Genus: Nesiarchus, Gemfish, Gemfish Snake Mackerel
body depth ~10% SL
tip both jaws: conical skin knob
tip both jaws: conical skin knob
D XIX-XXI + II
1 LL
pelvics I, 5, < pectorals
D & A: 2 rear finlets
skin smooth
NESIARCHUS
GEMFISH
Body fairly elongate, slender, compressed, depth 8-10% SL; head ~23% SL; operculum with 2 flat spines; lower jaw strong projecting; a large conical skin knob at tip of both jaws; top jaws with 0-3 pairs of fangs at front, lower jaws I pair; dorsal fin low, XIX-XXI (long-based) + II, 19-24 (short based); anal fin a little shorter than 2nd dorsal, II, 18-21; dorsal and anal fins with 2 finlets behind each in adults; pectorals short, 12-14; pelvics tiny, shorter than pectorals, I, 5: lateral line single, slopes down gradually to mid-side.
A genus with one, worldwide, temperate to tropical species.
