[5] One of the main distinguishing features of the Japanese Jack Mackerel is its bright yellow caudal fin which stands out compared to the rest of the species' coloration.

[6] The caudal fin on the side of jack mackerel is a much more complex structure of about 12 cm with a series of 6 bones, more than 20 soft rays projecting outwards and 6 muscles controlling its movement.

[2][7] Although these are the main population grounds of the Japanese Jack Mackerel, they are also found in southern Japan, the Korean peninsula and in the Pacific Ocean off the coast of southeast Asia, primarily in Taiwan.

[8][9] With the temperature varying between the northern and southern areas of the East China Sea by around 3 – 5 °C, migration between these regions is a highly beneficial strategy for the species, especially during maturation [6].

There are many spawning grounds for the Japanese Jack Mackerel, all of which make use of the Kuroshio and Warm Tsushima Currents to migrate into the Japan or East China seas.

[10][11] The only other intensive spawning ground is the coastal waters of Taiwan, which also uses the Kuroshio current to move into the Eastern China and Japan seas.

[8] Once mature, Japanese Jack Mackerels can be found at depths reaching up to 275 m.[2] The life cycle of the Japanese jack mackerel starts in the late winter and tend to spawn around late April to early July, as water temperatures begin to rise allowing larvae and juveniles to thrive.

[2][15] The species normally hunts in large schools but in the case of individuals residing in reefs, they have been documented accompanying jellyfish for both feeding and protective purposes.

[14] As a mature adult, the Jack Mackerel is hunted by other pelagic species such as tuna, sea lions, sharks, and dolphins.

[14][15] The Japanese jack mackerel is a fish predominantly caught using trawls, purse seines, traps, and on line gear.

[5] Due to the overfishing and exploitation of wild populations of Japanese Jack Mackerel and their major role in ocean ecosystems, annual catching limits have been applied since 1997.

[5] Some traditional Japanese dishes use jack mackerel as a key ingredient; it is commonly prepared as a form of furai (aji-furai あじフライ), salt-grilled (shioyaki-aji 塩焼きあじ), or used raw in sushi or as sashimi.

[citation needed] In the 1960s peak yields of Japanese jack mackerel were caught of around 550,000 tons/year, but before the 1970s this number decreased to around 200,000 tons/year which was an indicator of overfishing.

[5][9] Special conservation efforts have been put in place in key spawning grounds of the jack mackerel including the Uwa Sea and Bungo Channel among the southern islands of Japan.

[5][9] Scad are very popular seawater game fish highly prized especially by fishermen, because they generally put up a good fight when caught with a hook and line.