The Distribution of Dictyostelid Cellular Slime Molds in Southern California with Taxonomic Notes on Selected Species

Abstract

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.

Two species of dictyostelid cellular slime molds from Alaska

“…3) D. ammophilum, D. rosarium, D. sphaerocephalum and D. clavatum are nested fairly closely together. Also D. ammophilum, D. rosarium and D. sphaerocephalum frequently occur in marginal habitats that are very acidic, very alkaline and/or have very dry soils (Benson andMahoney 1977, Landolt et al 2006) and are frequently characterized by swirling aggregations having amorphous centers and failure to develop normally without the proximal presence of charcoal granules. In common with the rest of the species from Group 4, D. ammophilum generally exhibits solitary growth and has sorocarps of similar size (1.5-7 mm).…”

Do Interactions of Cellular Slime Mold Species Regulate their Densities in Soil?

“…On a broad scale, species diversity is negatively correlated with latitude (Cavender 1973). Local areas within latitudinal zones seem to have characteristic relative abundances of species (Cavender and Raper 1965, Benson and Mahoney 1977, Traub et al 1981, Raper 1984. In our area the four most commonly encountered species are: Dictyostelium mucoroides, Dictyostelium purpureum, Polysphondylium pallidum, and Polysphondylium violaceum.…”