillary barbels extend to the base of pelvic fins.
Habitat: Demersal; freshwater; brackish
Distribution: Wayanad range of hills, Western ghats, Bangladesh, Myanmar. Day 1865
reported as it is common in Karivannoor river in Trichur.
Local name: Kerala Mystus, Kotti (Mal.), Chillan koori (Mal.)
Remarks: The colour of the fish is leaden or brown above, lighter below, often with a
brown band along the flank. Upper half of dorsal fin darkish; anal fin with a dark band; a
dark blotch on base of caudal fin. It is of minor fishery value in Kerala where it is
obtained only occasionally. It attains a length of 14.5 cm SL.
2. Mystus keletius (Valenciennes)
(fig.24, Plate II – Fig.5)
Bagrus keletius Valenciennes, 1839, Hist. nat. Poiss., 14: 411 (type-locality:
Pondicherry).
Macrones keletius: Day, 1877, Fishes of India: 449, pl. 98, fig. 5; Day, 1889, Fauna Br.
India, Fishes, 1: 160
Mystus (Mystus) keletius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 92.
Mystus keletius: Jayaram, 1977, Rec. zool. Surv. India Occ. Pap., (8): 31, fig. 26A.
Diagnosis: Occipital process not extending to the basal bone of the dorsal fin. Median
longitudinal groove on the head is not extending to the base of occipital process.
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42
Maxillary barbels extend to the middle of the pelvic fins. Adipose dorsal fin small and
bump like and its insertion considerably behind the rayed dorsal fin.
Habitat: Common in lowland water bodies.
Distribution: Western Ghats of Kerala, Tamilnadu and Sri Lanka (Misra, 1976),
Karnataka.
Local name: Keletius mystus
Remarks: Jayaram, 1999 reported that record from Punjab (Johal & Tandon, 1979) may
be misidentification. Found in rivers and ponds, commonly in muddy pools and tanks
(Menon, A. G. K., 1999). Adults usually occur among marginal vegetation or roots in
both still and slow-flowing waters.
3. Mystus malabaricus (Jerdon)
(Fig.25, Plate VI-Fig.18)
Bagrus malabaricus Jerdon, 1849, Madras Jour. Lit. & Sci., 15: 338 (type-locality:
mountain streams of Malabar).
Macrones malabaricus: Day, 1877, Fishes of India: 450, pl. 101, fig. 2; Day, 1889,
Fauna Br. India, Fishes, 1: 160.
Mystus maydelli Rossel, 1964, Mitt. Zool. Mus.Inst. Hamburg, 61: 149, fig. 1 (type-
locality: Bhima river at Wadgoan, Maharashtra); Jayaram, 1977, Rec. zool. Surv.
India Occ. Pap., (8): 32 (Status discussed).
Mystus (Mystus) malabaricus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 93.
Diagnosis: Occipital process not extending to the basal bone of the dorsal fin. Median
longitudinal groove on the head not extending to the base of occipital process. Maxillary
barbel extend to the end of pelvic fins. Adipose dorsal fin long based and its insertion
behind the rayed dorsal fin after a short distance.
Habitat: Fresh water, mountain streams.
Distribution: India: Western Ghats from Karnataka, Kerala, Maharashtra,
Madhyapradesh and Assam. Common in Kabini, Chaliyar and Chalakudypuzha,
Karivannoorpuzha, streams in Parambikulam, Cheenkannipuzha and Achenkovil (Misra,
1976; Talwar and Jhingran, 1991; Easa and Basha, 1995; Jayaram 1981 a &1999).
Local name: Malabar mystus, Kallan koorie (Mal.)
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43
Remarks: Distinguished by a moderately long adipose fin, a deep caudal peduncle and a
dark midlateral stripe. This catfish which attains a length of 15 cm, contributes a minor
fishery in Kerala and Karnataka.
4. Mystus montanus (Jerdon)
(Plate II – Fig.6)
Bagrus montanus Jerdon, 1849, Madrs Jour. Lit. & Sci., 15(2) 337 (type-locality :
Manatoddy, Wynaad, Kerala State).
Macrones montanus : Day, 1877, Fishes of India : 449, pl. 101, fig. 4 ; Day, 1889, Fauna
Br. India, Fishes, 1: 159
Macrones montanus var. dibrugarensis Chaudhuri, 1913, Rec. Indian Mus., 8 : 254, pl.
9, figs 2, 2a, 2b (type-locality : Dibrugarh, assam) ; Jayaram, 1977, Rec. Zool.
Surv. India Occ. Pap., (8): 34 (Status discussed).
Mystus (Mystus) montanus : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 97.
Mystus (Mystus) vittatus dibrugarensis : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:
107.
Diagnosis: Bluish shoulder spot; and a silvery line along the side ending in a dark spot at
base of caudal; one or two light bands along sides above lateral line
Habitat: Fresh water rivers, demersal; brackish.
Distribution: India: Assam, Kerala State, Wayanad range of hills, Madhyapradesh,
Hoshangabad district, Javadi Hills, Eastern Ghats.
Local name: Wynaadu mystus
Remarks: This species attains a length of 15 cm, is of minor interst to fisheries.
5. Mystus oculatus (Valenciennes)
(Plate VII-Fig.19)
Bagrus oculatus Valenciennes, 1839, Hist. nat. Poiss., 14: 424 (type-locality: Malabar).
Macrones oculatus : Day, 1877, Fishes of India: 448, pl. 98, fig. 4; Day, 1889, Fauna Br.
India, Fishes, 1: 156
Mystus (Mystus) oculatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 98.
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44
Diagnosis: Occipital process extends to the basal bone of the dorsal fin; Median
longitudinal groove on the head extends to the base of occipital process. Maxillary barbel
extend to the middle of anal fin. Adipose dorsal fin short and its insertion considerably
behind the rayed dorsal fin.
Habitat: Demersal; freshwater; brackish, Adults inhabit rivers in plains and estuaries
Distribution: Kerala and Tamilnadu (Misra, 1976), Coimbatore District.
Local name: Malabar mystus. Koorie (Mal.)
Remarks: According to Easa & Shaji, 1997, this species is considered very rare. This
small catfish which attains a length of 15 cm is of only minor fishery value in Kerala.
6. Mystus punctatus (Jerdon)
(fig.23)
Bagrus punctatus Jerdon, 1849, Madras Jour. Lit. & Sci., 15: 339 (type-locality: Cauvery
river, Western Ghats).
Macrones punctatus: Day, 1877, Fishes of India: 445, pl. 100, fig. 3; Day, 1889, Fauna
Br. India, Fishes, 1: 153.
Mystus maydelli (nec Rossel) David et al., 1969, Bull. Cent. Inland Fish. Res. Inst.,
Barrackpore, (13): 68.
Mystus (Mystus) punctatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 102
Mystus punctatus: Jayaram et al., 1982, Rec. zool. Surv. India Occ. Pap., (36): 87, fig. 27.
Diagnosis: Occipital process long but not extending to the basal bone of dorsal fin.
Median longitudinal groove extends to the base of occipital process. One row of 10 solid
spots present on the lateral side. Maxillaries extend to the end of the pelvic fin.
Habitat: Demersal; freshwater, Inhabits rapid rivers and streams
Distribution: India: Bhavani river at base of Nilgiri Hills, Karnataka and Kerala State. In
Kerala: Western Ghats. Common in Kabini river (Misra, 1976).
Local name: Nilgiri mystus
Remarks: Distinguished from its congeners by a unique combination of the following
characters: head length 28.1- 29.6% SL, head depth 11.9-14.3% SL, depth of the caudal
peduncle 8.8-9.9% SL, eye diameter 13.8-15% HL.
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45
7. Mystus cavasius (Hamilton – Buchanan)
(fig.26, Plate VIII-Fig.23)
Pimelodus cavasius Hamilton-Buchanan, 1822, Fishes of ganges: 203, 379, pl. 11, fig.
67 (type-locality : Gangetic provinces).
Macrones cavasius: Day, 1877, Fishes of India : 447, pl. 100, fig. 1 ; Day, 1889, Fauna
Br. India, Fishes, 1 : 155
Mystus mukherjii Ganguli and Datta, 1975, Zool. Soc. India B. S. Chauhan Comm. Vol.:
293 (type-locality : Subarnarekha river, Bihar).
Mystus (Mystus) cavasius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 87, fig. 18.
Mystus cavasius : Jayaram, 1977, Rec. Zool. Surv. India Occ. Pap., (8): 29, fig. 21A.
Diagnosis: Adipose dorsal fin inserted immediately after the rayed dorsal fin. Occipital
process extends to the basal bone of the dorsal fin. Median longitudinal groove on the
head extends to the base of occipital process. Maxillary barbel extends beyond the base
of caudal fin.
Habitat: Found in tidal rivers and lakes; also canals, ditches, ponds, and inundated fields.
Distribution: Pakistan, India, SriLanka, Nepal, Bangladesh, Myanmar and Thailand
(Misra, 1976; Jayaram, 1981a &1999; Talwar and Jhingran, 1991). In Kerala it is
common in Chalakudy, Kabini and Chaliyar.
Local name: Gangetic mystus, Kotti (Mal.), Chillan koori (Mal.)
Remarks: Its pectoral spine can cause painful wounds (Talwar and Jhingran, 1991).
Found in the basin-wide tributary of the lower Mekong. Oviparous, distinct pairing
possibly like other members of the same family (Breder, C.M. and D.E. Rosen,
1966).
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46
Fig. 26
8. Mystus vittatus (Bloch)
(fig.22, Plate VII-Fig.20)
Silurus vittatus Bloch, 1797, Ichthyol. Hist. Nat., 11: 40, pl. 371, fig. 2 (type-locality:
Tranquebar, Tamil Nadu).
Macrones vittatus: Day, 1877, Fishes of India: 448, pl. 98, fig. 3, and pl. 99, fig. 4; Day,
1889, Fauna Br. India, Fishes, 1: 157.
Mystus (Mystus) vittatus vittatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 105,
Fig. 20
Diagnosis: Occipital process extends to the basal bone of the dorsal fin. Median
longitudinal groove on the head not extends to the base of the occipital process.
Maxillary barbels extend to the origin of anal fin.
Habitat: Demersal; freshwater; brackish; Adults inhabit standing and flowing waters.
Usually found among marginal vegetation in lakes and swamps with a mud
substrate.
Distribution: Throughout India, Pakistan, Bangladesh, Nepal, Myanmar, Thailand and
SriLanka.
Local name: Striped dwarf catfish, Manja koori (Mal.), Chillan Koori (Mal.)
Remarks: This species is included here as it is reported to be of distributed throughout
India. This is one of the most common, small sized catfishes caught in large quantities
from ponds, lakes, rivers, etc. in the Indian region. It attains a length of 21 cm in SL.
2. Family SILURIDAE
Sheat fishes
Diagnosis: Large sized, elongate fishes with a compressed body. Depressible teeth on
premaxillaries, mandible and vomer. Nostrils separated from each other by a short
distance, anterior tubular on tip of snout, posterior valved and situated before anterior
border of eyes. Barbels four to six, generally well developed. Nasal barbels invariably
absent. Gill openings very wide, extending upto lateral line, membranes free from each
other and isthmus. Branchiostegal rays 8-21.
