Pseudexostoma Chu, 1979

Alfred W. Thomson & Lawrence M. Page, 2006, Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes)., Zootaxa 1345, pp. 1-96: 81-82

publication ID

z01345p001

publication LSID

lsid:zoobank.org:pub:25EFA792-7DA4-4E0D-A69A-12591B8422DE

persistent identifier

http://treatment.plazi.org/id/E5755B8C-4B63-01CB-D8A9-B2A3904157A4

treatment provided by

Thomas

scientific name

Pseudexostoma Chu, 1979
status

 

Pseudexostoma Chu, 1979  ZBK 

Fig. 26

Pseudexostoma Chu, 1979  ZBK  : 78, 81. (Type species: Glyptosternum yunnanensis Tchang, 1935  ZBK  , by original designation). Gender neuter.

Diagnosis: Continuous post-labial groove; gill openings not extending onto venter; heterodont dentition in both jaws; outer teeth shovel-shaped and sparsely arranged in one or two rows, inner teeth conical and numerous; tooth patches separated in upper jaw; 16-18 branched pectoral rays.

Pseudexostoma  ZBK  is distinguished from Glyptosternon  ZBK  , Glaridoglanis  ZBK  , Euchiloglanis  ZBK  , Pareuchiloglanis  ZBK  and Parachiloglanis  ZBK  by having a continuous post-labial groove (Table 5). Pseudexostoma  ZBK  is distinguished from Myersglanis  ZBK  , Exostoma  ZBK  , Oreoglanis  ZBK  by having heterodont dentition in the upper jaw (vs. homodont = pointed in Myersglanis  ZBK  and Oreoglanis  ZBK  , and homodont = oar-shaped in Exostoma  ZBK  ), and from Myersglanis  ZBK  and Exostoma  ZBK  by having heterodont dentition in the lower jaw (vs. homodont = pointed in Myersglanis  ZBK  , and homodont = oar-shaped in Exostoma  ZBK  ). It is further distinguished from Exostoma  ZBK  by having 16-18 (vs. 10-11) branched pectoral rays, and from Myersglanis  ZBK  and Oreoglanis  ZBK  by having tooth patches separated in the upper jaw.

Description: 5-6 dorsal rays; 16-18 branched pectoral-fin rays; 6 pelvic-fin rays; 3-6 anal-fin rays. Head depressed; body elongate, depressed anteriorly. Eyes minute, dorsal, subcutaneous, dorsal. Lips thick, fleshy, papillated. Teeth of two distinct types in two wellseparated patches in both jaws; outer teeth shovel-shaped and sparsely arranged in one or two rows, inner teeth conical and numerous. Maxillary barbel with well-developed membrane, soft base, striated pad of adhesive skin. Gill openings narrow, extending only to a point above pectoral-fin base. Branchiostegal membranes confluent with isthmus. Coracoid process not externally visible. No thoracic adhesive apparatus. Paired fins plaited to form an adhesive apparatus.

Distribution: Irrawaddy and Salween drainages, Yunnan, China (Chu et al., 1999).