Channa rubora, Britz & Hui & Rüber, 2024

Britz, Ralf, Hui, Tan Heok & Rüber, Lukas, 2024, Four new species of Channa from Myanmar (Teleostei, Labyrinthici, Channidae), Raffles Bulletin of Zoology 72, pp. 1-25 : 9-12

Channa rubora , new species

( Figs. 8–10 )

Holotype. BMNH 2019.10 .16.194, 84.4mm SL mm SL; Myanmar, Kachin State, unnamed stream south of Mogaung , coll. Aung Myint, 23 February 2011.

Paratypes. BMNH 2019.10.16.195–206, 10 ex., 69.1– 98.2 mm SL; same information as holotype. BMNH

2019.10.16.260, 1 ex., 95.5 mm SL; same information as holotype. MTD 40207 , 78.8 mm SL; same information as holotype. — BMNH 2023.4.12.11–15, 5 ex., 65.4–127.5mm SL; same information as holotype.

Diagnosis. A member of the Gachua group distinguished from all other Myanmar members except C. ornatipinnis , C. pulchra , and C. stewartii by the presence of numerous black spots on the head and body (vs absence). It differs from the latter by the size of the spots (tiny, a quarter of pupil size vs. almost pupil size or larger) and by its unique fin colouration in life, consisting of a pectoral fin with orange fin rays, a bluish proximal blotch and 3–6 brown distal semicircular concentric bands, of dorsal-, anal- and caudal-fins with a blue middle section of the fin membranes margined by a proximal dark brown and distal bright orange rim in the dorsal and caudal fins and white rim in the anal fin (vs different colour pattern). It also differs substantially from all Myanmar Gachua group snakeheads by a genetic distance of 11.6–19.3% in the COI gene.

Description. See Figs. 8 , 10 for general appearance and Table 3 for morphometric information and Table 6 for select meristic characters. Body elongate, round in cross section anteriorly, laterally compressed at caudal peduncle, body depth 5.7–6.4 times in SL. Head large, length 3.2–3.5 times in SL. Head widest halfway between posterior margin of eye and that of opercle. Mouth large, maxilla extending posteriorly beyond jaw angle, lips fleshy. Premaxilla with multiple rows of small sharp, pointed teeth ( Fig. 9a ). Dentary also with several series of small teeth and an internal series of slightly larger teeth, but no canines ( Fig. 9b ). Vomer with an external series of small teeth and an internal series of a few large teeth ( Fig. 9a ). Palatine with several series of smaller teeth but no canines ( Fig. 9a ). Parasphenoid posteriorly at level of pharyngobracnhial 3 with two teeth ( Fig. 9d ). Hypobranchial 3 with a patch of tiny teeth ( Fig. 9c ). Ceratobranchial 5 with series of large teeth with anteriorly directed tips along posterior and medial margin and smaller teeth in middle and along anterior margin ( Fig. 9c ). Pharyngobranchial 2 elongate with several series of tiny teeth ( Fig. 9d ). Pharyngobranchial 3 with prominent teeth with recurved tips ( Fig. 9d ). Upper pharyngeal toothplate 4 with larger recurved teeth anteromedially and smaller teeth posterolaterally ( Fig. 9d ).

Pectoral–fin rays 13–15*. Dorsal-fin rays 34(1), 35(2), 36*(8), 37(6), or 39(1). Anal-fin rays 23(1), 24*(4), 25(7), 26(4) or 27(2). Caudal fin with 6+6*(12*), 6+7(2) or 7+6(1) principal rays and 2(2) or 3*(16) dorsal and 3*(15) or 4(3) ventral procurrent rays. 43(3), 44(9), 45*(3) or 46(2) vertebrae with 38 (2), 39(7), 40(5), 41*(3) or 42(1) abdominal and 4*(9) or 5(9) caudal vertebrae.

