Labeo chrysophekadion (BLEEKER, 1849)

Black Shark

SynonymsTop ↑

Rohita chrysophekadion Bleeker, 1849; Rohita cyanomelas Bleeker, 1852; Rohita polyporos Bleeker, 1854; Rohita koilogeneion Bleeker, 1857; Rohita sima Sauvage, 1878; Rohita pectoralis Sauvage, 1878; Morulius erythrostictus Fowler, 1934

Etymology

Labeo: from the Latin labeo, meaning ‘one with lips’, in allusion to the remarkably thick, fleshy lips in members of this genus.

chrysophekadion: from the Ancient Greek χρυσός (khrusós), meaning ‘gold’, and phekadion, meaning ‘lens-shaped spots’, in allusion to the scales on the body of adults, each of which has a golden centre.

Classification

Order: Cypriniformes Family: Cyprinidae

Distribution

Widespread in Southeast Asia, including the Mekong basin in Laos, Thailand, Cambodia, and Vietnam, the Dong Nai drainage in Vietnam, the Chao Phraya and Mae Klong systems in Thailand, and various smaller watersheds in southern Thailand (and possibly Myanmar), Peninsular Malaysia, and Indonesia (Greater Sunda Islands of Borneo, Sumatra, and Java).

In Borneo it has been recorded in the Kapuas River system in Kalimantan, the Indonesian portion of the island, but may also occur in the Malaysian states of Sarawak and Sabah.

Type locality is ‘Kalimas River, Surabaya, Java, Indonesia’, corresonding to what is now known as the Brantas River in East Java.

Habitat

Tends to inhabit larger river channels but also occurs in smaller tributaries, canals and inundated floodplains, less often in reservoirs and other man-made impoundments.

Adults undertake seasonal migrations to forage in floodplains and breed in upstream areas (see ‘Reproduction’).

Maximum Standard Length

500 – 600 mm.

Aquarium SizeTop ↑

Suitable only for public installations or the very largest, highly-specialised private aquaria.

Maintenance

A large, mature filter system, rigorous maintenance regime comprising weekly water changes of 50-70% tank volume, and provision of highly-oxygenated water with a degree of movement should be considered mandatory.

Smaller individuals will also appreciate a cave or shaded spot around which they may form a territory.

Water Conditions

Temperature: 20 – 26 °C

pH: 6.0 – 8.0

Hardness: 36 – 268 ppm

Diet

Primarily an aufwuchs grazer feeding on algae, small crustaceans, insect larvae, etc., and for it to develop its best colours and condition it should 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 fresh plant material.

Shelled peas, cucumber, blanched courgette, spinach and chopped fruit all make good additions to the menu. Once settled it will often ascend into midwater to feed and browse the biofilm that tends to form on rockwork and other solid surfaces.

Behaviour and CompatibilityTop ↑

This species can be belligerent and aggressively territorial towards conspecifics and similarly-shaped fishes, especially when space is limited.

Sexual Dimorphism

Sexually mature females are likely to be deeper-bodied and may grow larger than males.

Reproduction

Breeds on a seasonal basis in nature, at the onset of the wet season. It apparently spawns upstream of shallow sandbars where the eggs settle and hatch as the water begins to rise, with the fry moving into inundated riparian vegetation where they continue to follow the edge of the water as the flooding increases.

NotesTop ↑

L. chrysophekadion is also known as ‘black sharkminnow’. It continues to be available in the ornamental trade despite its patent unsuitability for the home aquarium, and an albino form has been selectively bred for the purpose.

It can be distinguished from other members of the genus by the following combination of characters: body and fins black; dorsal fin large, with anterior branched dorsal rays longer than head and distal margin straight to slightly concave; 15-18½ branched dorsal rays; both lips fringed; juveniles all black; large adults grey to black with a single iridescent spot on each scale.

The genus Labeo is an enigmatic grouping containg more than 100 species which is critically in need of revision. Members occur throughout much of Africa and Asia, and they are considered members of the tribe Labeonini within the putative cyprinid subfamily Cyprininae or simply the subfamily Labeoninae (name varies with author). According to the most recent phylogenetic research, this grouping is further divided into four subtribes; Labeoina, Garraina, Osteochilina, and Semilabeoina (Yang et al., 2012). Among these, Labeo is included in the Labeoina alongside Bangana sensu stricto (which includes the genus Nukta), Cirrhinus sensu stricto, Cirrhinus microlepis (which is of a different genetic lineage to other Cirrhinus species), Gymnostomus, and Incisilabeo.

Thirty Labeo species were used in the study, and the genus was found to be polyphyletic, although all were nested within the Labeoina clade (Yang et al., 2012). Labeo boggut, L. bata and L. bata var. formed a clade with Incisilabeo behri, Schismatorhynchos nukta, and Bangana dero (the type species of the genus) and B. sp. Salween. All other Labeo species comprised a group referred to as Labeo sensu stricto which also includes Gibelion catla, and the authors recommended that the latter be synonymised with Labeo, although this does not appear to have been widely accepted (eg. Kottelat, 2013).

References

1. Bleeker, P., 1849 - Verhandelingen van het Bataviaasch Genootschap van Kunsten en Wetenschappen. v. 23 (no. 12): 1-23
   Bijdrage tot de kennis der ichthyologische fauna van Midden- en Oost-Java, met beschrijving van eenige nieuwe species.
2. Freyhof, J., D. V. Serov and T. N. Nguyen, 2000 - Bonner Zoologische Beiträge (1-4): 93-99
   A preliminary checklist of the freshwater fishes of the River Dong Nai, South Vietnam.
3. 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.
4. Kottelat, M., 1998 - Ichthyological Exploration of Freshwaters 9(1): 1-128
   Fishes of the Nam Theun and Xe Bangfai basins, Laos, with diagnoses of twenty-two new species (Teleostei: Cyprinidae, Balitoridae, Cobitidae, Coiidae and Odontobutidae).
5. Kottelat, M., 2001 - WHT Publications, Colombo: 1-198
   Fishes of Laos.
6. Kottelat, M. and E. Widjanarti, 2005 - Raffles Bulletin of Zoology Supplement 13: 139-173
   The fishes of Danau Sentarum National Park and the Kapuas Lakes area, Kalimantan Barat, Indonesia.
7. Rainboth, W. J., 1996 - FAO, Rome: 1-265
   FAO species identification field guide for fishery purposes. Fishes of the Cambodian Mekong.
8. Roberts, T. R., 1989 - Memoirs of the California Academy of Sciences No. 14: i-xii + 1-210
   The freshwater fishes of western Borneo (Kalimantan Barat, Indonesia).
9. Stiassny, M. L. J. and A. Getahun, 2007 - Zoological Journal of the Linnean Society 150(1): 41-83
   An overview of labeonin relationships and the phylogenetic placement of the Afro-Asian genus Garra Hamilton, 1922 (Teleostei: Cyprinidae), with the description of five new species of Garra from Ethiopia, and a key to all African species.
10. 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.
11. Yang, L., M. Arunachalam, T. Sado, B. A. Levin, A. S. Golubtsov, J. Freyhof, J. P. Friel, W-J. Chen, M. V. Hirt, R. Manickam, M. K. Agnew, A. M. Simons, K. Saitoh, M. Miya, R. L. Mayden, and S. He, 2012 - Molecular Phylogenetics and Evolution 65(2): 362-379
    Molecular phylogeny of the cyprinid tribe Labeonini (Teleostei: Cypriniformes).