Clupisoma roosae

description

Description. (based primarily on the holotype) Body elongate, compressed; depth at dorsal origin about 4 1 / 2 in SL and slightly larger than HL. Dorsal profile of body nearly horizontal past dorsal fin, straight between dorsal-fin origin and snout; abdomen rounded anteriorly, indistinct midventral keel extends from level of pelvic-fin origin to vent; vent located at anal-fin origin. Lateral line complete, with short branches extending obliquely above and below for entire length. Vertebral column with 45 to 47 vertebrae and 11 or 12 ribs. Head nearly 5 in SL; compressed posteriorly, nearly as high as wide at middle of eye; opercular opening broad, extending from level of lateral line to anterior of isthmus, opercular membranes not connected to isthmus; posterolateral margin of operculum with posteriorly directed, fleshy lobe; tip of lobe rounded. Snout broadly rounded in lateral view, in dorsal view, snout margin trilobed, lobes not well defined; anterior naris located on anterior margin of snout; naris round and directed anteriorly, narial opening surrounded by reflexed skin; posterior naris an elongated slit, located slightly posterodorsal and medial to anterior naris, naris near

A new species of the Asian schilbid catfish genus Clupisoma from Myanmar, with a redescription of Clupisoma prateri Hora (Osteichthyes: Siluriformes: Schilbidae).

diagnosis

Diagnosis. A species of Clupisoma in which the pectoral spine does not reach past the base of the pelvic fin, the abdomen is keeled only from a vertical through the pelvic-fin origin to the anus, pectoral fin with a spine and 11 segmented rays, anal fin with 4 or 5 unbranched, and 43 - 50 branched rays, and first gill arch with fewer than 18 rakers on the outer face. The body is silvery or white below the lateral line posterior of the pectoral fin, and steel gray above; more anteriorly, the grayish region extends to level of the pectoralfin origin.

A new species of the Asian schilbid catfish genus Clupisoma from Myanmar, with a redescription of Clupisoma prateri Hora (Osteichthyes: Siluriformes: Schilbidae).

discussion

Remarks. Clupisoma roosae is readily distinguished from its congeners. It differs from Clupisoma prateri Hora, the only other congener in Myanmar, by its comparatively short abdominal keel, which extends only between the level of the pelvic fin origin and the vent. More anteriorly, the ventral margin of the abdomen is distinctly rounded. In contrast, the keel of C. prateri extends for most of the length of the abdomen. The two species can also be distinguished on body coloration. C. prateri is nearly uniformly silvery, with a greenish cast along the dorsal midline. In C. roosae, the posterior portion of the body is silvery or white below the lateral line and steel gray above. The two species can be further distinguished by a series of meristic differences that are summarized in Table 1. Clupisoma garua (Hamilton, 1822), from the Gangetic region of India and Bangladesh, can be distinguished from Clupisoma roosae in having substantially fewer branched anal-fin rays (fewer than 33 in C. garua, vs. more than 43 in C. roosae), as well as lacking an adipose dorsal fin, which is present in the new species. Hora (1937) described Clupisoma montana from the Teesta River, India, and Mirza and

A new species of the Asian schilbid catfish genus Clupisoma from Myanmar, with a redescription of Clupisoma prateri Hora (Osteichthyes: Siluriformes: Schilbidae).

distribution

Distribution. This species is known only from specimens found in the Myitkyina market. Fishes that supply the Myitkyina market come only from the upper reaches of the Irrawaddy River (U Tun Shwe, personal communication). The species appears to be collected by local fishermen routinely, but not in great numbers, inasmuch as specimens were routinely obtained by ichthyologists who visited the Myitkyina market in the late 1990 ' s. Collections made further down river in the Irrawaddy basin, including Mandalay, NyaungU, and the Shweli River mouth, did not include any specimens of this species, but did include specimens of its congener, Clupisoma prateri.

A new species of the Asian schilbid catfish genus Clupisoma from Myanmar, with a redescription of Clupisoma prateri Hora (Osteichthyes: Siluriformes: Schilbidae).