Blackfin tuna

Thunnus atlanticus

Family Scombridae - tunas

Body elongate, robust; snout pointed; color dark blue or black on back, lower sides and belly silvery to white, head silvery; 2 dorsal fins, 2nd dorsal fin and anal fin long, falcate (sickle-shaped); 7-9 finlets behind 2nd dorsal fin and anal fin; 2nd dorsal fin and finlets dusky sometimes with slight yellow color; pectoral fin moderately long, nearly reaching 2nd dorsal fin; 2 separated flaps (interpelvic process) in between the pelvic fins; caudal peduncle narrow with 2 well-developed lateral keels; a pair of smaller keels at base of tail.
Similar Species
The yellowfin and bigeye tunas have bright yellow finlets. The albacore tuna has a very long pectoral fin that reaches past the base of the 2nd dorsal fin. The bluefin tuna has a short pectoral fin, reaching only to middle of 1st dorsal fin. Also, its 2nd dorsal fin is reddish brown.
Gulf, open waters
Maximum Size
108 cm (3 1/2 ft) fork length, common to 72 cm (28 1/2 in) fork length
Fin Element Counts
D. XIII-XIV+12-15+7-9 finlets; A. II,11-15+7-9 finlets (explain)
Other Common Names
Previous Scientific Names
State size/bag limits