Electronic Journal of Ichthyology April, 2008 1: 18-30

ON THE POPULATION AND BREEDING ASPECTS OF IN FRESH WATER WETLANDS OF TAMIL NADU, PENINSULAR INDIA.

Rajagopal, B* and Priya Davidar

Department of Ecology & Environmental Sciences, Pondicherry University, Kalapet – 605 014, Pondicherry, India.

*Correspondence: Malankara Catholic College, Mariagiri, Kaliakkavilai – 629153, Kanyaku- mari District, Tamil Nadu, India. E-mail: [email protected], Telephone: +91 04651 244156.

Accepted: February 19, 2008

Abstract: Population structure and breeding pattern of a few species of catfish in wetlands from two geographically contrasting regions of peninsular India were studied. Findings of the study show that there is a marked difference in the structure of populations and breeding pat- tern existed for some species in the two regions. The reason attributes to different climatic factors found in these regions. Apart from this, functional and structural modifications in the anatomy of fish species, its physiological adaptation to the environment also contribute to these differences.

Key words: Distribution, Breeding, Seasonality, Rainfall, Recruitment.

Introduction Although various studies have been con- are an important part of the fish ducted on the of catfishes, the fauna in wetlands and many of them are ecology of catfishes in India is less known. economically important with high nutritive Studies in India have focused on feeding value. There are about 158 species of inland habits of several species of catfish (Kaliya- catfishes from 50 genera and 13 families in murthy and Rao 1970; Ramakrishnaiah India. The Indian families include , 1983-84; Santhanakumar and Job 1983-84; Siluridae, Schilbeidae, Pangasiidae, Ambly- Devi et al. 1992; Yusuf and Majumdar 1993; cipitidae, Sisoridae, Clariidae, Het- Raj 2002). Whereas, other aspects have been eropneustidae, Chacidae, Olyridae, Akysi- less well studied except a few conducted by dae, Ariidae and Plotosidae (Talwar and Kumar and Mittal (1993), Mukhopadhyay et Jhingran 1991). Diversity of catfish in India al. (1994). is the highest in Northeastern Hills, Gangetic In Tamil Nadu, some studies have been River System and the Western Ghats (Bar- conducted on the feeding ecology of catfish man 1994; Thomas et al. 2002). Generally, (Kaliyamurthy and Rao 1970; Santhanaku- catfishes dwell in diverse habitats such as mar and Job 1983-84; Raj 2002; Raghuna- upland streams, large river channels and sea- than et al. 2003). However, study on the sonal floodplain lagoons with broad feeding population of catfishes is limited, as for the niches that include detritivores, benthic in- other regions of India. sectivores and piscivores (Winemiller and We conducted this study in two regions Winemiller 1996). of southern India in order to look at the size Study on the population structure and dy- distribution of catfishes and to understand namics is important in understanding the life their breeding season in two geographically cycle and conservation of any fish species. varying regions.

