Threatened fishes of the world: Clarias dussumieridussumieri (Valenciennes, 1840) (Clariidae)

K. G. Padmakumar & L. Bindu & V. S. Basheer &

A. Gopalakrishnan .   

Received: 27 April 2009 /Accepted: 20 January 2010 /Published online: 23 February 2010# Springer Science+Business Media B.V. 2010

Common name: Valenciennes clariid. Vernacular:Naadanmushi/mozhi. Conservation status: Vulnerable(CAMP 1998). IUCN status: Not evaluated. Identifi-cation: Body compressed, dark above and pale below.Head greatly depressed, covered with osseous platesdorsally and laterally forming a cask covering adiverticulum of the gill cavity. Occipital processbroadly rounded. Distance from dorsal fin base to baseof occipital process 2–3.5 time head length. Mouthterminal and transverse with villiform teeth. Snoutbroad. Four pairs of barbels; maxillary barbels extend-ing beyond pectoral fin base, nasals to occipitalfontanel, outer mandibular to pectoral fin base andinner mandibular shorter. Dorsal fin with 66–69 finrays. Pectoral fin with spine serrated on posterior edge.Caudal fin round. Partial sequence information ofmitochondrial genes (16SrRNA, CO1, Cyt b) andnuclear gene (RAG2) showed significant genetic

divergence between C. dussumieri and the closestknown species C. batrachus. Maximum size: 50 cm(3 kg). Illustration by A. Biju. Distribution: Rivers andwetlands of South-western India (Gopalakrishnan andPonniah 2000). Abundance: Once prevalent in swampywaters; now recorded a sharp decline. Habitat andecology: Commonly found in ponds, streams andshallow derelict wetlands. They have biological andphysiological adaptations to low oxygen conditions.They are predatory and feed on small fishes, insectsand detritus. Reproduction: In nature, the fish has asingle spawning season coinciding with the south westmonsoon. Threats: The natural breeding area isreduced due to land reclamation and use of pesticidesand chemical fertilizers. Conservation action: Scien-tists from the Kerala Agricultural University studiedthe life history of natural populations and successfullybred and reared larvae in captivity. Recommendations:More studies are necessary to determine the presentdistribution and steps to ensure protection of theirhabitats. Also needed are population genetic studiescoupled with captive breeding for successful translo-cation and reintroduction efforts.

Environ Biol Fish (2010) 87:297–298DOI 10.1007/s10641-010-9598-9

K. G. PadmakumarRegional Agricultural Research Station,Kumarakom, Kerala, India 686566

L. Bindu (*)National Institute of Oceanography, Regional Centre,Kochi, India 682018e-mail: bindukylm@gmail.com

V. S. Basheer :A. GopalakrishnanNational Bureau of Fish Genetic Resources,Regional Centre,Kochi, India 682018

References

CAMP (1998) Conservation Assessment andManagement Plan forfreshwater fishes of India. Zoo Outreach Organization andNational Bureau of Fish Genetic Resources, Lucknow, 156 pp

Gopalakrishnan A, Ponniah AG (2000) Cultivable, ornamental,sport and food fishes endemic to Peninsular India withspecial reference to the Western Ghats. In: Ponniah AG,Gopalakrishnan A (eds) Endemic fish diversity of theWestern Ghats. NBFGR - NATP Publication 1, NationalBureau of Fish Genetic Resources, Lucknow, pp 13–32

298 Environ Biol Fish (2010) 87:297–298

Threatened fishes of the world: Clarias batrachus(Linn. 1758)

Sangram Ketan Sahoo & Shiba Shankar Giri &Suresh Chandra

Received: 19 May 2009 /Accepted: 4 February 2010# Springer Science+Business Media B.V. 2010

Keywords Clarias batrachus . Vulnerable

Common name: Magur, Walking Catfish. Conservationstatus: Vulnerable (CAMP 1998). Identification:Brownish black in colour. Elongated body with roundabdomen and laterally compressed tail. Head with twodepressions. Upper jaw slightly longer than lower. Themouth is wide and terminal. Four maxillary and fourmandibular barbells. The dorsal fin and anal fin bothlong, reaching caudal base. Caudal fin homocercal,separated from dorsal and anal fin. D 62–76, P 1/8–11,V 6–7, A 45–58, C 14–17. Illustration by S. Mahali.Distribution: It is native to Indian sub-continent(Jayaram 1981). Habitat and ecology: Inhabitsswampy areas and water bodies adjacent to paddyfields. Omnivore with broad feeding habits at differentlife stages (Hora and Pillay 1962). Reproduction: Itbreeds in second year of life during the monsoon(June–August) in vegetation under embankments.Parental care exists. The fecundity varies from 4000–

5000 (100 g females) and increases with fish size. Thehoney colour eggs are adhesive. Threats: Decliningpopulation is due to high fishing pressure and habitatloss from rapid urbanization. Conservation action: TheCentral Institute of Freshwater Aquaculture, India hasstarted working intensively on its propagation and feeddevelopment (Sahoo et al. 2005, 2008; Giri et al.2005). Seven other national Institutes are presentlyinvolved on its artificial propagation, sponsored byIndian Council of Agricultural Research, New Delhi.Recommendations: Mass production through hatcheryoperations, rearing young in natural waters andaquaculture of this species are necessary to restorepopulations. Remark: Ironically, it is recommended formonoculture in south-east Asia due to its highproduction potential and market demand.

Environ Biol FishDOI 10.1007/s10641-010-9627-8

S. K. Sahoo (*) : S. S. Giri : S. ChandraCentral Institute of Freshwater Aquaculture,Kausalyaganga,Bhubaneswar 751 002, Indiae-mail: sksahoo100@rediffmail.com

References

Conservation Assessment and Management Plan (CAMP)(1998) Executive summery report on Freshwater Fishesof India. National Bureau of Fish Genetic Resources,Lucknow and Zoo Outreach Organisation, Coimbatore,India, pp 1–10

Giri SS, Sahoo SK, Lenka S, Rangacharyulu PV, Paul BN,Sahu AK, Mohanty SN, Mukhopadhyay PK (2005)Effect of partial replacement of dietary fish-meal bymeat-meal, goat liver and shrimp-meal on growth andsurvival of Clarias batrachus (Linn.). Indian J Anim Sci75:977–981

Hora SL, Pillay TVR (1962) Handbook on fish culture in the Indo-Pacific region. FAO Fish Boil Tech Pap No14, pp 204

Jayaram KC (1981) The freshwater fishes of India, Pakistan,Bangladesh, Burma and Sri Lanka. Zoological Survey ofIndia, Calcutta, p 475

Sahoo SK, Giri SS, Sahu AK (2005) Induced spawning of Asiancatfish, Clarias batrachus (Linn.): effect of various latencyperiods and SGnRHa and domperidone doses on spawningperformance and egg quality. Aquacult Res 36:1273–1278

Sahoo SK, Giri SS, Chandra S (2008) Rearing performance ofClarias batrachus larvae: effect of age at stocking ongrowth and survival during fingerling production. Aqua-culture 280:158–160

Environ Biol Fish