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47
Rayed dorsal fin mostly one (two in Pinniwallago) short with four or five rays
and without a spine. Adipose dorsal fin absent. Paired fins laterally inserted. Pectoral fin
with a strong spine occasionally serrated. Anal fin very long, up to 93 rays extending
from just posterior to anal opening to caudal or confluent with it. Pelvic fins small, not
prominent, may be absent. Caudal fin rounded to weakly emarginated, with bluntly
rounded lobes, or forked. Lateral line straight, complete, and with short ventral branches,
dendritic or not, but no dorsal branches.
Air bladder large, attached to second to fourth vertebrae.
Lateral ethmoid with a slender posterior extension which meets a similar forward
extension of the sphenotic, so that frontal has no free edge, palatines reduced to a small
nodule, ecto-metapterygoids present, variously developed. Endopterygiod absent. Vomer
small dentigerous. Autopterotics and autosphenotics alone provide ventrally articular
facet for hyomandibular. Post temporals absent. Mesocoracoid in pectoral girdle present.
Ossified transcapular ligament antero-posteriorly compressed. Distal radials of
dorsal fin, pterygiophores absent. Articulations of anal fin rays with pterygiophores
shifted.
Vertebrae 52 to 74.
Habitat: Freshwater rivers
Distribution: World wide: India, Bangladesh, Indonesia, Malaya, Myanmar, Pakistan,
Srilanka, Thailand and Vietnam
In India: Of the five genera present in this family, three are reported from Kerala. They
are, Ompok, Wallago and Silurus. These three genera and 4 species (Ompok malabaricus,
Ompok bimaculatus, Silurus wynaadensis and Wallago attu) are discussed here with their
distribution in different parts of Kerala.
Key to Genera found in Kerala of the family Siluridae
1. Gape of the mouth very wide and very long, extending beyond eye
posteriorly(fig.27) [Eyes with free orbital rim, lying entirely above level of corner of
mouth, not visible from underside of head]
……………………………………………………................Wallago
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48
Fig. 27
= Gape of mouth not wide, not extending beyond eyes posteriorly (fig.28)................... 2
Fig. 28
2. Caudal fin rounded (fig. 29), truncate or weakly emarginate, medially with bluntly
rounded lobes; mandibular barbels one or two pairs; eyes not visible from below ventral
surface……............................................................................…....………………….Silurus
Fig. 29
= Caudal fin forked (fig.30). Mandibular barbels one pair; may be rudimentary. Eyes
visible from below ventral surface………….....……......................................…Ompok
Fig. 30
Genus OMPOK Lacepede
Ompok Lacepede, 1803, Hist. Nat. Poiss., 5: 49 (type species, Ompok siluroides
49
49
Lacepede = Silurus bimaculatus Bloch); Haig, 1951, Rec. Indian Mus., 48(3/4):
108-112 (Review); Parameswaran, 1968, J. zoo. Soc. India, 19 (1/2): 90-94
(review).
Callichorus Hamilton-Buchanan, 1822, Fish of Ganges: 149 (type-species: Silurus
(callichorus) pabda Hamilton-Buchanan).
Diagnosis: Body elongated, compressed. Abdomen rounded. Head small, broad.
depressed. Snout bluntly rounded, depressed. Mouth superior, moderately wide, its cleft
oblique, not extending to front border of eyes (fig.28). Eyes small, their ventral border on
level with corner of mouth, visible from below ventral surface of head. Lips thin. Jaws
unequal, lower jaw prominent, more or less elevated at symphysis. Teeth uniformly
villiform, depressible in bands on jaws, in two separate patches on palate, no teeth on
palatines. Two pairs of barbels, one pair each of maxillary and mandibular; latter
occasionally rudimentary or small.
Rayed dorsal fin inserted above last half of pectoral fin, with three or five rays
and without any spine. Adipose dorsal fin absent. Pectoral fin with 11 to 14 rays and a
feebly serrated or smooth spine; its length surpassing pelvic fins, pelvic fins with six to
ten rays. Anal fin very long, with 52 to 75 rays, close to caudal fin, free from it. Caudal
fin forked. Lateral line complete, simple.
Number of species: In India: 4 species
In Kerala: 2 species Ompok bimaculatus (Bloch), Ompok malabaricus (Valenciennes)
Habitat: Fresh water
Distribution: India, Bangladesh, Borneo, Java, Myanmar, Nepal, Sri Lanka, Sumatra and
Thailand.
Key to species found in Kerala
1. Caudal lobes rounded, lower border of eye on level with cleft of mouth [Anal fin
with 63 to 69 branched rays]…...............….....................................................Ompok
malabaricus
= Caudal lobes pointed, lower border of eye below level of the clet of mouth [Anal fin
with 57 or 58 branched rays; maxillary barbells extend posteriorly to (or slightly beyond)
anal fin base]................………........................................................... Ompok bimaculatus
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50
1. Ompok bimaculatus (Bloch, 1794)
(fig.31, Plate III – Fig.7)
Silurus bimaculatus Bloch, 1797, Ichthyol. Hist. nat. des. Poiss., 11: 17, pl. 364 (type-
locality: Malabar).
Callichorus bimaculatus: Day, 1877, Fishes of India: 476, pl. 110, figs 4, 5; Day, 1889,
Fauna Br. India, Fishes, 1: 131, fig. 57.
Callichorus macrophthalmus (Blyth) Day, 1877, Fishes of India: 478, pl. 110, figs 2, 3;
Day, 1889, Fauna Br. India, Fishes, 1: 152.
Callichorus gangeticus (Peters) Day, 1877, Fishes of India: 476; Day, 1889, Fauna Br.
India, Fishes, 1: 130.
Callichorus sindensis Day, 1877, Fishes of India: 476, pl. 110, fig. 1 (type-locality: Sind,
Pakistan); Day, 1889, Fauna Br. India, Fishes, 1: 130, Talwar, 1991, J. Inland
Fish Soc. India (in press) (Status discussed).
Ompok bimaculatus: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 189, fig. 35.
Ompok canio (Hamilton-Buchanan) Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 192;
Coad, 1981, Nat. Mus. Nat. Sci. Ottawa, (14): 15.
Ompok sindensis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 198.
Fig.31
Diagnosis: Dorsal fin with 4 branched rays and anal fin with 57-58 branched rays.
Maxillary barbels extend slightly beyond the anal fin origin. Colour silvery shot with
purple. A large dusky spot present at the shoulder region.
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51
Habitat: Fairly common in the rivers, streams and water bodies in the low lands. Occurs
in streams and rivers of all sizes with currents ranging from sluggish to moderate. Found
in quiet, shallow (0.5-1.5 m), often muddy water, in sandy streams, rivers and tanks
(Pethiyagoda, R. 1991). Also occurs in canals, beels and inundated fields. Moves into
freshly inundated habitats during the flood season
Distribution: Throughout India, Afganistan, Pakistan, Sri Lanka, Myanmar, Thailand,
Java, Sumatra, Borneo, China, Bangladesh, Malaya, Nepal, Vietnam and Yunnan.
Local name: Indian butter catfish
Remarks: It is considered a very tasty fish and is highly priced. It spawns during the
monsoons and thrives well in confined waters. It attains a length of 45 cm in SL.
2.Ompok malabaricus (Valenciennes)
(Plate III – Fig. 8)
Silurus malabaricus Valenciennes,1839, Hist. Nat. Poiss., 14: 353 (type-locality :
Malabar).
Callichorus malabaricus: Day. 1877, Fishes of India: 478, pl. 111, fig. 1; Day, 1889,
Fauna Br. India, Fishes, 1: 133.
Silurus goae Haig, 1951, Rec. Indian Mus., 48 (3/4) : 77, fig. 1 (type-locality : Goa and
Trivandrum) ; Jayaram, 1981, Handbook zool. Surv. India, (2): 211 ; Talwar,
1991, J. Inland Fish. Soc. India : (in press) (gangetic relationship and status
discussed).
Ompok malabaricus : Misra, 1976, fauna of India, Pisces (2nd ed.), 3: 193.
Diagnosis: Dorsal fin with 4 and anal fin with 63-69 branched rays. Maxillary barbels
extend slightly beyond the pelvic fin origin. Colour brown shot with purple. A large
dusky spot present at the shoulder region. Fins dusky.
Habitat: Found in rivers in plains and submontane regions. Common in rivers and
wetlands
Distribution: India: Known only from Goa and Kerala.
Local name: Goan catfish
Remarks: This catfish attains a length of 51 cm in SL; its interest to fisheries is not
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52
presently known.
2. Genus WALLAGO Bleeker, 1851
Wallago Bleeker, 1851, Natuurk. Tijdschr. Ned.-Indie, 1: 265 (type-species: Silurus
mulleri Bleeker = Silurus attu Schneider); Roberts, 1982, Copeia, (4): 890-894
(revision).
Wallagonia Myers, 1938, Copeia, (2): 98 (type-species: Wallago leerii Bleeker).
Diagnosis: Body elongated, laterally compressed. Abdomen rounded. Head fairly large,
deep and depressed. Snout spatulate, somewhat protruded. Mouth subterminal, oblique,
gape wide, reaching to or beyond anterior border of eyes (fig.27). Eyes small, with free
orbital margins above level of corner of mouth, not visible from below ventral surface.
Lips thin. Jaws subequal, lower jaw longer prominent. Teeth villiform in bands in jaws
and in patches on palate. Two pairs of barbels, one pair each of maxillary and
mandibular.
Rayed dorsal fin inserted above half of pectoral fin, with five rays and without a
spine. Adipose dorsal fin absent. Pectoral fins with 13 to 15 rays and a feeble, smooth
spine. Pelvic fins with 8 to 10 rays. Anal fin long with 72 to 96 rays free from caudal fin.
Caudal fin deeply forked with rounded lobes. Lateral line complete, well marked, simple.
Number of species: Only one species reported so far from India and kerala, Wallago attu.
Habitat: Freshwater habitat.
Distribution: India, Bangladesh, Java, Kampuchea, Malay peninsula, Myanmar,
Pakistan, Sri lanka, Sumatra, Thailand and Vietnam.
Species found in Kerala
1. Wallago attu (Bloch & Schneider)
(fig.32)
Silurus attu Schneider, 1801, Syst. Ichth.: 378, pl. 75 (type-locality: Malabar).
Wallago attu: Day, 1877, Fishes of India: 479, pl. 111, fig. 4; Day, 1889, Fauna Br.
India,
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53
Fishes, 1: 126, fig. 54; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 206, fig.
41.
Wallagonia attu: Hora, 1939, J. Bombay nat. Hist. Soc., 41(1): 64, pl. Redescription).
Wallagu attu valeya Deraniyagala, 1953, Spolia zeylan., 27: 15 (type-locality: Yakvala,
Ceylon); Roberts, 1982, Copeia, (4): 891 (Status clarified).
