research article high infestation by dawestrema...

Research ArticleHigh Infestation by Dawestrema cycloancistrioides inArapaima gigas Cultured in the Amazon Region Peru

Patrick D Mathews1 Antonio F Malheiros2 Narda D Vasquez3 and Milton D Chavez4

1 Department of Parasitology Institute of Animal Biology University of Campinas 13083-862 Campinas Brazil2 Department of Biological Science University of State of Mato Grosso 78200-000 Caceres Brazil3 Department of Tropical Aquaculture Institute of Biology National University of the Peruvian Amazon 765 Iquitos Peru4Department of Health Safety and Environment Enersul Limited Partnership Calgary Canada T2H 1M5

Correspondence should be addressed to Patrick D Mathews patrickmathews83gmailcom

Received 12 June 2014 Accepted 28 July 2014 Published 30 November 2014

Academic Editor Antonio Ortega-Pacheco

Copyright copy 2014 Patrick D Mathews et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The aim of this study was to evaluate the presence of Dawestrema cycloancistrioides in semi-intensive fish farming of fingerlingsof Arapaima gigas Between September and November 2013 60 individuals of A gigas born in captivity were collected in threeconcrete ponds from a semi-intensive fish farm in the Peruvian Amazon For the study of sclerotized structures parasites werefixed in a solution of ammonium picrate glycerine and mounted in Canada balsam To visualize internal structures parasites werefixed in hot formaldehyde solution (4) for staining with Gomorirsquos trichrome The parasitic indexes calculated were prevalencemean intensity and mean abundance This study identified a high infestation of a monogenean D cycloancistrioides in gills of AgigasThe prevalence was 100Themean intensity andmean abundance of the parasite were 1449 of parasites per individualThisstudy confirms the necessity of constant monitoring of fish in order to reduce fish mortality

1 Introduction

The Arapaima gigas is an endemic species of the BasinAmazon and is considered one of the largest freshwater fishin the world The A gigas can reach up to three meters inlength and 200 kg of total weight [1] and is amuch appreciatedspecies with great acceptance in the Amazonianmarket beingregarded as a protein source of the highest quality Howeverdue to its high nutritional demand for the population ofthe Amazon region in recent years the natural stocks ofthis fish have suffered drastic reduction [2] Farming paicheis thus a possible solution to the overexploitation of thisspecies in many rivers of the Amazon However to allow thebreeding it turns out that the necessity to solve the problemsregarding diseases and parasites upsurge which are affectingthis species in controlled environments as a consequence ofintensive farming under inadequate management

The dactylogyrid monogeneans are ectoparasites usu-ally attached to the gills of fish Like other monogeneansdactylogyrids have a direct life cycle and can easily multiply

anddisperse under fish culture conditions reaching very highintensities These monogeneans have been linked to majorlosses in fish culture [3 4] Recently studies in several speciesof farmed fishes in the Amazon region of Peru showed ahigh infestation by monogeneans species indicated as theprobable cause of high mortality [5ndash8]

Therefore with the gradual increase of intensive andsemi-intensive fish farming in the Peruvian Amazon thereis a need for constant monitoring of the fish for the diagnosisand timely control of infestations by monogeneans In thissense the present study aims to evaluate the monogeneaninfestation in A gigas bred in a fish farm in the PeruvianAmazon

2 Materials and Methods

21 Study Site and Animals Between September andNovem-ber 2013 the period which corresponds to the relative dryseason 60 individuals of the species A gigas (2040plusmn010 cm

Hindawi Publishing CorporationJournal of Veterinary MedicineVolume 2014 Article ID 245878 4 pageshttpdxdoiorg1011552014245878

2 Journal of Veterinary Medicine

of length and weight of 7606 plusmn 086 g) born in captivity(Figure 1) were collected in three concrete ponds from asemi-intensive fish farm belonging to the fish culture stationQuistococha Research Center located between the citiesIquitos and Nauta northeast of Department of Loreto Peru(3∘48101584048910158401015840 N and 073∘19101584018210158401015840W) The relative humidity inthis region varies between 80 and 100 Annual rainfallranged between 1500 and 3000mm at 328 mean sea level