18 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

Material and Methods Site selection & wetland description Study area Sites were selected based on their differ- Geography ences in geography, climate, rainfall pattern The study regions such as Kancheepuram and catfish species composition. Kanyaku- and Kanyakumari are situated in Tamil Nadu mari is located on the southern most end of State, southern India near two of India’s bio- the State near the Western Ghats and diversity hotspots such as the Eastern Ghats Kancheepuram is located on the north, near and the Western Ghats respectively. Among the Eastern Ghats. Although both the dis- 22 wetlands studied, 9 lie in Kancheepuram tricts have a few catfish species in common, and 13 are in Kanyakumari (Maps 1 & 2, they do have their own unique species. Dif- Table 1). Kancheepuram district is located ferent types of wetlands such as tanks, pools, on North East coast of Tamil Nadu, cover- lake and open wells were selected for study ing about 440 km2 (Square kilometers) area, based on the nature of their surface and sub- between 79o40’ to 80o20’ East and 12o30’ to strate (open or closed with vegetation), sea- 13o10’ North. Kancheepuram contains sonality (seasonal or perennial) and size, many wetlands as being an agricultural dis- based on the findings that different cat fish trict (< kanchi.tn.nic.in >). Kanyakumari dis- species prefers diverse habitats. (Kumar and trict has an area of 167 km2, which is located Mittal 1993). on southern most end of the Indian peninsula at about 77o15’ to 77o36’ E and 8o03’ to Fish collection, identification and meas- 8o35’ N (< kanyakumari.tn.nic.in >). urement Fish sampling was executed in between Rain the period of February 2003 and April 2004 Kancheepuram receives rain mainly from in the wetlands of Kancheepuram and Kan- North East monsoon. The rain in coastal ar- yakumari Districts in different seasons. The eas is normally heavier than inland region (< wetlands were sampled at different sites so kanchi.tn.nic.in >). Kanyakumari receives that a representative section of all habitats rainfall from both South West and North could be covered. Fish were collected with East monsoons. The mean annual rainfall is the help of local fishermen using cast and higher for Kanyakumari than in Kancheepu- seine nets. Seines were used for tanks and ram (Figure 1). Hence, wetlands in Kanya- pools with shallow waters (< 2 meters) and kumari retain water through the year due to cast net was used for tanks and lake with higher rainfall, whereas in Kancheepuram deep waters (>2m). The cast net used was of many wetlands dry up in summer prior to the 4m radius with 0.005m mesh size and two monsoon. types of seines used were of 70m long 6m wide with 0.01m mesh, and the other was of Flora 5m long 2m wide with 0.003m mesh. In ad- Flora of wetlands includes phytoplank- dition, sampling was done during peak sum- tons, micro-algae, (diatoms and other single mer when fish are harvested by draining out cellular algae) and macro vegetation. The the water from wetlands. Hence, all catfish aquatic macro-vegetation of studied wet- species of various sizes of each wetland lands can be classified into three distinct were sampled including juvenile. Different layers, such as emergent, floating and sub- type of nets were used as most of the wet- merged species. The diversity of aquatic lands had diverse habitats such as open wa- flora especially, floating vegetation in Kan- ter, covered water with vegetation, sluice yakumari is comparatively more than in etc. Moreover, only one type of net did not Kancheepuram. seem to be effective to collect all species as some species inhabited only in selected habi- tats (e.g - Ompok was collected only from the temporary pools in Puthery tank and not from main tank even after repeated efforts).

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20 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

21 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

Table 1. List of wetlands and their geographical location with area.

Name of Wetland Coordinates Area (ha) Kancheepuram District Latitude Longitude Chembarampakkam Lake 12o55’- 13o5’ N 80o 0’- 80 o 5’ E 35,700 Keeranallur tank 12o55’- 13o0’ N 79o 45’- 79o50’ E 75 Malayankulam tank 12o40’- 12o45’ N 79o 50’- 79o55’ E 250 Mathuramangalam pool 12o55’- 13o0’ N 79o 45’- 79o50’ E 0.1 Pallikaranai Wetland complex 12o55’- 13o0’ N 80 o10’- 80 o15’ E 594 Sivankoodal tank 12o55’- 13o0’ N 79o 45’- 79o 50’ E 100 Thenneri tank 12o50’- 12o55’ N 79o 50’- 79o 55’ E 800 Vandalur tank 12o50’-12 o55’ N 80o 0’- 80o 5’ E 75 Vijayanagar well 12o40’- 12o45’ N 79o45’- 79o50’ E 0.025 Kanyakumari District Erachakulam tank 8o10’- 8o15’ N 77o25’- 77o30’ E 100 Kakkulam tank 8o10’- 8o15’ N 77o25’- 77o30’ E 0.84 Kaniyakulam pool 8o10 - 8o15’ N 77o20 - 77o 25’ E 0.06 Mavadi pool 8o10 - 8o15’ N 77o20 - 77o 25’ E 0.5 Parakkai tank 8o 5’ - 8o10’ N 77 o 25’- 77 o 30’ E 200 Poochankulam tank 8o10’- 8o15’ N 77o25’- 77 o30’ E 0.6 Puthery tank 8o10’- 8o15’ N 77o25’- 77 o30’ E 300 Suchindram tank 8o5’- 8o10’ N 77o25’-77o 30’ E 50 Thathiyarkulam tank 8o10 - 8o15’ N 77o 25’- 77o 30’ E 38 Thazhakudy tank 8o10’- 8o15’ N 77o25’- 77o30’ E 100 Thengamputhur tank 8o 5’- 8o10’ N 77o 25’- 77o30’ E 250 Thotiode tank 8o10 - 8o15’ N 77o20’- 77o25’ E 4 Vishnupuram tank 8o10’- 8o15’ N 77o25’- 77 o30’ E 25

