| ການວິນິໄສ |
Diagnosis: caudal peduncle 2.9-3.2 times in SL, very slender, length 12.4-16.9 times depth (Ref. 81646).
Description: body firm, slender, depressed anteriorly, strongly tapered to caudal base; bony ridge behind dorsal fin to adipose fin, thin mid-dorsal, mid-ventral and bi-latero-ventral bony ridges along caudal peduncle; head slender and pointed, 5.4-6.2 times in SL, flat below, smooth and rounded above; snout long, 66% HL; nostrils in mid-snout, slightly nearer to eyes than to anterior tip; mouth small, oval-shaped, subterminal lips above fleshy, papillose, lower lips divided by firm triangular pad; barbels short, thick and papillose, maxillaries longest not reaching below orbits; eyes small, on posterior third of head, widely separated (interorbital width 1.7-2.4 times orbit diameter), orbits bony above; supraoccipital process slender, about half length of snout, nearly reaching nuchal shield; humeral process short, obscured; branchiostegal membrane united, straight or slightly concave edge, covered with radiating unculi; predorsal length 1/3 of SL; caudal peduncle long (length 2.9-3.6 times in SL), slender (length 9.3-16.9 times depth), depressed; fins large, pointed and falcate; origin of dorsal less than head length behind head; dorsal fin pointed, leading ray slender and stiff, hind edge straight to shallow concave in larger adults; pectorals large, falcate, not reaching base of pelvics, leading ray curved, pectinate, padded, outer rays lie horizontal, inner rays inclined dorsally; pelvics falcate, reaching beyond origin of anal fin base, leading ray curved, pectinate and padded; anal fin with straight hind edge, not reaching base of caudal; caudal with compact base, deeply forked with pointed lobes, ventral lobe longer; adipose short, triangular, over posterior anal base; ano-genital openings placed about mid-way between pelvic and anal fin base; males with short conical genital papilla (Ref. 81646).
Coloration: countershaded, dark grey to black or brown above, light creamy brown below from snout to anal fin, some sooty pigment to caudal; boundary between dorsal and ventral sections sharply demarcated along body below lateral line, dark patches above pelvic bases, 3-6 light patches or saddles on dorsal surface from behind head to caudal, head above dark grey, black or brown with light brown patches over gill covers and behind eyes; dark pre-orbital stripes sometimes evident; fins with grey-black rays, paired fins grey-black above with light medial section, outer rays of caudal dark grey-black (Ref. 81646). |
