The Yellowfin Tuna (Thunnus albacares) is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.
Although mainly found in deep offshore waters, yellowfin tuna may approach shore when suitable conditions exist. Mid-ocean islands such as the Hawaiian archipelago, other island groups in the Western Pacific, Caribbean, and Maldives islands Indian Ocean, as well as the volcanic islands of the Atlantic such as Ascension Island and Saint Helena, often harbor yellowfin feeding on the baitfish these spots concentrate close to the shoreline. Yellowfin may venture well inshore of the continental shelf when water temperature and clarity are suitable and food is abundant.
Yellowfin tuna often travel in schools with similarly sized companions. They sometimes school with other tuna species and mixed schools of small yellowfin, and skipjack tuna, in particular, are commonplace. They are often associated with various species of dolphins or porpoises, as well as with larger marine creatures such as whales and whale sharks. They also associate with drifting flotsam such as logs and pallets, and sonic tagging indicates some follow moving vessels. Hawaiian yellowfins associate with anchored fish aggregation devices and with certain sections of the 50-fathom curve.
Yellowfin tuna prey include other fish, pelagic crustaceans, and squid. Like all tunas, their body shape is particularly adapted for speed, enabling them to pursue and capture fast-moving baitfish such as flying fish, sauries, and mackerel. Schooling species such as myctophids or lanternfish and similar pelagic driftfish, anchovies, and sardines are frequently taken. Large yellowfins prey on smaller members of the tuna family such as frigate mackerel and skipjack tuna.
In turn, yellowfin are preyed upon when young by other pelagic hunters, including larger tuna, seabirds, and predatory fishes such as wahoo, shark, and billfish. Adults are threatened only by the largest and fastest hunters, such as toothed whales, pelagic sharks such as the mako and great white, and billfish like the Atlantic blue marlin and swordfish
But tuna are great at disguising themselves in the ocean. The tuna uses their secret camouflage to blend in with their surrounding and avoid potential predators. From above, the tuna's blue back blends in with the ocean floor. From below, it's silvery-white belly looks like the sunlight water above. But if they need to make a quick getaway the tuna can swim at speeds of about 13-18 miles per hour.