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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.

Kryptopterus vitreolus

The first trait we notice about Kryptopterus vitreolus 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 ( now Kryptopterus vitreolus) 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. vitreolus 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.

Kryptopterus vitreolus

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.

UPDATED 2013: This species was thought to be K. minor which has been exported extensively over the past 30 years but is only found in Borneo. Due to the work carried out by Ng & Kottelat this year (2013) this species (K. minor) has now been renamed as K. vitreolus.

Ghost Catfish, Asian Glass Catfish

None

Kryptopterinae

Asia: Known only from a series of coastal river basins of Peninsular Thailand draining into the Gulf of Thailand south of the Isthmus of Kra, plus a handful of rivers draining the Cardamom (Khao Banthat) Mountains in southeastern Thailand. Type locality: Thailand: Trat Province, Amphoe Khao Saming.

7.0cm (2¾ins)

24-28°C (75-83°F)

Rudimentry dorsal;one ray, maxillary barbels reaching to anal, 55-68 anal rays. Ventral rays 6. Dorsal profile arched with a nuchal concavity.

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 Kryptopterus vitreolus 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.

Unknown.

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.

Mandibular: In relation to the mandible or lower jaw.
Maxillary: In relation to the maxilla, the bone of the upper jaw.

Kryptopterus: Krypto = hidden; pterus = fin, (a reference to the almost invisible one-rayed dorsal fin).
vitreolus: means 'of glass’, in reference to the transparent appearance of this species.

Baench., Aquarium Atlas No1, 1989.
Kottelat, M. 2001 Fishes of Laos. WHT Publications Ltd., Colombo 5, Sri Lanka. 198 p.
Ng, H-H. and M. Kottelat, 2013 - Zootaxa 3630: 308-316 After eighty years of misidentification, a name for the glass catfish (Teleostei: Siluridae).
Rainboth, Walter J; Fishes of the Cambodian Mekong FAO.
Roberts, T.R. 1989 The freshwater fishes of Western Borneo (Kalimantan Barat, Indonesia). Mem. Calif. Acad. Sci. 14:210 p.
Sellick, Ian. Catfish Form and Function, "The Aquarist and  Pondkeeper", April 1986: 6-7.

Photo Credits

Top image: © Paul E. Turley
Bottom image: © Nathan Sudell