Taxonomy & naming
Jerdon described the species in 1849 as Barilius malabaricus, from northern Malabar in southern India. It is now placed in Opsarius. Opsarius is a genus of stream-dwelling cyprinids of South and Southeast Asia, formerly included in Barilius, with an elongate body and a wide mouth suited to taking insects at the surface.
Morphology
A slender, active stream fish with a wide mouth. FishBase gives a maximum of 3.5 in SL; colour has not been described in the sources the atlas uses.
Habitat
It lives in rivers and streams of the Western Ghats of southern India, and FishBase names the Payaswini and Vallapattanam rivers. Water parameters have not been published.
Feeding
Opsarius are active surface and midwater predators of insects that fall on the water, taking small invertebrates and sometimes small fish. The diet of this species has not been described separately.
Mating
Mating behaviour has not been described.
Breeding
Captive breeding has not been documented.
In the aquarium
Keep it in a long tank with strong flow, high oxygen, cool to moderate temperatures and a tight lid, since these fish jump. Keep a group, and give small live, frozen and floating foods. Care notes come from the genus.
Conservation
No IUCN Red List assessment is known for this species, so no category is given. Population status and threats have not been described.