tench

(Tinca tinca), a fish of the family Cyprinidae. The thick, deep body is covered with a thick layer of slime and small scales. The back is dark green, and the eyes olive with a golden hue. Length, approximately 30 cm (sometimes 60 cm); weight, about 500 g (sometimes 7.5 kg). Small barbels are at the corners of the mouth. Tench inhabit the fresh waters of Europe except for the river basins that flow into the Arctic Ocean. They live in the rivers and lakes of the European USSR and in the basins of the Ob’ and Enisei rivers. Slightly mobile bottom fish, they prefer standing and overgrown rivers and lakes. Because these fish can tolerate low oxygen content, they are found in bodies of water that temporarily lack oxygen. Sexual maturity is reached at three or four years of age, when the body measures more than 20 cm long. The fecundity is 300,000 to 400,000 eggs. Spawning occurs intermittently over an extensive period. Tench feed on small invertebrates and, less commonly, on aquatic plants. They are of little commercial importance. Tench are bred artificially to produce a golden variety, similar to the goldfish that is produced by breeding the silver carp.