Kayan basin

Acanthopsoides spp. are most closely related to the horse-faced loaches of the genus Acantopsis with which they often co-occur in nature, and thus commonly referred to as 'dwarf horse-face loaches'. Most are very difficult to tell apart but A. robertsi is quite easily identified since it's the only...

This species is uncommon in the aquarium hobby, although the scientific name is widely misapplied to Barbodes dunckeri, a similar-looking species native to Peninsular Malaysia and Singapore commonly referred to as 'clown barb' and labelled as B. everetti in the majority of available literature. The two are quite easy to tell apart, with B. everetti an overall less...

It can be told apart from other members of the B. pugnax group by the following characters: chin bar absent; prsence of transverse bars in the dorsal-fin; no transverse bars in caudal-fin; green iridescent scales present on opercle and body; anal fin with iridescent, light blue distal band; a pair black markings below the postorbital stripe on the opercle of females and juveniles; anal-fin rays 25-29 (mode 28); lateral scales 28-30 (mode 29); postdorsal scales 10-11 (mode 12); pelvic-fin length 34.8-50.6% SL; head length 33.4-36.8% SL; inter-orbital width 31.7-37.4% HL.

Not recommended for the standard community set-up for reasons already touched upon. It's requirements and disposition mean it's best kept alone or with very peaceful species since much bigger or more vigorous fishes are likely to intimidate and outcompete it. Some small cyprinids and loaches that inhabit similar environments in nature are compat...

This species is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

Prefers a dimly-lit aquarium with plenty of cover in the form of live plants, driftwood branches, terracotta pipes, plant pots, etc., arranged to form a network of nooks, crannies, and shaded spots. Surface vegetation such as Ceratopteris spp. is also appreciated and makes the fish less inclined to conceal themselves.

Type locality is given only as 'Sarawak state, Borneo, East Malaysia', with the material deriving from Sibu Division in western Sarawak. It's since been recorded at other localities within Sarawak, to which it appears endemic, but it remains unclear whether all represent a single species or not with those from the area around Lundu in northwestern Kuching Division in par...

This species occasionally appears in the aquarium hobby, but the trade is largely reliant on commercially-produced 'tiger barbs' of questionable origin. It was considered a synonym of P. anchisporus for a number of decades following Alfred (1963), but revalidated by Kottelat and Tan (2011).

Predominantly a riverine fish preferring clear, well-oxygenated, running waters with substrates of sand, gravel, rock or mud, typically flowing through tropical forest. In the habitat seen in our images sympatric fish species included Barbonymus balleroides, B. collingwoodi, Cyclocheilichthys repasson, C. apogon, Diplocheilichthys pleurotaenia, Garra borneensis, Leptobarbus hosii, and an unidentified Gastromyzon sp.