In fact G. farragus and G. ocellatus represent one of 12 pairs of cryptospecies to be found in the genus, differing in subtle aspects of patterning. Cryptospecies are defined as morphologically similar, but reproductively isolated species which in fishes often inhabit adjacent river basins but in some cases occur sympatrically. The phenomenon may be a result of parallel evolution, and is not normally considered to represent an early stage of speciation.

G. cornusaccus can be distinguished from congeners by the following combination of characters: secondary rostrum present; incomplete postoral pouch present reduced to pockets located posterior to mouth corners; sublacrymal groove present and visible when viewed laterally; juveniles with thick, cream-coloured bars and blotches on body, adults uniformly-coloured; head dorsum plain; subopercular groove absent; gill slit vertical; snout truncate when viewed dorsally; no scales on abdomen; 55-61 lateral line scale…

One of the more commonly-traded members of the genus and often found in mixed shipments which may contain other Gastromyzon spp. or related fishes like Beaufortia kweichowensis, these often labelled collectively as ‘Borneo sucker’, ‘Hong Kong pleco’, ‘butterfly loach’, etc. It’s sometimes misidentified as G. punctulatus, a species not currently traded which possesses yellow finnage and a lighter-coloured, less-intensely spotted body.

Field observations have revealed that individuals almost always position themselves facing into the flow, either along the sides, behind or under rocks, their specialised morphology (see ‘Notes’) allowing them to feed and maintain position without being swept away.

Not many fishes have been able to successfully colonise this narrow ecological niche, but syntopic species in nature include Gastromyzon extrorsus (Petagas River), G. introrsus, G. lepidogaster (Pad…

At one locality close to Ban Na Hwai, Chiang Mai Province, Thailand L. hasselti was collected from a shallow (<0.5 m) pool in a swampy zone between forest and rice fields. The substrate was of mud, there was no aquatic vegetation and it was being used as drinking water by local animals, with the only effluent connected to a 'small creek'. Other species found there were Physoschistura pseudobrunneana, Rasbora hobelmani and Systomus cf. orphoides.

This species is widely-distributed throughout Peninsular Thailand, Malaysia (Malay Peninsula plus the states of Sabah and Sarawak, Borneo), Singapore and Indonesia, with records from the Riau Archipelago, Sumatra, Java, Borneo, Bali, Lombok, and Sulawesi existing in the latter. Type locality is ‘Panimbang River, Perdana, Indonesia’.

It’s typically found in coastal, normally brac…

Juveniles of this 'species' (probably a group of species – see 'distribution') are traded in large numbers but it's still uncommon to see adult specimens in the hobby suggesting their needs are not catered for often enough. This is a shame as when maintained properly they're hardy, long-lived and interesting aquarium residents. Other trade names include 'long-nosed' and 'banana' loach. Please note although certain that more than one species is being tr…

The genus Puntius is currently viewed as something of a catch-all for well over 100 species of small to mid-sized cyprinid. Most experts agree that a full revision is required with the likely outcome that many species will be placed into new or different genera since it is clearly polyphyletic.

When describing the grouping in 1822 Hamilton identified the defining characteristics as: presence or absence o…

This species occurs in several colour forms depending on collection locality with some exhibiting more intense pigmentation in the fins or an additional reddish lateral stripe, for example. It’s sometimes said to closely resemble and occur sympatrically with Rasbora agilis, but that name is currently considered a junior synonym of the congener Trigonopoma pauciperforatum.

R. agilis had previously been us…

This species is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.