the number is highly variable (even within single populations and species), can change relatively fast in response to changes and genetic studies have shown that they often are of limited use in predicting relationships among populations (a large difference in gill raker number does not necessarily equal a distant relationship). Genetic differences between several of the recently proposed species, even ones that are relatively distinct morphologically, are very limited and sometimes they are not monophyletic. Various Coregonus, whether regarded as separate species or not, readily interbreed with each other. A review of whitefish in the United Kingdom found that the identification key provided in 2007 did not match most individuals and that solid evidence for more than one species in that region is lacking. Many European lakes have more than one Coregonus morph differing in ecology and morphology (especially gill rakers). Such morphs are sometimes partially reproductively isolated from each other, leading to suggestions of recognizing them as separate but clinal species. The morphs or clinal species may rapidly disappear (in 15 years or less, equalling three Coregonus generations) by merging into a single in response to changes in the habitat. A similar pattern can be seen in North America where the ciscoes of the Coregonus artedi complex in the Great Lakes and elsewhere comprise several, often co-occurring morphs or ecotypes, whose taxonomic status remains controversial. Species In 2017, FishBase listed 78 species, including the more than 50 proposed for Europe in 2007. Some of these are recently extinct (marked with a dagger, "†") and C. reighardi is likely extinct. Coregonus acrinasus Oliver M. Selz, Carmela J. Dönz, Pascal Vonlanthen, Ole Seehausen, 2020 Coregonus albellus Fatio, 1890 (autumn brienzlig) Coregonus albula Linnaeus, 1758 (vendace) †Coregonus alpenae (Koelz, 1924) (longjaw cisco) Coregonus alpinus Fatio, 1885 (kropfer) Coregonus anaulorum Chereshnev, 1996 Coregonus arenicolus Kottelat, 1997 Coregonus artedi Lesueur, 1818 (northern cisco or lake herring) Coregonus atterensis Kottelat, 1997 Coregonus austriacus C. C. Vogt, 1909 Coregonus autumnalis (Pallas, 1776) (Arctic cisco) Coregonus baerii Kessler, 1864 Coregonus baicalensis Dybowski, 1874 Coregonus baunti Mukhomediyarov, 1948 Coregonus bavaricus Hofer, 1909 Coregonus bezola Fatio, 1888 (bezoule) Coregonus brienzii Oliver M. Selz, Carmela J. Dönz, Pascal Vonlanthen, Ole Seehausen, 2020 Coregonus candidus Goll, 1883 Coregonus chadary Dybowski, 1869 (Khadary whitefish) Coregonus clupeaformis (Mitchill, 1818) (lake whitefish) Coregonus clupeoides Lacépède, 1803 (powan) Coregonus confusus Fatio, 1885 Coregonus danneri C. C. Vogt, 1908 Coregonus duplex Fatio, 1890 Coregonus fatioi Kottelat,