Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not the Mediterranean Sea. Longer-lived than the closely related yellowfin tuna, the bigeye has a lifespan of up to 12 years.
U.S. landings of Atlantic bigeye tuna have historically represented a small fraction (1% or less) of total Atlantic bigeye landings as this species is heavily targeted by other nations. Nonetheless, in the past few years, Atlantic bigeye tuna abundance has increased to sustainable levels. This species is attractive to our longliners as prices are high for top grades of bigeye tuna.
•Geographic range: In the Atlantic Ocean between 50°N and 45°S, but not in the Mediterranean Sea. In the western Atlantic, they can be found from Nova Scotia to Argentina, including the Caribbean and the Gulf of Mexico. Bigeye tuna is also found in the Pacific and Indian Oceans.
•Habitat: Bigeye tuna are a pelagic species – they are found from the surface to about 800 feet deep. They swim at deeper depths than other tropical tuna species, especially during the daytime. Larvae are found in tropical waters. The Gulf of Guinea, off the west coast of Africa, is a major nursery ground for Atlantic bigeye. As juvenile fish grow larger, they tend to move into temperate waters.
•Life span: Around 9 years
•Food: Fish, mollusks, and crustaceans
•Growth rate: Relatively fast.
•Maximum size: Ranges in length from 1.5 to 5.5 feet. Bigeye over 6.5 feet are rare.
•Reaches reproductive maturity: At about 3 ½ years old
•Reproduction: Bigeye spawn at least twice a year. Females can have from 2.9 million to more than 6 million eggs.
•Spawning season: Throughout the year when the environment is favorable, peaking in summer months.
•Spawning grounds: In tropical waters
•Migrations: Bigeye tuna are highly migratory. Young bigeye tuna form schools mostly mixed with other tunas such
as yellowfin and skipjack, especially in warm waters. These schools are often associated with drifting objects, whale
sharks, and sea mounts. Predators: Mainly large billfish and toothed whales.
•Commercial or recreational interest: Both
•Distinguishing characteristics: Bigeye tuna is dark metallic blue on the back and upper sides with white lower sides
and belly. The first dorsal fin is deep yellow, the second dorsal and anal find are brownish or yellowish with narrow black edges, and the finlets are bright yellow with broad black edges. Their bodies are stocky and robust, and adults' eyes are large.