CALIFORNIA FISH AND GAME California Fish and Game 86(4):244-258 2000 A LIST OF FRESHWATER, ANADROMOUS, AND EURYHALINE FISHES OF CALIFORNIA PETER B. MOYLE Department of Wildlife, Fish, and Conservation Biology University of California, Davis 1 Shields Avenue Davis, California 95616 e-mail: pbmoyle @ ucdavis.edu LIAM H. DAVIS California Department of Fish and Game 7329 Silverado Trail Yountville, California 94558 The freshwater fishes of California include 67 native resident or anadromous species, 53 non-native species, and 5 marine species that occur in fresh water, for a total of 125 species. Within these species, 100 taxa at lower levels (subspecies, Evolutionary Significant Units, runs of anadromous fish) are recognized. The number of freshwater fish species in California is increasing due to invasions of non-native fishes, which are becoming established at a rate of about 1 species every 3 years. Of the native fishes, 5 full species are extinct in California. Thus, the actual number of species maintaining populations in the state is 120. Of extant native species, 15 (22%) are threatened with extinction in the near future. Only 27 native species (40%) can be regarded as having secure populations. INTRODUCTION The fishes of California’s inland waters are a mixture of resident, anadromous, and euryhaline species, both native and non-native. The first attempt to compile a comprehensive list of these species was Evermann and Clark (1931), who listed 78 native species and 32 introduced species. Native species included an anomalous Pacific hagfish, Epatretus stouti, from the Eel River, 14 forms all now considered to be rainbow trout, and 18 other forms that are either no longer recognized as species or were mistakenly considered to be part of the California fish fauna. Of the 32 non-native species listed, 9 did not become established and brown trout were listed as 2 species. Thus only 67 (45 native, 22 non-native) of the 120 species of Evermann and Clark would be recognized in the fauna today. However, many of their species are now recognized as subspecies, a concept not in wide use by ichthyologists of that era. The next official list (Shapovalov and Dill 1950) included 101 species (64 native, 26 non-native, and 11 euryhaline marine), 89 of which are on the present list (although not necessarily by the same common or scientific names). This list also included 244