Batasio spp. are obligate inhabitants of headwater streams and the upper reaches of smaller rivers characterised by shallow, fast-flowing, highly-oxygenated stretches of riffles and runs broken up by pools or cascades in some cases. Images of the Ataran correspondingly depict flowing sections of forest-shaded, seemingly well-oxygenated headwaters containing clear water, a mixed sand/rock substrate and lots of submerged driftwood/leaf litter.

The vernacular name ‘lancer’ is derived from the extended dorsal spine possessed by several members of the genus, which currently contains 7 species. B. obscurus is diagnosable from congerners by the following combination of characters: mouth opening relatively small and narrow; oral dentition significantly reduced; dorsal-fin spi…

This species is exceptionally rare in the aquarium trade and can be distinguished from congeners by the following combination of characters: snout narrow with head appearing triangular as a resul…

This species is among the few members of the family to have been exported for the aquarium hobby. It can be differentiated from all other Akysis species by the following combination of characters: base of…

This species is among the few members of the family to have been exported for the aquarium hobby. It can be differentiated from all other Akysis species by the following combination of characters: base ofmeasures 17.1-19.2% of standard length (S…

This species is among the few members of the family to be exported for the aquarium hobby though is by no means common. It can be differentiated from a…

This species is among the few members of the family to be exported for the aquarium hobby and we’ve also seen it on sale under various names such as ‘orange-banded stone catfish’, ‘orange micro bumblebee catfish’, ‘Burmese orange mini bee catfish’ or more simply ‘wasp catfish’. Though the majority of forms are yellowish to orange in colouration there appears to exist a bright red variant which to date we’ve only seen in photos.

This species has been exported for the aquarium hobby on an extremely limited basis. It can be differentiated from all other Akysis species by the following combination of characters: head length 27.6–29.8% of standard length (SL); head width 21.9–25.1% SL; caudal peduncle depth 9.4–10.3% SL; length ofbase 23.0–25.2% SL; nasal barbel len…

This species is among the smaller members of the family. It can be differentiated from all other Akysis species by the following combination of characters: caudal peduncle length 16.1-19.8% of standard length (SL); caudal peduncle depth 6.5-9.3% SL; length of adipose-fin base 25.6-29.5% SL; interorbital distance 42.0-46.0% of head length (HL), eye diameter 13.0-20.0% HL; length of nasal barbel 44.0-66.0% HL; lateral margins of the head appear straight when viewed from above; possession of 0-5 se…

Apparently this species is polymorphic with body patterning varying significantly depending on locality. Individuals collected from black water habitats tend to be noticeably darker in overall colouration, for example, with this being particularly evident among populations from the Guiana Shield.

The genus Ageneiosus was at one point classified in…