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…

It can be distinguished from congeners by the following combination of characters: 61-68 scales in the lateral series; a small, well-defined, sometimes ocellated black spot on the shoulder and another in the centre of the caudal peduncle; body without longitudinal stripes formed by spots on scales; caudal fin uniformly dusky or colourless, lobes without stripes or black margins.

In the aquarium trade this species may also be seen on sale as ‘skinhead barb’. As with others in the genus little has been written regarding its captive care but it makes a peaceful and unusual addition to larger aquaria. The best way of obtaining it may be to keep an eye on shipments of wild fishes from Indochina and the Greater Sunda Islands as it’s rarely imported in large numbers and most often arrives as bycatch.

Typically inhabits slow-moving, shallow, shady rainforest streams and swamps with dense submerged and marginal vegetation. The conditions are often rather turbid and the substrate composed of mud or fallen leaves, twigs and branches. Such environments characteristically contain soft, weakly acidic water and are often dimly-lit due to the rainforest canopy above. The fish are found sheltering among overhanging tree roots and aquatic vegetation.

The genus Betta is the most speciose within the family Osphronemidae with almost 70 recognised members and looks set to grow further with new ones continuing to be described on a regular basis since the turn of the century. Member species have successfully adapted to inhabit a variety of ecological niches from stagnant ditches to flowing hill streams including some extreme environments such as highly acidic peat swamp forests.

The identity of this species was unclear for a number of decades prior to its redescription by Ng and Kottelat (2013).

The confusion originated with Brittan (1954) who misidentified specimens of R. tornieri as R. dusonensis and was exacerbated by Alfred (1963) who concluded that the holotype of R. dusonensis was conspecific with R. myersi.

This species was described from ‘Johore River, Segamat, Malaysia’, which corresponds to Segamat District within the the Johor River watershed, Johor state, southern Peninsular Malaysia, but the type specimens were obtained via a Singapore wholesaler so it’s possible that a mistake was made as there exist no other records of the species in Peninsular Malaysia.

It’s also been recorded from the Kapuas drainage…

D. foerschi is sometimes traded as ‘boomerang barb’ or ‘Foersch’s fire barb’ and is included in a group of closely-related, similar-looking fishes which were moved into the new genus Desmopuntius by Kottelat (2013).

It can be told apart from other vertically-striped congeners by possession of additional dark blotches between the second, third and fourth vertical bars and a further marking at the posterior base o…

This species was previously included in the Betta foerschi group of closely-related species within the genus, but following its redescription in 2012 now lends its name to the B. rubra group.

It was first placed into its own species group by Witte and Schmidt (1992), primarily on the basis of a triangular marking that appears below the eyes of the fish, although Tan and Ng (2005) suggested that this feature is insufficient to warrant the fo…