his catfish certainly proves the diversity
of the 2,000 or more species scattered around the globe, and as
such this pelagic (open water) species has a diurnal (active during
the day) lifestyle.
The first trait we notice about Kryptopterus
minor is of course its transparency hence the common name
of 'glass' or 'ghost' catfish. The body is virtually transparent
with scattered patches of pigment on the head and underbelly.
We can see the swim bladder inside the body cavity adjacent to
the pectoral fins and other internal structures, such as the vertabral
column, can be seen.
In its native waters you would think that such a soft bodied fish
would stand out and prove an easy meal for predators, but to the
contrary the glass cat can prove itself to do a disappearing act
in the more murky waters of its habitat. On the body, the number
of melanophores (black colour cells) is significantly reduced,
and the muscles and body are clear. The body wall contains flat
platelets of guanine in a silvery layer that acts as a mirror,
this reflects the general light and colour of the habitat, making
the fish effectively camouflaged.
There is a few so called 'glass catfishes' that are sold as such
in your local pet shop, fish such as the Asian glass cat, Ompok,
but they can be told apart, when young, from Kryptopterus
by its larger dorsal fin spines (4), or the African glass cats
belonging to the genus Parailia, which are in the Schilbeidae
family and have an extra pair of nasal barbels, and also possesses
an adipose fin. The main confusion with Kryptopterus is
that Tyson Roberts described K. minor which inhabits the
same environment as K. bicirrhis (Borneo) and is also transparent.
While there are several morphological differences between the
two species, the average aquarist would still find it difficult
to tell them apart, apart from the size difference of 6.5 for
K. minor and double the size of this for K. bicirrhis.
The 'glass catfish' does posses a dorsal as such but it consists
of only one spine and often than not it lies it down out of view.
It sports one pair of maxillary barbels and a very long anal fin
consisting of between 53 to 70 rays. It of course does not own
an adipose fin which it has in common with other 'glass cats'
of the family Siluridae.
So how do we keep the 'glass cat' happy,
by giving it more of its own kind, in other words buy at least
6 for a shoal, or preferably more, as they are not an expensive
fish by today's standards. If you keep them alone or less than
6 they will sulk and eventually will wither away and die. They
will shoal quite happily together head up and will stay shimmying
like this for a considerable amount of time, when now and again,
one will change its position in the group.
Rudimentry dorsal;one ray, maxillary barbels
reaching to anal, 55-68 anal rays. Ventral rays 6. Dorsal profile
arched with a nuchal concavity.
The body is virtually transparent with scattered
patches of pigment on the head and underbelly. Two thin lateral
body stripes stretching from head to caudal peduncle.
Keep them in a reasonably large tank, well
planted at the back and sides, and with a good flowing current from
your filter to imitate its habitat. It is a good community fish
and will not eat or harass other fish unless they are small enough
to be eaten, i.e.fry.
The only breeding report that I could unearth
was from a 1980 article in "The Aquarist and Pondkeeper",
on Kryptopterus bicirrhis which may have been K.
minor from a D. C. Powell who went
on to say and I quote: "We do not whether the species
is an egglayer or livebearer. Two young fish which suddenly appeared
in our tank were raised on infusoria and then Daphnia. A little
salt was added to the water" You can be sure that it is an
egglayer, it may even be an egg scatterer.
Will except flakefood but does relish small
livefood such as Daphnia and brineshrimp. This catfish is not too
good at collecting food from the aquarium floor, so feed as you
would for Characins & Barbs etc.
Sellick, Ian. Catfish
Form and Function, "The Aquarist and Pondkeeper",
April 1986: 6-7.
= hidden; pterus
= fin, (a reference to the almost invisible
one-rayed dorsal fin).
- in relation to the mandible or lower jaw.
Maxillary - in relation to the maxilla, the bone
of the upper jaw.
Baench., Aquarium Atlas No1, 1989.
Rainboth, Walter J; Fishes of the Cambodian Mekong FAO.
Kottelat, Maurice; Fishes of Laos.
Roberts, T.R. 1989 The freshwater fishes of Western
Borneo (Kalimantan Barat, Indonesia). Mem. Calif. Acad. Sci. 14:210
Paul E. Turley.
Bottom Picture: Nathan Sudell