or our first Factsheet of 2009 we welcome back regular contributor
Chris Ralph and a look at a member of the Bagridae
family, the two-spot catfish, Mystus bimaculatus.
I will now hand you over to Chris for
the lowdown on this pretty species.
belongs to the family Bagridae from Asia namely Sumatra Indonesia
and Malaysia. This catfish is documented as being found in the
peat swamps of Sumatra.
Mystus bimaculatus is sometimes
thought of as being a member of the family Pimelodidae from South
America, which clearly it is not due to the fact that this fish
has nasal barbels, which is something that pimelodids lack, also
coupled with the fact that this fish is Asian in origin. This
particular species is not commonly available, but is well worth
looking out for and is ideal for smaller aquariums.
Mystus bimaculatus prefer
to be kept in water which has a pH in the range of 6.0-7.0. This
catfish is ideally suited to temperatures in the range of 22-27ºC
I would suggest an Aquarium size of minimum, 48” x 18”
X 18” for a small shoal of these catfish, with plenty of
hiding places amongst bogwood and rocks. The ideal aquarium substrate
to use with these catfish is aquarium sand such as BD Aquarium
Sand. As with all other species of fish, water quality and general
husbandry is very important, and I would recommend that a minimum
of 25% water is changed on a weekly basis.
The natural habitat for this catfish is under serious threat from
human activity in the region.
The body of Mystus bimaculatus is
generally described as being torpedo, cigar shaped or moderately
elongated. The nostrils are described as being well separated. There
are four pairs of barbels, two pairs of mandibular barbels, one
pair of maxillary barbels and one pair of nasal barbels. All of
the barbels are described as being long with the nasal barbels extending
beyond the eyes and the maxillary barbels extending beyond the base
of the anal fin. The adipose fin is described as being much longer
than the base of the anal fin starting directly behind the dorsal
fin and extending almost to the base of the caudal fin.
The base colour of the body and head is described
as being uniform pale brown to almost pale pink in juvenile specimens.
The colour tends to pale towards the belly region. This catfish
is described as having two dark spots along the body with one being
situated behind the head, and the other on the caudal peduncle,
both of which are bordered with white colouration. As the fish matures
these spots especially the one at the base of the caudal fin tend
to fade. The remaining fins are described as being clear to yellowish
Wherever possible I would recommend that the
aquarist keep these catfish in a community aquarium in small groups
of six or more, but as the absolute minimum I would suggest three
specimens assuming that they are available in these numbers. These
catfish should not be kept with fish small enough to fit inside
their mouths as they would soon form part of their diet. Ideal tank
mates would include fish such as pearl gourami’s, golden barbs
and Odessa barbs to name but a few. In their natural habitat Mystus
bimaculatus would be found in relatively large shoals.
There are no documented reports of aquarium
spawnings of Mystus bimaculatus.
As with all the other catfish that I have
had the pleasure to keep over the years, Mystus bimaculatus
readily accepts a mixed and varied diet which includes granular
foods, frozen bloodworm and good quality flake to name but a few.
|As with most other species
of catfish the males tend to be more slender than the females.
It is documented that the males have small fleshy appendages
just prior to the anal fin which have a sexual function.
is defined as the tail fin.
Pectoral fins are defined as paired lateral
Dorsal fin is defined as the medial fin
on top of the back.
Adipose is defined as a second dorsal fin.
Dorsal is defined as being top or above.
Ventral is defined as bottom, below or
Caudal peduncle is defined as the usually
narrowing posterior part of the body between the anal and
caudal fins. Mandibular is defined as being
in relation to the mandible or lower jaw.
Maxillary is defined as being in relation
to the maxilla the bone of the upper jaw.
Nasal is defined as being in relation to
the nostrils or nares.
|Mystus from “mystax” meaning
whiskered or moustache (hair on the upper lip). Mystus was
first used by Belon in 1553 to describe all fish with whiskers;
bi meaning two and maculatus meaning spotted, hence with two