North Pacific daggertooth
soft rays: 14 - 17;
Vertebrae: 78 - 80. Dark brownish, silvery ventrally; paired fins and caudal fin uniformly black. Body extremely elongate. Large adults with a pair of dermal keels midlaterally on each side. Small, flexible projection at tip of lower jaw. Gill membranes joined forward, below anterior edge of eye, and free from isthmus. No rayed dorsal fin. No scales (Ref. 43939). In adults, head depth 29-33% of lower jaw length. Postorbital area 8.1-9.7% SL or 34.4-38.8% (less than 3 times smaller than HL). Rear edge of gill cover overlaps with the vertical of the 5th vertebrae. Postadipose distance 7-8% SL (Ref. 31260).