Bagarius Bleeker, 1853

Alfred W. Thomson & Lawrence M. Page, 2006, Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes)., Zootaxa 1345, pp. 1-96 : 26-27

Bagarius Bleeker, 1853

Fig. 9

Bagarius Bleeker, 1853 : 121. (Type species: Pimelodus bagarius Hamilton, 1822 , by monotypy). Gender masculine.

Diagnosis (based, in part, on Roberts 1983): Markedly heterodont teeth in lower jaw; branchiostegal membranes free from isthmus; anterior margin of pectoral-fin spine without serrations; well-developed maxillary barbel membrane; outer and inner mental barbels widely separated, origin of inner barbels anterior to origin of outer barbels; short nasal barbels; palatal teeth absent.

Bagarius is distinguished from all other genera in Sisorinae by having markedly heterodont teeth in the lower jaw. Teeth are present in two or three outer rows of relatively numerous, close-set conical teeth, and one or two inner rows of less numerous, widely separated, and much larger conical teeth (vs. dentition of the lower jaw consisting of only small conical teeth, or a roughened bony plate). Bagarius is further distinguished from Gagata by having the branchiostegal membranes free from the isthmus (vs. broadly fused to the isthmus), by having a well-developed maxillary barbel membrane (vs. not welldeveloped), and by having the outer and inner mental barbels widely separated, origin of inner barbels anterior to origin of outer barbels (vs. outer and inner mental barbels close together with their origins nearly parallel, in a transverse line). Bagarius is further distinguished from Nangra by having very short nasal barbels (length less then eye diameter vs. much greater then eye diameter, often as long as head), having shorter maxillary barbels (reaching slightly past pectoral-fin base vs. reaching to at least pelvic-fin base) and lacking palatal teeth. Bagarius is further distinguished from Gogangra by having a well-developed maxillary barbel membrane (vs. maxillary barbel membrane not well-developed) and by lacking serrations on the anterior margin of the pectoral spine (vs. having small serrations). Bagarius is further distinguished from Sisor by having gill openings wide and branchiostegal membranes free from isthmus (vs. gill openings moderate and branchiostegal membranes broadly fused to isthmus), serrations absent on the anterior margin of the pectoral-fin spine (vs. serrations present on both anterior and posterior margins of the pectoral-fin spine), by lacking a series of bony plates on the dorsum, by lacking a spine in the adipose fin, the uppermost caudal-fin ray not greatly elongated (vs. greatly elongated, more than half the length of the body), and by having the origin of the inner mental barbels anterior (vs. posterior) to the origin of the outer mental barbels.

Description: Dorsal fin with strong spine, 7 rays; pectoral fin with strong spine, 9-14 branched rays; 6 pelvic-fin rays; 13-17 anal-fin rays; 17 principal caudal rays. Head broad, moderately or strongly depressed. Maxillary barbel with well-developedmembrane, stiff base. Coracoid process not visible externally. Pectoral-fin spine smooth anteriorly and serrated posteriorly. Dorsal-fin spine smooth anteriorly and posteriorly. No thoracic adhesive apparatus. Paired fins non-plaited.

Distribution: Indus drainage in Pakistan and India, east (including peninsular India) to the Red River drainage in Vietnam and south throughout Indo-China including the Malay Peninsula and Indonesia (Roberts, 1983; Ng & Kottelat, 2000).