Distribution of San Joaquin foothill fishes: the distribution and ecological associations of fishes of the San Joaquin foothills, California

The objective of this study was to determine the distribution and interrelationships of the fishes of the San Joaquin River drainage of the Sierra Nevada foothills, which have not been adequately checked since 1898 and 1899 (Rutter, 1908). A complete distributional list of Central California fresh water species was compiled some forty years ago (Evermann, 1931) with subsequent distributional studies limited to one or a few species. Two major f a c t or have warranted this distributional study. (1) extensive development of the area since the turn of the century, which includes intensive agriculture, mining, industry, large population centers; and (2) widespread introduction of numerous species from the eastern United States, which have had considerable effects on the distribution of native fish fauna. These man oriented factors have drastically changed the distribution and quality of fresh water habitats. At this time four rather distinct associations of native and exotic species exist in the foothill streams of this drainage (Moyle and Nichols, in press). The distribution of these associations and the distributions of the individual species are charted.