Taxonomy & naming
Ng and Kottelat described Hyalobagrus flavus in 1998 from Danau Arang Arang near Muara Kompeh in Jambi Province, Sumatra. The genus Hyalobagrus holds a few miniature bagrids of the Sundaland peat swamps and is placed in Bagridae. The Catalog of Fishes lists the name as valid.
Morphology
FishBase gives a maximum of 1.5 in SL. The generic name refers to the pale, almost translucent look of these small bagrids, and the epithet flavus means yellow. Like other bagrids it has four pairs of barbels and a stout spine at the front of the dorsal and pectoral fins.
Habitat
FishBase describes it as a freshwater bottom fish, currently known only from the Batang Hari drainage in Sumatra and the Mentaya basin in southern Borneo. The type locality is a swamp lake, and the genus lives in acidic, tea-stained peat-swamp and blackwater water. FishBase gives no temperature, pH or hardness range for this species.
Feeding
The cached FishBase entry gives no diet. At 1.5 in the fish eats small live and frozen foods such as Daphnia, cyclops and bloodworm, taken near the bottom and in midwater.
Mating
Mating behaviour is not described for Hyalobagrus flavus.
Breeding
No breeding record for this species is known to the atlas.
In the aquarium
Three stores list it, so it reaches hobbyists as a wild-collected fish. Keep a group in a quiet tank with leaf litter, soft acidic water and small, peaceful tankmates; anything that can swallow a 1.5 in fish will do so. The spines are small but still catch in nets.
Conservation
The IUCN Red List carries Hyalobagrus flavus as Data Deficient, assessed in May 2019. Its known range is two peat-swamp drainages, and peat-swamp drainage and burning are the standing threat to fishes of this habitat.