Tuna is expensive, tuna costs around $200-600 per pound, and cod is in the $60-100 range. Tuna is expensive for the following reasons:

Bluefin tuna, one of the mackerel family of the suborder Scombroid of the order Perciformes of the order Orthopoda, is distributed in the tropical to temperate waters of the world's oceans and seas, inhabiting the depth of 50-2473 meters, the body length of up to 225 centimeters, for the migratory fish of oceanic nature, moving in flocks, is a carnivore, to fish It is a carnivorous fish that feeds on fish, cephalopods and crustaceans, and can be used as food fish, swimming fish and farmed fish.

The three bluefin tuna species, the southern, Atlantic and Pacific bluefin tuna, are all in danger of extinction due to overfishing because of their high commercial value, with the southern bluefin tuna and Atlantic bluefin tuna on the verge of extinction.

Also the bigeye tuna is a vulnerable species, and the yellowfin and albacore tuna are close to the endangered extinction level, and will all face extinction if protection measures are not adequate. In terms of other species, the blue and white marlin are also assessed as endangered, with the potential for global extinction.

The nutritional value of tuna is as follows:

1. Tuna is rich in protein, fat, vitamin D, and high in minerals such as calcium, phosphorus and iron.

2, the back of the tuna fish contains a large number of EPA, before the middle abdomen is rich in DHA. the proportion of DHA contained in this fish for the fish in the crown, is an excellent brain food.

3, tuna contains a large number of myoglobin and cytochrome, fatty acids, mostly unsaturated fatty acids.