Naked Tuna

Q: I heard there is a tuna that has no scales. What kind of tuna is it and where is it found? - Jason Andrews, Hackensack, New Jersey

A: The dogtooth tuna (Gymnosarda unicolor) is also known as the "scaleless tuna" because its body is naked from the pelvic fins back to the tail, except for scales on its curvy lateral line. The dogtooth's back and upper sides are a brilliant blue-black; the lower sides and belly are silvery. It has no spots, stripes or other markings but is characterized by its long, slender shape and, unusual for a tuna, prominent, sharp teeth.
The dogtooth tuna is found in tropical waters of the Indo-Pacific from the Red Sea and east Africa to Japan, Australia and the islands of the Marquesas, Tahiti and Pitcairn. A solitary tuna that preys on small schooling fishes, mainly around coral reefs, it grows to about 300 pounds.