Yellowfin Tuna are a member of the family Scombridae. These heavy-bodied fish are recognised by their bright yellow dorsal and anal fins and finlets. They have a dark blue back and a vivid broad golden yellow stripe that runs from eye to tail. They also have moderately long pectoral fins. Adult Yellowfin are opportunistic carnivores that feed on Squid, Skipjack Tuna, smaller Yellowfin Tuna, Mackerel, Pilchards and Pelagic Crabs.
Yellowfin Tuna reach a maximum length of 2.1 m and weigh 175 kg. Yellowfin Tuna caught off eastern Australia rarely exceed 190 cm in length and 100 kg in weight.
Yellowfin Tuna, also known as Yellowfin or Allison Tuna, are oceanic fish found in Australian waters from Torres Strait to eastern Tasmania and from the Northern Territory to south-western Australia. They may also be found in the brackish waters of estuaries. Sea surface temperature, salinity and dissolved oxygen concentration limit the distribution of Yellowfin Tuna. Yellowfin Tuna weighing less than 15 kg regularly form surface schools of similar sized fish of the same species or sometimes with other tuna species such as skipjack tuna (Katsuwonus pelamis). In waters off south-eastern Australia, adult Yellowfin Tuna tend to be more solitary. Yellowfin Tuna weighing more than 15 kg inhabit deeper waters above the thermocline, the boundary separating warmer surface waters and deep colder waters, and tend not to school.
Yellowfin Tuna that have a fork length less than 75 cm can be difficult to distinguish from small Bigeye Tuna (Thunnus obesus).
Yellowfin Tuna are fished in near-coastal and offshore regions of NSW and can be caught by trolling lures or fishing live or dead baits at anchor or on the drift. Pilchards, small Skipjack Tuna and Mackerel are common baits used by anglers. These tuna can also be caught from drifting boats using dead or live bait such as redfish or nannygai along with berley.