Anisonemidae is a small family of euglenid algae, with two accepted genera. It is the only family in the order Anisonemida.
The family consists of single-celled organisms with a larger posterior flagellum by means of which they are able to glide. They are phagotrophic, meaning that they feed by engulfing particles of food, and are non-photosynthetic.
The family was established by William Saville-Kent in a work published in 1880âÂÂ1881. Saville-Kent used a much wider circumscription than more recent sources. Historically, phagotrophic euglenids have been treated as animals, and named under the International Code of Zoological Nomenclature, hence the family name ending "-idae".
, two genera are accepted:
A third genus, Heteronema <small>Dujardin, 1841</small>, is listed by some sources. The status of the genus is unclear; it appears to be polyphyletic, with some species falling into the order Peranemida and others in Anisonemida. Many of its species have been transferred into Teloprocta, which is placed in Peranemida.