Catfish of the Month Right Arrow February 1997 • Article © Julian Dignall, uploaded February 01, 1997



Glass Catfish, Asian Glass Catfish, Indischer Glaswels (Germany), Indisk Glasmal (Sweden), Phantom Catfish, Thai-glasmalle (Denmark) - Kryptopterus vitreolus   Ng & Kottelat, 2013

Most people start keeping catfish for one or both of two reasons. The first is the misguided and widely perpetuated myth that they are all excellent scavengers and will compensate for over-feeding, under filtration, eat algae, eradicate snails and combat a multitude of aquatic evils. This is perhaps true, to varying degrees, of some catfish. I believe the other reason people start keeping catfish is that they are unusual. Glass catfish are one of the most unusual of an unusual bunch. You can see right through them.

I started with a trio of these fish. They were timid, but fed well and kept themselves to themselves. It struck me that these would be ideal fish to keep with Discus if they could tolerate higher temperatures that Discus prefer. I transferred my trio to the Discus tank successfully and increased the shoal to seven individuals who happily coexisted with the Discus, assorted Tetras and Corydoras also present.

True glass catfish are completely transparent. If you look at one through a magnifying glass you can see the heart beating within the silver reflective sac that houses all the fishes organs. This species is also unusual amongst catfish in that it is a midwater swimmer and is inactive at night. This is not your average catfish. Indeed, one of the most interesting (probably because unexplained) aspects of this odd fish is that almost immediately following death, the fish loses its transparency becoming milky white. This suggests that something Glass Catfish do while alive produces or maintains the transparent effect.

I have also seen the African Glass Cat - Parailia pellucida - labelled as the Glass Cat, so always keep your eyes peeled when you look at a tank of these fish for sale. While on the subject of keeping your eyes peeled, some of you may have noticed that we have labelled this fish with a scientific name different from that you find in most hobbyist books. It appears that the glass catfish has been misidentified for a long time now as Kryptopterus bicirrhis, this fish grows much larger (up to 10") and has more rays in its anal fin. It is quite possible that, at some point in the last 30 years or so, K. bicirrhis was the fish imported into the aquatic trade as the Glass Catfish. Given the lack of 10 inch Glass catfish around today it is probably safe to say this isn't the fish we encounter most frequently in the shops.


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Jump to next section Cat-eLog Data Sheet
Scientific Name Kryptopterus vitreolus  Ng & Kottelat, 2013
Common Names Glass Catfish
Asian Glass Catfish, Indischer Glaswels (Germany), Indisk Glasmal (Sweden), Phantom Catfish, Thai-glasmalle (Denmark)
Type Locality Thailand: Trat Province, Amphoe Khao Saming
Pronunciation Cry top ter russ. - vih TREE oh luss.
Etymology Kryptopterus: From the Greek kryptos, meaning hidden and pteryx, meaning fin; in reference to the reduced or absent dorsal fin of this group of fishes. From the diminutive form of the Latin adjective vitreus, meaning of glass, in reference to the transparent appearance of this species in life (which gives this species its common name of glass catfish).
Articles
Article - Shane's World Reproduction Captive spawning of Glass Catfish
Jump to next section Species Information
Size 80mm or 3.1" SL. Find near, nearer or same sized spp.
Identification Sometimes - the African Glass Cat, Parailia pellucida - is labelled as the Glass Cat, so always keep your eyes peeled when you look at a tank of these fish for sale. We have labelled this fish with a scientific name different from that you find in most hobbyist books. It appears that the glass catfish has been misidentified for a long time now as Kryptopterus bicirrhis, this fish grows much larger (up to 245mm) and has more rays in its anal fin. It is quite possible that, at some point in the last 30 years or so, K. bicirrhis was the fish imported into the aquatic trade as the Glass Catfish.
Sexing Unknown
Jump to next section Habitat Information
Distribution Known from the short, coastal drainages in peninsular Thailand debouching into the Gulf of Thailand south of the Isthmus of Kra (from about 8°38'N to 6°2'N), as well as similar rivers draining the southeastern face of the Khao Banthat (Cardamom) Mountains in southeastern Thailand.
Thailand Waters (click on these areas to find other species found there)

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pH 5.5 - 6.5
Temperature 21.0-26.0°C or 69.8-78.8°F (Show species within this range)
Other Parameters Slow moving water providing areas of current and areas of still water. This fish rests in still water and stalks in gentle current.
Jump to next section Husbandry Information
Feeding Will usually take prepared foods especially if moved by a current. Likes live brine shrimp and larger established fish relish bloodworm.
Furniture Plants are necessary to make this fish feel at home. Floating plants that diffuse overhead light help but are not mandatory. Open swimming space is required, as this fish favours swimming freely at feeding.
Compatibility Peaceful, will eat very small fry, but otherwise harmless.
Suggested Tankmates Keep in a shoal of at least four but preferably six or more individuals. Such a shoal of glass catfish will do well with small tetras, rasboras or danios. Provided its tankmates are not too boisterous this fish will do well in well planted community aquaria.
Breeding Little is known about the specifics of reproduction, appears to be an indiscriminate egg scatterer. See Shane's World article. .
Breeding Reports There is no breeding report.
Jump to next section Further Information
References Biogeographical Society of Japan (Tokyo), pp 309, Figs. 1-2
Registered Keepers Keeping this species? Why not .
There are 103 registered keepers, view all "my cats" data.
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Last Update 2018 Dec 07 11:27 (species record created: 1997 Feb 01 11:22)

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