Predorsal scales 7–8. Lateral line with 44–47 scales extending from shoulder girdle in a horizontal line, but dropping one scale row at scale 13–17, then continuing horizontally to end of caudal peduncle. Scales above lateral line 3.5 and below 5.5–6.5 at level of anal–fin origin. Postorbital scales 7–8. Circumpeduncular scales 24, including 9 larger scales on each side and 3 tiny scales along dorsal and ventral midline. Prepelvic scales 10–12. A single scale on ventral aspect of anguloarticular.

Colouration in preservative. See Fig. 8 . Head grey, rest of body maroon with series of 7–8 darker saddle-like blotches between base of dorsal fin and lateral line. Numerous small black spots on lateral and ventral sides of head and laterally on rest of body. Dorsal- and anal-fin rays light grey, intermittent membrane darker grey, with distal tips of dorsal- and anal-fin rays white. Pectoral fin with dark brown base and 3–4 dark semicircular concentric bands alternating with 3 lighter bands. Pelvic fins light beige.

Colouration in life. See Fig. 10 . Colour a light brown in dorsal third of head and body with light grey to blueish grey lips, lateral and ventral sides of head and ventral abdominal area. A series of 6–7 darker brown saddle like blotches running from dorsal-fin base anteroventrally to lateral midline of body. Head and body with tiny black spots of varying number. Dorsal fin with light brown base, blue middle, narrow dark submarginal band and bright orange rim with distalmost tips of rays sometimes white. Caudal fin with irregular dark markings on fin rays arranged in a ladder-like fashion, blue fin membrane, narrow submarginal dark band and bright orange rim. Anal fin with brown proximal and blue middle area, a darker submarginal band and a white or orange rim. Pectoral fin with dark brown base and 3–4 dark semicircular concentric bands alternating with 3 lighter bands. Pelvic fins light grey.

Distribution. The new species is known from streams in the mountain area south of Mogaung.

Etymology. The species name, rubora , a noun in apposition, is derived from the Latin nouns ‘rubor’ for redness, and ‘ora’ for rim. The name was inspired by the orange-red rim of the dorsal and caudal fins.

Remarks. This species has been traded as an ornamental fish since at least 2012 under the name “ Channa sp. red fin” and has been referred to as Channa sp. Mogaung in Conte-Grand et al. (2017) and Rüber et al. (2020). Aquarium reports suggest that this is a mouthbrooding species, in which larvae and small juveniles are of a yellow colour. Among the Gachua group species in Myanmar, C. rubora is readily distinguished from all other species by its colour pattern, specifically the numerous tiny spots on the head and flanks. It is also clearly distinguished from C. burmanica by presence of pelvic fins (vs. absence). From the other three species described in this paper, C. coccinea , C. pyrophthalmus , and C. rakhinica , C. rubora also differs in lacking caniniform teeth on the palatine and dentary.

Figures

Fig. 8. Channa rubora, BMNH 2019.10.16.194, 84.4mm SL; holotype, in dorsal (top), lateral (middle), and ventral (bottom) view; Myanmar, Kachin State, unnamed stream south of Mogaung.

Fig. 9. Channa rubora, MTD 40207, paratype, 78.8 mm SL. Volume rendered 3D models illustrating dentition on premaxilla, vomer and palatine, in ventral view (a), lower jaw (b) in dorsal view, ventral branchial arches (c) in dorsal view, and upper pharyngeal jaws and parasphenoid patch (d) in ventral view. Note absence of caniniform teeth on palatine and dentary. Abbreviations: cb 5, ceratobranchial 5; de, dentary; hb3, hypobranchial 3; pal, palatine; pb2, pharyngobranchial; pb3, pharyngobranchial 3; pmx, premaxilla; ps, parasphenoid up4, upper pharyngeal toothplate 4. Scale bars 0.5 cm.

Fig. 10. Channa rubora, paratypes, colouration in life, Myanmar, Kachin State, unnamed stream south of Mogaung, BMNH 2019.10.16.260 (top), 95.5 mm SL; BMNH 2019.10.16.195–206 (bottom), not measured, ca. 90 mm SL.