Japanese mackerel
Scomber japonicus
Japanese mackerel   This fish belongs to the group of quick and strong swimmers in pelagic zones of seas and oceans. Its streamlined body, thin, carrying powerful fin, caudal stalk with two keels and additional fins behind the dorsal and anal fins, and well-developed musculature allow the mackerel to develop high speed to maintain it for a long time. During migrations, the Japanese mackerel covers from 25 to 30 km in one day. It lives preferentially in subtropical waters, but every year when the water warms up in summer it appears in large numbers in Peter the Great by in fall to rapidly depart to the south.
    The mackerel is maximally 60 cm long at weight of 1.5 kg. In the waters of Peter the Great Bay, the mackerel spawns only when its population is high in warm years from June to August. Spawns roe at water temperatures ranging from +12 to +20oC, usually in the evening and at nighttime. Fertility fluctuates from 350 thousand to 2.5 million roes. Fertilized roe would float to the surface. The mackerel is a major commercial species, and judging by its bones found in numerous shell heaps, it was also successfully landed in Primorye in the remote past.