22 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

Therefore, use of different nets was man- fied in lab were also confirmed with Ichthy- datory in collecting fish specimen in an ef- ologists from ZSI (Zoological Survey of In- fective manner, as there is a possibility of dia, Southern Circle, Chennai). Morphomet- missing of some juveniles and species if ric measurements such as the standard large sized mesh nets or one type of net length, total length and weight of all indi- alone would have been used. viduals were measured using dial calipers, Fish sampling effort for cast net depended measuring scales and electronic balance. upon size (small / medium / large) of the wetland studied. As, sampling area covered Morphometric analysis in this net was comparatively smaller, three / Individuals of catfish belonging to differ- five / ten samples were done according to ent species were divided into various size the size of respective wetland. The duration classes based on their total length, from 10- of sampling effort for large seine was on an 50 mm (Millimeters) to 300-350 mm and average of 5 hours/seine/day and for small plotted in histograms. Comparisons were seine it was 30 minutes /seine/day. made for different size classes of fish col- Various fish species collected from dif- lected during the same season between two ferent wetlands were labeled and preserved regions and for the same region in two sea- in 10% formaldehyde solution. Standard sons using ‘χ2 test’. taxonomic keys of Day (1989), Talwar and Jhingran (1991), Jayaram (1999), Menon Recruitment analysis (1999) were used to identify the fish species. Relationship between juvenile recruit- Measurements of various body parts of a ment and rainfall were correlated. The rain- few individuals of each species were re- fall data for study areas were obtained from corded up to the nearest millimeter followed office of the Department of Statistics of by Biswas (1993), Ng (2004) to confirm the Government of Tamil Nadu in Kancheepu- identification. Finally, the specimens identi- ram and Kanyakumari districts respectively.