Fig. 32
Diagnosis: Dorsal fin with five and anal fin with 74-93 branched elements. Barbels two
pairs. Maxillary barbels extend beyond the origin of anal fin.
Habitat: Found in large rivers, lakes and tanks. A large, voracious and predatory catfish
which thrives in heels with grassy margin; mostly hides under holes in river banks and
canals. Associated with deep, still or slow-flowing water with a mud or silt substrate.
Sluggish and stays on muddy or silty bottom in search of food.
Distribution: India, Myanmar, Thailand, Vietnam, Kampuchea, Malay Peninsula, Java
and Sumatra.
Local name: Boal, Valla (Mal.), Manjavalla (Mal.), Thooli.
Remarks: This catfish is a good sport and can be easily taken on a hook with dead or live
bait. It is very destructive to other more valuable food fishes such as the major carps. It
grows to about 2 m and wighs more than 45 kg. It is rather sluggish and stays at the
bottom of water in search of food. If handled it bites strongly as it has a huge mouth with
formidable jaws, armed with bands of conical teeth. Due to its rich oil content it is liked
by many.
3. Genus SILURUS Linnaeus
Silurus Linnaeus, 1758, Syst. Nat. Ed. 10, p.301 (type species, Silurus glanis Linnaeus,
by subsequent disgnation by Bleeker, 1862, p.393).-kobayakawa, 1989, Jap. J.
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54
ichthyol., 36(2), 155-184 (revision).
Diagnosis: Body elongated, compressed. Abdomen rounded. Head small, broad,
depressed. Snout obtusely rounded. Mouth terminal, horizontal to somewhat oblique,
wide, gape of mouth reaching to below eyes. Eyes small, covered with skin above level
of angle of mouth not visible from below ventral surface. Lips thin. Jaws subequal. Teeth
uniformly villiform in bands on jaws and in one or two patches on palate. Two or three
pairs of barbels, one pair maxillary, rather heavy, flattened one or two pairs mandibular.
Rayed dorsal fin very small, inserted above tip of pectoral fins, with two to five
rays and without a spine. Adipose dorsal fin absent. Pectoral fins with 7 to 11 rays and a
spine whose anterior surface is smooth, granulated or serrated, but its posterior surface
strongly serrated in males, and weakly serrated or smooth in females. Pelvic fins with 7
to 10 rays. Anal fin very long based with 58 to 74 rays, confluent with caudal fin with a
distinct notch between them; anal rays covered by integument for most of their length.
Caudal fin rounded or truncate, with bluntly rounded lobes. Lateral line complete, simple.
Number of species: Only one species is reported from both India and Kerala. Silurus
wynaadensis Day
Habitat: Freshwaters of palearctic region, brackish.
Distribution: Assam, Eastern Himalaya, Western Ghats in Peninsular India and
Myanmar. Distributed throughout Eurasia except the central region (Talwar and jhingran,
1991)
Species found in Kerala
1. Silurus wynaadensis Day, 1873
(fig.33, Plate III – Fig.9)
Silurus punctatus Day, 1868, Proc. Zool. Soc. Lond.: 155 (type-locality: Wynaad, Kerala)
(name preoccupied by Silurus punctatus Cantor, 1842).
Silurus wynaadensis Day, 1873, Proc. Zool. Soc. Lond.: 237 (replacement name for
Silurus punctatus Day); Day, 1877, Fishes of India: 480, pl. 111, fig. 6; Day,
1889, Fauna Br. India, Fishes, 1: 119, fig. 50; Hora, 1937, Rec. Indian Mus.,
39(3): 342, fig. 8a.
Silurus cochinchinensis wynaadensis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:
202, Fig. 40.
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55
Fig. 33
Diagnosis: Barbels three pairs, Maxillary barbels extend beyond the pectoral fins. Anal
fin with 54-56 branched elements, caudal fin rounded.
Habitat: Occurs in fast flowing rivers, canal and streams, hides in holes and rocks
Distribution: Wayanad, Thung Bhadra river system (Shaji & Easa 2001).
Local name: Malabar silurus.
Remarks: It is a specis known only from South India. The colour of the fish is, in life,
leaden becoming purplish below with minute dots scattered over entire body;
occasionally a dusky finger-like mark on shoulder. This species attains a length of 30 cm;
of no interst to fisheries in Kerala.
3. Family SCHILBEIDAE
Schilbid Catfishes
Diagnosis: Medium to large sized fishes with a compressed body. Teeth on
premaxillaries, mandible and vomer. Nostrils widely separated, anterior wide, along front
border of snout; posterior slit-like or with a flap or simple, nearer eye than tip of snout.
Barbels two, four or eight, fairly well developed (vestigial or absent in Silonia). Gill
openings very wide, extending upto lateral line, membranes free from each other and also
from isthmus. Branchiostegal rays 5 to 12.
Rayed dorsal fin when present short, with five to seven rays and a spine, may be
absent also. Adipose dorsal fin generally present, may be absent. Paired fins inserted
laterally. Pectoral fins with a strong spine usually serrated. Anal fin very long, not
confluent with caudal fin. Caudal fin forked. Lateral line generally complete, simple.
Air bladder of varying types and shapes.
Lateral ethmoid facet for articulation of palatines more lateral than ventral. Palatines
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56
rod-like, broad. Endopterygoid occasionally present (Silonia). Ectopterygoid toothed.
Metapterygoid may have sutural contact with hyomandibular (exception Psedeutropius,
Neotropius). Autopterotics and autosphenotics provide ventrally articular facet for
hyomandibular, but variable; temporals present, connected to skull by sutures. Lower
limb of post-temporal moderate to well developed.
Vertebrae 47 to 58.
Habitat: Fresh water
Distribution: India, Africa, Malaya, Myanmar, Pakistan and Thailand.
Subfamily: 2 subfamilies are seen in family Shilbeidae, Subfamily Ailinae with dorsal fin
absent and Subfamily Schilbeinae with dorsal fin present. So far only the members of
subfamily Schilbeinae are reported from Kerala.
Subfamily SCHILBEINAE
Diagnosis: Dorsal fin and spine present. Adipose dorsal fin vestigial, small, may be
absent. Teeth on vomer large. Anal fin moderate.
Six vertebrae from the pars sustenaculum. Central limits of vertebra clear. Dorsal
lamina when present does not form an oblique ridge of bone. Cardinal groove may be
present or absent. Lateral process of supraethmoid extends over half of each premaxillae.
Inferior limb of post-temporal present. Sphenotic forms nerve foramen for the 7 th cranial
nerve.
Number of genera found in Kerala: 3 genera are so far reported from Kerala. They are
Pseudeutropius, Proeutropiichthys and Silonia
These 3 genera and their corresponding 3 species are discussed here with their
distribution in different parts of Kerala.
Key to genera of Schilbeinae found in Kerala.
1. Two or four barbels often vestigial or absent; nasal and one pair of mandibular
barbels absent.Teeth on jaws
caniniform…............................................................................Silonia
= Eight barbels. Teeth on jaws villiform……..........................………………….....……2
2. Caudal fin bent downwards from caudal peduncle onwards. Teeth on palate in
four small distinct patches which may be continuous, slightly separated or wide apart
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57
from each other[Air bladder of moderate size]……..
………………………............Proeutropiichthys
= Caudal fin normal, not bent downwards. Teeth on palate in two extensive patches.
[Cleft of mouth not oblique (Fig. 34);
Fig. 34
teeth on upper jaw not exposed; jaws not wide; Teeth on palate in two separate patches
(fig.35), widely separated which may be connected by a linear series. Posterior nostrils
narrow [Air bladder large]……………………………................................Pseudeutropius
Fig. 35
1. Genus PSEDEUTROPIUS Bleeker
Pseudeutropius Bleeker, 1862, Verh. Akad. Amsterdam, 14, p.398 (type species,
Eutropius brachypopterus Bleeker, Hora, 1941, Rec. Indian. Mus., 43 (2): 100-
105 (review).
Diagnosis: Body elongate, compressed, herring-shaped. Part of abdomen more or less
keeled. Head short, compressed. Snout sharp, conical, not pointed. Mouth wide,
subinferior, transverse, overhung by snout, moderately wide, its cleft not extending to
anterior border of eyes. Eyes large, ventro-lateral, partly below and behind level of cleft
of mouth with broad circular adipose lids, visible from below ventral surface. Lips thin.
Jaws subequal, upper jaw longer. Teeth small, villiform, in narrow bands on jaws and
palate; those on latter in two small widely separated but narrow patches, occasionally
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58
connected by a linear series. Four pairs of barbels: one each of maxillary, nasal and two
of mandibular.
Rayed dorsal fin short, inserted above half of pectoral fin with five or six rays and
a spine. Adipose dorsal fin short, posteriorly free. Pectoral fins with seven to nine rays
and a spine serrated along both margins. Pelvic fins with 6 rays. Anal fin long based, with
30-46 rays, not confluent with caudal. Caudal fin forked. Lateral line complete, simple.
Air bladder oval, slightly longer than broad, lying free in abdominal cavity,
supported anteriorly by bony vertebral elements, thin-walled, in contact with abdominal
skin above each pectoral fin, forming transluscent blister-like area.
Number of species: In India: 2
In Keala: 1 (Pseudeutropius mitchelli)
Habitat: Freshwater
Distribution: Widely distributed in the oriental region (Talwar and Jhingran, 1991;
Jayaram, 1981). Seen throughout India, Pakistan, Nepal, Bangladesh and Myanmar.
Species found in Kerala
Pseudotropius mitchelli Gunther
(fig.36)
Pseudeutropius mitchelli Gunther, 1864, Cat. Fishes Br. Mus., 5: 59 (type-locality:
“Madras Presidency”); Hora, 1941, Rec. Indian Mus., 43(2): 104(Identity
discussed); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 181.
Pseudeutropius sykesii (nec Jerdon) Day, 1877, Fishes of India: 473, pl. 109, fig.5; Day,
1889, Fauna Br. India, Fishes, 1: 140.
Fig. 36
Diagnosis: Anal fin with 32-34 branched elements. Barbels 4 pairs. Maxillary barbels
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59
extend about the middle of pelvic fins. Bluish silvery along the back becoming silvery on
the flanks. Dorsal and caudal fins grayish.
Habitat: Freshwater
Distribution: This endemic species is very rare. 3 specimens are reported from Periyar
and Chaliyar (Shaji &Easa, 2001)
Local name: Malabar patashi, Vellivallah (Mal.)
Remarks: This species is found only in the fresh waters of Kerala. It attains a length of
90 cm, is of no interst to fisheries. It is in fact a rather rare species.
Key to species: Maxillary barbels extend up to the midway of pelvic fin. Eye diameter
3.0 to 3.5 in head length. Nape slightly elevated. Teeth on palate in two small oval
patches.
