Yellowfin tuna (Thunnus albacares)
Yellowfin tuna is among the larger tuna species, reaching lengths of two meters, although the common size ranges 40–170 cm. It is an open‑water and oceanic species found worldwide in the tropical and subtropical waters of the Pacific, Atlantic, and Indian Oceans, between 40°N and 40°S, but mainly concentrated between 20°N and 20°S. This species forms both free and associated schools of similarly sized individuals, either in mono‑ or multi‑species groups. The free‑swimming schools tend to contain large individuals and are mono‑specific. Although not common elsewhere, in the Eastern Pacific, schools are often associated with dolphin pods. As for juveniles, they can form schools with skipjack and juvenile bigeye tuna in shallow waters. Schools may also occur in association with floating objects.