Species: Thunnus atlanticus, Blackfin Tuna

Thunnus atlanticus (Lesson, 1831)

Blackfin Tuna

Body elongate, fusiform, moderately compressed; no fatty eyelid; teeth slender, conical; top of tongue with 2 cartilaginous ridges; 19-25 gill rakers; 2 dorsal fins, barely separated, XIII + 14-15, first with prolonged spines anteriorly, giving a strongly concave upper profile; 2nd dorsal and anal fins not greatly elongated; 7-9 finlets after dorsal fin, 6-8 behind anal fin; pectoral fins moderately long, reaches under front of 2nd dorsal, usually 22-31% of fork length, tip straight; a short, forked bony process between pelvic fins;1 large + 2 small keels on tail base; tail fin deeply forked; indistinct corselet of larger scales on front of body, small scales cover body behind corselet; lateral line complete.

Back metallic dark blue, becoming silver on sides and belly; second dorsal and anal fins and finlets dusky with silvery cast.

Size: reaches 120 cm; 23 kg.

Habitat: oceanic pelagic.

Depth: 0-200 m.

Massachusetts to southern Brazil.