This species is now considered endemic to Java but has been confused with the congeners H. gracilis (from eastern Peninsular Malaysia), H. velox (Sumatra) and H. bongan (Borneo) in the past, while the population formerly considered to inhabit northwestern Peninsular Malaysia has been described as H. divaricatus (Ng and Kottelat, 2013).

This species cannot be considered a suitable home aquarium‚ subject given its eventual size plus the fact it can live for‚ several decades.

It can be told apart from most oth…

This species has been recorded from the Zhujiang (Pearl River), Changjiang (Yangtze River) and Qiantang Jiang in central and southern China.

Type locality is ‘Chang Jiang, China’, referring to the Yangtze.

It’s been adversely affected by dam construction and pollution across certain parts of its range and may be locally extirpated in some cases.

Members of this assemblage can be told apart from other congeners by possession of 44–46 vertebrae, an adipose-fin with a relatively short base (< 20 % SL), a colour pattern comprising either distinct black spots arranged in vertical columns or irregular black vertical lines running along the flanks, and normally a reddish or orangish caudal-fin in life.

This species appears to be unknown in the aquarium trade but is a valued food fish within its native range.

Hemibagrus has been divided into a number of putative species groups which may or may not represent monophyletic assemblages, and following a major review by Ng and Kottelat (2013) H. filamentus is included in the H. nemurus group.

The only other described member of the genus native to southwestern India is B. sharavtiensis which occurs a little further north than B. travancoria in Karanataka state. The two are easily distinguished by colour pattern in that B. travancoria possesses a darkish midlateral stripe and a poorly-defined, but normally visible, post-opercular spot, whereas B. sharavtiensis has no such mark…

Batasio havmolleri (Smith, 1931) is currently considered a junior synonym of B. fluviatilis.

Members of the genus Batasio are characterised by the following combination of characters; laterally-compressed body shape; presence of large sensory pores on the head; a narrow mental region; a pair of prominent posterior proces…

Batasio spp. are obligate inhabitants of headwater streams and the upper reaches of smaller rivers characterised by shallow, fast-flowing, highly-oxygenated stretches of riffles and runs broken up by pools or cascades in some cases. Images of the Ataran correspondingly depict flowing sections of forest-shaded, seemingly well-oxygenated headwaters containing clear water, a mixed sand/rock substrate and lots of submerged driftwood/leaf litter.

The vernacular name ‘lancer’ is derived from the extended dorsal spine possessed by several members of the genus, which currently contains 7 species. B. obscurus is diagnosable from congerners by the following combination of characters: mouth opening relatively small and narrow; oral dentition significantly reduced; dorsal-fin spi…

The vernacular name ‘lancer’ is derived from the extended dorsal spine possessed by several members of the genus, which currently contains 7 species. Among them B. macracanthus is most similar to B. majusculus and B. vaillantii but can be told apart from the former by possession of shorter pectoral spines (13.3 – 16.2% SL vs. 15.8 – 20.7%), shorter adipose fin (46.0 – 58.0% SL vs. 38.8 – 45.8%), less deep caudal peduncle (7.1 – 7.5% SL vs. 5.6-7.0%) and larger adult size. From B. vaillantii it di…