C. carsevennensis has formerly been synonymised with C. arnoldi but was considered separate by Zarske (2011) using the following combination characters: absence (vs. presence) of a silvery-white to white patch in the centre of some of the flank scales in males, particularly in the lower half of the body; absence (vs. presence) of a horizontal dark body bar in nuptial males; absence (vs. presence) of thin black margins in the dorsal, ventral and anal fins; eggs deposited among submerged vegetation (vs. eg…

This species is available in the aquarium hobby but is not traded in large numbers and may have been inadvertently hybridised with the similar-looking congener B. rubra prior to its description since they’re typically exported mixed together.

It’s included in the B. rubra group of closely-related species within the genus, an assemblage erected by Schindler and van der Voort (2012) who…

O. dogarsinghi and O. bernatziki are the only two Southeast Asian congeners to possess a large blotch at the caudal-fin base but in the former the blotch is vertically-orientated and hardly extends onto the fin itself (vs. laterally-elongate and extending onto the basal fin rays) and long (vs. short) barbels, while th…

This species has previously been considered synonymous with both O. ornatus and O. pulchellus but is currently considered to be distinct following (Tejavej, 2012).

It can be distinguished from congeners by a combination of characters including: small caudal spot presen…

This species is almost unheard of in the aquarium trade though may occasionally be exported among shipments of wild fishes from Sumatra.

It’s closely-related to K. bichirris but is told apart by presence (vs. absence) of a prominent, dark lateral stripe on each flank.

Kryptopterus species are found only in Southeast Asia and the genus has been consi…

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, Cha…

This species is likely to be traded for aquaria but probably misidentified as the very similar-looking K. cyrptopterus with which wild populations were formerly considered conspecific.

These two are closely-related and can be distinguished from congeners by the dorsal profile lacking a nuchal concavity (vs. possessing a nuchal concavity) and possessing short maxillary barbels (extending to the pectoral-fin base vs. ext…

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.

This fish is normally traded as A. nigropterus or A. cf. ansorgii although neither appears to be its correct name meaning it remains unidentified at present.

A. nigropterus is a valid congener that is not in the aquarium trade with little to no export from Lake Mai-Ndombe, to which it is endemic, while A. ansorgii is a synonym of Nannopetersius ansorgii.

Type locality is ‘Central Sumatra, Indonesia’, with additional records existing from Cambodia (Mekong drainage), Peninsular Malaysia (Perak River), Sumatra (from the Siak River, Riau province to the Musi River, South Sumatra (Sumatera Selatan) province) and Borneo (south and westwards from the Belait river basin in Brunei Darussalam to the Sambas drainage in West Kalimantan (Kalimantan Barat) province, Indonesia and probably in Sarawak, Malaysia).