Ministeria vibrans is a small single-celled eukaryote which feeds on bacteria. Although it is an opisthokont, it seems not to fit in any of the established opisthokont lineages such as choanoflagellates or animals. It might form the Filasterea group with Capsaspora, another opisthokont of uncertain placement. It is the only known opisthokont lineage which does not exhibit amoeboid cells or flagellated cells, having a spherical body.