Abstract
Two new species of sisorid catfish of the genus Pseudecheneis are described from tributaries of the Ganges River in Nepal: Pseudecheneis crassicauda and P. serracula. Pseudecheneis crassicauda can be distinguished from congeners by a unique combination of 38–39 vertebrae, caudal peduncle depth 6.0–6.6% SL, eye diameter 7.5–8.3% HL, length of adipose-fin base 20.3–24.3% SL, pelvic fins reaching the base of the first anal-fin ray, and the presence of pale spots on the body. Pseudecheneis serracula can be distinguished from congeners in having a unique combination of 36–38 vertebrae, strongly elevated neural spines of the last 2–3 preanal and first 6–7 postanal vertebrae, length of adipose-fin base 26.8–30.4% SL, pelvic fins reaching the base of the first analfin ray, and the presence of pale spots on the body.References
Allan, J.R. (1986) The influence of species composition on behavior in mixed-species cyprinid shoals. Journal of Fish Biology, 29 (Supplement A), 97–106.
Allan, J.R. & Pitcher. T.J. (1986) Species segregation during predator evasion in cyprinid fish shoals. Freshwater Biology, 16, 653–659.
Boucher, D.H., James, S. & Keeler, K.H. (1982) The ecology of mutualism. Annual Review of Ecology and Systematics, 13, 315–347.
Chu, X.-L. (1982) Phylogeny of the genus Pseudecheneis (Siluriformes: Sisoridae), with descriptions of two new species. Acta Zootaxonomica Sinica, 7, 428–437. [In Chinese, English summary]
Chu, X.-L., Mo, T.-P. & Kuang, P.R. (1990) Siluriformes: Sisoridae. In: Chu, X.-L.& Chen, Y.-R. (Eds) The Fishes of Yunnan, China. Part II. Science Press, Beijing. Pp. 170–225. [In Chinese]
de Pinna, M.C.C. (1996) A phylogenetic analysis of the Asian catfish families Sisoridae, Akysidae, and Amblycipitidae, with a hypothesis on the relationships of the neotropical Aspredinidae (Teleostei, Ostariophysi). Fieldiana: Zoology (New Series), 84, 1–83.
DeWitt, H.H. (1960) A contribution to the ichthyology of Nepal. Stanford Ichthyological Bulletin, 7, 63–88.
Edds, D.R. (1986a) The fishes of Royal Chitwan National Park. Journal of the Nepal Natural History Museum, 10, 1–12.
Edds, D.R. (1986b) Fishes of the Kali Gandaki/Narayani River, Nepal. Journal of the Nepal Natural History Museum, 10, 13–22.
Edds, D.R. (1987) Foods of some Nepalese fishes. Journal of the Nepal Natural History Museum, 11, 1–14.
Edds, D.R. (1993). Fish assemblage structure and environmental correlates in Nepal’s Gandaki River. Copeia, 1993, 48–60.
Gorman, O.T. (1988) The dynamics of habitat use in a guild of Ozark minnows. Ecological Monographs, 58, 1–18.
Greenberg, L.A. (1991) Habitat use and feeding behavior of thirteen species of benthic stream fishes. Environmental Biology of Fishes, 31, 389–401.
Matthews, W.J. (1998) Patterns in Freshwater Fish Ecology. Chapman & Hall, New York. 756 pp.
Mendelson, J. (1975) Feeding relationships among species of Notropis (Pisces: Cyprinidae) in a Wisconsin stream. Ecological Monographs, 45, 199–230.
Moyle, P.B. & Li, H.W. (1979) Community ecology and predator-prey relations in warmwater streams. In: Clepper, H. (Ed.), Predator-Prey Systems in Fisheries Management. Sport Fishing Institute, Washington, DC, 171–180.
Ng, H.H. & Rainboth, W.J. (2001) A review of the sisorid catfish genus Oreoglanis (Siluriformes: Sisoridae) with descriptions of four new species. Occasional Papers of the Museum of Zoology the University of Michigan, 732, 1–34.
Pitcher, T.J. (1986) Functions of shoaling in teleosts. In: Pitcher, T.J. (Ed.), The Behavior of Teleost Fishes. John Hopkins University Press, Baltimore, pp. 294–337.
Roberts, T.R. (1983) Revision of the South and Southeast Asian sisorid catfish genus Bagarius, with description of a new species from the Mekong. Copeia, 1983, 435–445.
Roberts, T. R. (1998) Pseudecheneis sympelvicus, a new species of rheophilic sisorid catfish from Laos (Mekong basin). The Raffles Bulletin of Zoology, 46, 289–292.
Roberts, T.R. & Ferraris, C.J.Jr. (1998) Review of South Asian sisorid catfish genera Gagata and Nangra, with descriptions of a new genus and five new species. Proceedings of the California Academy of Sciences, 50, 315–345.
Shrestha, J. (1981) Fishes of Nepal. Curriculum Development Centre, Tribhuvan University, Kathmandu, 318 pp.
Shrestha, J. (1994) Fishes, Fishing Implements and Methods of Nepal. Gupta, Lashkar, India, 150 pp.
Werner, E.E., Hall, D.J., Laughlin, D.R., Wagner, D.J., Wilsmann, L.A. & Funk, F.C. (1977) Habitat partitioning in a freshwater fish community. Journal of the Fisheries Research Board of Canada, 34, 360–370.
Zaret, T.M. & Rand, A.S. (1971) Competition in tropical stream fishes: support for the competitive exclusion principle. Ecology, 52, 336–342.
Zhou, W. & Chu, X.-L. (1992) A new species of Pseudecheneis with comments on osteological differentiations at species level (Siluriformes: Sisoridae). Acta Zootaxonomica Sinica, 17, 110–115. [In Chinese, English summary].