Thunnus alalunga

Common Name


Year Described

Bonnaterre, 1788


Dorsal Fin: XI-XIV, 12-16, followed by 7-9 finlets
Anal Fin: 11-16, followed by 7-8 finlets
Pectoral Fin: 30-36
Gill Rakers: 25-31 (on first arch)
Vertebrae: 39

Body fusiform, robust, and oval in cross-section. Snout about twice eye diameter. Adipose eyelid absent. Jaw extends to anterior half of orbit. Teeth small and conical. Two interpelvic processes; shorter than pelvic fins. Dorsal fins separated by a very small gap. Spiny dorsal fin long, with a strongly concave margin. Second dorsal and anal fin small with tall anterior lobes. Pectoral fins extremely long (reaching well beyond second dorsal fin). Caudal fin semilunate. Corselet not obvious but present. Body covered in small scales. Two small caudal keels with a larger median keel in between them. Liver striated.


Body white with an abruptly dark blue back. Often with a blue sheen on the dorsum and yellowish sheens ventrally. Upper fins and tail usually dusky to yellowish. Lower fins pale to yellowish. Caudal fin with white posterior border.


Maximum size to 130cm FL. Common to 90cm FL.


Epipelagic and mesopelagic in oceanic waters. Forms large schools.


Nova Scotia to Argentina, but rare or absent in the Gulf of Mexico.


Collette, B.B. 2002. Scombridae (pp 1836-1857). In: Carpenter. 2002. The living marine resources of the Western Central Atlantic. Vol. 3: Bony fishes part 2 (Opistognathidae to Molidae), sea turtles and sea mammals. FAO Species Identification Guides for Fisheries Purposes. American Society of Ichthyologists and Herpetologists Special Publication No. 5.

McEachran, J.D. and J.D. Fechhelm. 2005. Fishes of the Gulf of Mexico. Volume 2: Scorpaeniformes to Tetraodontiformes. University of Texas Press, Austin. i-viii +1-1004.