Lepidocephalichthys alkaia is distinguished from all other Lepidocephalichthys by a midlateral dark stripe on caudal fin, extending from base to terminus of fin, usually spanning rays 7–10. It is further distinguished from all Lepidocephalichthys by the combination of a truncated or rounded caudal fin; scales absent on top of head; usually dark stripe, sometimes dark spots on side; dorsal-fin origin just posterior to pelvic-fin origin; 8–10 predorsal, 8–10 postdorsal, dark bars on dorsum; moderate size (to 38 mm SL) (Ref. 83671).