Catfish · Glass & sheatfish cats

Kryptopterus baramensis

Ng, 2002

IUCNDATA DEFICIENT
DDnot on the EX–LC scale
CARESNOT LISTED
Scientific size10 in24.9 cm standard length
Temperature68–82 °F20–28 °C
pH6–7.5neutral
Depthnot recorded
DietMidwater micro-predator — small invertebrates and zooplankton in the wild; in the aquarium takes small live and frozen foods (bloodworm, daphnia, small crustaceans) and fine dry food once settled; shy and easily out-competed for food
BreedingNot established in captivity — glass catfish (Kryptopterus) are essentially unbred in the aquarium; the trade is entirely wild-caught
Sexual dimorphismMinimalNo documented external sexual dimorphism for this species
PhotographsSee photosGoogle Images →

Kryptopterus baramensis is a glass catfish described from the Baram River drainage of Sarawak, on northern Borneo, one of many similar-looking species in a genus notorious for outgrowing the tanks its wild-caught juveniles are sold into. It reaches close to 10 in — far larger than the shoaling "glass fish" seen at a few centimetres in shops — and like its relatives it is a scaleless, naked-skinned, midwater schooling fish that has never been reliably bred in captivity. Everything sold in the trade under this and neighbouring Kryptopterus names is wild-collected from Southeast Asian rivers.

What's in the name

Kryptopterus baramensiskrip-TOP-ter-us bar-uh-MEN-sis

Kryptopterus
  • kryptosGreekhidden, concealed
  • pteronGreekfin — together 'hidden fin', for the tiny or absent dorsal fin typical of the genus
baramensis
  • Baramplace namethe Baram River, Sarawak, Malaysian Borneo
  • -ensisLatinsuffix meaning 'of' or 'from' a place — together 'of the Baram [River]'

Taxonomy & naming

Kryptopterus baramensis was described by Heok Hee Ng in 2002, with its type locality in the Baram River drainage of Sarawak, Malaysian Borneo. It belongs to the family Siluridae — the sheatfishes — which also contains the European and Asian Silurus, the SE Asian Ompok and Wallago, and the rest of the glass catfish genus Kryptopterus. The Catalog of Fishes (Eschmeyer, CAS) treats Kryptopterus baramensis as a valid, currently accepted name; no older genus combination applies to this species, since it was described directly in Kryptopterus rather than transferred in from Silurus or another genus, as happened with some of its relatives historically.

The genus name Kryptopterus is Greek, from kryptos ("hidden") and pteron ("fin"), an old reference to the reduced or near-invisible dorsal fin typical of these catfishes. The species epithet baramensis simply means "of the Baram [River]", naming the Borneo drainage where the type specimens were collected. Kryptopterus is a taxonomically difficult genus — many similar, slender, translucent species have been split and re-split over the decades — so aquarium fish sold as "glass catfish" are frequently mislabelled or lumped under a better-known congener.

Morphology

Kryptopterus baramensis has the classic sheatfish-family body plan: elongated, laterally compressed, with a long-based anal fin running most of the length of the underside, no adipose fin, and — true to the genus name — a dorsal fin reduced to a tiny stub or absent altogether. A single pair of long maxillary barbels extends from the upper jaw. The body is scaleless and, in fresh specimens, semi-transparent to varying degrees, a feature shared across the smaller Kryptopterus species and the reason the group is sold generically as "glass catfish".

Maximum recorded size is 10 in SL (FishBase) — a substantially larger fish than the well-known, genuinely see-through Kryptopterus vitreolus and K. minor sold as a few centimetres in the pet trade. Because juveniles of several Kryptopterus species look alike at the small sizes offered for sale, buyers routinely underestimate how large a given individual will grow; this species is a clear case of that size trap. As in other scaleless catfish, the naked skin makes it more sensitive than scaled fish to copper-based and some other medications.

Habitat

The species is known from the Baram River drainage of Sarawak, on northern Borneo (Malaysia), where it occupies flowing freshwater river habitat typical of the genus — benthopelagic water in the middle and lower reaches of tropical Southeast Asian rivers. Congeners in the limpok/vitreolus group of Kryptopterus are documented from turbid, flowing rivers with moderate to strong current, at warm tropical temperatures with a hardness and pH profile spanning soft to moderately hard, roughly neutral water; the genus is not a soft, acidic blackwater specialist as a rule, so real numbers should be read from congener data rather than assumed.

