Patterning is highly variable depending both within and between populations and the species may comprise an assemblage containing a number of taxa (Kottelat and Lim, 1993; Tan and Kottelat, 2009). For example, those from Singapore and Johor possessing intricate mottling on the dorsal surface while individuals from Terengganu have a series of saddle-like markings either alternating or connecting with the midlateral markings.

Originally known only from Johor and Pahang states, Peninsular Malaysia but since recorded from the Batang Hari river drainage, Sumatra and the Kapuas system, Kalimantan Barat (West Kalimantan) province, Indonesian Borneo. Type locality is ‘Tahan River, Pahang, Malaysia’.

One of a handful of Pangio spp. traded under the generic name ‘eel loach’. Wild populations tend to differ in colour pattern to some extent, with some exhibiting a more intense lateral stripe while others display an irregular pattern of fine dark spots on the body, for example.

The differences in pelvic-fin structure and gill openings led Roberts to redefine the genus when describing H. eubranchus, whereas Tan (2006) expressed doubts that the two are even congeneric but was unable to reach a definitive conclusion in the absence of fresh material.

At any rate both species can be easily differentiated from Gastromyzon and Neogastromyzon spp. by observing the mo…

The distribution records for this species are somewhat confusing. It was described from the confluence of the Lamatang and Enim rivers, Palambang Province, Sumatra and has since been recorded from Thailand (Chao Phraya River), Peninsular Malaysia (Pahang River) plus the islands of Java (Solo River) and Borneo (Kapuas and Barito rivers).

The genus Kottelatlimia was erected by Nalbant (1994) to accommodate K. katik which had previously been assigned to Lepidocephalichthys but differs in various aspects noted earlier by Kottelat and Lim (1992) including: relatively small adult size; scaleless…

This species differs from congeners in the presence of papillae covering the mouthparts (lips, barbels, and lobes) which are absent in other species. It’s also the largest species in the genus and the serrae on the second pectoral fin rays in males form a broa…

Tan (2009) redescribed H. stephensoni and it possesses the following unique character set: sub-inferior mouth with thin barbels; five principle, 12-13 secondary pectoral fin rays (usually 12); scaleless belly; pattern of keeled scales on anterior, dorsal portion of body consisting of a single central keel in the posterior third of each scale; 43-50 lateral line…

The genus Homalopteroides was revalidated by Randall and Page (2012) and is told apart from the related Homaloptera by the following character combination: dorsal-fin origin above pelvic-fin; ≤ 60 lateral-line scales; ≤ 30 predorsal scales; oral morphology consisting of two thin and widely separated rostral barbels on each side of the mouth, thin crescent-shaped lips, the absence of any structure such as a mental pad or lobes between the lateral portions of the lower lip, and a chin that extends anterior to the lateral portions of the lower lip.

An obligate dweller of swiftly-flowing streams and headwaters containing clear, oxygen-saturated water. It often inhabits riffles and runs and is likely to show a preference for shallower zones. Substrates are generally composed of gravel, rocks, boulders or bedrock carpeted with a rich biofilm formed by algae and other micro-organisms.

Juveniles are often found in slower-moving stretches with gravel substrate and submerged tree roots. In both cases patches of aquatic plants are only occasionally pres…