pirum gemmata pirum gemmata pirum gemmata is a unicellular eukaryote that belongs to the ichthyosporea clade, a group of protists closely related to animals. p. gemmata was isolated from the gut contents of a marine invertebrate, specifically the detritivorous peanut worm phascolosoma agassizii. pirum gemmata pirum gemmata (ichthyosporea), nuclei stained in blue with dapi scientific classification domain: eukaryota (unranked): opisthokonta (unranked): holozoa class: ichthyosporea order: ichthyophonida genus: pirum species: p. gemmata binomial name pirum gemmatamarshall, 2008 p. gemmata’s growth under culture conditions, is through the development of a mature syncytial stage that undergoes sporogenesis and eventually releases endospores through one or more openings in the parent cell wall. mature cells are multinucleated, with a cell wall, and can measure up to 200 μm. endospores are amoeboid and some have pseudopod-like cell extensions. taxonomy p. gemmata is a member of the ichthyosporea clade, which is the earliest branching holozoan lineage. applications p. gemmata can easily be cultured axenically in marine broth medium. given its phylogenetic position as a close unicellular relative of animals, p. gemmata could potentially provide important insights into the origin of multicellular animals.