Bloaters

Bloaters is a common name applied to several freshwater whitefish in the genus Coregonus. The name most often refers to the lake bloater, Coregonus hoyi, a small to medium-sized whitefish of North American lakes in the Great Lakes region. As a group they are part of the subfamily Coregoninae within the salmonid family.

Taxonomic classification has varied, with some authorities recognizing distinct species and others treating certain populations as forms of Coregonus hoyi or related species. In common usage, "bloater" can refer to multiple lake-associated whitefish forms that share a laterally compressed body and a silvery coloration.

Bloaters typically have a deep, laterally compressed body, a small head, and a relatively large eye. They are generally pale or silvery with minimal markings. Size ranges roughly from 20 to 40 cm in length, with individuals exceeding 40 cm rare.

They inhabit cold, clear freshwater lakes, often occupying midwater to deep-water zones. They spawn during winter or early spring, often on rocky or sandy substrates in shallow nearshore areas.

Diet consists mainly of zooplankton in juvenile stages, shifting to benthic invertebrates and small crustaceans as adults.

Historically important to commercial fisheries in the Great Lakes; populations have declined due to overfishing, habitat alteration, and competition with invasive species such as alewives and predation by sea lampreys. Some populations are protected or managed with harvest quotas and habitat restoration; overall status varies by lake.