Oocystaceae is a family of green algae, in the class Trebouxiophyceae. Molecular phylogenetic studies mostly (but not always) place the family in the order Chlorellales, as sister to Chlorellaceae. The type genus is Oocystis.
Members of Oocystaceae are common microalgae in freshwater habitats, and a few occur in semi-saline.
Description Members of the family Oocystaceae consist of cells which are solitary or found in colonies of 2, 4, 8, 16, or more. Cells are typically oval to ellipsoidal, sometimes spherical, rhomboid, spindle-shaped or lemon-shaped. Cells, when colonial, may be arranged into coenobia or pseudofilaments. Cells contain multiple chloroplasts of varying morphology—usually parietal, sometimes radial or spongiform, and with or without a pyrenoid. The cell wall is multilayered, often thickened at the poles, and may be smooth, warty or covered in spines.
A uniting ultrastructural feature of all members of this family is the multiple-layered cell wall, with the cellulose fibrils in each layer organized perpendicularly to those of adjoining layers.
Reproduction occurs asexually and via the production of multiple autospores. The daughter cells often remain in the expanded mother cell wall.
Classification Traditionally, genera and species within Oocystaceae have been separated from each other based on morphology. However, microalgae typically have very few morphological features for classification, and the morphological features may have evolved more than once. Currently, molecular phylogenetics form the basis of species and genera.
Morphologically, there were three subfamilies: Eremosphaeroideae, Lagerheimioideae and Oocystoideae. Molecular data has revised this to the three current subfamilies: Eremosphaeroideae, Makinoelloideae, and Oocystoideae.
List of genera , AlgaeBase accepted the following genera:
Amphikrikos Korshikov – 6 species Catenocystis F.Hindák – 2 species Cerasterias Reinsch – 2 species Chodatella Lemmermann – 4 species Chodatellopsis Korshikov – 1 species Chondrosphaera Skuja – 1 species Coenolamellus Proshkina-Lavrenko – 1 species Crucigeniella Lemmermann – 2 species Cryocystis Kol ex Komárek & Fott – 2 species Dactylococcus Nägeli – 2 species Dendrocystis Iyengar – 1 species Densicystis X.Liu, H.Zhu, H.Song, Q.Wang, X.Xiong, C.Wu, G.Liu & Z.Hu – 1 species Didymocystis Korshikov – 2 species Droopiella Darienko, Rad-Menéndez, C.Campbell & Pröschold – 3 species Ecballocystis Bohlin – 9 species Ecballocystopsis Iyengar – 5 species Ecdysichlamys G.S.West – 5 species Echinocoleum C.-C.Jao & K.T.Lee – 3 species Elongatocystis L.Krienitz & C.Bock – 1 species Eremosphaera De Bary – 8 species Ettliella F.Hindák – 1 species Euchlorocystis X.Liu, H.Zhu, H.Song, Q.Wang, X.Xiong, C.Wu, G.Liu & Z.Hu – 1 species Fotterella R.Buck – 1 species Franceia Lemmermann – 12 species Glochiococcus De Toni – 1 species Gloeotaenium Hansgirg – 2 species Gloxidium Korshikov – 1 species Granulocystis Hindák – 6 species Granulocystopsis Hindák – 6 species Hemichloris Tschermak-Woess & Friedmann – 1 species Juranyiella Hortobagyi – 1 species Keriochlamys Pascher – 1 species Kirchneriellosaccus A.K.Islam – 1 species Kufferathiella Molinari, Mayta & Guiry – 1 species Lagerheimia Chodat – 25 species Lagerheimiella – 3 species Makinoella Okada – 1 species Micracantha Korshikov – 1 species Mycacanthococcus Hansgirg – 3 species Mycotetraedron Hansgirg – 1 species Nephrochlamys Korshikov – 6 species Oocystaenium Gonzalves & Mehra – 1 species Oocystella Lemmermann – 7 species Oocystidium Korshikov – 2 species Oocystis Nägeli ex A.Braun – 52 species Oocystopsis Heynig – 1 species Oonephris Fott – 2 species Pachycladella P.C.Silva – 3 species Palmellococcus Chodat – 3 species Pilidiocystis Bohlin – 2 species Planctonema Schmidle – 1 species Planctonemopsis Liu, Zhu, Liu, Hu & Liu – 1 species Planktosphaerella Reisigl – 1 species Pseudobohlina Bourrelly – 1 species Pseudochlorococcum P.A.Archibald – 2 species Pseudococcomyxa Korshikov – 5 species Quadricoccopsis X.Liu, H.Zhu, H.Song, B.Liu, Q.Wang, G.Liu & Z.Hu – 3 species Quadricoccus Fott – 5 species Rayssiella Edelstein & Prescott – 3 species Reinschiella De Toni – 1 species Reticulocystis X.D.Liu, G.X.Liu & Z.Y. Hu – 1 species Rhombocystis Komárek – 3 species Saturnella Mattauch & Pascher – 3 species Schizochlamydella Korshikov – 1 species Scotiella Fritsch – 9 species Selenoderma K.Bohlin – 3 species Sestosoma Hortobagyi – 1 species Siderocystopsis E.M.F.Swale – 4 species Tetrachlorella Korshikov – 5 species Thelesphaera Pascher – 1 species Trigonidiella P.C.Silva – 1 species Trochiscia Kützing – 33 species Willea Schmidle – 10 species
Phylogeny Phylogenetic studies suggest the following relationships (note the polyphyly or paraphyly of several genera, in particular the type genus Oocystis):
The genera Tetrastrum and Planctonema are incertae sedis taxa: they are sister to the rest of Oocystaceae and may be classified as such, but do not show the characteristic ultrastructure of Oocystaceae.
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