Lalhlimpuia's Snakehead

description

Description. Body elongate, cylindrical anterior to dorsal-fin origin, increasingly compressed posteriorly. Dorsal profile rising evenly from tip of snout to dorsal-fin origin, then sloping gently posteriorly to end of caudal peduncle. Ventral profile almost straight. Head large, profile slightly convex laterally in dorsal view, length 3.0 – 3.4 times in SL. Head widest halfway between posterior margin of eye and that of opercle. Eyes small, closer to snout tip than to distal opercular margin. Caudal peduncle length 1.2 times its depth. Mouth terminal, large, with lower jaw protruding; posterior end of maxilla and premaxilla extending beyond posterior margin of eye; lips thick. Both jaws with rows of sharp, pointed teeth. Lower jaw with two rows of teeth. Vomer with canine-like teeth with eight to ten bigger teeth. Palatine teeth small, numerous. Fifth ceratobranchial slender, with numerous teeth. Dorsal-fin rays 34 (2), 35 (2), 36 (12) or 37 (2). Anal-fin rays 23 (2), 24 (11) or 25 (5). Pectoral-fin rays 13 (12) or 14 (6). Pelvic-fin rays 5 (18). Principal caudal-fin rays 12 (1), 13 (15) or 14 (2). Total vertebrae 45 (1) or 47 (1). Cheek scales in 5 (17) or 6 (1) rows. Pre-dorsal

Channa aurantipectoralis, a new species of snakehead from Mizoram, north-eastern India (Teleostei: Channidae)

diagnosis

Diagnosis. The species resembles members of the Channa gachua species group (sensu Britz 2008) in overall morphology and colour pattern, but differs from all of them in having uniformly-coloured bright-orange pectoral fins, lacking any spots, stripes or bands, and a dark V-shaped blotch on the dorsal surface of head in life. It further differs from other species of the genus by the combination of the following characters: absence of scales on the gular region, presence of a large scale on each side of the ventral surface of the lower jaw, 51 – 64 lateral-line scales, 34 – 37 dorsal-fin rays, 23 – 25 anal-fin rays, 13 – 14 pectoral-fin rays, 5 ½ – 6 ½ / 1 / 7 ½ – 8 ½ transverse scale rows.

Channa aurantipectoralis, a new species of snakehead from Mizoram, north-eastern India (Teleostei: Channidae)

discussion

Discussion Musikasinthorn & Taki (2001) broadly divided the family Channidae into two major groups based on the presence or absence of scales on the gular region. Species belonging to the first group are characterized by possessing scales on the gular region, viz. Channa bankanensis (Bleeker), C. lucius (Cuvier), C. micropeltes (Cuvier) and C. pleurophthalma (Bleeker) along with the three species of the African genus Parachanna. Species of the second group lack scales on the gular region and comprise the rest of the genus Channa. Li et al. ’ s (2006) molecular phylogenetic study of channids supported this division based on the single morphological character. Channa aurantipectoralis differs from C. bankanensis, C. lucius, C. micropeltes and C. pleurophthalma and all the species of Parachanna in lacking (vs. having) scales on the gular region. Britz (2008) observed that species in clade 6 and 7 in Li et al. ’ s (2006) phylogenetic tree share a colour pattern characterized by a varying number of dark and light semi-circular bands on the pectoral fin. He proposed this unique pattern as the defining character for his ‘ Channa gachua species group’. The group has been acknowledged by su

Channa aurantipectoralis, a new species of snakehead from Mizoram, north-eastern India (Teleostei: Channidae)

distribution

Distribution. Presently known only from Seling and Keisalam Rivers (small tributaries of Karnaphuli River) of Dampa Tiger Reserve, Mizoram, India (Fig. 3). The Karnaphuli River, originating from the hills of Mizoram- Tripura border, flows southwest along the Mizoram-Bangladesh border and then through the Chittagong Hill tract of Bangladesh and finally empties into the Bay of Bengal.

Channa aurantipectoralis, a new species of snakehead from Mizoram, north-eastern India (Teleostei: Channidae)