Characterized by having oral disc narrower than head; teeth extremely degenerated; usually 52-59 trunk myomeres; coloration consisting of light tan to silver gray above, yellow or white below; and yellow or gray fins (Ref. 86798). Other adult diagnostic features: 7.5-17.8 cm TL and wet weight 0.9-3.0 g for individuals 8.2-12.0 cm TL. Body proportions, as percentage of TL (based on 166 specimens measuring 7.5-16.5 cm TL): prebranchial length, 6.9-13.0; branchial length, 8.4-12.8; trunk length, 42.8-57.3; tail length, 23.4-35.0; eye length, 0.9-2.1; disc length, 2.8-6.7. Urogenital papilla length, as a percentage of branchial length, in 71 spawning males measuring 10.2-14.6 cm TL, 23.1-60.0. Trunk myomeres, 53-62. Dentition: marginals, 63-67; supraoral lamina, 2 unicuspid teeth; infraoral lamina, 5-13 unicuspid teeth; 3-4 endolaterals on each side; endolateral formula, 2-1-2 with variations, including 1-1-1, 2-3-2 and 2-3-3; 2 rows of
anterials; first row of anterials, 4-5 unicuspid teeth (some teeth may even be found on the anterior field between the supraoral lamina and the first row of anterials); 1-2 rows of exolaterals on each side; 0-1 row of posterials; first row of posterials, when present, may be complete (13% of individuals) or incomplete (87%) with 1-22 unicuspid teeth; transverse lingual lamina, undetermined number of unicuspid teeth, the median one of undetermined size; longitudinal lingual laminae each with an undetermined number of unicuspid teeth. Velar tentacles, 3-5, with tubercles. Body coloration (live) of spawning individuals, dorsal aspect mottled gray-brown and ventral aspect light silvery-yellow. Lateral line neuromast pigmentation unrecorded. Caudal fin pigmentation, darkly pigmented, but the extent of coverage has not been reported. Caudal fin shape, spade-like. Oral fimbriae number unrecorded. Oral papillae, 12-20 (Ref. 89241).