Labiobarbus ocellatus (HECKEL, 1843)

SynonymsTop ↑

Cyrene ocellata Heckel, 1843; Dangila microlepis Bleeker, 1852

Etymology

Labiobarbus: from the generic names Labeo and Barbus.

ocellatus: from the Latin ocellatus, meaning ‘having small eyes’, in allusion to this species’ colour pattern comprising a dark spot on the anterior portion of the body and another on the caudal peduncle.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Native to Peninsular Malaysia and the Greater Sunda Islands of Sumatra and Borneo where it has been recorded from several major river basins including the Pahang, Batang Hari and Kapuas.

Type locality is given simply as ‘Borneo’.

Habitat

A pelagic species primarily occurring in rivers but also some lakes, and is known to move into seasonally inundated floodplains or forested areas during the wet season.

In the diverse Danau Sentarum lake system in the upper Kapuas River basin, Kalimantan Barat (West Kalimantan), Borneo, sympatric species include Scleropages formosus, Barbonymus gonionotus, B. schwanenfeldii, Crossocheilus nigriloba, Cyclocheilichthys janthochir, C. repasson, Epalzeorhynchos kalopterus, Leptobarbus hoevenii, Luciosoma spilopleura and various smaller cyprinids.

Maximum Standard Length

160 – 180 mm.

Aquarium SizeTop ↑

An aquarium with base measurements in excess of 150 ∗ 45 cm will be required for long-term maintenance.

Maintenance

This species will do well in most well-maintained larger aquaria but is best maintained in a set-up designed to resemble a flowing river or stream, with a substrate of variably-sized rocks, gravel and some large water-worn boulders.

This can be further furnished with driftwood branches, and while the majority of plant species will fail to thrive in such surroundings hardy types such as Microsorum, Bolbitis or Anubias spp. can be grown attached to the décor. In this kind of environment it will display more natural behaviour and can be kept alongside other species that enjoy similar conditions. Bright lighting will also promote the growth of aufwuchs upon which the fish will graze.

Like many fishes that naturally inhabit running waters it’s intolerant to the accumulation of organic wastes and requires spotless water at all times in order to thrive. It also does best if there is a high level of dissolved oxygen and a decent level of water movement in the tank so a external filters, powerheads or similar should be employed in order to obtain the desired effect.

Water Conditions

Temperature: 20 – 28 °C

pH: 6.0 – 7.5

Hardness: 36 – 215 ppm

Diet

In nature it grazes the biofilm that covers submerged surfaces, feeding on algae, including diatoms, small crustaceans, insect larvae, etc. For it to develop its best colours and condition it should therefore be offered regular meals of small live and frozen foods such as chironomid larvae (bloodworm), Daphnia and Artemia along with good quality dried flakes, granules and plenty of vegetable matter.

Fresh fruit and vegetables such as cucumber, melon, blanched spinach or courgette can be offered occasionally and home-made, gelatine-bound recipes containing a mixture of dried fish food, puréed shellfish, fresh fruit and vegetables, for example, are also proven to work well.

Behaviour and CompatibilityTop ↑

Relatively peaceful and makes a good subject for the well-chosen, larger community of stream-dwelling Indochinese species.

It is gregarious by nature and ideally should be kept in a group of at least six. The fish show better colours in the presence of conspecifics, are less nervous and the display on the whole will appear more natural-looking. SF members who have kept it report that it can act skittishly in the absence of similarly-sized tankmates.

Sexual Dimorphism

Unconfirmed but sexually mature females are likely to be deeper-bodied than males.

Reproduction

As far as we know it has not been bred in aquaria.

NotesTop ↑

L. occelatus is occasionally available in the ornamental trade, typically under a name such as ‘Bornean eye-spot silver shark’ or the invalid scientific name Cirrhinus chinensis.

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.

In recent studies the genus Labiobarbus is usually grouped within the cyprinid subfamily Labeoninae. Several authors including Roberts (1989) have argued that the generic name Dangila (Valenciennes, 1842), which was officially used for over 100 years, should continue to take precedence.

However according to rules set out in the modern-day International Code of Zoological Nomenclature Labiobarbus is the correct name on the basis of priority, having first been proposed by van Hasselt in 1823. Further doubts that van Hasselt and Valenciennes may have described two different fish were settled by Roberts (1993) who found that they were the same.

Members are most-easily distinguished from their close relatives by the possession of two pairs of well-developed barbels, an extremely long dorsal-fin with 4 simple and 18-30 branched rays and unique soft mouth parts which lack unculi (these form ridge-like rows on the lips of other Labeonins).

References

1. Heckel, J. J., 1843 - E. Schweizerbart'sche Verlagshandlung. Stuttgart. v. 1 (pt 2): 990-1099
   Ichthyologie [von Syrien]. In: J. von Russegger. Reisen in Europa, Asien und Africa, mit besonderer Rücksicht auf die naturwissenschaftlichen Verhältnisse der betreffenden Länder unternommen in den Jahren 1835 bis 1841, etc.
2. Kottelat, M., 2013 - Raffles Bulletin of Zoology Supplement 27: 1-663
   The fishes of the inland waters of southeast Asia: a catalogue and core bibiography of the fishes known to occur in freshwaters, mangroves and estuaries.
3. Roberts, T. R., 1993 - Raffles Bulletin of Zoology 41(2): 315-329
   Systematic revision of the Southeast Asian cyprinid fish genus Labiobarbus (Teleostei: Cyprinidae).
4. Yang, L. and R. L. Mayden, 2010 - Molecular Phylogenetics and Evolution 54(1): 254-265
   Phylogenetic relationships, subdivision, and biogeography of the cyprinid tribe Labeonini (sensu Rainboth, 1991) (Teleostei: Cypriniformes), with comments on the implications of lips and associated structures in the labeonin classification.