2. Genus PROEUTROPIICHTHYS Hora
Proeutropiichthys Hora, 1937, Curr. Sci., 5, 353 (type–species, Eutropius
macrophthalmus Blyth); Hora, 1941, Rec. Indian Mus., 43 (2): 105-110 (Review);
Talwar, 1991, Copeia (in Press) (Review).
Diagnosis: Body elongate, compressed; herring –shaped; part of abdomen more or less
keeled. Head short, oval, compressed. Snout broad, rounded, nearly on a line with level
of back. Mouth subterminal, small, crescentic, cleft slightly ascending. Eyes
conspicuously large ventro-lateral, in anterior half of head visible from below ventral
surface. Lips thin. Jaws subequal, lower jaw broadly pointed in middle. Teeth small,
villiform in bands on jaws and in four oval patches forming a semilunar band on palate.
Four pairs of barbels, one each of maxillary, nasal and two of mandibular.
Rayed dorsal fin inserted above last quarter of pectoral fins, with six to eight rays
and a spine. Adipose dorsal fin short, posteriorly free. Pectoral fins with 8 to 11 rays and
a spine serrated along both margins. Pelvic fins with six rays. Anal fin long with 42 to 52
rays, not confluent with caudal. Caudal fin deeply forked, bent downwards from caudal
peduncle. Lateral line complete, simple.
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60
Air bladder not extensive, moderate sized, lying free in abdominal cavity.
Number of species: In India: 1 species with two sub species
In Kerala: 1 species (Proeutropiichthys takree takree)
Habitat: Fresh water
Distribution: Widely distributed in the oriental region (Talwar and Jhingran, 1991).
India, Deccan, Myanmar
Species found in Kerala
Proeutropiichthys takree takree (Sykes)
(Fig. 37)
Hypophthalmus taakree Sykes, 1838, Proc. Zool. Soc. Lond., (pt.6): 163; Sykes, 1841,
Trans. Zool. Soc. Lond., 2: 369, pl. 64, fig. 4 9type-locality: Beema river nr. Pairgoon,
Maharashtra).
Schilbe sykesii Jerdon, 1849, Madras Jour. Lit. Sci., 15: 335 (type-locality: Cauvery
river); Hora, 1941, Rec. Indian Mus., 43(2):105 (status discussed).
Pseudeutropius taakree: Day (partim), 1877, Fishes of India: 471, pl. 109, fig. 4; Day
(partim), 1889, Fauna Br. India, Fishes, 1:138.
Proeutropiichthys taakree: Misra (partim), 1976, Fauna of India, Pisces (2nd ed.), 3: 176.
Fig. 37
Diagnosis: Dorsal fin with 6-8 and anal fin with 40-50 branched elements. Barbels four
pairs and the maxillary barbels extend up to the pelvic fins, colour silvery.
Habitat: Found in freshwater and tidal rivers
Distribution: India: Western Ghats, Kerala, And Maharashtra
Local name: Indian takree
Remarks: The colour of the species is silvery when it is caught in life. It is distributed in
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the Peninsular India. This catfish attains a length of 40 cm SL and is of minor interest to
fisheries.
3. Genus SILONIA Swainson
Silonia Swainson, 1839, Natural History Animals, Fishes, 2 : 305 (type-species : Silonia
lurida Swainson = Pimelodus silondia Hamilton – Buchanan) ; Hora, 1938, J.
Bombay nat. Hist. Soc., 40(2) : 137-147 (Review).
Silundia Valenciennes, 1840, Hist. Nat. Poiss., 15 : 49 (type-species : Pimelodus silondia
Hamilton-Buchanan).
Silonopangasius Hora, 1937, Curr. Sci., 5 : 352 (type-species : Ageneiosus childreni
Sykes) ; Silas, 1952, Proc. Nat. Inst. Sci. India, 18 (5) : 433 (Status discussed).
Diagnosis: Body elongate, compressed. Abdomen rounded. Head moderate sized,
compressed, anteriorly rounded. Snout obtusely rounded. Mouth anterior, wide, obliquely
directed upwards. Eyes moderate sized, situated laterally behind angle of mouth, visible
form below ventral surface. Posterior nostril enlarged medial to anterior one and
transversely oriented. Lips thin. Jaws equal. Highly specialized, enlargedcanine teeth
onjaws, villiform on palate; jaw teeth project outside mouth opening (Fig.38). Two pairs
of barbels; one of maxillary, small, in a groove; one of mandibular; either of the pair may
become vestigial or absent.
Rayed dorsal fin inserted above half of pectoral fins with 7 rays and a spine.
Adipose dorsal fin short, posteriorly free. Pectoral fins with 11 to 13 rays and a strong
spine serrated along both edges. Pelvic fins with 6 rays. Anal fin long with 40 to 46 rays.
Caudal fin deeply forked. Lateral line complete, indistinct.
Air bladder generally reduced, tick walled, not enclosed in bone.
Habitat: Inhabits estuaries, also ascending large rivers.
Distribution: India, Bangladesh, Myanmar and Nepal
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Fig. 38
Species found in Kerala
1. Silonia childreni (Sykes)
Ageneiosus childreni Sykes, 1838, Proc. Zool. Soc. Lond., (pt. 6): 165; Sykes, 1841,
Trans. Zool. Soc. Lond., 2: 375 (type-locality: Mula Mutha river nr. Poona).
Silundia sykesii Day, 1876, Trans. Linn. Soc. (Zool), 12: 569 (type-locality: Krishna
river.); Day, 1877, Fishes of India: 487, pl. 114, fig.2; Day, 1889, Fauna Br.
India, Fishes, 1: 144.
Silonopangasius childreni: Hora, 1941, Rec. Indian Mus., 43(2): 98, fig. 1c.
Silonia childreni: Silas, 1952, Proc. Nat. Inst. Sci. India, 18 (5): 433; Misra, 1976, Fauna
of India, Pisces (2nd ed.), 3: 183 (nec fig. 33)
Diagnosis: Barbels two pairs, nasal and maxillaries; maxillaries extend up to the
operculam or little beyond. Bluish on the back and whitish on the flanks and abdomen.
Air bladder large (Fig. 39), longer axis transversely disposed. Mandibular barbels equal
to the diameter of eyes.
Fig. 39
Habitat: Fresh water, Occur in large rivers and reservoirs
Distribution: It is reported to occur in Western Ghats, Krishna and Godavari river
systems (Talwar and Jhingran, 1991). Also reported from Cauvery river systems.
Local name: White catfish
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Remarks: It attains a length of 48 cm and forms an important food fish in Maharashtra. It
is a dominant species in the catches from deep waters, especially during the monsoon
months (April-July). This species is a highly predaceous fish in the Cauvery river
damaging stocks of Gonoproktopterus dubius, etc.
4. Family SISORIDAE
Sisorid catfishes
Generally small to medium sized fishes with head and anterior part of body
depressed, and tail compressed or entire body compressed. An adhesive apparatus on
thorax may be present or absent. Teeth on premaxillaries and mandible; palate edentate.
Nostrils close together, slit-like, separated by nasal barbel of varying lengths. Barbels
eight, generally well developed, in some genrea thick, fleshy with broad bases. Gill
openings wide or narrow , restricted to sides; free or confluent with isthmus.
Rayed dorsal fin short, with or without a spine. Adipose dorsal fin smooth,
generally free, but in some genera confluent with caudal, in some rudimentary,
represented by a small short spine (Sisor). Paired fins inserted horizontally, may or may
not be plaited below. Pectoral fins with or without a spine, denticulated either on inner or
outer margin, or on both; in some genera outermost ray pinnate, cartilaginous, a spine in
typical sense being absent; outermost ray of pelvic fins thick, pinnate. Anal fin short, not
confluent with caudal. Caudal fin deeply forked, emarginated, truncate or rounded.
Lateral line present, complete.
Air bladder small, partly enclosed in a bony capsule.
Lateral ethmoid facet for articulation of palatines more lateral than ventral.
Palatines very well developed, broad. Endopterygoid absent, ecto and meso-pterygoid
present, variously developed. Metapterygoid connected to hyomandibular. Prevomer
small, edentate. Autosphenotics alone provide ventrally the articular facet for
hyomandibular. Post-temporals present, united to skull with sutures, with inferior limb
weak, fused to basioccipital.
Vertebrae 34-40.
Habitat: Fresh water
Distribution: India, Bangladesh, China, Malaya, Myanmar, Nepal, Pakistan, Thailand,
and Vietnam. Not known so far from Sri Lanka.
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Number of genera: 18 genera are so far reported from India. But only a single genus is
reported from Kerala, Glyptothorax.
Genus GLYPTOTHORAX Blyth
Glyptothorax Blyth, 1861, J. Asiat. Soc. Beng., 29: 154 (type species: Glyptothorax
trilineatus Blyth); Hora, 1923, Rec. Indian Mus., 25 (1): 8-44 (Binomics); Menon,
1954, Rec. Imdian Mus., 52 (1): 27-54 (Revision); Li, 1986, Indo-Pacific Fish
Biology: 521-528 (Synopsis).
Superglyptothorax Li, 1986, Indo-Pacific Fish Biology: 524 (type-species: Glyptothorax
coheni Ganguly, Datta and Sen).
Paraglyptothorax Li, 1986, Indo-Pacific Fish Biology: 524 (type-species: Glyptosternum
pallozonum Lin).
Diagnosis: Body elongate, moderately or greatly depressed. Body smooth or rough with
granules or tubercles. Abdomen slightly flat to rounded. Head small, covered with thick
skin, depressed. Snout conical, not pointed. Mouth inferior, transverse, narrow. Eyes
dorsal, small, not visible from below ventral surface. Lips thick, fleshy, papillated. Jaws
subequal, upper jaw the longer. Teeth villiform in jaws; palate edentate. Ventral surface
of body provided with an adhesive apparatus with or without a central pit or depression
on thorax. Four pairs of barbels; one pair each of maxillary, nasal and two of mandibular;
maxillary pair with broad bases. Gill membranes united with each other and also with
isthmus. Cubito-humeral and scapular processes indistinct, covered by skin.
Rayed dorsal fin inserted above half of pectoral fins with 5-7 rays and a spine.
Adipose dorsal short, high, posteriorly free. Pectoral fins with 6-11 rays and a spine,
strong, broad, serrated with antrorse teeth along inner edge. Fins may be enveloped in
skin. Pelvic fins with six rays. Paired fins may be plaited below. Anal fin short, with 7 to
14 rays. Caudal fin deeply forked. Lateral line complete, simple.
Air-bladder enclosed in bone.
Habitat: Fresh water
Distribution: India, Bangladesh, East Indies, Iraq, Myanmar, Nepal, Pakistan and
Thailand.
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Number of species: 32 species are reported from India, in which 5 species are reported
from Kerala.
