Chum salmon

Chum salmon (Oncorhynchus keta )

The chum salmon (Oncorhynchus keta; Russian Кета ​​/ Keta, of which the scientific name was derived; english Chum salmon; German and dog salmon ) is a kind of living in Pacific salmon.

Features

The chum salmon can be up to 100 inches long and can weigh over 15 kilograms. In the sea it has a silvery blue-green color and unlike other Pacific salmon species less or no points; large specimens are steel- blue on the back. In fresh water, the males have a dunkelolivgrünen to black back, reddish gray sides with vertical green stripes and a dark gray belly. The females are similarly colored, but with undeutlicherer drawing.

The undivided dorsal fin has 10 to 14, the anal fin 13 to 17 soft fin rays. There are 12 to 15 rakers on the first gill arches.

Dissemination

The chum salmon is found on the American coast of the Pacific Ocean from Alaska to Oregon, to a lesser extent along the California coast as far as San Diego, on the Asiatic coast of the Bering Sea and Sea of ​​Okhotsk south to Japan and Korea. Relatively few Ketalachse swim through the Bering Strait and reached the opening into the Chukchi Sea, East Siberian Sea and Laptev Sea to the rivers Lena and the Beaufort Sea to the Mackenzie.

Way of life

The salmon are born in lakes and some fast flowing rivers on the mainland, leaving only a few months. Then they migrate to the ocean, which takes up to three years. There they stay for two to four years until they float back to their birth waters to spawn there and die for it. The chum salmon reached the age of four to seven years.

The female lays 3,000 to 4,500 up to nine millimeter eggs in one to two meters long, dug with the tail on the seabed depression which is then covered by the male with a several -square-foot sand hill and watched a few days. Some salmon spawn in July-August, others wander the rivers (such as the Amur and its tributaries ) up to 2000 km upstream and spawn in September to December. Up to the hatching of the young fish pass 60 to 120 days.

Juveniles feed on zooplankton and insects, adult fish of molluscs, crustaceans and smaller fish.

Use

The relatively frequent chum salmon has long been the least economically estimated Pacific salmon species, especially on the American side of the Pacific. Since the 1980s, however, its importance grew mainly turn in Japan and Russia. Demand is particularly the large -grained, red keta caviar.

In Russia, the Ketalachsfang is prohibited in rivers.