Glyptothorax chimtuipuiensis, Anganthoibi & Vishwanath, 2010

Anganthoibi, N. & Vishwanath, W., 2010, Glyptothorax chimtuipuiensis, a new species of catfish (Teleostei: Sisoridae) from the Koladyne basin, India, Zootaxa 2628 (1), pp. 56-62 : 57

Glyptothorax chimtuipuiensis , new species

( Figs. 1a–c )

Type material. Holotype: MUMF 10022 , 57.8 mm SL; India: Mizoram, Koladyne River at Kolchaw, Lawntlai District , 22°23′N, 92°57′E, K. Nebeshwar & party, 25 April, 2008.

Paratypes: MUMF 10023 , 6 , 33.7–55.3 mm SL; data as for holotype; one paratype (46.0 mm SL) was dissected for osteology .

Diagnosis. A species of short, stout Glyptothorax , with granulated skin; the dorsal profile is greatly arched anterior to the adipose fin; the dorsal spine is short and smooth, its length 5.1–8.9% SL; the pectoralfin length is 16.8–21.9% SL, the ventral surface of its first simple ray plaited; the adipose-fin base length is 22.1–27.3% SL; the thoracic adhesive apparatus is chevron shaped, wider than long, the median ridges of the apparatus perpendicular to its base, slightly diverging laterally ( Fig. 1c ), its base concave, open caudally, with a shallow depression at its posterior end followed by a small fold of skin.

Description. See Table 1 for morphometric data. Body short, stout, compressed on caudal peduncle; dorsal profile rising evenly from tip of snout to dorsal-fin origin, slightly humped between occiput and dorsalfin origin, thereafter sloping slightly ventrad to end of caudal peduncle. Ventral profile flat, slightly concave up to ventral-fin origin, then sloping gently upward from end of pelvic-fin base to end of anal fin. Anus and urogenital openings located immediately anterior to anal-fin origin. Skin granular on dorsal and lateral surfaces of head and fin bases, becoming prominently wrinkled after fixation in 10% formalin. Head greatly depressed; snout truncate; mouth subterminal, lips broad, fleshy. Upper lip continuing into maxillary barbel, supported by a flap of skin. Upper jaw longer than lower; teeth on upper jaw in a single broad patch, those on lower jaw in two distinct patches interrupted by a fold of skin originating from lower lip. Eyes small, oval. Thorax with a chevron-shaped adhesive apparatus with 11–16 ridges, medially perpendicular to its base, slightly divergent laterally. Base of apparatus concave, open caudally, with a shallow depression at its posterior end followed by a small fold of skin.

Barbels in four pairs: nasal barbel arising from internarial septum, reaching up to posterior margin of eye when adpressed; maxillary barbel supported by a large flap of skin, extending up to end of pectoral-fin base; outer mandibular barbel longer than inner, reaching gill opening.

Dorsal fin located closer to snout than to caudal-fin base, its posterior margin straight, bearing I,6 rays. Dorsal spine short, weak, smooth, extending up to half of fin height. Pectoral fin with I,6,i rays, extending slightly posterior to vertical through dorsal-fin origin, its spine broad, serrated anteriorly with 7 serrae.Ventral surface of spine plaited with 4–11 oblique plicae, regularly arranged proximally, becoming irregular distally. Pelvic fin with i,3,i rays, extending slightly beyond vertical through adipose-fin origin, not reaching anal opening. Adipose fin long, its base 1.5–1.7 as long as that of dorsal fin, originating at vertical slightly in advance of anal fin origin. Anal fin with ii,8 rays, its anterior margin straight or slightly convex, posterior margin straight. Caudal fin emarginate, with i,7,8,i rays, appearing forked when wrinkled skin is folded.

Occipital process in contact with first dorsal-fin pterygiophore. Vertebrae 20+15=35.

Coloration. In 10% formalin: dorsal and lateral surfaces of head and body dark grey, ventral portion anterior to pelvic-fin origin cream-colored. Dorsal, pectoral, pelvic and anal fins with brown base and hyaline distal margins. Caudal fin brown, with a dark grey band at base; tips of lobes hyaline. Adipose fin yellowish grey with white edge. Maxillary and nasal barbels dark grey dorsally, their ventral portions cream-colored. Mandibular barbels cream-colored.

Distribution. Known only from the type locality, the Chimtuipui River, a tributary of the Koladyne River at Mizoram (Koladan drainage), India ( Fig. 2 ).

Etymology. The species is named after the Chimtuipui River, its type locality.

Figures

FIGURE 1. Glyptothorax chimtuipuiensis, n. sp. (holotype, MUMF 10022, 57.8 mm SL): a. lateral aspect; b. dorsal aspect; c. ventral aspect.

FIGURE 2. Map showing type locality of Glyptothorax chimtuipuiensis.