Clarias

Clarias is a genus of catfishes (order Siluriformes) of the family Clariidae, the airbreathing catfishes. The name is derived from the Greek chlaros, which means lively, in reference to the ability of the fish to live for a long time out of water.[1]

Clarias Temporal range: Lower Pliocene - recent
Walking catfish, Clarias batrachus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Clariidae
Genus:	Clarias Scopoli, 1777
Type species
Silurus anguillaris Linnaeus, 1758
Species
Many, see text.
Synonyms
Chlarias Scopoli, 1777 Macropteronotus La Cepède, 1803 Clarias Cuvier, 1816 Cossyphus M’Clelland, 1844 Phagorus M’Clelland, 1844 Dinotopteroides Fowler, 1930 Prophagorus Smith, 1939 Anguilloclarias Teugels, 1982 Brevicephaloides Teugels, 1982 Clarioides Teugels, 1982 Platycephaloides Teugels, 1982

Taxonomy

Clarias has been found to be paraphyletic. A species of Heterobranchus (H. longifilis) clusters deeply inside the Clarias group.[2]

Distribution

They are found in inland waters throughout much of the Old World, and are one of the most widespread catfish genera in the world.[3][4] The genus is found in Southeast Asia and East Asia westwards through India and the Asia Minor to Africa.[5] The diversity of these catfishes is highest in Africa.[6] Some (notably the walking catfish) have become pest species where they have been accidentally introduced, and particularly in Cuba were their introduction was intentional.

Description

Clarias species are recognized by their long-based dorsal and anal fins, which give them a rather eel-like appearance. These fish have slender bodies, a flat, bony head, and a broad, terminal mouth with four pairs of barbels. They also have a large, accessory breathing organ composed of modified gill arches.[3][5] Also, only the pectoral fins have spines.[7]

Importance to economy

Yam pladuk fu (Thai: ยำปลาดุกฟู): shredded and deep fried Clarias (pla duk) catfish with salad

Many of the species are of great economic importance in both fisheries and fish culture.[6]

Species

Clarias liocephalus

There are currently 61 species recognized in this genus:

African species

Clarias agboyiensis Sydenham, 1980 Clarias albopunctatus Nichols & La Monte, 1953 Clarias alluaudi Boulenger, 1906 (Alluaud's catfish) Clarias angolensis Steindachner, 1866 Clarias anguillaris Linnaeus, 1758 (mudfish) Clarias buettikoferi Steindachner, 1894 Clarias buthupogon Sauvage, 1879 Clarias camerunensis Lönnberg, 1895 Clarias cavernicola Trewavas, 1936 (cave catfish) Clarias dhonti Boulenger, 1920 Clarias dumerilii Steindachner, 1866 Clarias ebriensis Pellegrin, 1920 Clarias engelseni Johnsen, 1926 Clarias gabonensis Günther, 1867 Clarias gariepinus Burchell, 1822 (North African catfish) Clarias hilli Fowler, 1936 Clarias jaensis Boulenger, 1909

Clarias laeviceps T. N. Gill, 1862 Clarias laeviceps dialonensis Daget, 1962 Clarias laeviceps laeviceps T. N. Gill, 1862 Clarias lamottei Daget & Planquette, 1967 Clarias liocephalus Boulenger, 1898 (smoothhead catfish) Clarias longior Boulenger, 1907 Clarias maclareni Trewavas, 1962 Clarias macromystax Günther, 1864 Clarias ngamensis Castelnau, 1861 (blunt-toothed African catfish) Clarias nigromarmoratus Poll, 1967 Clarias pachynema Boulenger, 1903 Clarias platycephalus Boulenger, 1902 Clarias salae Hubrecht, 1881 Clarias stappersii Boulenger, 1915 (blotched catfish) Clarias submarginatus W. K. H. Peters, 1882 Clarias theodorae M. C. W. Weber, 1897 (snake catfish) Clarias werneri Boulenger, 1906 (Werner's catfish)

