Developayellidae

Developayellidae (or Developayellaceae in botanical nomenclature) is a family of predatory single-celled eukaryotes. It belongs to the monotypic order Developayellida (or Developayellales) and class Developea, which is part of the stramenopiles. All known members consume bacteria as prey, except for the genus Develorapax, which consumes other eukaryotes.^[1]

Developayellidae
Light and transmission electron microscopy images of Develorapax marinus
Scientific classification
Domain:	Eukaryota
Clade:	Sar
Clade:	Stramenopiles
Subphylum:	Bigyromonada
Class:	Developea Aleoshin et al. 2016 ex Cavalier-Smith 2017
Order:	Developayellida Cavalier-Smith 1997
Family:	Developayellidae Cavalier-Smith 1997
Genera
Cubaremonas Develocanicus Develocauda Developayella Develorapax Mediocremonas

Taxonomy

The first known genus of developayellids, Developayella, was described in 1995. Due to many similarities shared with opalinids and heterokont algae, it was considered a member of the stramenopiles,^[2] a diverse group of protists distinguished by two unequally sized flagella, one of which has tripartite mastigonemes (hair-like structures).^[3]

In 1997, Thomas Cavalier-Smith proposed Developayella as the evolutionary link between pseudofungi and opalinids, and described higher taxon ranks to accommodate this genus: family Developayellaceae, order Developayellales, and class Bigyromonadea, in the stramenopile phylum Bigyra.^[4] The concept of 'bigyromonad' was later expanded to include the class Pirsonea, another group of phagotrophic stramenopiles.^[5][6]

In 2016, a second genus Develorapax was described, and the class Developea was created to accommodate both genera.^[7] In 2017, Cavalier-Smith validated the order- and family-level names for this group under zoological nomenclature: Developayellida and Developayellidae, respectively.^[6] The group was further expanded in 2020 and 2022 with the description of four new genera: Mediocremonas,^[8] Develocauda, Develocanicus and Cubaremonas.^[1]