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 ...
heterokont
Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which ...
s. 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
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
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
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (21 October 1942 – 19 March 2021), was a professor of evolutionary biology in the Department of Zoology, at the University of Oxford.
His research has led to disc ...
) 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 d ...
Cavalier-Smith 1995 (comprising
Hypogyristea 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 d ...
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 d ...
Cavalier-Smith, 2000 (comprising ''
Bolidomonas'' 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
Gyrista is a phylum of heterokont protists containing three diverse groups: the mostly photosynthetic Ochrophyta, the parasitic Pseudofungi, and the recently described group of nanoflagellates known as Bigyromonada. Members of this phylum are ch ...
, along with
Pseudofungi
Pseudofungi is a grouping of heterokonts, also known as the Heterokontimycotina. It consists of the Oomycota and Hyphochytridiomycetes. Although numerous biochemical, ultrastructural, and genetic traits clearly place them in the heterokonts, the ...
and
Bigyromonada
Bigyromonadea is a recently described non-photosynthetic lineage of Heterokont
Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are al ...
. It contains two infraphyla:
Diatomista, containing diatoms and related groups, 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 d ...
, 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
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 d ...
**Superclass
Limnistia
***Class
Eustigmatophyceae
Eustigmatophytes are a small group (17 genera; ~107 species) of eukaryotic forms of algae that includes marine, freshwater and soil-living species.
All eustigmatophytes are unicellular, with coccoid cells and polysaccharide cell walls. Eus ...
***Class
Chrysomonadea Chrysophyceae
***Class
Picophagea Synchromophyceae **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 ...
***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 ...
****Subclass
Raphidophycidae
****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
**** Genu ...
***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
****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
Yellow-green algae or the Xanthophyceae (xanthophytes) are an important group of heterokont algae. Most live in fresh water, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamento ...
_Heterokontae_.html" ;"title="Tribophyceae ;
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 Olisthodis ...
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_.html" ;"title="Pelagophyceae.html" ;"title="Pelagophyceae">Pelagophyceae ">Pelagophyceae.html" ;"title="Pelagophyceae">Pelagophyceae ****?Subclass Sulcophycidae
***Class Pinguiophyceae
**Superclass
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 d ...
***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. Bolidophyc ...
***Class
Diatomeae 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