23 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

Results season with many smaller individuals (Fig- Population Structure ure 5). Size (Length) distribution of catfishes in Comparison on same species in different the study areas regions indicated that the size structure is Among the catfish species of Kanyaku- significantly different for H. fossilis (χ2 = mari district, Heteropneustes fossilis (Bloch 16.2, p < 0.001) and M. vittatus (χ2 = 6.1, p 1794) has a broad size distribution (50-350 < 0.05). mm) and Ompok malabaricus (Valenciennes Seasonal comparison (between the dry 1840) (200-300 mm) has a narrow size dis- and wet seasons) within region also showed tribution. In Kancheepuram, H. fossilis has that there is a significant difference in the the broad size distribution (50 – 250 mm) as population structure of H. fossilis (χ2 = 38, p that in Kanyakumari and Pseudeutropius < 0.0001) and M. vittatus (χ2 = 23.8, p < atherinoides (Bloch 1794) has a narrow size 0.0001) in Kanyakumari and for M. vittatus distribution (50 - 100 mm). (χ2 = 79.9, P < 0.0001) in Kancheepuram. In the present study, species with maxi- For three species (H. fossilis, M. armatus mum size were of H. fossilis (Total length - and P. atherinoides), the smallest size class 320 mm) and O. malabaricus (TL - 265 was recorded during dry season. Although, mm). Species with smaller size were of Mys- M. vittatus had smallest individuals in the tus vittatus (Bloch 1794) (TL - 39 mm), same dry season in Kancheepuram, it was armatus (Day 1865) (TL - 57 mm), during the wet season in which smallest in- Mystus montanus (Jerdon 1849) (TL - 72 dividuals were recorded for this species in mm) and P. atherinoides (TL - 50 mm). Kanyakumari (Figures 4 & 5). Size distribution of individuals of re- gional species in the wetlands of two dis- Juvenile Recruitment and the Rainfall tricts has been illustrated (Figure 2). Among Simple correlation and test of signifi- common species of both districts, H. fossilis cance on its values shows that the influence was larger in Kanyakumari than in of rainfall over juvenile recruitment is sig- Kancheepuram. M. vittatus was almost in nificant for a few species in Kanyakumari same size in both districts (Figure 3). Re- during wet season {H. fossilis (r = 0.83, p < gional comparison shows that generally 0.005); M. armatus (r = 0.83, p < 0.005) and there is a statistically significant difference M. vittatus (r = 0.64, p < 0.005)}. in the population structure of H. fossilis (χ2 = 10.4, p < 0.01) and M. vittatus (χ2 = 4.7, Discussion p < 0.05). Population Structure Comparisons of size distribution of catfish Among species of Kanyakumari district, species between dry and wet seasons H. fossilis has a broad size distribution and Seasonal comparisons between two dis- O. malabaricus has narrow size distribution, tricts showed that M. vittatus from both dis- although both grow normally to the same tricts were almost similar in size and small size. In Kancheepuram, H. fossilis has broad sized individuals were recorded in size distribution as that in Kanyakumari and Kancheepuram during the dry season. H. P. atherinoides has narrow size distribution. fossilis had many small individuals and wide The reason for narrow range of size distribu- size ranges especially during the dry season. tion of O. malabaricus in Kanyakumari at- P. atherinoides had similar size ranges dur- tributes to its distinct seasonal breeding be- ing both dry and wet seasons (Figure 4). havior that occurs in suitable habitats with In Kanyakumari, H. fossilis and M. ar- favourable environmental parameters. matus had many small individuals with wide Moreover, the laboratory experiments size range particularly during dry season. M. showed that Ompok perished the following vittatus had wide size ranges during the wet day upon

24 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

25 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

26 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

its introduction into the aquarium, whereas season. Karamchandani and Motwani other species (Mystus and Heteropneustes) (1955), Saxena (1972), Winemiller (1991) thrived well for many days. This shows that have also studied over this hypothesis. the turbidity and oxygen content of water are Karamchandani and Motwani (1955), likely to influence the survival and breeding Saxena (1972) have stated that collection of of O. malabaricus and hence they have a larvae and juveniles of Rita rita (Hamilton seasonal pattern of breeding, limited size in 1822) from River Ganga during July and population. August months shows that the breeding sea- The broad size distribution of H. fossilis son for this species might be from March to might be due to multi seasonal and aseasonal August. Comparisons on population size breeding nature. Hence, all size classes were structure and gonad condition of seven represented in the sample for this species. common Serranochromis species during two Moreover, H. fossilis can withstand a wide different seasons (falling water – May to range of environments, as they are air- August and low water – September to De- breather and a hardy species. Therefore, this cember) in the Upper Zambezi River flood- has succeeded in multiseasonal breeding. plain indicate that these species initiates Although, M. vittatus could tolerate anoxic spawning near the end of low water period conditions to a certain extent in aquaria, its (Winemiller, 1991). tolerance was comparatively lower than that Seasonal comparison in the present study of H. fossilis. on size class distribution shows that H. fos- Comparing to size distributions of species silis has smaller individuals (50, 100 mm) shared between the study regions, Kanya- during both dry and wet seasons in Kanya- kumari has larger individuals than that of kumari, and in Kancheepuram it was during Kancheepuram. The reason might be due to dry season. The pattern of distribution of favourable environmental factors such as juveniles of H. fossilis in Kanyakumari con- uniform supply of water due to high rainfall, firm that breeding season of this species is diverse vegetation in wetlands. These factors aseasonal and multiseasonal in this region. ultimately support the food abundance for Generally, breeding season could be a few fish in wetlands of former district than latter. months before dry or wet season in Kanya- Statistically significant difference ob- kumari and mostly before dry season in tained in population size structure of a few Kancheepuram. The basis for aseasonal re- species (H. fossilis and M. vittatus) during a production of H. fossilis is due to different particular season (dry) in two regions and monsoonal rains such as Southwest and different seasons within region might relate Northeast in Kanyakumari. Rainy season is to the difference in their breeding seasons. predominant during April - June (South- According to Bhatt (1971), males below 8 west), August – November (Northeast) in cm and females below 8.5 cm of Mystus vit- Kanyakumari and September – November tatus were immature and males above 8cm (Northeast monsoon) in Kancheepuram. and females above 8.5 cm were reproduc- Chang and Navas (1984) have also found tively mature. In the present study, both ma- that presence of juveniles in dry season indi- ture and immature individuals were seen (0- cated that the spawning season was not so 50, 50-100, 100-150 mm), indicating popu- distinct for Dormitator latifrons (Richardson lations of M. vittatus. Accordingly, they are 1844) and its reproduction occurred through comprised of different generations. the year, which resembles the multiseasonal breeding pattern of H. fossilis in the present Breeding study. Distribution of juveniles of certain spe- Similarly, breeding season for M. vittatus cies in two different seasons has been used is before the wet period in Kanyakumari, in this study to speculate upon their breeding which is from December – March. Whereas,

