The ochrophytes, subphylum Ochrophytina, is a group of mostly

photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

heterokonts. Their

plastid The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids) is a membrane-bound organelle found in the Cell (biology), cells of plants, algae, and some other eukaryotic organisms. They are considered to be intracellular endosy ...

is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum denominated Ochrophyta. Some authors (e.g., Cavalier-Smith) divided it into two subphyla,

Phaeista The ochrophytes, subphylum Ochrophytina, is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum den ...

Cavalier-Smith 1995 (comprising

Hypogyristea The ochrophytes, subphylum Ochrophytina, is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum den ...

and

Chrysista The ochrophytes, subphylum Ochrophytina, is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum den ...

in some classifications, or Limnista and Marista in others) and

Khakista The ochrophytes, subphylum Ochrophytina, is a group of mostly photosynthetic heterokonts. Their plastid is of red algal origin. The classification of the group is still being worked out. Originally, the ochrophytes were regarded as a phylum den ...

Cavalier-Smith, 2000 (comprising ''

Bolidomonas ''Triparma'' is a genus of unicellular algae in the family Triparmaceae in the order Parmales. They form siliceous plates on the cell surface that aid in identification. ''Triparma'' is distinguished by its possession of three shield plates, th ...

'' and

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

s). Others prefer not to use the subphyla, listing only lower taxa (e.g., Reviers, 2002, Guiry & Guiry, 2014). However, it is currently regarded as a subphylum inside of the phylum Gyrista, along with Pseudofungi and Bigyromonada. It contains two infraphyla: Diatomista, containing diatoms and related groups, and

, containing brown and golden algae and related groups.

Phylogeny

The cladogram below shows the evolutionary relationships between all ochrophyte classes. It is based on the latest phylogenetic analyses:

Classification

Below is the present classification of ochrophytes, with the inclusion of three new classes of algae described in 2019, 2020 and 2021. *Infraphylum

**Superclass Limnistia ***Class Eustigmatophyceae ***Class

Chrysomonadea The Chrysophyceae, usually called chrysophytes, chrysomonads, golden-brown algae or golden algae are a large group of algae, found mostly in freshwater. Golden algae is also commonly used to refer to a single species, ''Prymnesium parvum'', which ...

Chrysophyceae ***Class

Picophagea Picophagea, also known as Synchromophyceae, is a class of photosynthetic heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most ...

Synchromophyceae Picophagea, also known as Synchromophyceae, is a class of photosynthetic heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most ...

**Superclass

Raphidoistia The raphidophytes, formally known as Raphidomonadea or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes a ...

***Class

Raphidomonadea The raphidophytes, formally known as Raphidomonadea or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes a ...

****Subclass

Raphidophycidae The raphidophytes, formally known as Raphidomonadea or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryote, eukaryotic algae that includes both marine (ocean), marine and fresh water, ...

****Subclass Raphopoda **Superclass Fucistia ***Class Aurophyceae ****Subclass Aurearenophycidae ****Subclass Phaeothamniophycidae ***Class

Chrysomerophyceae Chrysomerophyceae is a monotypic class of photosynthetic heterokont eukaryotes. Taxonomy * Class Chrysomerophyceae Cavalier-Smith 1995 ** Order Chrysomeridales O'Kelly & Billard ex Preisig *** Family Chrysomeridaceae Bourrelly 1957 **** Genus ...

***Class Chrysoparadoxophyceae ***Class Phaeosacciophyceae ***Class Schizocladiophyceae ***Class

Phaeophyceae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and po ...

Fucophyceae ; Melanophyceae (“brown algae”) ****Subclass

Discosporangiophycidae Discosporangiales is an order of brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown alg ...

****Subclass

Ishigeophycidae Ishigeales is an order of brown algae. It includes two families, Ishigeaceae and Petrodermataceae. The genus ''Diplura The order Diplura ("two-pronged bristletails") is one of three orders of non-insect hexapods within the class Entognath ...

****Subclass Dictyotophycidae ****Subclass

Fucophycidae Fucophycidae is a subclass of Phaeophyceae (brown algae) which contains the most complex and evolved orders of Chromista algae. The members of this subclass have stalks with several morphological forms and distinct structures, characterized by ...

***Class Xanthophyceae Heterokontae ">Tribophyceae ; Heterokontae (“yellow-green algae”) *Infraphylum Diatomista **Superclass Hypogyrista ***Class

Dictyochophyceae Dictyochophyceae sensu lato is a photosynthetic lineage of heterokont algae. Taxonomy * Class Dictyochophyceae Silva 1980 s.l. ** Subclass Sulcophycidae Cavalier-Smith 2013 *** Order Olisthodiscales Cavalier-Smith 2013 **** Family Olisthodiscac ...

Dictyochia ; Alophycidae ****Subclass

Pedinellia The axodines are a group of unicellular stramenopiles that includes silicoflagellate and rhizochromulinid algae, actinomonad heterotrophic flagellates and actinophryid heliozoa. Alternative classifications treat the dictyochophytes as heterokont ...

Actinochrysophyceae (“axodines”) ****Subclass Pelagophycidae Pelagophyceae ">Pelagophyceae.html" ;"title="Pelagophyceae">Pelagophyceae ****?Subclass Sulcophycidae ***Class Pinguiophyceae **Superclass

***Class

Bolidophyceae Bolidophyceae is a class of photosynthetic heterokont picophytoplankton, and consist of less than 20 known species. They are distinguished by the angle of flagellar insertion and swimming patterns as well as recent molecular analyses. Bolidophyce ...

***Class

Diatomeae A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

Bacillariae ; Bacillariophyceae ****Subclass Corethrophycidae ****Subclass

Rhizosoleniophycidae Rhizosoleniophycidae or Rhizosoleniineae is a grouping of centric diatoms. See also * Coscinodiscineae References SAR supergroup suborders Coscinodiscophyceae {{Diatom-stub ...

****Subclass Eucentricophycidae ****Subclass Bacillariophycidae Pennatia ; =Pennatophycidae*Ochrophytina ''incertae sedis'' **Class Olisthodiscophyceae

Notes

References

SAR supergroup phyla {{heterokont-stub