The first trait we notice about Kryptopterus bicirrhis 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. 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.

Acknowledgements : Asian catfish specialist Shane Linder for his help in preparing this factsheet.