Heliovermida

Heliovermida is a phylum of Symbiozoans that retained their photosynthetic capabilities. Most members of this group have sessile adult stages that strictly rely on photosynthesis for energy, though members of this group have reverted to fauna-like niches on several different occasions.

Class Caulivermida
The basalmost class of Heliovermids.

Class Phytoptera
An entirely aquatic class of Heliovermids that became fauna-like in niche.

Class Autogonimida
''A diverse class of Heliovermid characterized by sequential hermaphroditism; that is, young motile male morphs produce sperm, and older sessile female morphs produce egg cells. Many members are either floral or faunal in the mature female stage.''

Class Allogenerivermes
''A class of Heliovermids characterized by alternation of generations between small gametozoons, which produce gametes, and an asexual generation which grows from motile larvae to sessile floral adults. The adults typically collect water at their head.''