22 Physicochemical Parameters of theWater Theparameterswere measured three times daily (at 7 AM and noon and at 5PM) with daily checks of dissolved oxygen pH temperatureand conductivity by means of an YSI multiparameter meter(Model MPS 556) Ammonium values hardness carbondioxide and total alkalinity were monitored weekly in themorning at 8 AM using a complete package for analysis offreshwater (LaMotte AQ-2)

23 Parasitological Analysis Following that the fish weresacrificed by cerebral puncture and placed in individualcontainers For examination of the gills the samples wereseparated and placed in glass containers with a 1 4000formalin solution After one hour the gills were stirred inthe same solution and then removed from the containersHelminthes were allowed to settle on the bottom of theglass containers in the remaining formalin solution andsubsequently collected with the aid of a small probe anda dissecting microscope (Nikon SM-30) For the study ofsclerotized structures parasites were fixed in a solution ofammonium picrate glycerine (GAP) andmounted in Canadabalsam according to Thatcher [9] Some specimens weremounted unstained in Gray and Wessrsquo medium To visualizeinternal structures parasites were fixed in hot formaldehydesolution (4) for staining with Gomorirsquos trichrome Theidentification of the parasites was based on the methodologyof Thatcher [9] and Kritsky et al [10]

The parasitic indexes calculated for assessing the levelof infestation of parasites in the fish prevalence (numberof hosts infected divided by the total number of hosts in asample) mean intensity (total number of parasites divided bynumber of hosts infected) and mean abundance (number ofparasites divided by the total number of hosts in a sample) arethe same as those described in Bush et al [11] The researchwas authorized by the Research Institute of the PeruvianAmazon

3 Results

Themoribund fishes collected for analysis were in emaciatedcondition Due to the accumulation of mucus the gills werepale and viscous The necropsy of fingerlings from A gigasevidenced the infestation byDawestrema cycloancistrioides inthe gill filaments of the fish (Figure 2) Indeed the totalityof the examined fish (60) showed a high parasitic infestation(Table 1)

In the present study the values of the physicochemicalparameters of the water from the culture ponds were dis-solved oxygen (574 plusmn 08mgLminus1) pH (684 plusmn 010) temper-ature (24 to 30∘C) and conductivity (1061 plusmn 140 120583s cmminus1)

Figure 1 Specimen of Arapaima gigas collected from culturedponds

(a)

1 2

3

(b)

Figure 2 Dawestrema cycloancistrioides (a) total (b) Posteriorregion 1mdashventral bar 2mdashventral anchor 3mdashdorsal anchor Scalebars = 10120583m

Table 1 Parasitic indexes of Dawestrema cycloancistrioides in juve-niles of paiche (Arapaima gigas) cultured in the Peruvian Amazon

Parasitic indexes Dawestrema cycloancistrioidesPrevalence () 100Abundance 8695Mean abundance 1449Mean intensity 1449

ammonium values (020 plusmn 010mgLminus1) hardness (2040 plusmn160mgLminus1) carbon dioxide (31 plusmn 06mgLminus1) and totalalkalinity (1612 plusmn 080mgLminus1)

Journal of Veterinary Medicine 3

4 Discussion

In intensive fish farming diseases outbreaks are a majorconcern to the farmers because in such systems fish areexposed to a high number of stressors (poor water qualitycrowdingmanipulation breeding and transport) whichmaynegatively affect their immune system and disease resistance[12 13] Water temperature of the fish ponds presented astrong variation during the present study reaching its lowestvalues (24∘C) during the first hours of the day and the highestvalues (30∘C) between noon and three hours later In the samesense in our study the concentration of ammonia found inthe ponds of cultivated A gigas was not within the expectedrange of values for tropical species In this context the fishare subjected to stress thus becoming more susceptible toinfestation by parasites and reduced disease resistance [1415]We suspect that the high parasitism bymonogeneans wasdue to the imbalance in the homeostasis of fish

