Channa brunnea, Praveenraj & Uma & Moulitharan & Kannan, 2019

Praveenraj, Jayasimhan, Uma, Arumugam, Moulitharan, Nallathambi & Kannan, Rajesh, 2019, Channa brunnea, a new species of snakehead (Teleostei: Channidae) from West Bengal, India, Zootaxa 4624 (1), pp. 59-70 : 60-65

Channa brunnea , new species

( Figs. 1–3 )

Holotype: ZSI FF 8040, 110 mm SL; India, West Bengal, Jalpaiguri district, a swamp in Bhalka forest in the vicinity of the Sankosh River (26°30’3.6”N; 89°50’32.6”E), Bipul Gope , 7 February 2019.

Paratypes: ZSI FF 8041, 4, 87.0– 99.3 mm SL (87.0 & 87.5 mm SL DNA barcoded); JPC-29-33, 5, 78.7–98.2 mm SL (98.2 mm SL cleared, stained and DNA barcoded), same collection data as holotype.

Diagnosis. Channa brunnea is distinguished from all known species of Channa , except C. asiatica , C. orientalis , C. burmanica , C. bleheri , C. nox , C. hoaluensis , C. ninhbinhensis and C. andrao , by the absence of pelvic fins. Channa brunnea resembles C. bleheri in general appearance, but live specimens are readily distinguished by a pale to dark brownish body, and the cheek and opercle with dark brown scales extending to the upper half of body and forming oblique lines (vs. brownish body, cheek and opercle with blue or orange scales, extending to the upper and lower half of body forming oblique lines in C. bleheri ); having the pectoral fin ochre, with 4–6 black bands, the bands sometimes coalescing to form an irregular pattern in adults (vs. pectoral fin orange, with 5–6 semicircular black bands discreet, not coalesced in C. bleheri ) ( Fig. 4B ). The new species further differs from C. bleheri in having more scale rows between the dorsal-fin origin and lateral-line (4½–5½ vs. 3½); more pre-anal scales (22–26 vs. 17–20); and 2 rows of teeth in the fifth ceratobranchial, the outer row with 16 large conical teeth (vs. 3 rows of teeth, the outer row with 13 large conical teeth); dentary with 20 large, stout, conical teeth in the inner row (vs. 32 medium-sized conical teeth). Channa brunnea differs from C. orientalis in having ochre to bright orange blotches in the caudal fin (vs. absence of blotches, see Pethiyagoda, 1991), more anal-fin rays (24 vs. 21–22), more vertebrae (43 vs. 38–40), and in their reproductive behaviour: guarding a nest of floating eggs (vs. male mouthbrooding, see Ettrich, 1989). Channa brunnea can be easily distinguished from the Southeast Asian species of pelvic fin-less Channa , viz. C. asiatica , C. nox , C. hoaluensis and C. ninhbinhensis , by its smaller size (adults not exceeding 150–160 mm SL), and having the pectoral fin with black semicircular bands, compared to an adult size of 200–340 mm SL, and pectoral fin devoid of any black bands (see Courtenay & Williams, 2004; Zhang et al., 2002; Nguyen, 2011). In life, C. brunnea can be readily distinguished from C. asiatica and C. nox by the absence of dark chevrons and white spots on the lateral body, and a large ocellus on the caudal peduncle (see Courtenay & Williams, 2004; Zhang et al., 2002). Based on data from Zhang et al., (2002) and Nguyen (2011), the new species can be further distinguished from C. asiatica , C. nox , C. hoaluensis and C. ninhbinhensis by possessing fewer dorsal and anal-fin rays (35–37 vs. 47–51 and 24 vs. 28–32), fewer vertebrae (43 vs. 45–57) and greater pre-dorsal length (33.1–36.3 vs. 26.9–33.3, respectively). Based on the description of C. burmanica by Chaudhuri (1919), Channa brunnea differs from that species in having fewer lateral-line scales (43–46 vs. 51), fewer anal-fin rays (24 vs. 28) and more pre-anal scales (22–26 vs. 20). In life, C. brunnea differs from C. andrao in its overall body color (brown vs. light grey), presence of blotches in the caudal (vs. absence of any blotches) ( Fig. 4C ), and in the shorter dorsal and analfin base length (57.6–60.9 vs. 64.6–68.8% SL and 3 6.5–40.7 vs. 40.8–44.5% SL, respectively).

Description. For general appearance, see Figs. 1–3 . Morphometric data are presented in Table 1. A dwarf Channa (110–130 mm SL) of the C. gachua -species group (sensu Britz, 2008). Body elongate, round in cross section anteriorly up to origin of anal fin, progressively compressed towards caudal peduncle; body depth 5.4–7.1 times in SL. Head large, 3.2–3.5 times in SL, convex in dorsal view. Head widest between posterior margins of eye and the opercle. Eye small, its diameter less than snout length. Mouth large, maxilla extending beyond posterior margin of eye. Both jaws with small sharp teeth. Premaxilla with 4–5 rows of minute, conical, recurved teeth. Vomer with two pairs of stout caniniform teeth. Dentary with two rows of teeth, inner row with 20 medium-sized to large, stout, pointed, conical teeth; outer row with medium-sized, villiform teeth terminating in three rows at jaw symphysis. Palatine with two rows of teeth, inner row with stout, recurved, conical teeth, outer row with small, conical teeth. Fifth ceratobranchial with two rows of teeth, outer row with 16 stout, pointed teeth, inner row with numerous, minute, conical teeth.

