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bloater (Coregonus hoyi)
Photo © Konrad P. Schmidt, University of Minnesota

Features and Behaviors


The bloater has two small flaps of skin between the nostrils on its broad snout. The tail is forked. There are no spots on the silver, silver-green or silver-blue body. The body is elliptical. The average length for a bloater is about eight inches.


The bloater usually lives in large lakes at depths of 100 to 600 feet. It got its name because when it is brought to the surface from the depths where it lives, the gas bladder expands, giving it a bloated appearance. This fish reaches maturity in about three years. Spawning occurs from January through March with the female depositing 4,000 to 18,000 eggs. The incubation period for the eggs is four months. Young bloaters are midwater plankton feeders at least until the end of their second year. During their third year they become bottom feeders, eating small crustaceans.

Illinois Range


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae

Illinois Status: common, native