Percarina

(Percarina demidoffi), a fish of the family Per-cidae. The percarina reaches a length of 10 cm. It is similar to the ruff (Acerina) but differs in that it has separated dorsal fins and dark dorsal spots. The fish is found in the most freshened northern parts of the Sea of Azov and the Black Sea (the estuaries of the Dnestr, Iuzhnyi Bug, and Dnieper rivers). The percarina reaches sexual maturity in the second year. Spawning occurs from June through August, with the minute roe being deposited on the bottom. The percarina is a bottom dweller and feeds during the night on invertebrates, goby fry, and the tiulka (Clupeonella). It in turn is eaten by the pike perch (Lucioper-cd). The percarina is a trash fish. It produces enormous amounts of slime and, thereby, reduces the value of fish catches, particularly of Clupeonella. The fish is used in the production of inorganic fertilizer and meal.