Dorsal-fin rays 35 (3), 36* (6), 37 (1); anal-fin rays 24* (10); pectoral-fin rays 14* (7), 15 (3); principal caudalfin rays 13 (10); pelvic fin absent. Lateral-line scales 43 (2), 44* (3), 45 (3), 46 (2), extending horizontally from cleithral region, dropping one scale row at scale 12* (2), 13 (4), 14 (3), 15 (1), then continuing horizontally to the caudal peduncle. Transverse scales 4½*(9)–5½(1)+1+5½*(1)–6½(9). Pre-dorsal scales 7 (2), 8* (5), 9 (3). Pre-anal scales 22* (2), 24 (4), 25 (2), 26 (2). Cheek scales 6* (10).Vertebrae 43.

Coloration. In life ( Figs 2 , 4A ), body uniformly brown with dark-brown oblique markings on upper half. Head and cheek brown, with dark-brown or red scales forming irregular patches. Lips light-brown anteriorly, tinged with blue towards angle of gape. A bluish patch beneath the eye. Opercular membrane bluish. Dorsal fin ochre to brown, with bright orange to ochre distal margin, followed by wavy brown and ochre patterned sub-margin. Anal fin membrane bluish with black rays, distal margin black with pale-grey rim. Pectoral fin bright orange to ochre, with 4 to 6 broad, black semi-circular bands, sometimes coalesced to form an irregular pattern. Pectoral fin interspace broader than black semi-circular bands. Caudal fin brown, bordered with bright orange to ochre distal margin, followed by brown sub-margin; three to four ochre blotches sometimes coalescing to form a broad transverse band. Well-conditioned adult aquarium specimens with evenly dark brown body, sometimes with dark-brown scales scattered on lateral body; cheek with patches of red scales ( Fig. 4A ).

In ethanol ( Fig. 1 ), body uniformly dark grey; cheek and opercular area grey, becoming lighter towards throat with marbled grey and whitish-cream reticulated pattern. Branchiostegal membrane dark grey, isthmus and the ventral region grey. Pectoral fin grey, with 4–6 black semi-circular bands similar to live specimens. Dorsal, anal and caudal fin dark grey with ochre and orange blotches replaced by creamy white.

Distribution and Habitat. Known from the swamps of Bhalka forest, near the vicinity of Sankosh River, Jalpaiguri district, West Bengal, India. The habitat is a swamp with silty bottom and lush aquatic vegetation.

Etymology. The specific epithet “ brunnea ” is a Latin adjective meaning ‘brown’, an allusion to the overall brownish colour of the body.

Remarks. This species is popularly known in the aquarium trade as Channa sp. “Chocolate bleheri” or “Brown bleheri”. They lay floating eggs, with the male guarding the nest ( Fig. 5 ) (Dominik Niemeier, pers. comm.).

Genetic analysis. The three cox1 sequences of C. brunnea ( MK424817 , MK424818 , MK431774 ) had 100% BLAST similarity with the sequences labelled as Channa bleheri ( MF496702 & MF496704 ) in Conte-Grand et al. (2017), both of which were barcoded from specimens purportedly collected from northern West Bengal. The maximum likelihood phylogenetic tree reveals C. brunnea to be distinct from C. bleheri , forming a separate clade ( Fig. 5 ). Channa brunnea differs genetically from C. bleheri by a K2P distance of 9.8–10.6%. Further, it also differs from C. andrao ( KY563773 ), C. asiatica ( MF496669 ), C. burmanica ( MF496707 ), C. orientalis ( MF496870 ) and C. cf. nox ( MF496708 ) by distances of 16.8, 22.2, 13.8, 16.8 and 24.0 % respectively.

Figures

FIGURE 1. Channa brunnea, holotype, ZSI FF 8040, 109.8 mm SL, West Bengal, Jalpaiguri district, a swamp originating from the Bhalka forest in the vicinity of the Sankosh River (26°30’3.57”N; 89°50’32.63”E).

FIGURE 2. Channa brunnea A. Holotype, ZSI FF 8040, 109.8 mm SL, B. Paratype, ZSI FF 8041, 99.3 mm SL.

FIGURE 3. Teeth pattern. 1st row (A, B)—Channa brunnea, Paratype, 98.2 mm SL (JPC-33); 2nd row (C, D)—Channa bleheri (JPC-28). (1st column—Fifth ceratobranchial, 2nd column—Dentary).

FIGURE 4. A. Channa brunnea, uncatalogued aquarium specimen (Photo by Shankar Balasubramanian), B. Channa bleheri, ZSI FF 8039, 87.3 mm SL, C. Channa andrao, JPC-34, 102.2 mm SL.

FIGURE 5. A male C. brunnea (uncatalogued) guarding the fertilised buoyant eggs, documented by a German fish hobbyist (Photo by Dominik Niemeier).