Five new species of dictyostelid social amoebae (Amoebozoa) from Thailand

BACKGROUND: Dictyostelid cellular slime molds (dictyostelids) are common inhabitants of the soil and leaf litter layer of fields and forests, along with animal dung, where they feed mostly on bacteria. However, reports on the species diversity of dictyostelids in South Asia, particularly Thailand, are limited. The research reported in this paper was carried out to increase our knowledge of the species diversity of this group of organisms in northern Thailand. RESULTS: Forty soil samples were collected at four localities in northern Thailand to assess the species richness of dictyostelids. These samples yielded five dictyostelid isolates that were not morphologically consistent with any described species. Based on molecular signatures, all five of these isolates were assigned to the family Cavenderiaceae, genus Cavenderia. All five share a number of morphological similarities with other known species from this family. The new taxa differ from previously described species primarily in the size and complexity of their fruiting bodies (sorocarps). This paper describes these new species (Cavenderia aureostabilis, C. bhumiboliana, C. protodigitata, C. pseudoaureostipes, and C. subdiscoidea) based on a combination of morphological characteristics and their phylogenetic positions. CONCLUSIONS: At least 15 taxa of dictyostelids were obtained from the four localities in northern Thailand, which indicates the high level of species diversity in this region. Five species were found to be new to science. These belong to the family Cavenderiaceae, genus Cavenderia, and were described based on both morphology and phylogeny.