The yellowfin tuna (Thunnus albacares) is a fish built for speed and endurance. Its streamlined body is metallic dark blue on the back, blending into yellow or silver on the belly. The belly is patterned with numerous broken lines, and a vivid golden stripe runs along each side of the body, from the eye to the tail. The yellowfin tuna has two dorsal fins, the second one of which can be very long and is situated directly over the long anal fin. The pectoral fins, those found on each side of the body, are also long, often reaching beyond the space between the two dorsal fins. The fins can be retracted so that water flows even more smoothly over its body when swimming. Tiny fins (or finlets), run down the top and bottom side of the body, from the second dorsal fin and the anal fin to the tail. These finlets, along with the dorsal and anal fins, are bright yellow, giving this fish its common name. The finlets are bordered by a narrow black band.