Yellowfin tuna

Dorsal spines (total): 11-14; Dorsal soft rays (total): 12-16; Anal spines: 0; Anal soft rays: 11-16; Vertebrae: 39. This large species is distinguished by the following characters: elongate, fusiform body, slightly compressed laterally; total gill rakers on first gill arch 26-34; dorsal fins 2 and separated only by a narrow interspace, the second followed by 8-10 finlets; anal fin followed by 7 to 10 finlets; large specimens may have very long second dorsal and anal fins, becoming well over 20% of fork length; pectoral fins moderately long, usually reaching beyond second dorsal-fin origin but not beyond end of its base, usually 22-31% of FL; 2 flaps (interpelvic process) between pelvic fins; body with very small scales; corselet of larger scales developed but not very distinct; caudal peduncle very slender, bearing on each side a strong lateral keel between 2 smaller keels; no striations on ventral surface of liver; swimbladder present. Colour of back metallic dark blue changing through yellow to silver on belly; belly frequently crossed by about 20 broken, nearly vertical lines; dorsal and anal fins, and dorsal and anal finlets bright yellow, the finlets with a narrow black border (Ref. 9684).