A review of non-commensal loxosomatids: collection, culture, and taxonomy, with new implications to the benefit of commensalism (Entoprocta: Loxosomatidae)

Entoprocts are suspension feeders that create water currents using ciliary tentacles and catch food particles in the currents. To date, a total of about 180 species have been recognized in this phylum, among which about 140 are solitary and others are colonial. Unlike the colonial species that mostly attach on nonliving substrates, most of the solitary entoprocts (loxosomatids) have been found in association with other animals (Nielsen 1964, Soule & Soule 1965), and thus, this animal group has been recognized as a commensal one (Hyman 1951, Brusca & Brusca 1990, Ruppert & Burnes 1994, Nielsen 2001).