27 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish the breeding season in Kancheepuram, is pattern of breeding season of some species prior to the dry period, which is during Au- from Brazil region could be due to its prox- gust to December (Northeast monsoon). imity to the Amazon forest, which obtains These results show that M. vittatus however better rainfall in different seasons. Whereas, found in both regions, its breeding season in other species found in regions with particu- these regions is very different. The reason is lar seasonal and low rainfall has a wet sea- due to different rainfall patterns found in sonal breeding pattern. these districts as already mentioned for H. fossilis. Influence of environmental factors on re- Interestingly, Bhatt (1971) has also found cruitment that M. vittatus breeds during August – Sep- Although, H. fossilis and M. armatus had tember in Aligarh, as the result of present juveniles during both wet and dry seasons in study obtained for this species in Kanyakumari, correlation results suggest Kancheepuram. The maturity and fecundity that however, they breed during wet period, of Rita rita of Ganga River system was stud- predominant breeding occurs only during the ied by Saxena (1972). He has concluded that dry season. the peak period of spawning of Rita rita Correlation between rainfall and juvenile takes place during July to August. Thakur recruitment is apparent for a few species (H. (1978) experimented with the maturity and fossilis, M. armatus and M. vittatus with 5% spawning of Clarias batrachus (Linnaeus significance) during the wet season in Kan- 1758) collected from wild and found that the yakumari. This result also supports said idea species has a very short spawning period on the breeding season of these species in during July- August. Study on the breeding the region, approximately a few months be- behaviour of Pseudeutropius taakree (Sykes fore North East monsoon (August – Decem- 1839) in Nagarjunasagar reservoir, Andhra ber) that is during March – July, in other Pradesh shows that the species breeds during words during dry season. June-September (Ramakrishnaiah 1983-84). Karamchandani and Motwani (1955) These findings suggest that the said catfish have also collected larvae and juveniles of species including M. vittatus breed during Rita rita, a catfish from River Ganga during northeast monsoon (August – October) in July and August months which is generally a many states of India whichever obtain better rainy season in the region. They also con- rainfall only during this season. cluded that breeding season for this species However, scientists from other countries might be in between March and August. have also reported the dry seasonal repro- This finding looks similar to the results of duction for a few catfish species, as that of present study. the results obtained for M. vittatus in Kan- Although, aseasonal reproduction has yakumari, which is during December – been observed for H. fossilis in Kanyaku- March. Trajano (2003) has found that sea- mari, M. vittatus has a seasonal breeding in sonal reproduction is most common for the this region suggesting that rainfall alone subterranean catfish, Vegitglanis zammara- does not have an influence over the breed- noi (Gianferrari, 1923) in Brazil region, ing. Additionally, a few other environmental which is during dry and hot season (January and / or physiological factors are also in- to March). volved in determining this. Findings of said literature together with Kumar and Mittal (1993) have confirmed results of the present study suggest that a that being an air breather, H. fossilis can few catfish species seen in regions, which withstand widely differing habitats including obtain moderately a heavy rainfall in multi- the low oxygen condition. This adaptation ple seasons, wait for the rain to get over and supports the survival and reproduction of start breeding immediately, in other words this species in different habitats and seasons during the dry period. The reason for such a apart from the rainfall. Singh and Agarwal

