Kryptopterus limpok

Kryptopterus: from the Greek kryptos, meaning 'hidden', and pterýgio, meaning 'fin', in reference to the reduced or absent dorsal-fin in members of this genus.

Type locality is 'Palembang, Sumatra, Indonesia', but this species is widely-distributed throughout much of Southeast Asia including major river systems in Thailand, Laos, Cambodia, Vietnam and Peninsular Malaysia plus the Greater Sunda Islands of Sumatra, Borneo and Java.

It's been extensively recorded from the Mekong, Chao Phraya, Mae Klong, Batang Hari, Rajang and Kapuas rivers plus numerous smaller drainages across this range.

Inhabits flowing rivers and larger streams typified by turbid water with suspended sediment.

A very large aquarium with base dimensions in the region of 240 ∗ 60 cm96 ∗ 24 in would be required for long-term care.

Décor is relatively unimportant although this species prefers weakly-lit conditions and may become skittish in the absence of cover.

Do not add introduce it to a biologically immature aquarium as it can be susceptible to swings in water chemistry.

Probably a predator feeding on small invertebrates and zooplankton in nature.

In the aquarium offer a varied diet comprising sinking dried foods, live and frozen bloodworm, Tubifex, etc., and perhaps the occasional small earthworm.

Generally peaceful though it may predate on smaller fishes and is somewhat timid so does not compete well with much larger, robust or otherwise boisterous species.

Peaceful, comparably-sized cyprinids, loaches and other catfishes perhaps constitute the best options but be sure to research your choices thoroughly prior to purchase.

K. limpok is gregarious and tends to form schools so ideally four or more specimens should be purchased.

This species is almost unheard of in the ornamental trade.

It can be told apart from congeners by possession of an extremely long mental barbel extending beyond the tip of the pectoral-fin.

Kryptopterus species are found only in Southeast Asia and the genus has been considered polyphyletic since Bornbusch (1995) with some former species already moved to the genera Phalacronotus and Micronema.

Those still contained within the genus are assigned to a number of putative species groups as follows:

K. bicirrhis group: K. bicirrhis, K. lais, K. palembangensis, K. macrocephalus, K. minor, K. piperatus, K. vitreolus
K. cryptopterus group: K. cryptopterus, K. geminus
K. limpok group: K. limpok, K. mononema, K. dissitus, K. baramensis, K. hesperius
K. schilbeides group: K. schilbeides, K. paraschilbeides

Bombusch (1995) identified the K. bicirrhis group as a distinct clade although he didn’t propose any synapomorphy to diagnose it.

Ng and Kottelat (2013)[8] later noted that members normally have fewer anal-fin rays (46–67 vs. 64–85) than other congeners and placed K. piperatus and K. vitreolus within the group based on this character.