Danau Sentarum

Prefers a dimly-lit aquarium with plenty of cover in the form of live plants, driftwood branches, terracotta pipes, plant pots, etc., arranged to form a network of nooks, crannies, and shaded spots. Surface vegetation such as Ceratopteris spp. is also appreciated and makes the fish less inclined to conceal themselves.

While separating some of the fish that may be found on sale as 'C. siamensis' is a tricky task, C. nigriloba is quite simple to identify. The dark lateral body stripe uniquely breaks up into a series of blotches when the fish are sparring, stressed or sleeping and the lower caudal fin lobe contains dark pigmentation suffused with red. The latter feature has given rise to the trade name of 'penguin flying fox'.

In the aquarium trade this species may also be seen on sale as 'skinhead barb'. As with others in the genus little has been written regarding its captive care but it makes a peaceful and unusual addition to larger aquaria. The best way of obtaining it may be to keep an eye on shipments of wild fishes from Indochina and the Greater Sunda Islands as it's rarely imported in large numbers and most often arrives as bycatch.

In the exceptionally diverse Danau Sentarum lake system of the upper Kapuas River basin, West Kalimantan, sympatric species include Scleropages formosus, Barbonymus gonionotus, B. schwanenfeldii, Crossocheilus nigriloba, Cyclocheilichthys apogon, C. repasson, Epalzeorhynchos kalopterus, Labiobarbus ocellatus , Leptobarbus hoevenii, Luciosoma spilopleura plus various representatives of Barbodes, Rasbora and Osteochilus.

The pinkish-white form of this species is among the most widely-traded aquarium fishes in the world but does not occur naturally and is in fact a leucistic variant bred specifically for ornamental purposes. The 'short-bodied' or 'balloon' variety also continues to be fashionable but under no circumstances do we recommend the purchase of these intentionally disfigured animals which tend to have much shorter life spans than the naturally-shaped fish. There also exists a less-po...

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...

It can be distinguished from congeners by the following combination of characters: 61-68 scales in the lateral series; a small, well-defined, sometimes ocellated black spot on the shoulder and another in the centre of the caudal peduncle; body without longitudinal stripes formed by spots on scales; caudal fin uniformly dusky or colourless, lobes without stripes or black margins.

This species is occasionally marketed as 'Burmese Rainbow Barb' in the ornamental trade. others may have been exported in small numbers or as bycatch among shipments of other species. It was referred to as Mystacoleucus marginatus for decades, but that name is a simultaneous subjective synonym of M. obtusirostris following Kottelat (2013).

Images depict clear, tea-coloured forest streams with dense marginal vegetation and substrates of sand and/or small rocks and pebbles. It's also known from environments with sandy substrate and organic debris in the form of submerged roots/branches and le...

This species is often confused with the nominal congeners C. marulius (Hamilton, 1822) and C. melanoptera (Bleeker, 1855) with all three presenting taxonomic problems. For example, C. marulioides exhibits a number of variations in colour pattern depending on collection locality with the most common possessing a brownish base colour with a series of dark, chevron-like markings along each flank and some scales margined posteriorly in white.

Given its wide natural range it seems logical that this species is or has been available in the aquarium trade, although its correct name may never have been applied. It is told apart from congeners by the following combination of characters: two pairs of barbels; a continuous midlateral stripe from the tip of the snout to the base of the caudal-fin, with a conspicuous small blotch at the posterior extremity, faintly marked on the caudal-fin; a faint mark between the anus and the anal-fin origin in juveniles; a narrow mouth.

In aquarium literature this species is also referred to as 'fine scaled tiger fish', 'Indonesian tiger fish', 'Sumatran tiger fish', 'Indo datnoid', and 'Indo dat'. The common name of 'tiger fish' is also used in reference to the African alestid genus Hydrocynus, and the more appropriate 'tiger perch' was suggested by Roberts and Kottelat (1994).

This species is also known by the vernacular 'jungle perch' or 'sidebar barb' and should not be considered an aquarium subject in all but the most extreme circumstances since it can grow to over 2 feet in length, weigh in excess of 5 kg and is a powerful, pelagic predator. It's also a popular sport fish with a reputation for striking hard.

Apparently native to Peninsular Malaysia plus the Greater Sunda Islands of Borneo, Sumatra, and Java. Reports of this species from the Mekong, Chao Phraya, and other rivers in Indochina refer to the congener L. rubripinna (see 'Notes'). Type locality is 'Indonesia: Borneo: Kalimantan Selatan: Banjarmasin'.

It is thought to have been extirpated from the Chao Phraya and Mae Klong rivers, Lake Songkhla, and the entire island of Java due to a variety of anthropogenic factors, and the Mekong populations have also been drastically reduced. In particular, it is sensitive to pollution and gillnetting, and is heavily overfished.

This species is distinguished from its Australian congeners S. jardinii and S. leichardti by possessing a lower number of lateral line scales (21-26 vs 32-36). It occurs naturally in a number of colour forms of which three were elevated to distinct species status in 2003, but the current majority view is that all represent S. formosus pending a detailed review. Kottelat (2013) mentions that the red form may...