28 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

(1986) have quoted that rains and floods will Bhatt, V.S. (1971). Studies on the biology of change the water quality, and this change some freshwater fishes. Part. V: Mystus may stimulate fish for maturation. vittatus Bloch. J. Bombay Natl. Hist. Soc. The distribution of juveniles and signifi- 68 (3): 556-572. cant results obtained from correlation analy- Biswas, S.P. (1993). Manual of Methods in sis strongly support the argument that breed- Fish Biology. South Asian Publishers, ing season of H. fossilis and M. vittatus in New Delhi. 157 pp. Kanyakumari is during December – March, Chang, B.D. & Navas, W. (1984). Seasonal which is a dry weather period. However, variations in growth, condition and gonads juveniles are recorded for these species dur- of Dormitator latifrons Richardson in the ing the dry season in Kancheepuram; where Chone river basin, Ecuador. Journal of correlation results are not significant, indi- Fish Biology. 24: 637-648. cating that the breeding season of these spe- Day, F. (1989). The fauna of British India cies in kancheepuram is not so clear. including Ceylon and Burma – Fishes (Volume I & II). Today and Tomorrow’s Conclusion Printers and Publishers, New Delhi. 548, Results of this study show that patterns of 509 pp. rainfall and breeding apparently influence Devi, N.T., Anwar, S. & Siddiqui, M.S. the population dynamics of some catfish (1992). On the food of the catfish Rita rita species in these regions. Species with differ- Ham. of the river Yamuna in North India. ent breeding seasons have a wide range of Journal of the Inland Fisheries Society of size distributions and those have a particular India. 24 (1): 34-39. breeding season has only a narrow and uni- Jayaram, K.C. (1999). The fresh water fishes form size distribution. Although, rainfall in- of the Indian region. Narendra Publishing fluences the breeding season of fish, there House, New Delhi. 551 pp. are several other factors including the Kaliyamurthy, M. & Rao, K.J. (1970). Pre- physiological adaptations such as air- liminary observations on the food and breathing nature play a vital role together feeding habits of some fishes of the Pulicat with the rainfall in determining the breeding Lake. J. Inland Fisheries Soc. India. IV: of fish. 115-121. Karamchandani, S.J. & Motwani, M.P. Acknowledgements (1955). Early life history, bionomics and We express our sincere thanks to Dr. R. J. breeding of Rita rita Ham. Journal of the Ranjit Daniels, Director, Care Earth, Chen- Zoological Society of India. 7 (2): 115 – nai and Dr. Robert B. Grubh, Director, Insti- 126. tute for Restoration of Natural Environment, Kumar, C.R.A. & Mittal, D.D. (1993). Habi- Nagercoil for all their favour and supports. tat preference of fishes in wetlands in rela- We thank Dr. Rema Devi, Senior Scientist, tion to aquatic vegetation and water chem- Zoological Survey of India, Chennai who istry. J. Bombay Natl. Hist. Soc. 90: 181- helped us in specimen identification, Dr. 191. Mark Henry Sabaj, Collection Manager, All Menon, A.G.K. (1999). Checklist fresh wa- Catfish Species Inventory, U.S.A, Dr. K. O. ter fishes of India. Zoological Survey of Winemiller, Professor, Department of Wild- India Publication, Calcutta. 366 pp. life and Fisheries, Texas University, Dr. M. Mukhopadhyay, M.K., Vass, K.K., Mitra, Maehata, Lake Biwa Museum, Shiga, Japan K., Bagchi, M.M. & Biswas, D.K. (1994). for sending us literatures on catfish ecology. Environmental impact assessment on the fish Rita rita in the river Ganga in West References Bengal. J. Inland Fisheries Soc. India. Barman, R.P. (1994). Fish fauna of Tripura, 26(1): 116-120. North-East India. Journal of the Bombay Natural History Society. 91: 37-46.