Parasites that have a direct life cycle such as mono-geneans are more frequently found in lentic environmentsand this type of environment favors the transmission ofthese parasites [3] In regions with tropical and semitropicalclimates the life cycle of monogenean can be completed inless than one day and the monogeneans proliferate rapidly[3 9] The climate in the region of this study is tropicalhumid with annual average temperature of 283∘C andrelative humidity of 85 favoring the speed of life cycleIn the earthen ponds where fish were collected the watercirculation is almost negligible or nonexistent and the samehave a high density of fish population These drawbacksfavor the contact with the monogeneans [3] and may justifythe fact that the fishes have shown elevated prevalence ofmonogenean

In A gigas three species of monogeneans assigned toDawestrema genus (D cycloancistrium D cycloancistrioidesandD punctatum) have been reported from natural environ-ments and two in specimens from fish farming (D cycloan-cistrium and D cycloancistrioides) [9 10 16 17] evidencing ahigh specificity of Dawestrema species parasitizing A gigasHowever this specificity may be related to the fact thatmany of monogeneans which parasitize fish are host-specificbecause they have co-evolved with their hosts [18]

In the present study D cycloancistrioides showed highparasitism along with prevalence rates of 100 Our resultsagree with Hargreaves and Tucker [15] who reported similarprevalence with mean intensity and mean abundance of 280for specimens of A gigas collected from fish farming inBrazil In addition Gross et al [14] reported a prevalence of100 from an aquarium in the United States confirming theoccurrence of this parasite in cultivated A gigas

5 Conclusion

The results of this study and studies addressing variousaspects of parasites in other cultivated species confirm thenecessity of constantmonitoring of fish seeking the diagnosisand timely control of infestations by monogeneans in orderto reduce fish mortality

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors thank Conselho Nacional de DesenvolvimentoCientifico e Tecnologico (CNPq) for a postdoctoral fellow-ship to Antonio F Malheiros and Narda D Vasquez is inreceipt of a fellowship from CONCYTEC

References

[1] E AOno R Roubach andM F Pereira ldquoPirarucu production-advances in central Amazon Brazilrdquo Global Aquaculture Advo-cate vol 6 pp 44ndash46 2003

[2] M Casares M A Arevalo and E Fernandez ldquoNotes on thehusbandry of the arapaimaArapaima gigas at lsquoFauniarsquo MadridrdquoZoologische Garten vol 72 no 4 pp 238ndash244 2002

[3] J Flores-Crespo and C F Flores ldquoMonogenean parasites inMexican fish a recapitulationrdquoTecnica PecuariaMexico vol 41no 2 pp 175ndash192 2003

[4] D C Kritsky and F Stephens ldquoHaliotrema abaddon n sp(Monogenoidea Dactylogyridae) from the gills of wild andmaricultured West Australian dhufish Glaucosoma hebraicum(Teleostei Glaucosomatidae) in Australiardquo Journal of Parasitol-ogy vol 87 no 4 pp 749ndash754 2001

[5] D P Mathews J P D Mathews and O R Ismino ldquoMassiveinfestation byGussevia undulata (PlatyhelminthesMonogeneaDactylogyridae) in fingerlings of Cichla monoculus cultured inthe Peruvian Amazonrdquo Neotropical Helminthology vol 6 no 2pp 231ndash237 2012

[6] D P Mathews J P D Mathews and O R Ismino ldquoParasiticinfections in juveniles of Prochilodus nigricans kept in a semi-intensive fish farm in the Peruvian Amazonrdquo Bulletin of theEuropean Association of Fish Pathologists vol 33 no 1 pp 28ndash32 2013

[7] P D Mathews O Mertins J P D Mathews and R IOrbe ldquoMassive parasitism by Gussevia tucunarense (Platy-helminthes Monogenea Dactylogyridae) in fingerlings ofbujurqui-tucunare cultured in the Peruvian Amazonrdquo ActaParasitologica vol 58 no 2 pp 223ndash225 2013

