A survey of the Lake Superior cisco complex using integrated morphological and genetic tools reveals a presumed extinct species, Shortnose Cisco (Coregonus reighardi)

Throughout the 19th and 20th centuries, anthropogenic activities resulted in losses of ciscoes in the Laurentian Great Lakes (LGL) and only Lake Superior was left with a relatively intact complex. In 1929, W. Koelz described six cisco species from Lake Superior: Coregonus artedi, C. hoyi, C. kiyi, C. zenithicus, C. reighardi, and C. nigripinnis. Of these, artedi, hoyi and kiyi remain abundant in Lake Superior, zenithicus is considered extirpated throughout the LGL except in Lake Superior, and reighardi and nigripinnis are considered extinct. We present results reaffirming the presence of artedi, hoyi, and kiyi, and the presence of the presumed extinct reighardi. Our analysis did not confirm the presence of zenithicus and nigripinnis. The principal morphological characters that distinguish artedi, hoyi, kiyi, and reighardi reflect habitat and trophic specialization: eye size, gillraker length and gillraker spacing. The discovery of reighardi is expected to stimulate conservation and restoration of rare ciscoes in the LGL, and our integrated morphological and genetic approach can provide insights into the evolution, diversity, and ecology of ciscoes.