Diversity of freshwater mollusc in the Western Ghats

Suri Sehgal Centre for Conservation Science, Ashoka Tr st for Research in Ecolog and the En ironment

N.A. Aravind* and N.A. Madhyastha**Ashoka Trust for Research in Ecology and the Environment

(ATREE), Bangalore- 560024.

**Malacology Centre, Poorna Prajna College, Udupi- 576101.

DIVERSITY OF FRESHWATER MACROINVERTEBRATES

HABITAT DIVERSITY OF FRESHWATER ECOSYSTEMS

PONDS LAKES

STREAMS AND RIVERS BACKWATERS AND ESTUARIES

FRESHWATER BIODIVERSITY HOTSPOTS OF THE WORLD

The Western Ghats is a hotspot for freshwater fishes, crabs and Mollusks

Estimated numbers of described and undescribed terrestrial and freshwater mollusc

70000

ity

50000

60000

Max Undescribed

Described

mol

lusc

div

ersi

pec

ies)

50000

40000

Min

Non

mar

ine

m(N

um

ber

of

sp

30000

20000 Max

N (

10000Min

Source: Lydeard et al. 2004

Freshwater0

Terrestrial

Taxonomic break up of Indian freshwater mollusc fauna

Gastropods Bivalves Total Western Ghats

Families 12 09 21 13Genus 36 21 57 20Species 170 113 214 60

Source: Subba Rao 1989 and Shivaramakrishnan et al. 1999

Cremnochonchus sahydarensisLithtotis rupicola

Arsidopsis sp

Arsidopsis footi

Arsidopsis sp, Pseudomulleria dalyii

Cremnochonchus sp

Paracrostoma tigrina, Paracrostoma martini

Habitat preference of freshwater molluscs of the Western Ghatsof the Western Ghats

Rivers and stream are species rich habitats

70

Arsidopsis footi Pseudomulleria dalyiHabitat distribution of Freshwater molluscs

40

50

60

ices

10

20

30

40

Perc

ent s

pe

0

10

Lentic Lotic Both

Habitat

Zoo-geographically interesting species in the Western Ghats

Marine elements in the freshwater mollusc fauna of the Western Ghats

Neritinea perottetiana (Neritidae)

Cremnoconchus syhadrensis (Litterorinidae)

Zoo-geographical significance of Western Ghats molluscan fauna

Cremnochonchus

Pseudomulleria

Paracrostoma

Cremnochonchus sp.• Member of marine family• Shows that Part of the Western• Shows that Part of the Western

Ghats was under the sea• Highly specialsed habitat-Highly specialsed habitat

waterfalls• Only on the western slopes

Zoo-geographically interesting species in the Western Ghats

Family: Etheriidae

Genus: 3

Species: 3

South America, Madagascar, Tropical Africa and IndiaAfrica and India

A Gondwana relict cemented bivalve of the Western GhatsA Gondwana relict, cemented bivalve of the Western Ghats

Pseudomulleria dalyiiy

Only Five populations of <2000 individuals

Family Etheridae-A G d l d li tAn Gondwanaland relict

PseudomulleriaPseudomulleria

Western Ghats

EtheriaAcostea

Africa and Madagascar Colombia

Adamietta

… Into IndiaAdamietta

Brotia

BrotiaAdamietta

Paracrostoma

Adamietta

“…origins of the Indian biota (freshwater g (mollusc) are more complex and diverse

than assumed under the standard Mesozoic vicariance model…”

Kohler and Glaubrecht 2007

Importance

• Food: – For humans: Clams, Pila, Thiara etc– AnimalsAnimals

• Nutrient cycling: In Terrestrial and FreshwaterIndicator of ecosystem health Bioindicators• Indicator of ecosystem health-Bioindicators

• Agricultural pests• Invasive

Threats

THREAT STATUS OF RIVER CATCHMENTS OF THE WORLDWORLD

River catchments of peninsular India is most threatened

Pollution GastropodsBivalves

Dams Bivalves Gastropods

Mines Bivalves Gastropods

Agriculture Bivalves Gastropods

Urbanization Bivalves Gastropods

Percentage of extinct animals in different faunal groupsfaunal groups

C t

Others0%

Crustaceans1%

Amphibians1% Reptiles

3%

Insects10%

MammalsMollusca

43%

Mammals11%

Fishes12%12%

Birds

Source: www.redlist.org.

Total number of threatened species of molluscmollusc

12221200

1400

708800

1000

pec

ies

429400

600

# s

p

41

0

200

T rr tri l Fr h t r M rin L t C n rnTerrestrial Freshwater Marine Least ConcernGroup

Source: www.redlist.org.

India and Western Ghats???India and Western Ghats???

O l ONE h b li t d d IUCN dOnly ONE has been listed under IUCN red list category

Pseudomulleria dalyii

The big challenge of freshwater biodiversityConservation-

Environmental water demand and social requirement

Significant wetlands of the western ghats and their western ghats and their conservation status

GODAVARI CATCHMENT

WetlandHabitats

Nos./Region/Locality

PROTECTION

Rivers 3 large, 13 3 RiverKRISHNA Rivers 3 large, 13medium and 17

minor

3 River Sanctuaries

(Fish)

Backwaters Ashamudi, 2 Ramsar sites

CATCHMENT

Kuttanad, Vembanad, Kole

wetlands (Kerala)CAUVERY

Estuaries/Mangroves

Bharatapuzha,Netravathi, Gurupura, Gangolli

NilCAUVERYCATCHMENT

Gangolli, Sharavathi,

Aghanasini, Kali, Mandovi

A Gap AnalysisNo comprehensive assessment of freshwater biodiversity of the regiony g

F t i t di f h t llFew taxonomic studies on freshwater molluscs

Little information available on the distribution and ecology of the most of the speciesgy p

Few studies on the river ecology and its interaction with other species

AcknowledgementsAcknowledgements

Dept. of Science and Technology

EndemicsEndemics

Current Threats (Contd..)

DAMS MINES

MINES AGRICULTURE EXPANSION

Current Threats

RIPARIAN DEFORESTATION WASTE DISPOSAL

INFRASTRUCTURE DEVELOPMENT INDUSTRIAL POLLUTION

Endemism and habitat preference of freshwater molluscs of The Western Ghats

Rivers and stream are species rich habitatsRivers and stream are species rich habitats.

70

Arsidopsis footi Pseudomulleria dalyiHabitat distribution of Freshwater molluscs

40

50

60

ices

10

20

30

40

Perc

ent s

pe

0

10

Lentic Lotic Both

Habitat