Adults: 11.8-27.3 cm TL; body wet weigth of a 22.1 cm TL individual, 19.8 g; body proportions, as percentage of TL (based on 112 specimens measuring 11.8-27.3 cm TL): prebranchial length, 14.3-17.6; branchial length, 9.4-12.6; trunk length, 37.5-48.2; tail length, 20.9-31.7; eye length, 2.2-3.5; disc length, 6.5-11.7; trunk myomeres, 59-70. Adult dentition: marginals, 54-67; supraoral lamina, 3, rarely 4 unicuspid teeth, the median one smaller than the lateral ones; infraoral lamina, 5-6 unicuspid teeth; 4 endolaterals on each side; endolateral formula, typically 2-3-3-2; 2 rows of anterials; first row of anterials, 3 unicuspid teeth; exolaterals absent; 1 row of posterials, 14-21 teeth, 2-3 lateralmost on each side bicuspid and the internal ones unicuspid; transverse lingual lamina, 13-20 unicuspid teeth, the median one slightly enlarged; longitudinal lingual laminae parentheses-shaped and each with 17-27 unicuspid teeth. Velar tentacles in adults, 11-15 with wings. Adult body coloration (preserved), uniformly dark, almost black; lateral line neuromasts darkly pigmented; extent of caudal fin pigmentation, 75% or more; caudal fin shape, spade-like; oral fimbriae, 117; oral papillae, 17.