Additional new species suggest high dictyostelid diversity on Madagascar

Abstract

Dictyostelids are a monophyletic group of sorocarp-forming social amoebae in the major eukaryotic division Amoebozoa. Members of this taxon, which is made up of almost 200 described species, are common in terrestrial soils globally. Still, the alpha diversity is not well known in many areas, and new species are frequently recovered. The highest species richness is found in the tropics. Here, five new species are described from soil samples collected in Madagascar. These species-Cavenderia basinodulosa, C. canoespora, Heterostelium radiatum, H. versatile, and Raperostelium stabile-are described based on both morphological characteristics and molecular data, with sequence data from the rDNA small subunit (SSU). The five new species are morphologically disparate, ranging from relatively small, robust taxa such as R. stabile to taxa with variable morphologies such as the larger H. radiatum and H. versatile and the yellow-tinted and irregularly branched species C. canoespora and C. basinulosa. These new species, together with earlier work where 13 other species were described from the island, suggest that there is a range of genetically diverse and highly morphologically variable dictyostelid taxa occurring on Madagascar, suggesting biogeographic patterns even within these very small organisms.

Diversity of Dictyostelid Cellular Slime Molds, Including Two Species New to Science, in Forest Soils of Changbai Mountain, China

“…Dictyostelid cellular slime molds (dictyostelids) are a monophyletic group of sorocarp-forming social amoebae belonging to the supergroup Amoebozoa ( 1 , 2 ). Dictyostelids feed upon bacteria and yeasts, and these organisms are common in the soil and leaf litter layer of forests and other types of vegetation.…”

“…Dictyostelid spores can be carried on and dispersed by water, earthworms, pillbugs, humans, Drosophila flies, rodents, terrestrial salamanders, and ground-feeding migratory songbirds ( 3 , 14 – 19 ). Dictyostelids are widespread throughout the world and have been shown to display biogeographical patterns ( 2 ).…”