Channa diplogramma

For other uses, see Channa diplogramma (disambiguation).

Channa diplogramma
Malabar snakehead, Channa diplogramma
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Channidae
Genus:	Channa Scopoli, 1777
Species:	Channa diplogramma Day, 1865

The Malabar snakehead [C. diplogramma], is one of the most enigmatic and least known of all channids. Sir Francis Day [1] described Ophiocephalus diplogramma in 1865 based on one juvenile specimen (42 mm in length) collected near the mouth of the Cochin River in the port city of Cochin (Southwestern India), and called it Malabar snakehead. The color pattern of this juvenile matched with that of juveniles of another species of snakehead, O. micropeltes originally described by Cuvier and Valenciennes [2] from Java, Indonesia. This possibly led Francis Day to synonymise C. diplogramma with C. micropeltes in 1878 [3]. The close similarity, rarity of adult specimens in museum collections, and the fact that no taxonomist has studied this snakehead since its description, resulted in the acceptance of the synonymy by subsequent taxonomists.^{[citation needed]} In 2011 the C. diplogramma, has been shown to be a valid species 134 years after it was synonymised [4], making it a valid endemic species of peninsular India.

Biology

Channa diplogramma shows multiple color phases during its life history, which makes local fishers, believe that they are different species. The different specimens are also known by different vernacular names (Pulivaka, Karivaka, Manalvaka, and Charalvaka). All these specimen in different color phases occur sympatrically and utilize the same ecological habitat.

Distribution

Channa diplogramma is endemic to the southern Western Ghats of peninsular India. It is known from the Rivers (including its principal reservoirs) Meenachil, Manimala, Pampa, Achenkovil and Kallada in Kerala state, as well as the Chittar and Tambraparini Rivers (and its reservoirs) in Tamil Nadu state in India.

Identification

Channa diplogramma differs from all other species in the genus by its high number of lateral line scales (103–105 vs. 36–91). It further differs from all other Channa species, except C. bankanensis, C. lucius, C. micropeltes and C. pleurophthalma by the presence of gular scales, a patch of scales between the anterior tips of the lower jaws, visible in ventral view. Channa diplogramma differs from C. bankanensis, C. lucius, and C. pleurophtalma by having a very different color pattern. C. diplogramma differs from its sister species C. micropeltes by a combination of characters viz., number of caudal fin rays, lateral line scales, scales below lateral line; total vertebrae, pre-anal length and body depth.

Conservation Status

Channa diplogramma is listed as a 'Vulnerable' species in the IUCN Red List of Threatened Species in view of its restricted distribution and threats including fishing, habitat loss and pollution.

References

• [1] Day F (1865) On the fishes of Cochin, on the Malabar coast of India. Part I. Acanthopterygii. Proceedings of the General Meetings for Scientific Business of the Zoological Society of London 1865(pt 1): 2–40. Continues as Part II, 286–318.
• [2] Cuvier G, Valenciennes A (1831) Histoire naturelle des poissons, Vol.7. Levrault, Paris-Strasbourg.
• [3] Day F (1878) Fishes of India; being a natural history of the fishes known to inhabit the seas and freshwaters of India, Burma and Ceylon.
• [4] Benziger A, Philip S, Raghavan R, Anvar Ali PH, Sukumaran M, et al. (2011) Unraveling a 146 Years Old Taxonomic Puzzle: Validation of Malabar Snakehead, Species-Status and Its Relevance for Channid Systematics and Evolution. PLoS ONE 6(6): e21272. doi:10.1371/journal.pone.0021272