Dorsal spines (total): 0; Dorsal soft rays (total):
4; Anal spines: 0; Anal soft rays: 65 - 71; Vertebrae:
47 - 52. Head width 11.7-13.6% SL; caudal peduncle
depth 5.2-5.9% SL; anal fin rays 65-71; and vertebrae
47-52. Elongated and compressed body. Mouth large
and oblique. Teeth in villiform bands on the jaws.
Maxillary barbels extends slightly below the posterior
border of the eyes. Mandibular pair very short, almost
equal to one eye diameter. Anal long, inserted well
behind the dorsal fin with 66-71 branched rays. Pectoral
spine serrated on its inner edge. Caudal deeply forked.
Habitat: Occurs most frequently in
large slow-flowing rivers and lakes. Migrates into
inundated forest during periods of high water, where
it can be found around submerged woody vegetation.
Colouration: Dorsal surface and sides
of head pale brown, fading to a lighter colour on
flanks and thickened integument over anal fin. Lateral
line with a thin black stripe. Another faint black
midlateral line below lateral line variably present,
usually as series of scattered melanophores broadening
both at humeral region and base of caudal peduncle
to form dark roughly elliptical spots. Maxillary and
mandibular barbels pale brown, gradually fading in
colour distally. Anal fin with hyaline ventral margin.
All other fins hyaline, with small dark-brown spots
present in some sp. Diet: Feeds on
fishes and crustaceans. Remarks:
This species was described from the Mekong River drainage
in Cambodia (Fang and Chaux in Chaux and Fang 1949),
and has often been considered a junior synonym of
O. hypophthalmus (e.g. Rainboth 1996), until
Ng (2003) demonstrated it to be a valid species.
Asia:Known from the Mekong, Chao Phraya and Pasak
River drainages in IndoChina. Type locality:
Ferraris, C.J. Jr.,
2007. Checklist of catfishes, recent and fossil (Osteichthyes:
Siluriformes), and catalogue of siluriform primary
types. Zootaxa 1418:1-628. Ng, H.H., 2003. A review of the Ompok
hypophthalmus group of silurid catfishes with the
description of a new species from South-East Asia.
J. Fish Biol. 62:1296-1311. Ng, H.H. 2012. Ompok urbaini. The
IUCN Red List of Threatened Species 2012: