A new sisorid catfish of the Genus Exostoma Blyth from Manipur, India

Abstract

Manuscript 1546; © ZOO; Date of publication 21 December 2006 Received 01 April 2006; Revised received 13 November 2006 Finally accepted 08 December 2006 W See Images in the web supplement at www.zoosprint.org ABSTRACT A new sisorid catfish, Exostoma barakensis is described from the Iyei River (Barak drainage) of Manipur, India. It is distinguished from E. berdmorei in having deeper body, its depth 15.6 (14.0-16.5) vs. 10.9 % SL; less numbers of anal fin rays ii, 41⁄2 -5 vs. i, 6; broadly rounded vs. pointed snout; emarginated vs. deeply forked caudal fin. It differs from E. labiatum in having deeper caudal peduncle, its height 49.8 (44.1-56.7) vs. 31.2-38.7 % caudal peduncle length; interdorsal space present vs. absent; less number of pectoral fin rays i, 10-11 vs. i, 12-13; caudal emarginated vs. forked. It differs from E. vinciguerrae in having wider head, its width 88.9 (85.2-91.6) vs.105.1 (105-108) % HL; smaller eye, its diameter 9.6 (7.3-11.6) vs.16.2 (16.0-16.4) % HL. It also differs from E. stuarti in having shallower body, its depth 15.8 (14.2-16.9) vs. 18.1 % SL; longer snout, its length 59.5 (58.1-61.5) vs. 47.6 % HL; larger eye, its diameter 9.6 (7.311.6) vs. 4.7 % HL; deeper caudal peduncle, its height 49.8 (44.1-56.7) vs. 42.8 % caudal peduncle length. Exostoma vinciguerrae and E. stuarti that synonymised under E. labiatum have been examined and found to have distinguishable differences from E. labiatum, and therefore have been resurrected as valid species.