29 Rajagopal, Davidar, 2008 On the Population and Breeding Aspects of Catfish

Ng. H.H. (2004). Ompok platyrhynchus, a Thakur, N.K. (1978). On the maturity and new silurid catfish (Teleostei: Siluridae) spawning of an air-breathing catfish from Borneo. Zootaxa. 580: 1-11. Clarias batrachus Linn. Matsya. 4: 59-66. Raghunathan, M.B., Devi, K.R. & Indira, Thomas, K.R., George, M.J. & Babu, C.R. T.J. (2003). Food spectrum of the freshwa- (2002). Fresh water fishes of Southern ter fishes of Tamilnadu. Indian Hydrobiol- Kerala with notes on the distribution of ogy. 6 (1&2): 115-124. endemic and endangered species. J. Bom- Raj, A.J.A. (2002). Conservation of threat- bay Nat. Hist. Soc. 99 (1): 47-53. ened fish species by induced breeding Trajano, E. (2003). Ecology and ethology of techniques. Ph.D. Thesis. CARE, St. Xa- Subterranean Catfishes. in Arratia, G., Ka- vier’s College, Tirunelveli, India. poor, B.G., Chardon, M. & Diogo, R. (ed): Ramakrishniah, M. (1983-84). Some obser- Catfishes (2): 601-635. Science Publish- vations on the biology of Pseudeutropius ers, Inc. Enfield (NH), USA. taakree Day : A schilbeid catfish from Na- Winemiller, K.O. (1991). Comparative ecol- garjunasagar reservoir. Matsya. 9-10: 100- ogy of Serranochromis species (Teleostei: 109. Cichlidae) in the Upper Zambezi river Santhanakumar, G. & Job, S.V. (1983-84). floodplain. J. Fish Biol. 39: 617-639. Feeding biology of Mystus keletius Valen. Winemiller, K.O. & Winemiller, L.C.K. Matsya. 9-10: 25-32. (1996). Comparative ecology of catfishes Saxena, R.K. (1972). Studies on the maturity of the Upper Zambezi River floodplain. J. and fecundity of Rita rita Hamilton of Fish Biol. 49: 1043-1061. Ganga river system. J. Inland Fisheries Yusuf, Z.A. & Majumdar, P.K. (1993). Soc. India. IV: 169-182. Morphology of the alimentary canal and Singh, H.R. & Agarwal, N.K. (1986). food habit of Mystus gulio Ham. from sa- Spawning ecology of Schizothorax plagio- line sewage-fed wetlands at Minakhan. J. stomus Heckel from Garhwal Himalaya. Inland Fisheries Soc. India. 25 (1): 58-61. Proc. National Symp. Fish. 82-85. Talwar, P.K. & Jhingran, A.G. (1991). Websites Inland Fishes of India and adjacent coun- < fishbase.org > tries (Volume I & II). Oxford & IBH Pub- < kanchi.tn.nic.in > lishing Co. Pvt. Ltd., New Delhi. 541: < kanyakumari.tn.nic.in > 542-1158 pp.

======Copies of the PDF file of this work have been deposited in the following publicly accessible libraries: 1. Na- tional Museum of Natural History, Smithsonian Institution, Washington D.C. USA; 2. Natural History Museum, London, UK; 3. California Academy of Sciences, San Francisco, California, USA; 4. Department of Ichthyol- ogy, Museum National d'Histoire Naturelle, 75005 Paris, France; 5. Senckenberg Museum, Frankfurt/Main, Germany; 6. National Museum of Natural History, Leiden, The Netherlands. 7. The Gitter- Smolartz Library of Life Sciences and Medicine, Tel Aviv University, Israel; 8. The National and university Library, Jerusalem, Is- rael; 9. Library of Congress, Washington, D.C. USA; 10. South African Institute for Aquatic Biodiversity, Gra- hamstown, South Africa; 11. The National Science Museum, Tokyo, Japan; 12. The Swedish Museum of Natural History, Stockholm, Sweden.

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