[8] D PMathews A FMalheiros O R Ismino andND VasquezldquoJainus amazonensis (Monogenea Dactylogyridae) parasites ofBrycon cephalus (Gunther 1869) cultured in the lowland of thePeruvian Amazonrdquo Croatian Journal of Fisheries vol 72 no 2pp 83ndash86 2014

[9] V E Thatcher Amazon Fish Parasites Pensoft PublishersMoscow Russia 2nd edition 2006

[10] D C Kritsky A Boeger andV EThatcher ldquoNeotropicalmono-genea 7 Parasites of the pirarucu Arapaima gigas (Cuvier)with descriptions of two new species and redescription ofDawestrema cycloancistrium Price and Nowlin 1967 (Dacty-logyridae Ancyrocephalinae)rdquo Proceedings of the BiologicalSociety of Washington vol 98 no 2 pp 321ndash331 1985

[11] A O Bush K D Lafferty J M Lotz and A W ShostakldquoParasitology meets ecology on its own terms margolis et alrevisitedrdquo Journal of Parasitology vol 83 no 4 pp 575ndash5831997


[12] R Y Sado A J A Bicudo and J E P Cyrino ldquoDietarylevamisole influenced hematological parameters of juvenilepacu Piaractus mesopotamicus (Holmberg 1887)rdquo Journal of theWorld Aquaculture Society vol 41 supplement 1 pp 66ndash752010

[13] A K Jha A K Pal N P Sahu S Kumar and S C MukherjeeldquoHaemato-immunological responses to dietary yeast RNA 120596-3 fatty acid and 120573-carotene in Catla catla juvenilesrdquo Fish andShellfish Immunology vol 23 no 5 pp 917ndash927 2007

[14] A Gross C E Boyd and C W Wood ldquoNitrogen transfor-mations and balance in channel catfish pondsrdquo AquaculturalEngineering vol 24 no 1 pp 1ndash14 2000

[15] J A Hargreaves and C A Tucker Managing Ammonia in FishPonds vol 4603 Southern Regional Aquaculture Center 2004

[16] C J Bonar S L Poynton Y F Schulman R L Rietcheckand M M Garner ldquoHepatic Calyptospora sp (Apicomplexa)infection in a wild-born aquarium-held clutch of juvenilearapaima Arapaima gigas (Osteoglossidae)rdquoDiseases of AquaticOrganisms vol 70 no 1-2 pp 81ndash92 2006

[17] C S O Araujo S M Andrade M Tavares-Dias et alldquoParasitic infections in pirarucu fry Arapaima gigas Schinz1822 (Arapaimidae) ket in a semi-intensive fish farm in CentralAmazon Brazilrdquo Veterinarski Arhiv vol 79 no 5 pp 499ndash5072009

[18] A Simkova O Verneau M Gelnar and S Morand ldquoSpecificityand specialization of congeneric monogeneans parasitizingcyprinid fishrdquo Evolution vol 60 no 5 pp 1023ndash1037 2006

Submit your manuscripts athttpwwwhindawicom

Veterinary MedicineJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Veterinary Medicine International



International Journal of

Microbiology


AnimalsJournal of

EcologyInternational Journal of


PsycheHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Evolutionary BiologyInternational Journal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Biotechnology Research International


Agronomy




Journal of Parasitology Research

Hindawi Publishing Corporation httpwwwhindawicom


Volume 2014

Zoology

GenomicsInternational Journal of


InsectsJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


VirusesJournal of

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Cell BiologyInternational Journal of



Case Reports in Veterinary Medicine


of length and weight of 7606 plusmn 086 g) born in captivity(Figure 1) were collected in three concrete ponds from asemi-intensive fish farm belonging to the fish culture stationQuistococha Research Center located between the citiesIquitos and Nauta northeast of Department of Loreto Peru(3∘48101584048910158401015840 N and 073∘19101584018210158401015840W) The relative humidity inthis region varies between 80 and 100 Annual rainfallranged between 1500 and 3000mm at 328 mean sea level

