The shortnose cisco (Coregonus reighardi) is a species of freshwater fish in the salmon family (family Salmonidae). The species is resident to the Nearctic ecozone, formerly occurring in Lakes Huron, Michigan, and Ontario in Canada and the United States. The last reported population was restricted to Georgian Bay off Lake Huron in Canada.
Reaching a maximum recorded length of 14 in (36 cm) and a maximum recorded weight of 1.2 lb (540 g), the shortnose cisco is distinguished from the other whitefishes by its thicker body (nearly circular in cross-section), short head (the source of the fish’s common name), and small eye.
Like many Coregonus species, the shortnose cisco is poorly understood, and little is known about its breeding or life-cycle except that it spawns in the spring at the lake bottom. The oldest specimen collected was eight years of age. The fish feeds on crustaceans, mollusks, and zooplankton.
The IUCN considers C. reighardi to be Critically Endangered on the basis of plummeting population, caused by environmental degradation. The U.S. Fish and Wildlife Service and the Province of Ontario’s Ministry of Natural Resources, however, consider the species already extinct, on the basis that no specimen has been collected since 1985. The species was last confirmed present in Lake Ontario in 1964, in Lake Michigan in 1974, and in Georgian Bay in 1985. Predation by the alien sea lamprey (Petromyzon marinus), in combination with commercial overfishing, has contributed to the fish’s drastic reduction in numbers and possible extirpation.