Tuna – About the Species and Characteristics
Tuna are sea water fish belonging to the family Scombridae, mostly belonging to the genus Thunnus. Tuna are known to be fast swimmers and are capable of swimming up to speeds of 70 kilometers per hour. Tuna is unlike other fish because its muscle tissue ranges from pink to dark red which is owed to their myoglobin levels, which is found to be higher in tuna than in other fish.
The tuna is a streamlined fish, stout in the middle and then tapering to points at both ends. Two closely spaced dorsal fins can be found rising from its back. There are also seven to ten yellow finlets that fun between these fins and the tail. The tuna has a very slender caudal peduncle which has three stabilizing keels on each side. This species’ dorsal side is generally metallic dark blue in color while the underside is silvery or white.
Tuna are considered epipelagic-to-midwater fish, which means they inhabit the upper and middle layers of ocean water. They can be found in oceans all over the world except in polar seas. They roam long distances in an extensive north-south pattern and even the transoceanic migration patters. These fish migrate on a yearly cycle.
Tuna normally travel in small schools which range from six to 40 fish. Their prey depends on what is locally available but their common food is herring, menhaden, hake, cod, bluefish, whiting, mackerel, squid and crustaceans. Their large size owes their lack of or few predators like the billfish, sharks, and toothed whales.