Coregonus hoyi

Species of fish

Coregonus hoyi, also known as the bloater, is a species or form of freshwater whitefish in the family Salmonidae. It is a silvery coloured herring like fish, long. It is found in most of the Great Lakes and in Lake Nipigon, and inhabits underwater slopes. This fish is not to be confused with the extinct deepwater cisco (Coregonus johannae), a large fish that shared a common name with the bloater.

The bloater is a small, silvery coloured whitefish with a pink and purple iridescence. It has a greenish tinge above, and a whitish belly. It is very similar to the kiyi, from which it may be distinguished by its lighter upper lip and smaller eye.

The bloater is native to all of the Great Lakes (except Lake Erie) and in Lake Nipigon. Across its range it is in decline, and it is listed as Vulnerable to global extinction by the IUCN Red List. and also by sea lamprey predation

However, efforts to re introduce the species in to Lake Ontario have been met with great success. Multiple North American fishery agencies have aided in the bloater's return to the lake, due to the positive impact it could have on its food web. Recent studies have shown that this fish has made a surprising comeback, and it is now re established in Lake Ontario. State, provincial and federal agencies aim to stock 500,000 Coregonus hoyi into Lake Ontario by the year 2015.

The specific epithet of the bloater is given after Dr. P. R. Hoy of Racine, Wisconsin. Dr. Hoy collected the first specimens of this species in 1870 while dredging in Lake Michigan at least 16 mile (26 km) off Racine, at depths of 50 to 70 fathoms (90–130 m). Hoy did not describe the fish himself, but had ichthyologist James W. Milner name the species. Milner placed it in the genus Argyrosomus, now considered a junior synonym of Coregonus, the genus in which the bloater is now placed. The generic name Coregonus, given by Carl Linnaeus in his 1758 tenth edition of Systema Naturæ, is derived from Greek and means "angled eye", referring to the tilted pupil of whitefishes. It is closely related to the cisco or lake herring, Coregonus artedi, and the shortjaw cisco, both of which it is known to hybridise with. The bloater is one of the several taxa in the Coregonus artedi complex of freshwater whitefishes, which sometimes all are considered to belong to a single species.

The bloater is found at depths of
Spawning occurs all year round, but is usually in the winter or autumn. Spawning occurs at depths of The amount of eggs produced by the female varies depending upon her size, and ranges between 3,230 and 18,768. It is slow growing, because of the scarcity of food in its habitat. The bloater's average length at maturity is , and maximum age reported from otoliths is 10 years.