Prostomatida is an order of ciliates. There are 24 species of Prostomatida, in 3 genera and 2 families. It includes groups like Metacystidae and Apsiktratidae.
Definition: The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.
Definition: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)