This species is distinguished by the following set of characters: dorsal- and anal-fin are rays not covered with black fleshy skin; no pectoral fins; pelvic fins inserted closer to the caudal-fin base; IV photophores 38-39; IP photophores begin halfway posteriorly on the isthmus; within the subgenus, it differs from P. achirus, P. caerulescens, P. coffea, and P. corynodes by the length of the gill-filament on first branchial arch which is reduced (vs. normal or very long); differs from P. phyllopogon by the number of dorsal-fin rays 13-15 (vs. 20-23) and IV photophores 38-39 (vs. 30-31); differs from P. mirabilis by lacking the blue luminous tissue (vs. present) and barbel with elongate stem and whiplike filament (vs. short stem and bifid filament) (Ref. 87305).