Those species that are the main subject of fishing effort in a fishery. The tropical‑tuna fisheries, depending on their fishing strategy, target skipjack, yellowfin and/or bigeye tuna; while the fisheries that cover temperate waters also target bluefin and albacore species. Considerations such as size also matter since tunas that are undesirably small for processing are also sometimes called bycatch.
See also ALB, BET, BFT, SKJ, YFT.