Dorsal soft rays (total): 4; Anal soft rays: 54 -
74. Two pairs of barbels; maxillary barbels reaching
pelvic fins or anal fins; mandibulary barbels minute,
about as long as diameter of eye. Eyes small, covered
by skin. Dorsal and pelvic fins small; anal fin long;
pectoral fins well developed vomerine teeth in 2 patches.
Brown, usually marmorated body with conspicuous round
black blotch above pectoral base and a smaller sometimes
indistinct spot at the caudal peduncle. The genus
is recognized to be paraphyletic. The species of Ompok
have been grouped into species groups, such as the
Ompok bimaculatus group (O.
malabaricus, O. miostomus, O. siluroides),
the O. eugeneiatus group (O.
pinnatus), the O. hypophthalmus group
(O. hypopthalmus, O.
urbaini), and the O. leiacanthus
group (O. fumidus, O. jaynei, O. leiacanthus).
On the other hand, the monophyly of these species
groups is not strong enough to reassign species to
other genera. The O. eugeneiatus group is
likely to be more closely related to Kryptopterus
than the other Ompok species. Habitat:
Occurs in streams and rivers of all sizes with currents
ranging from sluggish to moderate. Diet:
Moves into freshly inundated habitats during the flood
season and feeds on crustaceans and mollusks. Etymology:
–oides, having the form of: Silurus, a related
genus from Europe, but in this case perhaps referring
to catfishes in general. Remarks:
This species was at one time a synonym for O.
bimaculatus but this species has a silver body.
Asia:Mekong and Chao Phraya River drainages in
Indochina, the Malay Peninsula, the Barito River drainage
in southern Borneo and Java.
Froese, R. and D. Pauly.
Editors. 2014. FishBase.World Wide Web electronic
publication. www.fishbase.org, ( 11/2014 ). Kottelat, M., 2001. Fishes of Laos.
WHT Publications Ltd., Colombo 5, Sri Lanka. 198 p.
1996. Fishes of the Cambodian Mekong. FAO Species
Identification Field Guide for Fishery Purposes. FAO,
Rome, 265 p.