Known only from Kanyakumari District, Tamil Nadu state, at the southern tip of the Indian peninsula. Type locality is the Kodayar River drainage and it’s also been collected in the Paralayar and Pamburivaikal river systems.

No precise data is available but it’s certainly a pelagic, riverine species with habitats likely to vary depending on locality and time o…

There is a case, however, to suggest that D. exclamatio is not actually a distinct taxon but rather a natural hybrid between D. assimilis and a D. arulius-like fish (possibly D. rubrotinctus) which occur together at its type locality in the Kallada River at Thenmalai.

The potential of hybridisation is evidenced by the somewhat intermediate colour pattern in that it possesses a (roughly) W-shaped mid-lateral blot…

S. chalakkudiensis can be told apart from S. denisonii by possession of an inferior mouth (vs. subterminal) and presence of a black marking in the dorsal-fin (vs. absence), and the scarlet body stripe being duller and terminating beneath or anterior to the dorsal-fin origin (vs. brighter and terminating beneath the centre of the dorsal-fin).

‘N.‘ anguilla can be told apart from other Indian members of the genus by possessing dark flank markings which are partially or completely merged to form a lateral stripe, and an almost-complete lateral line extending to the anal-fin.

Kottelat (2012) states that its generic placement requires additional study hence the genus name i…

Type locality is ‘Netravati River, Dharmasthala, Karnataka State, India’, with the species subsequently recorded from the Kabini (aka Kabani) River basin and it may be endemic to these two drainages.

While the Netraviti flows through Karnataka in its entirety before emptying into the Arabian Sea just south of the city of Mangalore, th…

This species is still considered a member of the genus Nemacheilus by some sources, but it was reclassified and placed in Acanthocobitis by Grant (2008).

Acanthocobitis sinuata, generally considered a junior synonym of A. mooreh (Kottelat, 2012b), also appears distinct and differs in geographical distribution plus number of dorsal-fin rays (2-3/9-10 in A. mooreh vs. 2/8-9 in A. sinuata) and some aspects of colour pattern.

A. sinuata is currently considered a synonym of A. mooreh by most authorities.

This appears attributable to a lack of recent study since the two differ in distribution plu…

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…

Mostly known from slow-moving, relatively shallow tributaries and minor rivers with substrates of mud, sand or gravel. Aquatic plants are only occasionally present but riparian vegetation apparently grows thickly at some localities.

In the Schutunga River, part of the Mansai River drinage which is itself a tributary of the Brahmaputra in West Bengal state, In…

This species continues to be mislabelled as O. melastigma, a name currently considered invalid by the majority of recent workers, or O. javanicus, a valid but distinct taxon. Roberts (1998) demonstrated that MClelland’s description of Aplocheilus melastigmus, later renamed O. melastigma, does not correspond with any known Oryzias species from the Indian subcontinent or Myanmar since it’s said to have a dark spot in the dorsal-fin and an excessively slim body, among other anomalies.