Canned Bigeye Tuna Chunk in Oil

Clean and sanitary processing environment

Tuna, (genus Thunnus), also called tunny, any of seven species of oceanic fishes, some very large, that constitute the genus Thunnus and are of great commercial value as food. They are related to mackerels and are placed with them in the family Scombridae (order Perciformes). Tunas vary considerably, both within and among species.

Tunas are elongated, robust, and streamlined fishes; they have a rounded body that tapers to a slender tail base and a forked or crescent-shaped tail. In colour, tunas are generally dark above and silvery below, often with an iridescent shine. They have a conspicuous keel on either side of the tail base, a row of small finlets behind dorsal and anal fins, and a corselet of enlarged scales in the shoulder region. Another notable feature is a well-developed network of blood vessels below the skin that acts as a temperature-regulating device associated with long-term, slow swimming. Because of this vascular system, tunas are unique among fishes in their ability to maintain the temperature of their bodies above that of the surrounding water, often between 5 and 12 °C (9 and 21.7 °F) above ambient water temperature. Some muscles may even be up to 21 °C (almost 39 °F) higher than the surrounding water.