Key to species of Glyptothorax seen in Kerala
1. Adhesive apparatus on thorax as long as broad or broader than long (fig 40);
Adhesive apparatus feebly developed [Body with three white transverse bands]
……………………………………………………………………G. anamaliensis
Fig. 40
= Adhesive apparatus on thorax longer than broad (Fig. 41); Adhesive apparatus well
developed extending forwards to a point between union of gill membranes to isthmus
…………......……………….......................……........…….2
Fig. 41
2. Occipital process not reaching basal bone of dorsal fin (fig. 42); [Paired fins
pliated ventrally (fig. 43); maxillary and nasal barbels long, dorsal fin nearer to snout tip;
Nasal barbells extend beyond eye; Maxillary barbels extend for some distance beyond
upper angle of gill openings]………...................................................……......………..G.
housei
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Fig. 42
Fig. 43
= Occipital process reaching basal bone of dorsal fin (fig. 44)…….................…………..3
Fig. 44
3. Least height of caudal peduncle 2.6 to 2.7 in its length. Body with two light
longitudinal bands [Pectoral spine shorter than head length]……..............…..........
…….G. annandalei
= Least height of caudal peduncle 1.5 to 2.0 in its length. Body without bands………….4
4. Paired fin plaited (fig. 43). Skin granulated. Rayed dorsal fin height 1/4depth of
body [Pectoral spine equal or more than head length]....………………….……............G.
lonah
= Paired fins not plaited (fig. 45). Skin smooth or occasionally tuberculated. Rayed dorsal
fin height 1.0 to 1.3 times depth of body................................................G. madraspatanum
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Fig. 45
Species found in Kerala
1. Glyptothorax anamaliensis Silas
(Fig. 46)
Glyptothorax anamalaiensis Silas, 1951, J. Bombay nat. Hist. Soc., 50(2): 370 (type-
locality: Anamai Hills, Western Ghats); Jayaram, 1979, Rec. zool. Surv. India
Occ. Paper, (14): 34, figs 24 A, B (after Silas).
Fig. 46
Diagnosis: Maxillary barbels extend beyond the base of pectoral fins. Adhesive thoracic
apparatus feebly developed. Body with three transverse white bands. One at the dorsal
origin, second at the origin of the adipose dorsal and third one at the bifurcation of the
caudal peduncle.
Habitat: Fresh water, Found in mountain rapids
Distribution: Anamalai Hills and Chaliyar rivers in the Western Ghats of Kerala (Silas,
1951; Easa and Basha, 1995)
Local name: Anamalai sucker catfish
Remarks: This species is common in the streams at base of the Anamalai hills (Kerala)
but is of no interst to fisheries. It attains a length of about 10 cm.
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2. Glyptothorax annandalei Hora, 1923
(Fig. 47, Plate VII Fig.21, Plate VIII-Fig.22)
Glyptothorax annandalei Hora, 1923, Rec. Indian Mus., 25(1): 14, pl. 1, fig. 3 (type-
locality: Bhavani river at base of Nilgiri Hills); menon, 1954, Rec. Indian Mus.,
52(1): 52; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 258, pl. 11, fig. 1;
Jayaram, 1979, Rec. zool. Surv. India Occ. Paper, (14): 34, fig. 30A.
Diagnosis: Occipital process reaching basal bone of dorsal fin. Maxilary barbels extend
beyond the base of pectoral fins. Adhesive thoracic apparatus well developed. Body dark
with two longitudinal stripes along the flanks.
Fig. 47
Habitat: Found attached to the rocks, boulders and bed rocks of the fast flowing clear
rapids. Crabs are the major predators of this species.
Distribution: Bhavani river at the base of Nilgiris (Hora, 1923), South India, Western
Ghats Vindhya mountains and Nepal. In Kerala it is known from Kunthi, Kabini and
Periyar river (Rema Devi and Indra, 1986; Easa and Basha, 1995; Arun et al. 1996; Gopi,
1998).
Local name: Annadale’s sucker catfish
Remarks: This catfish attains a length of 11.5 cm; of no interest to fisheries.
3. Glyptothorax housei Herre, 1942
(Plate IV – Fig.10)
Glyptothorax housei Herre, 1942, Stanford Ichthyol. Bull., 2(4): 117, fig. (type-locality:
Anamalai Hills, Western Ghats); Silas, 1951, J. Bombay nat. Hist. Soc., 50: 369;
Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 267.
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Diagnosis: Occipital process not reaching the basal bone of dorsal fin. Maxillary barbels
slightly beyond the base of pectoral fins. Adhesive thoracic apparatus well developed.
Body pinkish or reddish with yellow or dusky mottling. Dorsal fin inserted nearer to the
snout tip than the base of the adipose dorsal fin.
Habitat: Fresh water, Found in mountain rapids
Distribution: Western Ghats- Anamalai Hills, Puthuthottam estate, Kerala (Herre, 1945)
Local name: Herre’s sucker catfish
Remarks: This catfish attains a length of 10 cm; of no interest to fisheries.
4. Glyptothorax lonah (Sykes, 1839)
(Fig. 48a & 48b, Plate IV – Fig.11)
Bagrus lonah Sykes, 1838, Proc. Zool. Soc. Lond., (pt. 6): 164 (type-locality: Deccan).
Glyptosternum lonah: Day (partim), 1877, Fishes of India: 496, pl. 113, fig. 5; Day
(partim),1889, Fauna Br. India, Fishes, 1: 196, fig. 72.
Glyptothorax dekkanensis (Gunther) Hora, 1923, Rec. Indian Mus., 25(1): 24, fig. 3.
Glyptothorax lonah: Hora, 1938, Rec. Indian Mus., 40(4): 371, pl. 7 figs 1, 2 (Systematic
position discussed); Misra, 1976, Fauna of India, Pisces (2 nd ed.), 3: 270, pl. 11,
figs. 7 & 8.
Fig. 48a
Diagnosis: Adhesive thoracic apparatus well developed. Maxillary barbels extend
posteriorly to the middle of the pectoral fin. Yellowish brown above and lighter below. A
light strek along the lateral line present (Hora, 1938).
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Fig. 48b
Habitat: Fresh water
Distribution: Deccan, Godavari and Krishna river systems. In Kerala it is known from
Chalakudy River (Hora, 1938; Ajithkumar et al. 1999).
Local name: Deccan sucker catfish
Remarks: This catfish bears a close resemblance to the goonch, Bagarius bagarius. When
a fleshy caught and alive, the colours are strikingly beautiful. It attains a length of about
15 cm; of no interest of fisheries.
5. Glyptothorax madrapatanum (Day)
(Fig. 49)
Glyptosternum madraspatanum Day, 1873, J. Linn. Soc. Lond., 11: 526 (type-locality:
Bhavani river at base of Nilgiri Hills); Day, 1877, Fishes of India: 498, pl. 116,
fig. 4; day, 1889, Fauna Br. India, Fishes, 1: 200.
Glyptothorax madraspatanum: Menon, 1954, Rec. Indian Mus., 52(1): 31
(Redescription); Misra, 1976, Fauna of India, Pisces (2nd ed), 3: 27; Jayaram,
1979, Rec. zool. Surv. India Occ. Paper, (14): 40, fig. 27.
Glyptothorax madraspatanus: Hora and Law, 1941, Rec. Indian Mus., 43(2): 255.
Diagnosis: Adhesive thoracic apparatus well developed. Occipital process reaching the
basal bone of dorsal fin. Maxillary barbels extend posteriorly to the base of the pectoral
fins. Body dark with three yellowish bands.
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Fig. 49
Habitat: Fresh water, Occurs in mountain rapids, benthopelagic.
Distribution: Western Ghats and Mettuppalayam in Coimbatore district (Hora, 1923). It
is common in Periyar, Chaliyar and Kabini River (Easa and Basha, 1995; Arun, 1997).
Anamalai hills, Nilgiri Hills, Cauvery River.
Local name: South Indian sucker catfish
Remarks: This catfish which attains a length of 11.5 cm is of no fishery value.
5. Family CLARIIDAE
Air breathing catfishes
Large sized elongate fishes with a compressed body. Teeth on premaxillaries, mandible
and vomer. Nostrils widely separated, anterior tubular, situated near tip of snout, posterior slit-
like and with nasal barbel. Barbels eight, well developed. Gill openings wide, extending to above
base of pectoral fins. An air-breathing organ arising from the branchial arches ma be present.
Branchiostegal rays 7 to 9.
Rayed dorsal fin very long, separate or continuous with caudal fin without a spine. No
adipose dorsal fin. Paired fins inserted horizontally. Pectoral fins with a strong spine, may be
serrated; in some genera fin vestigial. Anal fin long, not confluent with caudal. Caudal fin
rounded. Lateral line present, complete. Air-bladder reduced, consisting of two thin walled sacs
united by a transverse tube; two lateral chambers covered by incomplete bony capsule.
Habitat: Fres waters
Distribution: Asia and Africa. Vastly represented in Africa.
Number of genera: In India:2
In Kerala: 2 (Clarias, Horaglanis)
Key to genera of Clariidae
1. Eyes absent. Pectoral fins rudimentary. Accessory dendritic apparatus in gill
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cavity not well developed [Lateral line
faint]......................................................................Horaglanis
= Eyes present. Pectoral fins well developed. Accessory dendritic apparatus in gill cavity
well developed (fig. 5) [Lateral line distinct]..........................................................Clarias
1. Genus CLARIAS Scopoli
Clarias Scopoli, 1777, Introductio ad historiam Naturalam: 445 (type-species, Silurus
anguillaris Linnaeus), Teugels & Roberts, 1987, Zool. J. Linn. Soc., 90: 95 (Type-
species designated); Hora, 1936, Rec. Indian Mus., 38(3): 347-350 (Review).
Diagnosis: Body elongated, compressed. Abdomen rounded. Head moderate sized,
greatly depressed, covered with osseous plates dorsally and laterally forming a cask
covering a diverticulum of the gill cavity. Snout broadly rounded or pointed. Mouth
terminal, fairly wide, transverse. Eyes small, dorsolateral with free orbital margins, not
visible from ventral surface. Lips fleshy, papillated. Jaws subequal; upper jaw longer.
Teeth villiform in broad bands or patches on jaws and palate. Four pairs of barbels, one
pair each of maxillary, nasal and two of mandibular. Gill membranes deeply notched,
partly united with each other, free from isthmus. An accessory respiratory dendritic
branchial organ attached to second to fourth branchial arches present (fig. 5).
Rayed dorsal fin long, with 62 to 77 rays and without any spine, commencing
from near occiput and extending to but not continuous with caudal. Adipose dorsal fin
absent. Pectoral fins with 7 to 11 rays and a strongly serrated spine; spine enveloped in
skin. Pelvic fins with 6 rays. Anal fin long with 45 to 63 rays. Caudal fin almost rounded.
Lateral line complete, simple.
Air bladder reduced, consisting of two thin walled sacs united by a transverse
tube; the lateral chambers covered by incomplete bony capsule.
Habitat: fresh waters
Distribution: Africa and South Asia.
Number of species: In India: 4
In Kerala: 2
Key to species
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1. Snout more or less pointed. Nasal barbels much less than half of head length
[Pectoral spine strongly serrated on its outer border].....................................Clarias
dussumieri dayi
1. Snout broad. Nasal barbels not more than two times in head length [Dorsal fin
with 66 to 69 rays. Pectoral spine strongly serrated on its posterior
border]..........................................
