Burnt-tailed Shark

The burnt-tailed barb is closely related to the bala shark (B. melanopterus). It differs from its congener by a shorter snout, grooves which are posteriorly directed at rictus curved (vs. straight in the bala shark), and narrower black margins on the pelvic and anal fins (on distal third or less compared to the bala shark where the black margins are on distal half or more).

It is endemic to Thailand where known from the Mae Klong and Chao Phraya River basins. It has also been reported from the Mekong Basin in Vietnam, Cambodia and Laos, but confirmed records from this basin are lacking and this is not recognized as part of its range by the IUCN. The closely related B. melanopterus has been reported from the same rivers, but this is due to confusion with B. ambusticauda; the true native range of B. melanopterus is further south in the Malay Peninsula, Borneo and Sumatra. Large numbers of B. melanopterus are exported from Thailand for the aquarium trade, but these are all captive bred. According to Kittipong Jaruthanin, a Thai expert on freshwater fish and aquatic animals, the burnt-tailed barb likely did not have reddish-orange fins (as shown in illustrations). He discovered the last known specimen in 1986, in a Bang Mot tangerine orchard canal that draws water from the Chao Phraya River, in Thung Khru district (then Rat Burana district), Bangkok. In his view, if the fish had such fin coloration, it would have been clearly classified as a distinct species long ago. Instead, he believes its fins had fewer black markings than yellowish-white areas, and its head was shorter and blunter than that of the bala shark. Despite surveys within its native range, it has not been recorded in more than three decades and is likely extinct. …