If you like Danios you will love Opsarius! They are lively, very elegant swimmers, more similar in behavior and appearance to trout than to other danios. As a popular collective name for the group, which includes the genera Opsarius, Barilius, Raiamas and Opsariichthys with a total of about 70 species in Asia and Africa, “Trout danios” fits very well. However, the classification of the genera is not always unanimous, because they are quite similar in their overall habitus.
This is also the case with Opsarius barna, which was already scientifically described in 1822 and is now and then classified in the genus Barilius. Currently, however, the up to 15 cm long danio is classified in the genus Opsarius. In fact this is not only an academic question, because it has been shown in aquaristic practice that Opsarius species are much more compatible than Barilius species. In the case of Barilius – according to practical experience – it is necessary to keep as many animals as possible (preferably 10 or more) in aquariums as large as possible with strong currents, so that intra-species aggression is kept within limits, while Opsarius are also well tolerated in smaller groups (from 5 specimens) in normal sized aquariums (10x the body length with appropriate width and height) and aquarium-standard currents.
Opsarius barna is found along the foot of the Himalayas and is widely distributed. Accordingly, the adaptability is good. However, these subtropical fish should not be kept year in and year out at constantly high temperatures. 16-20°C in winter and 24-26° in summer (a few degrees above or below will not hurt, but should not last for long periods) are just right.
Eaten is dry, frozen and live food of suitable size, vegetable food does not interest O. barna. Males grow slightly larger than females and appear more high-backed. We know nothing about breeding Opsarius in the aquarium; the closely related Barilius and Raiamas species are bottom spawners, depositing their spawn in sand and gravel.
For our customers: the animals have code 372832 on our stocklist. Please note that we only supply wholesale.
Text & photos: Frank Schäfer