A phylogenetic and morphological re-investigation of Diaphanoeca spiralifurca, Didymoeca elongata and Polyoeca dichotoma (Acanthoecida/Choanomonadida) from the Caribbean Sea

Acanthoecid choanoflagellates are described and classified according to their distinct siliceous lorica, a unique morphological characteristic within protistan species. Only recently it has become clear that beside morphological and developmental data on the lorica molecular data, mainly based on SSU rDNA, it is necessary to resolve phylogenetic relationships within this group. Previously Didymoeca elongata was thought to be an endemic species from Taiwanese waters. However, this species has now been found in the Caribbean Sea at several sampling sites along with two other species, Diaphanoeca spiralifurca and Polyoeca dichotoma. By sequencing the SSU rDNA and other genes and by adding light and electron microscopical data to the description of these species, the taxonomy and phylogeny of Acanthoecida is being better understood.