or our first Factsheet of 2009
we welcome back regular contributor Chris Ralphand a look at a member of the Bagridae family,
the two-spot catfish, Mystus bimaculatus.
I will now hand you over to Chrisfor 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.
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
bimaculatus- head view
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 or 71-81ºF.
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
The natural habitat
for this catfish is under serious threat from human
activity in the region.
Spot Catfish, Two Spot Pink Pim
Sumatra, Indonesia and Malaysia.
125mm s.l. (standard length
– this is the measurement of the fish from the
tip of the snout to the base of the caudal peduncle).
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 in colour.
Care & Compatibility
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
There are no documented reports
of aquarium spawnings of Mystus bimaculatus.
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.
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.
is defined as a second dorsal fin.
Caudal is defined as the tail fin. Caudal peduncle is defined as the usually
narrowing posterior part of the body between the anal
and caudal fins. Dorsal is defined as being top or above. Dorsal fin is defined as the medial
fin on top of the back. 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. Pectoral fins are defined as paired
lateral fins. Ventral is defined as bottom, below
meaning whiskered or moustache (hair on the upper
lip). Mystus was first used by Belon in 1553 to describe
all fish with whiskers. bimaculatus: bi meaning
two and maculatus meaning spotted, hence with two
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