These pelagic and neritic fish live in tropical and subtropical waters of all oceans, between 61 ° C. w. and 51 ° s w. [3] In the Atlantic Ocean are quite rare. [4] The water temperature in the habitat is about 28 ° C [3] . Off the coast of Russia in the warm season they go into the Gulf of Peter the Great. Form large jambs [5] . They are found at a depth of up to 200 m [4] . The Auxis thazard thazard subspecies is widespread in the tropical and subtropical waters of all oceans, and the Auxis thazard brachydorax subspecies lives in the eastern Pacific Ocean [4] .
Antique engraving of mackerel tuna (1884)
The maximum fish size is 65 cm. The maximum recorded mass of captured fish is 1.7 kg [4] . In mackerel tuna, a spindle-shaped dense body, rounded across. The teeth are small, conical. There are 2 dorsal fins. In the first dorsal fin, 10-12 spiny and 10-13 soft rays [3] . Behind the second dorsal and anal fins lies a series of 7–9 small additional fins. The pectoral fins are short, but they reach an imaginary vertical line drawn along the edge of the devoid of scale area behind the carapace in front of the body [6] . In the anal fin there are 10-14 soft rays [3] . On both sides of the caudal peduncle lies a long medial keel and 2 small keels on its sides closer to the caudal fin. The ventral surface of the body behind the well-developed shell in the front part, formed by large scales, is devoid of scales. In the part of the corset that runs along the lateral line in the region of the second dorsal fin, there are only about 5 rows of scales. The swim bladder is absent. The number of vertebrae is 39, of which 19 are in the caudal region of the spine. The back is bluish, which turns into dark purple and almost black on the head. Behind the first dorsal fin, the back is covered by 15 narrow dark, wavy, oblique or almost horizontal stripes [5] . The underside of the body and belly are white without spots and stripes. The ventral and pectoral fins are purple, the outer edge is black [6] .
Mackerel tuna lead a flock of life in the surface layers and often jump out of the water [7] . Often found together with striped tuna and form schools with large mackerel [5] .
Propagate by spawning. The breeding season depends on the area of habitat. In the eastern part of the Pacific Ocean, mature individuals are found all year round. Off the coast of Costa Rica, spawning takes place with the greatest intensity from December to April, and in Japan the peak occurs in July. In the southern Indian Ocean, the breeding season lasts from August to April, to the north of the equator from January to April. The maximum fecundity is estimated at 1.37 million eggs per year, and in the Indian Ocean varies between 200 thousand and 1.06 million eggs for spawning, depending on the size of the female [6] . In the waters of Thailand, female mackerel tuna reaches puberty with a length of 31–33 cm. Life expectancy is estimated at 4 years. In the equatorial Atlantic, one-year-old fish have an average length of 22.9 cm, two-year-olds - 30.4 cm, three-year-olds - 36.7 cm, and four-year-olds - 40.4 cm [4] .
The diet mainly consists of large planktonic crustaceans and small fish [5] . Cannibalism is common. Large tuna, marlin , barracuda and sharks prey on mackerel tuna. These fish, due to their large number and wide distribution, are an important component of the trophic chain [6] .
It is the subject of commercial fishing [8] . Mackerel tuna are hunted with hook fishing gear, gill nets and purse seines . These fish serve as raw materials for the production of canned food [6] . These fish are caught as by- catch during the fishing for yellowfin tuna and skipjack using purse seines. The International Union for Conservation of Nature has rated the conservation status of the species as “Least Concerned” [4] .
World catches of mackerel tuna| Year | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 |
| Catch, thousand tons | 17.74 | 89.85 | 83.88 | 93.86 | 81.35 | 99.8 | 82.5 | 81.33 | 89.08 | 122.53 |
