Taxonomy & naming
Bleeker described the species in 1849 as Rohita chrysophekadion, from the Kalimas River at Surabaya. It is now placed in Labeo, with the authority in parentheses. Labeo is a large genus of labeonine cyprinids with a ventral, fringed mouth used to scrape algae and detritus from hard surfaces, found in Africa and Asia.
Morphology
Juveniles are velvet black with a slightly paler tail and a ventral, sucker-like mouth. Adults grow large, reaching 35.5 in TL according to FishBase, and may fade towards grey.
Habitat
It lives in large rivers and floodplains of Southeast Asia, including the Mekong and Chao Phraya, the Malay Peninsula and the islands of Sumatra, Borneo and Java. FishBase lists it as potamodromous, migrating between floodplain and river, and gives a temperature of 75–81 °F, pH 6.5 to 7.5 and hardness up to 15 dH.
Feeding
Labeo graze algae, periphyton and detritus from rocks, wood and the bottom, and take some plant matter and small invertebrates. The diet of this species has not been described separately.
Mating
Mating has not been described in detail. Labeo are generally seasonal egg-scatterers that move to flooded areas or rapids to spawn.
Breeding
Breeding in captivity has not been documented. Large Labeo used in aquaculture are spawned with hormones.
In the aquarium
Juveniles sold as black sharks outgrow most home tanks. A fish of up to roughly 35.5 in needs a very large tank or pond, and adults are territorial and aggressive towards other bottom fish. It is not suited to a community tank beyond the first year or so.
Conservation
The IUCN Red List category is Least Concern, assessed in 2020. Threats have not been described.