22 Physicochemical Parameters of theWater Theparameterswere measured three times daily (at 7 AM and noon and at 5PM) with daily checks of dissolved oxygen pH temperatureand conductivity by means of an YSI multiparameter meter(Model MPS 556) Ammonium values hardness carbondioxide and total alkalinity were monitored weekly in themorning at 8 AM using a complete package for analysis offreshwater (LaMotte AQ-2)

23 Parasitological Analysis Following that the fish weresacrificed by cerebral puncture and placed in individualcontainers For examination of the gills the samples wereseparated and placed in glass containers with a 1 4000formalin solution After one hour the gills were stirred inthe same solution and then removed from the containersHelminthes were allowed to settle on the bottom of theglass containers in the remaining formalin solution andsubsequently collected with the aid of a small probe anda dissecting microscope (Nikon SM-30) For the study ofsclerotized structures parasites were fixed in a solution ofammonium picrate glycerine (GAP) andmounted in Canadabalsam according to Thatcher [9] Some specimens weremounted unstained in Gray and Wessrsquo medium To visualizeinternal structures parasites were fixed in hot formaldehydesolution (4) for staining with Gomorirsquos trichrome Theidentification of the parasites was based on the methodologyof Thatcher [9] and Kritsky et al [10]

The parasitic indexes calculated for assessing the levelof infestation of parasites in the fish prevalence (numberof hosts infected divided by the total number of hosts in asample) mean intensity (total number of parasites divided bynumber of hosts infected) and mean abundance (number ofparasites divided by the total number of hosts in a sample) arethe same as those described in Bush et al [11] The researchwas authorized by the Research Institute of the PeruvianAmazon

3 Results

Themoribund fishes collected for analysis were in emaciatedcondition Due to the accumulation of mucus the gills werepale and viscous The necropsy of fingerlings from A gigasevidenced the infestation byDawestrema cycloancistrioides inthe gill filaments of the fish (Figure 2) Indeed the totalityof the examined fish (60) showed a high parasitic infestation(Table 1)

In the present study the values of the physicochemicalparameters of the water from the culture ponds were dis-solved oxygen (574 plusmn 08mgLminus1) pH (684 plusmn 010) temper-ature (24 to 30∘C) and conductivity (1061 plusmn 140 120583s cmminus1)

Figure 1 Specimen of Arapaima gigas collected from culturedponds

(a)

1 2

3

(b)

Figure 2 Dawestrema cycloancistrioides (a) total (b) Posteriorregion 1mdashventral bar 2mdashventral anchor 3mdashdorsal anchor Scalebars = 10120583m

Table 1 Parasitic indexes of Dawestrema cycloancistrioides in juve-niles of paiche (Arapaima gigas) cultured in the Peruvian Amazon

Parasitic indexes Dawestrema cycloancistrioidesPrevalence () 100Abundance 8695Mean abundance 1449Mean intensity 1449

ammonium values (020 plusmn 010mgLminus1) hardness (2040 plusmn160mgLminus1) carbon dioxide (31 plusmn 06mgLminus1) and totalalkalinity (1612 plusmn 080mgLminus1)


4 Discussion





5 Conclusion




Acknowledgments


References



























Microbiology


AnimalsJournal of








Volume 2014



Agronomy







Volume 2014

Zoology



InsectsJournal of




VirusesJournal of







4 Discussion





5 Conclusion




Acknowledgments


References



























Microbiology


AnimalsJournal of








Volume 2014



Agronomy







Volume 2014

Zoology



InsectsJournal of




VirusesJournal of





















Microbiology


AnimalsJournal of








Volume 2014



Agronomy







Volume 2014

Zoology



InsectsJournal of




VirusesJournal of






research article high infestation by dawestrema...

Documents