As river-dwelling schooling fish, Kryptopterus species are adapted to open water with cover nearby (submerged wood, overhanging vegetation) rather than to still, heavily planted pools — a detail that matters for replicating suitable aquarium conditions.

Feeding

Kryptopterus baramensis is a midwater micro-predator. Like its better-studied relatives, it hangs in loose or tight shoals in open water and picks off small invertebrates and zooplankton drifting past — insect larvae, tiny crustaceans and similar prey — rather than foraging on the bottom.

In the aquarium, glass catfish of this genus take small live and frozen foods readily (bloodworm, daphnia, brine shrimp, small crustaceans) and will accept fine dry food once well settled, though they are shy feeders that are easily out-competed by bolder, faster tankmates. Feeding needs to be deliberate — offered where the shoal is holding station, spread out, and not dominated by more assertive fish — to make sure every individual is getting food.

Mating

No courtship or spawning behaviour has been documented for Kryptopterus baramensis specifically. Glass catfish in this genus are essentially unknown to spawn in home aquaria, and the limited information available for the genus as a whole comes from wild-collected broodstock rather than observed captive courtship, so nothing specific can be said about pairing, triggers or spawning sites for this species.

Breeding

Glass catfish of the genus Kryptopterus are essentially not bred in captivity, and Kryptopterus baramensis is no exception — the entire aquarium trade in this and closely related species is supplied by wild-caught fish taken from Southeast Asian rivers, not captive-bred stock. Larger relatives in the Siluridae, such as Ompok and Wallago, are river spawners that are mostly propagated at commercial farm scale using hormone induction rather than natural aquarium breeding.

There is no reliable account of a hobbyist or commercial breeder closing the life cycle of K. baramensis in captivity. Prospective keepers should treat any wild population as the sole source of this species and should not expect it to reproduce in a home aquarium.

In the aquarium

Kryptopterus baramensis is a genuine size-trap fish: it can reach nearly 10 in, several times the size of the small "glass fish" typically sold in shops, and very few home aquaria are actually sized for an adult. Anyone buying juveniles of this species needs to plan for a large, long, well-covered tank with strong filtration and open swimming space, or reconsider the purchase. It should always be kept in a shoal — glass catfish are nervous, schooling fish that stress badly and refuse to feed when kept alone or in twos or threes.

Being scaleless, it is medication-sensitive: dose copper-based treatments and other medications conservatively, following a reduced-dose protocol as is standard practice for naked-skinned catfishes. It should be moved in a soft net or, better, a container rather than a coarse net, since it is a delicate, easily damaged fish even without spines to snag. Water flow and turnover should be on the stronger side to reflect its river origin, and tankmates should be calm enough not to outcompete a shy, midwater shoaler for food. As with the whole genus, no aquarium-bred stock exists, so purchases directly support wild collection.

Conservation

The IUCN Red List lists Kryptopterus baramensis as Data Deficient, with no formal assessment year available — a common status for narrow-range Southeast Asian river fishes that have not been the subject of dedicated population surveys. Its known distribution is confined to the Baram River drainage of Sarawak, Borneo, a single-river range that would leave the species vulnerable to any serious degradation of that system even though current population trends are not documented.

Because the aquarium trade in this species (and in Kryptopterus generally) draws entirely on wild-collected fish, sustained demand adds direct collection pressure on top of the habitat concerns — deforestation, sedimentation and water-quality changes — that affect Bornean rivers generally. No dedicated conservation programme for this species is known.

Sources

  1. FishBase — Kryptopterus baramensis Ng, 2002
  2. Seriously Fish — Kryptopterus limpok profile (congener, water chemistry and husbandry reference)
  3. IUCN Red List — Kryptopterus baramensis

Last reviewed 2026-07-01.

How to cite

Aquarist Atlas (2026). Kryptopterus baramensis. Aquarist Atlas.https://www.aquaristatlas.com/catfish/kryptopterus-baramensis/

← All catfish