PrimoryeSea
Pink or humpbacked salmon, Oncorchynchus gorbuscha
Pink or humpbacked salmon        Smallest representative of   Pacific salmons. Passing species. Enters Primorye rivers all over the coastline from Peter the Great Bay to the northernmost areas, where its more numerous range in the northern Pacific is as wide as that of the keta, from the shores of Korea on the coast of Asia to the coast of California in North America. In RussiaТs polar region, is widespread till River Lena.
   Its body is well proportioned and covered with little scales. The sides and abdomen are in the sea, and when the gorbuscha enters rivers they are of silvery color; the back is dark. The sideline is distinguishable well. The tail fin has large and small dark spots, and the back small spots. After entering rivers and staying in fresh water, the gorbuscha acquires a wedding attire: its body flattens and becomes brown, the head and fins become black, and the jaws warp to develop big teeth. A hump grows on the backs of males; hence the name of the species. The scale caves into the skin to fuse with it. The body shape becomes ugly, not resembling the one at sea.
   Normally, gorbuschaТs maximum length does not exceed 68 cm, and its mass 3 kg, though cases are known of some specimens being as long as 76 cm and weighing from 5 to 7 kg having been landed. The sizes of gorbuscha caught at approaches to the coasts of Primorye vary widely from 30 to 66 cm; however, specimens whose size ranges from 42 to 59 cm and weighing from 1.2 to 2.3 kg prevail. The males are as a rule larger than the females. Gorbuscha is a rapidly growing species that matures in its second year.
   The Primorye gorbuscha school spends its sea life period in the southern and southwestern areas of Japan Sea. There they intensely feed on large plankton crustaceans, squids, and anchovy to start their northward spawning migration to the rivers of Primorye and Sakhalin in April. By the end of May, gorbuscha reaches the latitudes of northern Primorye, and in June migrates to the coastal waters, to pre-estuary spaces of spawning rivers. In Primorye, rivers start running in June to continue to run till the end of August.
   Gorbuscha spawn chiefly along river main beds and partly along lower reaches of large tributaries.  The lower boundary of spawning grounds passes at 2-3 km from river estuaries, and the upper boundary in relatively large rivers 15-30 km away. As a rule, the spawning grounds are situated on shoals with clear water and on unsilty soil consisting of gravel and pebbles with sand admixture. Spawning begins in August to continue till mid-September.  The female would lay row in one, two or three nests to cover them with pebbles. This results in an oval spawning mound 1.5-3.5 m long and up to 60 cm wide. The soil layer over the roe is 30-35 cm thick. During several days lasting about one week, the females would protect their roe to not allow other species to spawn on the same site, and then, completely weakened, would be carried away by currents to die. After spawning, the males would also die. The embryos would peck from there in 90-120 days after fertilization (approximately in the second half of December) to stay in their nests till spring, feeding on yolk sac reserves. In late April, the larvae would start to emerge into the water to be carried away by the river current.
   After emerging into the sea, the young would for about one month stick to shallows near the seacoa
start to actively feed on small crustaceans. They would then leave for the open waters of Japan Sea to return to their native rivers for reproduction after spending from twelve to eighteen months in the sea. Significantly, the homing instinct in gorbuscha is pronounced less distinctly than in other Pacific salmon. Gorbuscha is the most numerous representative of Pacific salmon, ranking first among them in fish harvests. The Primorye gorbuscha school, unlike those of Sakhalin and Kamchatka, is relatively small and subject, like in other areas, to significant fluctuations from year to year.
  
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