THE DISTRIBUTION OF DICTYOSTELID CELLULAR SLIME MOLDS IN SOUTHERN CALIFORNIA WITH TAXONOMIC NOTES ON SELECTED SPECIES

The occurrence and distribution of Dictyostelid cellular slime molds in southern California were investigated by means of a clonal isolation technique that permitted quantitative sampling of populations. Thirteen species were isolated. These include (in approximate order of decreasing frequency): Dictyostelium rosarium Raper and Cavender, D. mucoroides Brefeld, D. sphaerocephalum (Oud.) Sacc. and March., D. aureum Olive, Polysphondylium pallidum Olive, D. minutum Raper, D. giganteum Singh, D. purpureum Olive, P. violaceum Brefeld, D. mucoroides variant, Acytostelium leptosomum Raper and Quinlan, D. polycephalum Raper, and a new species of Dictyostelium. D. rosarium and D. aureum, both rarely reported in the literature, were common and widespread. Trends in habitat preference of the Dictyostelids encountered are discussed. Selected taxonomic details are provided for D. rosarium, D. aureum and members of the “D. mucoroides complex“—D. mucoroides, D. sphaerocephalum, D. giganteum, and a D. mucoroides variant.