Abstract
Exostoma dulongensis sp. nov., a new species of sisorid catfish from the genus Exostoma Blyth, 1860, is described from the Xiaojiang River and Dulongjiang River, tributaries of N’mai Hka River in the Irrawaddy basin, Yunnan Province, China. Exostoma dulongensis sp. nov. is the seventeenth species reported within this genus and is most similar to Exostoma ericinum Ng 2018 in morphology but can be distinguished by the following characters: tip of pelvic fin far from anus vs. reaching when depressed; nasal barbel reaching or surpassing posterior edge of orbit vs. just reaching middle of orbit; greater preanal length (70.9%–80.1% SL vs. 67.7%–70.5%); and longer dorsal to adipose length (13.5%–23.8% SL vs. 8.0%–12.0%). The new species can also be distinguished from all known congeners by the following characters: adipose fin confluent with caudal fin and without incision; caudal fin weakly forked; 40–43 vertebrae; and pectoral fin extending to vicinity of dorsal fin origin.
References
Blyth, E. (1860) Report on some fishes received chiefly from the Sitang River and its tributary streams, Tenasserim Provinces. Journal of the Asiatic Society of Bengal, 29 (2), 138–174.
Chen, X.Y. (2013) Checklist of fishes of Yunnan. Zoological Research, 34 (4), 281–343.
Chen, X.Y., Poly, W.J., Catania, D. & Jiang, W.S. (2017) A new species of sisorid catfish of the genus Exostoma from the Salween drainage, Yunnan, China. Zoological Research, 38 (5), 291–299.
https://doi.org/10.24272/j.issn.2095-8137.2017.065
Chu, X.L. & Mo, T.P. (1990) Sisoridae. In: Chu, X.L., Zheng, B.S. & Dai, D.Y. (Eds.), Fauna Sinica Osteichthyes Siluriformes. Science Press, Beijing, pp. 114–181.
Chu, X.L., Mo, T.P. & Kuang, P.R. (1990) Siluriformes: sisoridae. In: Chu, X.L. & Chen,Y. R. The Fishes of Yunnan, China. Part 2. Science Press, Beijing, pp. 218 -220.
Darshan, A., Vishwanath, W., Abujam, S. & Das, D.N. (2019) Exostoma kottelati, a new species of catfish (Teleostei: Sisoridae) from Arunachal Pradesh, India. Zootaxa, 4585 (2), 369–377.
https://doi.org/10.11646/zootaxa.4585.2.10
Ferraris, C.J. (2007) Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa, 1418 (1), 1–628.
https://doi.org/10.11646/zootaxa.1418.1.1
Gong, Z., Lin, P., Liu, F. & Liu, H. (2018) Exostoma tibetana, a new glyptosternine catfish from the lower Yarlung Tsangpo River drainage in southeastern Tibet, China (Siluriformes: Sisoridae) Zootaxa, 4527 (3), 392–402.
https://doi.org/10.11646/zootaxa.4527.3.8Hora, S.L. (1923) Notes on fishes in the Indian Museum, V. On the composite genus Glyptosternon McClelland. Records of the Indian Museum, Calcutta, 25 (Pt. 1), 1–44, pls. 1–4.
Hora, S.L. & Silas, E.G. (1952) Notes on fishes in the Indian museum. XLVII. Revision of the Glyptosternoid fishes of the family Sisoridae with description of new genera and species. Records of the Indian Museum, 49, 5–29.
Kottelat, M. (2013) The fishes of the inland waters of Southeast Asia: a catalogue and core bibliography of the fishes known to occur in freshwaters, mangroves and estuaries. The Raffles Bulletin of Zoology, Supplement (27), 1–663.
Lalramliana, Lalronunga, S., Lalnuntluanga & Ng, H.H. (2015) Exostoma sawmteai, a new sisorid catfish from northeast India (Teleostei: Sisoridae). Ichthyological Exploration of Freshwaters, 26 (1), 59–64.
Ng, H.H. (2018) Exostoma ericinum, a new glyptosternine catfish from southwestern China (Teleostei: Siluriformes:Sisoridae). Zootaxa, 4420 (3), 405–414.
https://doi.org/10.11646/zootaxa.4420.3.6
Ng, H.H. & Jiang, W.S. (2015) Intrafamilial relationships of the Asian hillstream catfish family Sisoridae (Teleostei: Siluriformes) inferred from nuclear and mitochondrial DNA sequences. Ichthyological Exploration of Freshwaters, 26 (3), 229–240.
Ng, H.H. & Kottelat, M. (2018) A New Glyptosternine Catfish from Northern Myanmar (Teleostei: Siluriformes: Sisoridae).Copeia, 106 (1), 63–69.
https://doi.org/10.1643/CI-17–613
Ng, H.H. & Kottelat, M. (1999) Oreoglanis hypsiurus, a new species of glyptosternine catfish (Teleostei: Sisoridae) from Laos. Ichthyological Exploration of Freshwaters, 10 (4), 375–380.
Ng, H.H.(2015) Phylogenetic systematics of the Asian catfish family Sisoridae (Actinopterygii: Siluriformes). Ichthyological Exploration of Freshwaters, 26 (2), 97–157.
Ng, H.H. & Vidthayanon, C. (2014) A review of the glyptosternine catfish genus Exostoma Blyth 1860 from Thailand, with descriptions of two new species (Teleostei: Siluriformes). Zootaxa, 3869 (4), 420–434.
https://doi.org/10.11646/zootaxa.3869.4.6
Roberts, T.R. & Ferraris, C.J. (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 (14), 315–345.
Tamang, L., Sinha, B. & Gurumayum, SD. (2015) Exostoma tenuicaudata, a new species of glyptosternine catfish (Siluriformes: Sisoridae) from the upper Brahmaputra drainage, northeastern India. Zootaxa, 4048 (3), 441–445.
https://doi.org/10.11646/zootaxa.4048.3.9
Thomson, A.W. & Page, L.M. (2006) Genera of the Asian catfish families Sisoridae and Erethistidae (Teleostei: Siluriformes). Zootaxa, 1345 (1), 1–96.
https://doi.org/10.11646/zootaxa.1345.1.1
Thoni, R.J. & Gurung, D.B. (2018) Morphological and molecular study of the torrent catfishes (Sisoridae: Glyptosterninae) of Bhutan including the description of five new species. Zootaxa, 4476 (1), 40–68.
https://doi.org/10.11646/zootaxa.4476.1.5