Diagnosis |
Schistura sirindhornae is distinguished from all other congeners in having overlapping scales on the entire body similar to the scales of balitorids, transparent scales on the belly and thorax, a lateral-line canal that is similar to that of most cyprinids and balitorids in being present across the entire lateral-line surface of the scale instead of being represented only by a pore, and a unique color pattern of irregular brown bars on the back and side of the faint yellow-orange body, a bright triangular orange mark on the occiput, an orange crown-shaped mark between the eyes, an uninterrupted black mark along the base of the dorsal fin, a crescent-shaped bar on the base of the caudal fin, and bright iridescent orange areas on the upper and lower extremities of the caudal-fin base. Scales are generally larger than those of other nemacheilids with a larger focal area (Ref. 102608).
Description: large nemacheilid with moderately elongated, robust body; body anteriorly rounded in cross section, body depth/ width at dorsal-fin origin 1.2±0.10 times, slightly compressed posteriorly; body depth/ width at anal-fin origin 2.0±0.55 times, caudal peduncle slightly compressed; maximum body depth between pectoral-fin base and dorsal-fin origin; dorsal-fin origin slightly posterior to pelvic-fin origin; dorsal fin with 3 simple and 6½-7½ branched rays; distal margin of dorsal fin straight or slightly convex; anal fin with 3 simple, 5½ branched rays, with tip nearly reaching caudal-fin base; pelvic fin with 1 simple ray, 7-8 branched rays, not reaching beyond anus; axillary pelvic lobe present; pectoral fin rounded, reaching half distance to pelvic-fin base, with 1 simple ray, 8-10 (rarely 8) branched rays, reaching half-way between its origin and pelvic-fin origin; anus closer to anal fin than to pelvic-fin; caudal fin with 8+8 branched rays, deeply emarginated, lobes rounded; 19 trunk- and 11 caudal-vertebrae; caudal peduncle length/depth 1.0±0.08 times; head moderately large 4.3±0.65 times in SL; eye relatively small, 0.4±0.04 times in interorbital space, 14.4±0.74% HL; mouth moderately large, width 39.5±3.78% HL; anterior nostril with flap-like tube with low anterior rim; mouth arched, width 1.8±0.26 times in mouth length; processus dentiformis present on upper jaw, broadly rounded, none on lower jaw; lips thick, upper lip with well-marked median incision, small furrows on entire length; lower lip with broad median interruption with prominent pad on each side, and thin flap of lip on corner of mouth, occasionally including 3-5 furrows; sometimes smooth in fresh specimens, with black spot on pads; inner rostral barbel reaching beyond vertical to nostril, length 1.0±0.13 times in snout length (33.9±3.02% HL); outer rostral barbel reaching beyond vertical through posterior rim of eye, length 0.8±0.10 times in snout length, 48.0±4.50% HL; maxillary barbel 45.7±2.93% HL, 0.8±0.07 times in snout length; largest individual 78.9 mm SL; body completely covered with exposed, non-embedded scales, including between belly and thorax; scales larger than in other nemacheilids, closely resembling those of balitorids, with large focal area; lateral line complete to hypural plate, ends slightly before posterior margin of caudal peduncle with 118-123 scales; lateral-line canal similar to that of cyprinids and balitorids in being present across entire lateral-line surface of scale instead of being represented only by pore; scales absent on head; cephalic lateral line system with 7 supraorbital, 4+10-12 infraorbital, 8-10 preoperculo-mandibular, and 3 supratemporal pores; stomach syphonal, intestine straight with single bend; gas bladder with 2 encapsuled chambers united by short encapsuled duct; lips and barbels covered with unculi (Ref. 102608).
Coloration: live specimens: golden brown on back and side of body, venter white; numerous irregular dark brown bars punctuated by bright, luminous orange vertical bars across back and side of body similar to the tiger, Pantera tigris; dark longitudinal stripe on side of body posterior to dorsal fin; pelvic and anal-fin rays hyaline; head with orange crown-like mark between eyes, triangular-shaped bright orange mark on occiput; underside of head uniformly light gray, slightly paler on gular region; numerous minute chromatophores on median incision of lower lip; all barbels bright orange with becoming darker proximally and lighter distally; dark crescent-shaped bar on caudal-fin base; color variation not correlated with size or sex in specimens examined. Freshly preserved specimens in alcohol ranged from light to dark brown, becoming lighter on venter; dorsal portion of head with crown-shaped mark; upper lip and rostral barbels with black pigment of varying density, being lighter distally; black pigment on lower lip usually present and concentrated medially; lateral pattern varying substantially among individuals; side of body usually with dark brown bars reaching ventrally to lower level of pectoral-fin base; most specimens with black stripe with indistinct outline along posterior half of body; no dark pigment on fins (Ref. 102608). |