Bivagina is a genus of monogeneans.

As all Monogenea, species in the genus are ectoparasites that affect their host by attaching themselves as larvae on the gills of fish and grow into adult stage.

This larval stage is called oncomiracidium, and is characterized as free swimming and ciliated.

[1] Members of the genus Bivagina are characterised by a symmetrical haptor, a few testes, a cirrus and/or genital atrium unarmed and two vaginal pores armed or unarmed.

[citation needed] Currently ten species are recognized:[2]