Synonym/common names:
Big Eye, Big Eye Tuna, Big Eye Tunny, Big-Eye Tuna, Big-Eye Tunny, Bigeye, Bigeye Tuna, Bigeye Tuna Fish, Bigeye Tunny, Bigeye-Tuna, Bigeyed Tuna, Coffrey, Tuna.
Names in different languages:
Netherlands: Grootoogtonijn, Spain: Patudo, Italy: Tonno obeso, Denmark: Storøjet tun, Germany: Grossaugenthun, Portugal: Atum patudo, France: Thon obése, Japan: Mebachi, Indonesia: Tuna mata besar, Papua New Guinea: Matana Bwabwatana, China: 大目仔, Philippines: Bangkulis.
Habitat:
The Bigeye tuna appears in areas where seawater temperatures range from 13°-29°C, but the optimum temperature is between 17° and 22°C. The variation in occurrence of Bigeye tuna is closely related to seasonal and climatic changes in surface temperature and the thermocline.
Juveniles and small adults of Bigeye tuna school at the surface in groups of their own or mixed with other tunas, the adults on the other hand stay in deeper waters.
Distinctive Features:
The Bigeye tuna is also one of the larger species, the body is at its deepest near the middle of first dorsal fin base. The first arch consists of 23 to 31 gill rakers. The pectoral fins are very long in smaller individuals, but moderately long (22 to 31% of fork length) in large individuals (over 110 cm fork length).
Coloration:
Bigeye tunas are dark metallic blue on the back and upper sides and white on the lower sides and belly. The first dorsal fin is deep yellow, second and anal fins are light yellow. The finlets are bright yellow and edged with black. The pectoral fin exceeds the edge of the second dorsal fin.
Size, Age, and Growth:
The Bigeye is a fast growing tuna and can reach about 198 cm. They live 7 to 8 years and are able to reproduce when they’re 3 years old. They feed near the top of the food chain, preying on fish, crustaceans, and squid. They’re also prey for many top predators including larger tunas and billfish.
Reproduction:
At the age of maturity (about 3-4 years and weight 25 kg) are known to spawn in the Gulf of Mexico and in the Mediterranean Sea. In the Pacific Ocean, spawning occurs northeast of the Philippines. Female Bigeye tuna can be weighing between 270 to 300 kg and may produce as many as 10 million eggs per spawning season. Bigeye tuna has an annual batch fecundity of 4 to 60 million eggs.
Conservation:
WCPO, IO, AO they are all in an healthy condition, below MSY (Maximum sustainable yield), except Eastern Pacific Ocean’s Bigeye is in an overfished condition. The stock in WCPO has been subjected to overfishing for over one decade, but hasn’t become overfished because to the higher-than-average levels changes in recent years. The International Union for the Conservation of Nature and Natural Resources (IUCN) listed 2011 the Bigeye as vulnerable in their “red list”.
For comments and to add additional information, please email to: support@atuna.com