............................................................................................ Clarias dussumieri dussumieri
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Species found in Kerala
1. Clarias dussumieri dussumieri Valenciennes
(Plate IV – Fig.12 & Plate V – Fig.13)
Clarias dussumieri Valenciennes, 1840, Hist. nat. Poiss., 15: 382 (type-locality:
Pondicherry; Malabar); Day (partim), 1877, Fishes of India: 484; Day (partim), 1889,
Fauna Br. India, Fishes, 1: 117; Hora, 1941, Rec. Indian Mus., 43(2): 113. fig. 6;
Misra, 1976, Fauna of India, Pisces (2nd ed. ), 3: 130.
Diagnosis: Dorsal fin with 66 to 69 and anal fin with 45 to 59 elements. Maxillary
barbels extend beyond the pectoral fin base. Dark brown on the back and pale below and
flanks.
Habitat: Fresh water, Found in ditches; prefers lower reaches of streams, rivers and canal
with muddy bottom; commonly found in ponds, swamps and paddy fields.
Distribution: Peninsular India (Goa, Kerala, Karnataka and Pondicherry)
Local name: Valenciennes clariid
Remarks: This species is similar to C. dussumieri brachysoma in general appearance but
differ from it in having 1) Dorsal fin with 66 to 69 rays (in C. dussumieri brachysoma
dorsal fin is with 70 to 77 rays) and 2) Pectoral spine strongly serrated on its posterior
border (in C. dussumieri brachysoma pectoral spine is rough externally).
2. Clarias dussumieri dayi Hora
(Plate V – Fig.14)
Clarias dussumieri (nec Valenciennes) day (partim), 1877, Fishes of India : 484 ; Day
(partim), 1889, Fauna Br. India, Fishes, 1: 117.
Clarias dayi Hora, 1936, Rec. Indian Mus., 38 (3) : 350, fig. 4c (type-locality : Wynaad,
Kerala) ; Misra (partim), 1976, Fauna of India, Pisces (2nd ed.), 3: 129.
Clarias dussumieri dayi : Silas, 1952, Proc. Nat. Inst. Sci. India, 18: 435.
Diagnosis: Distance from dorsal fin base of occipital process 2.0 to 3.5 times in head
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length. Snout pointed nasal barbels more than two times in head length.
Habitat: Fresh water, demersal.
Distribution: Wayand Hills, Kerala. So far this specimen is known only from the type
specimen collected by Day in 1877. The only report available after its original description
is by Manimekalan (1998) from Mudumalai Wildlife Sanctuary. Talwar and Jhingran
(1991) treated this species as a separate species where as Jayaram (1981 a) considered it
as a subspecies.
Local name: Malabar clariid
Remarks: This is a very rare species being known only by a single specimen, 17.5 cm in
length collected by Dr. F. Day in 1877.
2. Genus Horaglanis Menon
Horaglanis Menon, 1951, Rec. Indian Mus., 48(1): 60 (type species Horaglanis krishnai
Menon); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 132-133 (Review).
Diagnosis: Body elongated. Abdomen rounded. Head short, devoid of osseous plates,
globular. Snout truncated. Mouth subvertical, fairly wide, crescentic. Eyes absent. Lips
thick, fleshy. Jaws subequal. Teeth villiform, closely set in broad bands or patches in
jaws and palate. Four pairs of barbels, one pair each of maxillary, nasal and two of
mandibular. Gill membranes united with each other and also with isthmus. Two small
bony structures corresponding to the second and fourth arch represent the dendritic
apparatus.
Rayed dorsal fin long, with 23 rays, commencing in the beginning of the third of
the distance between the tip of snout and caudal fin base, and extending to caudal but free
from it. Adipose dorsal absent. Pectoral fins vestigial, with a central axial ray which bears
six small rays distally and nine smaller rays on the sides. Pelvic fins with 6 rays. Anal fin
long with 17 rays, free from caudal. Caudal fin rounded. Lateral line faint.
Air bladder bag like, laterally broader than long, slightly notched at the anterior
end, completely free.
Habitat: Inhabit in wells
Distribution: India: Kottayam, Kerala state.
Number of species: This genus is represented by a single species Horaglanis krishnai
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Menon and it is known only from Kerala.
1. Horaglanis krishnai Menon
(Fig. 50, Plate V – Fig.15)
Horaglanis krishnai Menon, 1951, Rec. Indian Mus., 48(1): 64, figs 2, 3 & pl. 1, figs1-3
(type-locality: well at Kottayam, Kerala); Misra, 1976, Fauna of India, Pisces (2nd ed.), 3:
132. pl.2, figs 3-4.
Fig. 50
Diagnosis: Body elongated and cylindrical. Head short and tubular. Eyes absent. Barbels
four pairs. Dorsal and anal fin long based. Pectoral fin vestigial.
Habitat: This is restricted to subterranean wells in Kottayam district of Kerala. Migrate
from one well to another through underground water channels.
Distribution: Reported only from Kottayam District of Kerala.
Local name: Indian blind catfish
Remarks: Bones of the skull firmly articulated. Brain teleostean. Absence of eyes
brought about the degeneration of the optic lobes. Skin devoid of scales
6. Family HETEROPNEUSTIDAE
Stinging catfishes; Airsac catfishes
Diagnosis: Moderate sized elongate fishes with a compressed body. Teeth on
premaxillaries, mandible and vomer. Nostrils widely separated, anterior produced into a
short tube, on tip of snout, posterior slit-like behind nasal barbels. Barbels eight, well
developed. Gill openings wide, extending to above base of pectoral fins. A long air-sac
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extends posteriorly from gill chamber through muscles of back to tail (fig.6).
Branchiostegal rays seven.
Rayed dorsal fin short and without any spine. Paired fins inserted horizontally.
Adipose dorsal fin absent or represented by a low ridge. Pectoral fins with a strong spine,
serrated. Anal fin long, just reaching or united with caudal. Caudal fin almost rounded.
Lateral line present, complete.
Habitat: Fresh water
Distribution: India, Bangladesh, Myanmar, Pakistan, Sri Lanka, Thailand and Vietnam.
Absent from Malaya and East Indies.
Number of genus: 1, Genus Heteropneustes Muller
1. Genus Heteropneustes Muller
Heteropneustes Muller, 1840, Arch. Anat. Physio., p.115 (type-species, Silurus fossilis
Bloch, by monotypy).- Hora, 1936, Rec. Indian Mus., 38, pp.208-209 (review).- Jayaram,
1980, Occ. Papers ZSI, No. 23, p.11.
Saccobranchus Valenciennes, 1840, Hist. nat. Poiss., 15, p.399 (type-species,
Silurus singio Hamilton-Buchanan = S. fossilis Bloch).
Diagnosis: Body elongate, compressed. Abdomen rounded. Head moderate sized, greatly
depressed, its dorsal and lateral parts covered with bony plates. Snout flat. Mouth
terminal, transverse, narrow. Eyes small, lateral, in anterior part of head, not visible from
below ventral surface. Lips fleshy, papillated. Jaws subequal. Teeth villiform in broad
bands on jaws and in two oval patches on palate. Four pairs of barbels; one pair each of
maxillary, nasal and two of mandibular. Gill membrane separated by a deep notch, not
united with isthmus.
Rayed dorsal fin short, inserted above tip of pectoral fins with six to eight rays
and without any spine. Adipose dorsal absent or represented by a low adipose ridge,
along posterior third of caudal region. Pectoral fins with seven or eight rays and a strong
spine serrated along inner edge. Pelvic fins with 6 rays. Anal fin long with 60 to 79 rays,
just reaching or confluent with caudal fin. Caudal fin almost rounded. Lateral line
comlete, simple.
Air-bladder greatly reduced, consisting of two thin walled pyriform sacs
enclosed in incomplete bony capsules. Sacs united by a transverse tube which is
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connected with oesophagus through a slender tube.
Habitat: Fresh water
Distribution: Widely distributed in the oriental region. India, Bangladesh, Laos, Nepal,
Pakistan, Sri Lanka and Thailand.
Number of species: In India and in Kerala: 2 species, Heteropneustes fiossilis and H.
microps
Key to species of Genus Heteropneustes found in Kerala
1. Anal fin separated from the caudal fin by a deep notch. Occipital process not
reaching base of dorsal
fin....................................................................................................H. fossilis
= Anal fin confluent with caudal fin. Occipital process reaching base of dorsal
fin.........................................................................................................................H. microps
1. Heteropneustes fossilis (Bloch)
(Figure 51, Plate VI – Figs.16 &17)
Silurus fossilis Bloch, 1794, Naturgesch. Ausl. Fische, 8: 46, pl. 370, fig. 2 (type-locality:
Tranquebar, Tamil Nadu).
Saccobranchus fossilis: Day, 1877, Fishes of India: 486, pl. 114, fig.1: Day, 1889, Fauna
Br. India, Fishes, 1: 125, fig. 53.
Heteropneustes fossilis: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 135, fig. 24.
Fig. 51
Diagnosis: Anal fin separated from the caudal fin by a deep notch. Occipital process not
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reaching base of dorsal fin
Habitat: This species in quite common in the fresh water low lands. Found mainly in
ponds, ditches, swamps and marshes, but sometimes occurs in muddy rivers. Can tolerate
slightly brackish water.
Distribution: India, Pakistan, Nepal, Bangladesh, Sri Lanka, Myanmar, Thailand and
Laos. Also reported from Andaman and Nicobar Islands.
Local name: Stinging cat fish, Scorpion catfish, Kari (Mal.), Kadu (Mal.).
Remarks: It is a fish of high economic importance. This is primarily a fish of ponds,
ditches, swamps and marshes. It is able to tolerate slightly brackish water. Its air
breathing apparatus enables it to exist in almost any kind of water. It attains a length of
30 cm and is in greast demand because of its medicinal value. The fish is much dreaded
because of its aggressive behaviour and can inflict painful wounds with its potentially
dangerous pectoral spines.
2. Heteropneustes microps (Gunther)
(Fig.52)
Saccobranchus microps Gunther, 1864, Cat. Fishes Br. Mus., 5: 31 (type-locality : Sri
Lanka) ; Day, 1877, Fishes of India : 486 ; Day, 1889, Fauna Br. India, Fishes,
1 : 125.
Heteropneustes microps : Misra, 1976, Fauna of India, Pisces (2nd ed.), 3 : 137 ;
Srivastava and Datta Munshi and Srivastava, 1988, Natural History of Fishes and
Systematics of Freshwater Fishes of India : 298, pl. 37, fig. 2.
Fig. 52
Diagnosis: Anal fin confluent with caudal fin. Occipital process reaching base of dorsal
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fin.
Habitat: The air sac catfish has been found in an area heavily modified by man, where it
inhabits swamps and similar still, often turbid waters, such as irrigation ditches. It
inhabits both fresh and brackish waters.
Distribution: North India: Bihar and Uttar Pradesh (Datta Munshi & Srivastava, 1988).
Very rare in Sri Lanka.
