Sisor Hamilton, 1822

Alfred W. Thomson & Lawrence M. Page, 2006, Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes)., Zootaxa 1345, pp. 1-96: 37-38

publication ID

z01345p001

persistent identifier

http://treatment.plazi.org/id/BB1BE4CE-F5BF-4512-E95A-51404BFF04D9

treatment provided by

Thomas

scientific name

Sisor Hamilton, 1822
status

 

Sisor Hamilton, 1822  ZBK 

Fig. 13

Sisor Hamilton, 1822  ZBK  : 208, 379. (Type species Sisor rabdophorus Hamilton, 1822  ZBK  , by monotypy). Gender masculine.

Diagnosis: Series of bony plates extending from dorsal fin to base of caudal fin; spine in adipose fin; uppermost caudal-fin ray long, more than half length of body; branchiostegal membranes broadly fused to isthmus; outer and inner mental barbels widely separated, with origin of outer barbels anterior to origin of inner barbels; minute teeth in lower jaw, dentition essentially consisting of roughened plate; large serrations on anterior margin of pectoral spine; well-developed maxillary barbel membrane; palatal teeth absent.

Sisor  ZBK  is distinguished from erethistids and all other sisorids by having a series of bony plates extending from the dorsal fin to the base of the caudal fin, and an adipose fin with a spine. It is distinguished from all other Sisorinae  by having the uppermost caudal-fin ray long (vs. short), more than half the length of the body; outer and inner mental barbels widely separated, with the origin of the outer barbels anterior to the origin of the inner barbels (vs. nearly in a straight line in Gagata  ZBK  , origin of inner mental barbels anterior to origin of outer mental barbels in Bagarius  ZBK  and Gogangra  ZBK  , and either nearly in a straight line or origin of inner mental barbels anterior to origin of outer mental barbels in Nangra  ZBK  ), by having minute teeth in the lower jaw (dentition essentially consisting of a roughened plate vs. teeth of the lower jaw markedly heterodont in Bagarius  ZBK  , and small and conical in Gagata  ZBK  , Gogangra  ZBK  , and Nangra  ZBK  ), and by having large serrations on the anterior margin of the pectoral spine (vs. no serrations in Bagarius  ZBK  , Gagata  ZBK  , and Nangra  ZBK  , and small serrations in Gogangra  ZBK  ).

Sisor  ZBK  is further distinguished from Bagarius  ZBK  , Gogangra  ZBK  and Nangra  ZBK  by having the branchiostegal membranes broadly fused to the isthmus (vs. free from the isthmus). Sisor  ZBK  is further distinguished from Gagata  ZBK  and Gogangra  ZBK  by having a well-developed maxillary barbel membrane, and from Nangra  ZBK  by its lack of palatal teeth and short maxillary barbel not reaching the pectoral-fin base (vs. barbel reaching to at least the pelvic-fin base).

Description: Dorsal fin with 1 spine, 5-6 dorsal rays; pectoral fin with 1 spine, 9-11 rays; 6-8 pelvic-fin rays; 4-6 anal-fin rays. Head moderately narrow, strongly depressed. Body extremely narrow, strongly depressed. Eyes small, dorsolateral, subcutaneous. Maxillary barbel not extending posteriorly beyond head; barbel with well-developed membrane, stiff base. Coracoid process present but short. Pectoral-fin spine strongly serrate anteriorly and posteriorly. Dorsal-fin spine finely serrate anteriorly, smooth posteriorly. No thoracic adhesive apparatus. Paired fins non-plaited.

Distribution: Indus drainage, Pakistan, east to the Ganges and Brahmaputra drainages, India (Ng, 2003; Vishwanath & Darshan, 2005).