Malabar snakehead


The Malabar snakehead is a vulnerable species of snakehead from freshwater in the Western Ghats in India. Until 2011, it was usually included in the giant snakehead, C. micropeltes.

Taxonomy

Sir Francis Day described Ophiocephalus diplogramma in 1865 based on one juvenile specimen collected near the mouth of the Cochin River in the port city of Cochin, 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 from Java, Indonesia. This possibly led Francis Day to synonymise C. diplogramma with C. micropeltes in 1878. The close similarity, rarity of adult specimens in museum collections, and because no taxonomist had studied this snakehead since its description, resulted in the acceptance of the synonymy by subsequent ichthyologists. In 2011, C. diplogramma was shown to be a valid species 134 years after it was synonymised, making it an 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. All these specimen in different color phases occur sympatrically and use the same ecological habitats.

Distribution

The Malabar snakehead is endemic to the southern Western Ghats of peninsular India. It is known from the Meenachil, Manimala, Pampa, Achenkovil and Kallada rivers in Kerala, as well as the Chittar and Tambaraparani rivers in Tamil Nadu.

Identification

The Malabar snakehead differs from all other species in the genus by its high number of lateral line scales. 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. C. diplogramma differs from C. bankanensis, C. lucius, and C. pleurophtalma by having a very different color pattern, and from its sister species C. micropeltes by a combination of characteristics, viz. number of caudal fin rays, lateral line scales, scales below lateral line; total vertebrae, pre-anal length, and body depth.

Conservation status

The Malabar snakehead is listed as a Vulnerable species in the IUCN Red List in view of its restricted distribution, and threats including fishing, habitat loss, and pollution.