Diagnosis: large, well pronounced supraorbital process present on infraorbital IV, reaching rostral border of eye; fenestra between scapulo-coracoid and cleithrum present; no contact between entopterygoid and quadrate; no pale spot on skull roof; high number of dorsal (118-160) and anal (105-155) fin rays (Ref. 81644). High number of vertebrae (92-105)(Ref. 58516, 81644). Body lateral line system clearly visible as a white dotted line along flank (Ref. 58516).

Description: body extremely elongate, abdominal depth 3.2-7.2% SL (mean 4.4); long dorsal and anal fins, continuous with caudal fin; dorsal fin rays 118-160 (mode 135), anal fin rays 105-155 (mode 120); distance between supraoccipital process and dorsal fin 6.6-13.1% SL (mean 10.2); pectoral fins present, length between 32-57.8% skull length. Pectoral spine only shows serrations on posterior margin; pelvic fins absent in most cases; skull short, 5.8-13.8% SL (mean 8.5); skull width 55.6-90.7% skull length; skull roof (exposed bony part in between bulging jaw muscles) very narrow, 12-31.1% (mean 18.3) skull length; jaw muscles hypertrophied and bulging (generally bulging in larger specimens); eyes bordered by small infraorbital bones, of which postorbital one has a plate-like outgrowth and bears a supraorbital process, reaching rostral border of eye; eyes small, without free orbital rim; upper lip slightly extends beyond lower lip (Ref. 81644).

Coloration: body colour gradually fades from dark brown on dorsal side to whitish brown on ventral side, both sides separated by a white dotted line, representing the lateral line; skin on jaw muscles shows paler brownish colour than surrounding skin of head; alcohol preserved specimens generally paler; no distinct pale region on skull roof; unpaired fins coloured as body, paired fins usually paler (Ref. 81644).