On to the month of August 2005 we welcome
back author Chris Ralph who is the catfish expert to the U.K. fishkeeping
magazine 'Tropical Fish'. Chris concentrates on his favourite cats
'The biggies' with a look at the Asian catfish, Ompok bimaculatus.
Ompok bimaculatus (Bloch,
his particular species can be found widespread
throughout Asia in the rivers of Afghanistan to China, Thailand
and Borneo. This particular catfish has endangered status in the
Western Ghats in India and is documented as being found in both
freshwater and brackish environments. Ompok bimaculatus
naturally occurs in streams and rivers which range in size and flow
with currents that can best be described as sluggish to moderate.
The rivers are usually quite shallow ranging from 0.5 to 1.5m in
depth, and are often muddy and murky. These large catfish are also
found in canals and inundated fields into which they move during
the flood season. These catfish can attain a length of 450mm or
18” standard length.
The ideal water parameters for these catfish
are pH in the range of 6-8, hardness in the range of 4-28°dGH
and temperature in the range of 20-26°C. This is one of the
larger species of catfish, and due to the size that it can attain
I would not recommend that you keep this catfish in with small fish
as they are most likely going to form part of its diet. Also this
particular species requires a larger size aquarium and I would suggest
a minimum of 72” x 24” x 24” for it. You are most
unlikely to see this catfish amongst importations due to the fact
that it is a food fish in the countries in which it naturally occurs.
Where offered for sale as a food fish you might encounter Ompok
bimaculatus being sold fresh or smoked on skewers!
siluriodes was at one time a synomyn for O. bimaculatus
but O. siluriodes has a marbled body pattern against
the silver of O. bimaculatus.
The body is elongated?
The dorsal fin is described as being small and has a total of 4
soft rays, whilst the anal fin which is described as being long
has a total of 54-74 soft rays. The pelvic fins are described as
being small with 7-8 soft rays. The pectoral fins have 12-14 soft
rays. The caudal fin is forked. Ompok bimaculatus has two
pairs of barbels; one pair of maxillary barbels which reach the
reaching anal fin; and one pair of mandibular barbels which are
described as being small in length. The eyes are small and are covered
by skin. Ompok bimaculatus is described as having vomerine
teeth in 2 patches.
The base colour of the body is silver, with
a conspicuous round black blotch above and behind the pectoral fin
base. The second of the two spots is at the base of the caudal peduncle
hence the species name bimaculatus.
is described as being peaceful but, has quite a large mouth, and
it is for this reason that I would suggest that you keep this catfish
as part of a shoal of its own kind or with other large species of
There are no known documented spawnings of
this catfish in aquaria, which is most likely due to the fact that
this catfish is rarely imported and also due to the size of aquarium
required. Whilst there are no documented aquarium spawnings it is
documented that these catfish are bred in India using hormone injections.
|The males tend to be more
slender than the females and are described as having serrations
on the posterior edge of the pectoral fin spines, whilst the
female’s pectoral fins lack these serrations.
The natural diet of this catfish includes
vegetable matter, fish, crustaceans and molluscs. In captivity these
catfish readily accept catfish pellets, prawns and frozen foods.
Froese, R. and
D. Pauly. Editors. 2005. FishBase.World
Wide Web electronic publication. www.fishbase.org, version (07/2005).
It has been suggested that the name is a bad reproduction
of the Malay name 'limpok'. Or from the vernucular
bimaculatus : With two spots
- in relation to the mandible or lower jaw.
Maxillary - in relation to the maxilla, the bone
of the upper jaw.
Vomerine - teeth present on the vomer.
Vomer - the anterior bone in the mid-line
of the roof of the mouth.
© Beta Mahatvaraj @
Callichrous bimaculatus, Pseudosilurus bimaculatus, Phalacronotus
siluroides, Ompok siluroides, Ompok canio, Silurus canio, Schilbe
pabo, Silurus chechra, Silurus duda, Callichrus affinis, Callichrus
immaculatus, Callichrus nebulosus, Wallago microcephalus, Silurus
mysoricus, Silurus indicus, Callichrous gangeticus, Callichrous
macrophthalmus, Callichrous sindensis, Wallago miostoma, Ompok
|Two-spot Glass Catfish,
Glass Catfish, Butter Catfish
|Siluridae or Sheathfishes
|Indian subcontinent and
|72” x 24” x
24” (180 x 60 x 60mm)
|450mm s.l. (standard length
is the measurement from the tip of the snout to the base of
the caudal peduncle).
| 6.0 - 8.0
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