Local name: Sri Lanka stinging cat fish, Kari (Mal.), Kadu (Mal.)
Remarks: This species which attains a length of 30 cm is esteemed as food for its
invigorating qualities.
7. Family ARIIDAE
Sea catfishes
Robust large sized, more or less elongate fishes with a compressed body. Teeth on
premaxillaries, mandible, vomer and palatines, may be absent on either of latter two or on
both. Nostrils close together, posterior with a valve, but without a barbel. Barbels two or
six, moderate to well develop (no nasal barbels). Gill openings wide, extending to base of
or above base of pectoral fins. Branchiostegal rays five or six.
Rayed dorsal fin short with a pungent spine. Adipose dorsal fin smooth, not
confluent with either rayed dorsal or with caudal fins. Paired fins inserted horizontally
and plain. Pectoral fins with a sharp, serrated spine. Anal fin moderately long, not
confluent with caudal. Caudal fin forked or bifurcate. Lateral line present, generally
complete.
Air bladder large, with thick walls, in abdominal cavity, not enclosed in bone.
Habitat: Shores, estuaries and seas
Distribution: Subtropical regions
Number of genera: In India: 5 genera
In Kerala: 1 (Arius Valenciennes)
1. Genus Arius Valenciennes
Mouth-breeding catfiahes
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Arius Valenciennes IN: Cuvier &Valenciennes 1840, Hist. Nat. Poiss., 15, p.53 (type-
species, Pimelodus arius Hamilton- Buchanan, by absolute tautonymy).
Tachysurus Lacepede, 1803, Hist. nat. poiss., 5, p.150 (type-species, Tachysurus sinensis
Lacepede, by monotypy).
Chandy, 1954, Rec. Indian Mus., 51 (1), pp. 1-18 (synopsis of species, key).- Jayaram,
1982, Occ. Papers zool. Surv. India, 37, pp. 1-33 (revision).
Diagnosis: Body elongate, compressed. Abdomen rounded. Head large, subconical,
depressed, exposed, with more or less granular or rugose osseous shields on dorsal
surface, or covered with thin skin. Snout conical or pointed obtusely. Mouth subterminal,
moderate or large, transverse. Eyes lateral or slightly directed upwards with free orbital
margin, in middle or anterior part of head, may or may not be visisble from below ventral
surface. Lips thin. Jaws subequal, upper jaw projecting. Teeth villiform, granular or
conical on jaws and palate, in bands or patches. Three pairs of barbels; one pair
maxillary, two mandibular. Gill membranes united, connected with isthmus but with a
free posterior margin.
Rayed dorsal fin inserted above middle or last quarter of pectoral fins with six or
seven rays and a pungent, strong spine. Adipose dorsal short or of moderate length,
posteriorly free. Pectoral fins with nine to twelve rays and a strong serrated spine. Pelvic
fins with six rays. Anal fin short with 14 to 24 rays. Caudal fin forked with rounded or
acute lobes. Lateral line prominent, complete, simple. Air-bladder large, heart shaped,
free, not enclosed in bone.
Habitat and Distribution: Seas and estuaries of tropical regions ascending to within
tidal influence or even entering fresh water
Number of species in India: 11 species are reported from India
In Kerala: 1 species (Arius arius)
1. Arius arius (Hamilton-Buchanan)
(Fig. 53)
Pimelodus arius Hamilton-Buchanan, 1822, Fishes of Ganges: 170, 376 (type-locality:
estuaries of Bengal).
Arius buchanani Day, 1877, Fishes of India: 463, pl. 105, fig. 6 (type-locality: Hoogly
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River at Culcutta; Burma); Day, 1889, Fauna Br. India, Fishes, 1: 181.
Tachysurus arius: Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 32, fig. 3.
Arius arius: Jayaram., 1982, rec. zool. Surv. India Occ. Paper, (37): 16, fig. 12.
Fig. 53
Diagnosis: Teeth on palate as a single oval or elongated patch on each side (fig 53);
Pectoral spine shorter or equal to dorsal spine. Palate teeth loosely packed, irregularly
ovate in shape. Anal fin with 20 or 21 rays. Horn-like conical projection of palate teeth
patch present anteriorly. Dorsal fin with a filamentous prolongation.
Habitat: Seas and Estuaries
Distribution: India: Kerala, Orissa, Tamil Nadu and West Bengal. Myanmar.
Local name: Marine catfish, Hamilton's catfish, Theadfin seacatfish
Remarks: This is an estuarine catfish and is common in estuaries, tidal rivers and
brackish water lakes of India. . It attains a length of 20 cm; common as 15 cm standard
length.
8. Family PLOTOSIDAE
(Eel tail catfish)
Large sized elongate fishes with a compressed body and tapering or bluntly
rounded tail. Teeth on premaxillaries, mandible and vomer. Nostrils widely separated,
anterior tubular, in front border of upper lip, posterior slit-like, between eye and upper
lip. Barbels eight, well developed; occasionally labial folds at angle of mouth produced
into short barbels. Gill openings wide, extending to above base of pectoral fins. Gill
membranes free from each other may be totally or partly united with isthmus or free from
it.
Two rayed dorsal fins, first small with a smooth or serrated spine; second very
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long, confluent with procurrent caudal (dorso-caudal fin). No adipose dorsal fin. Pectoral
fins laterally inserted with a strong serrated spine. Pelvics inserted horizontally. Anal fin
many rayed, confluent with caudal fin. A well developed dendritic organ between vent
and anal fin present. Caudal fin pointed. Lateral line conspicuous, represented by distant
pores.
Air-bladder fairly large in proportion to body size, free, not enclosed in bone.
Palatined rod like, 3/5th of autosphenotics provide facet for articulation of
hyomandibular. Endopterygoid absent. Ectopterygiod small, toothless, suturally
articulated to the long, flat, metapterygoid. Metapterygiod suturally connected with
hyomandibular. Post-temporals connected to skull by ligament. Inferior limb of post-
temporals well developed, attached to basioccipital. Mesocoraccoid in shoulder girdle
present.
Habitat: Mainly marine, entering rivers and with some permanently fluviatile species.
Distribution: Indo-Pacific Ocean
Number of genera: Only a single genus – Plotosus
Genus Plotosus Lacepede
Plotosus Lacepede, 1803, Hist. nat. Poiss. , 4, p.129 (type-species, Platystacus
anguillaris Bloch = Silurus lineatus Thunberg); Gomon and Taylor, 1982, J. L. B.
Smith Inst. Icthyol. Sp. Publ., (22): 1-16 (Review).
Diagnosis: body elongate, compressed. Abdomen subcylindrical, tail tapering. Head
moderately depressed, short, covered with thin skin. Snout bluntly rounded. Mouth
transverse, cleft not extending to orbit, slightly overhung by snout. Eyes moderate, in
anterior half or middle of head. Lips thick papillated or with laminated folds, upper lip
prominent. Jaws equal. Teeth pleuriserial, conical on upper jaw, molariform on lower
jaw, molar-like on palate.
Two dorsal fins; first inserted above pectoral fin base, with four to six rays and a
pungent spine, second long, uniformly low, united with caudal. No adipose dorsal fin.
Pectoral fins with 9 to 13 rays and a weak strong serrated spine. Pelvic fins with 10 to 16
rays. Anal fin long, confluent with caudal fin with 58 to 131 rays. A dendritic post-anal
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apparatus close behind anal fin present. Caudal fin bluntly pointed or rounded. Lateral
line complete, conspicuous with distant pores.
Habitat: Marine habitat but visit fresh water.
Distribution: India, Bangladesh, Myanmar, Pakistan, SriLanka, Red sea, Seychelles,
Natal, Mauritius, Malaya, Singapore, Thailand, Indonesia, Amoy, Hong Kong, Japan,
Philippines, British N. Guinea, Australia and Tahiti (Jayaram 1991).
Remarks: These fishes are marine but they visit fresh water.
Number of species: In India: 3
In Kerala: 2 species (Plotosus lineatus, Plotosus canius)
Key to species of Genus Plotosus found in Kerala
1. Body with two or three prominent pale stripes, two extending onto head (stripes often
indistinct in large specimens); nasal barbels short; total rays in confluent median fins 139
to 200……………………………………………………………………..….…P. lineatus
= Body without stripes; nasal barbels long, reaching well behind eyes, usually to nape;
eyes small, the diameter 8.3 to 14.3 times in head length; large vermiform papillae on gill
arches and gill filaments………………………………………………….…….P. canius
1. Plotosus canius Hamilton-Buchanan
(Fig. 54, Plate IX-Fig.24)
Plotossus canius Hamilton-Buchanan, 1822, Fishes of Ganges : 142, 374, pl. 15, fig. 44
(type-locality : rivers of lower bengal) ; Day, 1877, Fishes of India : 482, pl.112,
fig. 3 ; Day, 1889, Fauna Br. India, Fishes, 1 : 113, fig. 47 ; Misra, 1976,Fauna of
India, Pisces (2nd ed.), 3 : 150, fig. 26.
Fig. 54
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Diagnosis: Body plain without any stripes; Nasal barbels extending considerably beyond
eyes. Colour generally olive-green without any stripes on body. Eye diameter 8.3 to 14.3
times in head length.
Habitat: Marine, Found mostly in estuaries and lagoons, and sometimes up rivers in
nearly fresh waters. Occurs in the lower parts of rivers in freshwater or brackish water
and in coastal seas
Distribution: India: Andaman Islands, Kerala, Maharashtra, West Bengal, Bangladesh,
Malaya, Myanmar, Pakistan and Sri Lanka.
Local name: Canine catfish-eel, Black-tip catfish
Remarks: This catfish contributes a moderate fishery in the Hooghly estuary (West
Bengal) and also in other brackish water lakes along the east coast of India. It attains a
length of 150 cm; common to 80 cm. The flesh is readily marketable. It is a suitable
species for brackish water fish culture in India.
2. Plotosus lineatus (Thunberg)
(Fig. 55, Plate IX-Fig.25)
Silurus lineatus Thunberg, 1787, K. Vetensk. Akad. Nya Handl., 12: 190 (type-locality:
Indian Ocean).
Plotosus arab (Bleeker) Day, 1877, Fishes of India: 483, pl. 112, fig. 4; Day,1889, Fauna
Br. India, Fishes, 1: 113; Misra, 1976, Fauna of India, Pisces (2nd ed.), 3: 148.
Plotosus anguillaris (Bloch) Misra, 1962, Rec. Indian Mus., 57: 117.
Fig. 55
Diagnosis: Body with two or three prominent pale stripes. Two dorsal fins; first inserted
above pectoral fin base, with four to six rays and a pungent spine, second long, uniformly
low, united with caudal. No adipose dorsal fin. Pectoral fins with 9 to 13 rays and a weak
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strong serrated spine. Pelvic fins with 10 to 16 rays. Anal fin long, confluent with caudal
fin with 58 to 131 rays. A dendritic post-anal apparatus close behind anal fin present.
Caudal fin bluntly pointed or rounded.
