Specimens examined:13 (HL 55〜65 mm, TL 296+〜330+ mm).
Counts:BR 7; D (1st) U, 9〜11; P1 21〜24; P2 9 (rarely 8 or 10); GR (inner row on 1st arch) 1〜2+7〜9.
近縁種のN.suilla, N. bairdii, N. aequalisでは吻端の2個の変形鱗は肥大しない。 (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 9 (rarely 8 or 10). Two large scutes present at snout tip (see Fig.). Suborbital ridge developed. Underside of snout scaly (see Fig); gular part and branchiostegal membrane naked. Upper jaw 24.0〜27.4%, interorbital 17.6〜22.1%, barbel 5.5〜9.1% of HL, respectively.
Distribution:
Middle western Atlantic.
Remarks:
N. suilla, N.bairdii, and N. aequalis lack enlarged scutes at snout tip. (Arai)