Diagnosis: dorsal and anal fins always confluent with caudal fin (Ref. 57129, 81644). Body very elongate, maximum body depth 14-15% standard length (Ref. 57129), abdominal depth 4.5-8% SL (mean 6) (Ref. 81644). Head very short, 12.5-14.3% standard length; lateral cephalic bones separated from each other by a distinct gap (Ref. 57129). Distance between supraoccipital process and dorsal fin short, 5-14% SL; pectoral fins present, 30-56% skull length, supported by a short spine (about half of fin length); pelvic fins always present and short; skull short, 11-18% SL (mean 13), with a very narrow roof, 9-23% (mean 14) head length, partially covered by jaw muscles; these muscles almost completely exposed dorsally and laterally and frequently bulging (especially in larger specimens); supraoccipital process short and narrow, 10-20% (mean 16) head length; eyes very small (4-9%), bordered by small infraorbital bones (hard to observe externally); barbels long, maxillary longest (86-155% skull

length); maxillary barbel connected at base to large skin folds that border mouth opening; when mouth is closed, these skin flaps are folded and conspicuous in dorsal view; internal mandibular barbel shortest, 58-99% (mean 76) head length (Ref. 81644).

Coloration: in life: uniformly light brown (Ref. 81644). Preserved specimens: brownish-black on back and sides, light brown on belly (Ref. 57129). Ventral prepelvic region slightly paler than rest of body (Ref. 81644).