Dogtooth tuna - Gymnosarda unicolor
Dogtooth tuna, Gymnosarda unicolor, also known as white tuna, is a species of pelagic marine fish which belongs to the family Scombridae. The dogtooth tuna can reach a length of 190 to 248 centimetres (75 to 98 in) in males and a weight of 130 kilograms (287 lb). The average length commonly observed is around 40 to 120 centimetres (16 to 47 in). They have 12 to 14 dorsal soft rays and 12 to 13 anal soft rays.
The lateral line undulates strongly. These large tunas have a streamlined shape and a distinctive body coloration: brilliant blue green on the back, silvery on the side, and whitish on the belly, with two white tips on the two back fins close to the caudal peduncle. They always swim with open jaws. tonno dente di cane
The upper jaw of the large mouth reaches the eye. The dogtooth tuna is widespread throughout the tropical waters of the Indo-Pacific area from the eastern coast of Africa, Red Sea and Maldives included, to French Polynesia and oceanic islands of the Pacific Ocean, north to Japan, south to Australia. These offshore fishes can be found mainly in reef environments with smaller fish being more commonly found near shallow reef areas and larger ones haunting deep reef drop off areas, seamounts and steep underwater walls. Usually they are solitary or occur in small schools, to a depth of 10 to 300 metres (33 to 984 ft).
The dogtooth tuna is one of the apex non-pelagic predators in its environment, sharing that position with giant trevally, Napoleon wrasse, and large groupers, as well as reef, bull and tiger sharks. These aggressive opportunistic predators feed on small schooling fishes and squids, and are capable of taking a wide variety of prey items. In most areas, the mainstay of its diet probably consists of pelagic schooling fish found near reef habitat.
Preliminary estimates of longevity indicate a maximum observed age of at least 20 years. The dogtooth tuna is appreciated in most of its range as a fine food fish and also as a game fish sought by both rod and reel anglers and spearfishermen.
Dogtooth tuna used to be mostly taken as an incidental catch by anglers trolling for other gamefish – with natural baits for black marlin, for instance, or with lures for wahoo and Spanish (narrowbarred) mackerel. In the last 10 to 15 years there has been more dedicated effort directed at this species because of its rarity and sporting qualities.
(extract from Wikipedia)
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