A New Member of the Mycetozoa

Abstract

A new mycetozoan, CaVOSTELIUM apophysatum (CAVOSTELIACEAE) is described. It is holozoic in nutrition, being readily cultured on bacteria grown on weakly nutrient agar. The vegetative cells alternate readily between amoeboid (with filopodia) and flagellate stages. Flagellate cells typically have one anterior flagellum, but some cells (all uninucleate) have more, in which case the flagella are not paired. In the process of sporulation, a single amoeba produces a short stalk with inner and outer membrane and small sporangium with 1 or 2 spores. When the fruiting body is submerged in water the stalk becomes inflated with a gas pressed out of the area between sporangial wall and outer membrane. Sexual reproduction was not observed. The organism is of unknown relationship to other groups of mycetozoa. It is widely distributed on dead vegetation in warmer parts of the world.