Habitat: Marine and fresh water, the only catfish found in coral reefs. Also found in
estuaries, tide pools and open coasts.
Distribution: India: Kerala, Gujarat, Maharashtra, Tamil nadu. Pakistan: Makran,
Myanmar, Sri Lanka.
Local name: Striped eel-catfish, Coral catfish
Remarks: This is a marine catfish which penetrates brackish and fresh waters. It attains a
length of 30 cm and important in fishery industry.
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DISCUSSION
Kerala exhibit high variability in fish assemblages. Highest diversity of species is
reported in this region. Many of the catfishes reported from Kerala are endemic to this
region. Batasio travancoria is the only species reported from the genus Batasio.
Horabagrus brachysoma is highly abundant where as Horabagrus nigricollaris is a
recently described species. Highest number of species is reported from the Genus Mystus,
8 species. The Genus Silurus include a species known only from South India, Silurus
wynaadensis. The family Schilbeidae includes two subfamilies but only the subfamily
Schilbeinae include members reported from Kerala. This subfamily has three genera
with single species each seen in Kerala. The species are Psedeutropius mitchelli,
Proeutropiichthys takree takree and Silonia Childreni. Family Sisoridae consist of 1
genus with 5 species. They are the category of sucker catfishes. The members of the
family Clariidae are highly endemic to Kerala. Their number is found to decrease year by
year and they have reached a stage of extinction. Horaglanis krishanai Menon is a
species so far reported only from the wells of Kottayam district of Kerala. The family
Heteropneustidae includes the stinging catfishes. The family Ariidae and Plotosidae
include the fishes that are seen marine habitat, entirely different from the other members
of this order. These fishes but visit freshwater at regular intervals.
Some members of the genus bear very close similarity to each other so that
identification is difficult. Such resemblances and differences of related species important
to taxonomy are discussed below in detail.
Batasio travancoria shows similarity to Batsio batasio in general appearance but
differ from it in having 1) Body without longitudinal bands or spots (Body marked with
longitudinal bands in B.batasio, 2) Occipital process not reaching basal bone of dorsal
fin, separated by a considerable distance (Occipital process extends to the basal bone of
dorsal fin in B. batasio) and 3) Pores on dorsal surface of head present (in B. batasio, no
pores on dirsal surface of head).
Horabagrus brachysoma comes very near Horabagrus nigricollaris in general
appearance but differs from it in having 1) a black ocellus at the humeral region (in H.
nigricollaris no such ocellus occurs but a saddle shaped band over the nape).
Horabagrus nigricollaris is a recently described species from Chalakudy River at
Vettilappara. This species come very near Horabagrus brachysoma in general
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appearance but differs from it in having 1) A saddle shaped band over the nape (such a
band is absent in H. Brachysoma); 2) No ocellus at the humeral region (A black ocellus
present at the humeral region in H. brachysoma).
Mystus armatus is morphologically very much similar to Mystus castaneus in
general appearance but differ from it in having a thin, dark band running along the length
of the body (Mystus castaneus does not possess such dark band).
Mystus keletius is morphologically similar to Mystus malabaricus in general
appearance but differ from it in having 1) Body depth 4 times in standard length (Body
depth 4.5 to 6 times in standard length in M. malabaricus, 2) A light band above and
below lateral line (A dark band only along the lateral line ending with a dark blotch at
base of caudal fin in M.malabaricus) and 3) maxillary barbel extend to the middle of
pelvic fin (maxillary barbel extend to the end of pelvic fin in M. malabaricus).
Mystus montanus resembles Mystus vittatus in general appearance but differ from
it in having 1) Eye-diameter 3.5 to 4 times in head length (in M. vittatus , eye diameter
4.5 to 6 times in head length, 2) Pectoral fin with 6 rays (in M. vittatus pectoral fin with
9 soft rays and 3) body marked with one or two longitudinal light bands above lateral line
(in M. vittatus body marked with 3 or 4 longitudinal pale blue or dark brown or black
bands above and below lateral line).
Mystus cavasius resembles Mystus pulcher in general appearance and also in the
presence of a dark spot on base of caudal fin but differ from it in having 1) Median
longitudinal groove on head extends to base of occipital process (in Mystus pulcher
median longitudinal groove on head not extends to base of occipital process).
Ompok malabaricus is similar in appearance to Ompok bimaculatus in outer
appearance but differ from it in having anal fin with 63 to 69 branched rays (In O.
bimaculatus anal fin is with 57 or 58 branched rays.
Pseudeutropius mitchelli is similar to P. atherinoides in general appearance , but
differ from it in having 1) Eye diameter 3.0 to 3.5 in head length (In P. atherinoides eye
diameter 2.5-3.0 times in head length) 2) Nape slightly elevated (In P. atherinoides nape
well elevated) and 3) Teeth on palate in two small oval patches (In P. atherinoides teeth
on palate in two narrow separate cresecentic patches).
Proeutropiichthys taakree taakree is similar to P. takree macrophthalmos in
general appearance but differ from it in having 1) Interoperculum with two prominent
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spurs separated by a notch ( in P. takree macrophthalmos interoperculum is rounded
without any spurs), 2) Eye diameter 2.75 to 3.0 times in head length (in P. takree
macrophthalmos eye diameter is 3.5 to 3.6 times in head length and 3) Maxillary barbels
extend to pelvic fins (in P. takree macrophthalmos the maxillary barbel extend only upto
tip of pectoral fins).
Silonia childreni is similar to Silonia silondia in general appearance but differs
from it in having 1) Large air bladder (In S. silondia air bladder is greatly reduced), 2)
Maxillary barbel long, extending to operculum (In S. silondia maxillary barbels minute,
not extending beyond orbit) and 3) mandibular barbels equal to diameter of eyes (In S.
silondia mandibular barbels vestigial).
G. lonah resemble G. madraspatanum in general appearance but differ from it in
having 1) Paired fin plaited (Paired fins not plaited in G. madraspatanum), 2) Skin
granulated (Skin smooth or occasionally tuberculated in G. madraspatanum) and Rayed
dorsal fin height 1/4depth of body (Rayed dorsal fin height 1.0 to 1.3 times depth of body
in G. madraspatanum).
Clarias dussumieri dussumieri is similar to C. dussumieri brachysoma in general
appearance but differ from it in having 1) Dorsal fin with 66 to 69 rays (in C. dussumieri
brachysoma dorsal fin is with 70 to 77 rays) and 2) Pectoral spine strongly serrated on its
posterior border (in C. dussumieri brachysoma pectoral spine is rough externally).
Heteropneustes fossilis is similar to H. microps in general appearance but differs
from it in having 1) Anal fin separated from the caudal fin by a deep notch (in H. microps
anal fin confluent with caudal fin) and 2) Occipital process not reaching base of dorsal fin
( In H. microps occipital process reaching base of dorsal fin).
Heteropneustes microps is similar to H. fossilis in general appearance but differ
from it in having 1) anal fin confluent with caudal fin (In H. fossilis anal fin separated
from the caudal fin by a deep notch) and 2) occipital process reaching base of dorsal fin
(In H. fossilis occipital process not reaching base of dorsal fin.
Arius arius is similar to A. gagora in general appearance but differs from it in
having 1) Anal fin with 20 or 21 rays (in A. gagora, anal fin with 18 or 19 rays), 2) Horn-
like conical projection of palate teeth patch present anteriorly (in A. gagora, horn like
conical projection of palate teeth patch present posteriorly) and 3) Dorsal fin with a
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filamentous filamentous prolongation (in A. gagora dorsal fin without a filamentous
prolongation).
Plotosus canius is similar in appearance to P. limbatus but differ from it in having
1) Nasal barbels extending considerably beyond eyes (in P. limbatus nasal barbels not
extend farther than hind border of eyes) and 2) Eye diameter 8.3 to 14.3 times in head
length (in P. limbatus eye diameter 5 to 9 times in head length).
Plotosus lineatus bear similarity with P. canius in general appearance but differ
from it in having three prominent pale stripes on the body (in P. canius body is plain
without any stripes).
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SUMMARY
The contribution made by scientists all over the world on the systematics of the
Order Siluriformes was briefly reviewed in this small work with special reference to the
Catfishes seen in Kerala. The live samples caught from the river using various fishing
nets and the dead samples collected from the markets were transported to the laboratory
for further analysis. Using standard taxonomical textbooks the samples were identified
and the species was described. A dichotoumous key was prepared for the Family, Genera
and species found in Kerala. An analysis on the resemblances and differences of related
species were discussed.
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CONCLUSION
The study was conducted to review the catfishes found in Kerala. From the study
it was found that Kerala catfishes belong to 8 families, 15 gnera and 31 species. Majority
of the fishes are highly endemic to Kerala seen only in specific geographic regions. Some
of the fishes are at the verge of extinction, like Clarias dussumieri dussumieri where as
some of them are known only by the description like Clarias dussumieri dayi. A
scientific approach is needed to protect these economically important food and aquarium
fishes to protect from extinction. Also a detailed taxonomic study should be conducted in
this area of Kerala catfishes to avoid the confusion in scientific identification.
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PLATE I
Fig. 1 Batasio travancoria(Courtesy to Planetcatfish.com)
Fig.2 Horabagrus brachysoma
Fig.3 Horabagrus nigricollaris(Courtesy to Planetcatfish.com)
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98
PLATE II
Fig.4 Mystus armatus
Fig.5 Mystus keletius(Picture by Jayasinghe A.)
Fig.6 Mystus montanus
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99
(Courtesy to Scotcat.com)
PLATE III
Fig.7 Ompok bimaculatus(Courtesy to Scotcat.com)
Fig.8 Ompok malabaricus(Photo by Manimekalan A.)
Fig.9 Silurus wynaadensis100
100
(Picture by Day, 1877)
PLATE IV
Fig. 10 Glyptothorax housei(Photo by Manimekalan A.)
Fig. 11 Glyptothorax lonah(Picture by Day, 1877)
Fig. 12 Clarias dussumieri dussumieri
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PLATE V
Fig. 13 Head of Clarias dussumieri dussumieri
Fig. 14 Clarias dussumieri dayi
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Fig. 15 Horaglanis krishnai (Photo by K. Subhash Babu)
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PLATE VI
Fig. 16 Heteropneustes fossilis
Fig. 17 Heteropneustes fossilis
Fig. 18 Mystus malabaricus(Courtesy to Planetcatfish.com)
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PLATE VII
Fig. 19 Mystus oculatus(Courtesy to kerala-nadu.blogspot.com)
Fig. 20 Mystus vittatus(Courtesy to Scotcat.com)
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Fig. 21 Glyptothorax annandalei(Courtesy to Planetcatfish.com)
PLATE VIII
Fig. 22 Adhesive apparatus of G. annandalei(Courtesy to Planetcatfish.com)
Fig. 23 Mystus cavasius(Photo by Khan M. M.)
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PLATE IX
Fig.24 Plotosus canius
(Courtesy to flickr.com)
Fig. 25 Plotosus lineatus
(Courtesy to encyclopedia of life)
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107