近縁種のN. sclerorhynchusでは,鱗上の小棘が針状で腹鰭は9軟条と多い(Marshall and Iwamoto, 1973)。 (荒井)
Distinctive characters:
(Family): Urogenital opening immediately behind anus. Usually two dorsal fins. Scales usually armed with spinules. (Genus): Anus situated midway between pelvic bases and origin of anal fin or slightly anterior. A small black dermal window of light organ between pelvic bases. Second spinous ray of 1st dorsal fin serrated. Gill rakers on 1st arch less than 12. No dark band along anterolateral margin of snout. (Species): Pelvic fin rays 7. Terminal snout scutes small (see Fig.). Suborbital ridge developed. Gill rakers on inner side of 2nd arch 8〜10. Underside of snout, gular part, and branchiostegal membrane naked. Spinules on body scale flattened, relatively broad. Upper jaw 28.7〜30.7%, interorbital 18.4〜23.3%, barbel 11.9〜16.1% of HL, respectively.
Distribution:
Middle western Atlantic.
Remarks:
The species resembles N. sclerorhynchus, but the latter has needle-like spinules on scales and 9 pelvic fin rays (Marshall and Iwamoto, 1973). (Arai)