Asian species

Clarias abbreviatus Valenciennes, 1840 Clarias anfractus H. H. Ng, 1999 Clarias batrachus Linnaeus, 1758 (Walking catfish) Clarias batu K. K. P. Lim & H. H. Ng, 1999 [5] Clarias brachysoma Günther, 1864 Clarias cataractus Fowler, 1939 Clarias dayi Hora, 1936 Clarias fuscus Lacépède, 1803 (Hong Kong catfish) Clarias gracilentus H. H. Ng, K. H. Dang & V. T. Nguyen, 2011 [8] Clarias insolitus H. H. Ng, 2003 [3] Clarias intermedius Teugels, Sudarto & Pouyaud, 2001 [6] Clarias kapuasensis Sudarto, Teugels & Pouyaud, 2003 Clarias leiacanthus Bleeker, 1851 Clarias macrocephalus Günther, 1864 (bighead catfish) Clarias dussumieri Valenciennes, 1840 Clarias magur F. Hamilton, 1822 Clarias meladerma Bleeker, 1846 (blackskin catfish) Clarias microspilus H. H. Ng & Hadiaty, 2011 [9] Clarias microstomus H. H. Ng, 2001 [4] Clarias nebulosus Deraniyagala, 1958 Clarias nieuhofii Valenciennes, 1840 (slender walking catfish) Clarias nigricans H. H. Ng, 2003 [10] Clarias olivaceus Fowler, 1904 Clarias planiceps H. H. Ng, 1999 Clarias pseudoleiacanthus Sudarto, Teugels & Pouyaud], 2003 Clarias pseduonieuhofii Sudarto, Teugels & Pouyaud, 2004 [7] Clarias serniosus H. H. Ng & Kottelat, 2014 [11] Clarias sulcatus H. H. Ng, 2004

Fossil species

• Clarias falconeri † Lydekker, 1886, from India

Invasive species

Clarias catfish and primarily Clarias batrachus (walking catfish) have been introduced to many different areas of the world, where they are causing problems for the native wildlife. The effect of introduction of these fish varies from area to area, but as they are predatory, they often affect the local wildlife by eating other fish, birds, and amphibians. In Florida, the fish are causing problems by invading aquaculture farms and preying on the fish cultivated there.[12] Countries where one or several Clarias species have been introduced include Indonesia, the United States, Hong Kong, China, UK, Papua New Guinea, Guam, Taiwan, Thailand, and Cuba.

References

1. Froese, Rainer and Pauly, Daniel, eds. (2011). Species of Clarias in FishBase. December 2011 version.
2. Mwita, CJ; Nkwengulila, G. (2008). "Molecular phylogeny of the clariid fishes of Lake Victoria, Tanzania, inferred from cytochrome b DNA sequences". Journal of Fish Biology. 73 (5): 1139–1148. doi:10.1111/j.1095-8649.2008.01935.x.
3. Ng, Heok Hee (2003). "Clarias insolitus, a new species of clariid catfish (Teleostei: Siluriformes) from southern Borneo" (PDF). Zootaxa. 284: 1–8. doi:10.11646/zootaxa.284.1.1. Retrieved 2009-06-24.
4. Ng, Heok Hee (2001). "Clarias microstomus, a New Species of Clariid Catfish from Eastern Borneo (Teleostei: Siluriformes)" (PDF). Zoological Studies. 40 (2): 158–162. Archived from the original (PDF) on 2011-07-19. Retrieved 2009-06-24.
5. Lim, Kelvin K. P.; Ng, H. H. (1999). "Clarias batu, a New Species of Catfish (Teleostei: Clariidae) from Pulau Tioman, Peninsular Malaysia" (PDF). The Raffles Bulletin of Zoology (6): 157–167. Archived from the original (PDF) on 2011-06-06. Retrieved 2009-06-24.
6. Teugels, Guy G.; Sudarto; Pouyaud, Laurent (2001). "Description of a New Clarias Species from Southeast Asia Based on Morphological and Genetical Evidence (Siluriformes, Clariidae)" (PDF). 25 (1): 81–92. Archived from the original (PDF) on 2010-12-26. Retrieved 2009-06-24. Cite journal requires |journal= (help)
7. Sudarto; Teugels, Guy G.; Pouyaud, Laurent (2004). "Description of a New Clariid Catfish, Clarias pseudonieuhofii from West Borneo (Siluriformes: Clariidae)" (PDF). Zoological Studies. 43 (1): 8–19. Retrieved 2009-06-24.
8. Ng, H. H.; Dang, K. H. & Nguyen, V. T. (2011). "Clarias gracilentus, a new walking catfish (Teleostei: Clariidae) from Vietnam and Cambodia" (PDF). Zootaxa. 2823: 61–68. doi:10.11646/zootaxa.2823.1.4.
9. Ng HH & Hadiaty Rk (2011) Clarias microspilus, a new walking catfish (Teleostei: Clariidae) from northern Sumatra, Indonesia. Journal of Threatened Taxa 3(3): 1577-1584. http://www.threatenedtaxa.org/ZooPrintJournal/2011/March/ng.htm Archived 2012-03-22 at the Wayback Machine
10. Ng, Heok Hee (2003). "Clarias nigricans, a New Species of Clariid Catfish (Teleostei: Siluriformes) from Eastern Borneo" (PDF). The Raffles Bulletin of Zoology. 51 (2): 393–398. Retrieved 2009-06-24.
11. Ng, H.H. & Kottelat, M. (2014): Clarias serniosus, a new walking catfish (Teleostei: Clariidae) from Laos. Zootaxa, 3884 (5): 437–444.
12. issg Database: ecology of Clarias batrachus

External links