Opalozoa is a subphylum of

heterotrophic A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

protists A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the excl ...

of the phylum

Bigyra Bigyra is a grouping of heterokont organisms. It includes Bicosoecida, Blastocystis and Labyrinthulida. It has also been described as containing Opalozoa, Bicoecia, and Sagenista. Phylogeny The cladogram below shows the internal relationship ...

, and is the sister group to

Sagenista Sagenista is a group of heterokonts containing the labyrinthulids and Eogyrea, a class of yet uncultured protists. Originally, it contained the Labyrinthulids and bicosoecids. However at present the bicosoecids have been removed, and Eogyrea wer ...

. Opalozoans are non-photosynthetic

heterokonts 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, whi ...

that are ancestrally

phagotrophic Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is c ...

but many times have evolved to be

osmotrophic Osmotrophy is a feeding mechanism involving the movement of dissolved organic compounds by osmosis for nutrition. Organisms that use osmotrophy are called osmotrophs. Some mixotrophic microorganisms use osmotrophy to derive some of their energy. ...

saprotrophs in the gut of vertebrate animals.

Taxonomy

History: phylum Opalozoa

In 1993 the name “Opalozoa” referred to a group of protists that was very different from what it is now. It was a

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

composed of many unrelated zooflagellates, grouped together because of the common presence of tubular mitochondrial cristae and the lack of

cortical alveoli The cortical alveoli (singular: cortical alveolum) are cellular organelles composed of vesicles located under the cytoplasmic membrane, to which they give support. They have been defined as membrane sacs that strengthen the cellular cortex through ...

or rigid tubular ciliary hairs ( retronemes). It also included the

opalinid The opalines are a small group of peculiar heterokonts, currently assigned to the family Opalinidae, in the order Slopalinida. Their name is derived from the opalescent appearance of these microscopic organisms when illuminated with full sunli ...

proteomyxid Proteomyxidea is a class of Cercozoa. Although it is known to be paraphyletic, further research is needed before its classification can be improved. References External links Cercozoa classes {{Cercozoa-stub ...

s and

plasmodiophorid The Phytomyxea are a class of parasites that are cosmopolitan, obligate biotrophic protist parasites of plants, diatoms, oomycetes and brown algae. They are divided into the orders Plasmodiophorida ( ICZN, or Plasmodiophoromycota, ICBN) and Ph ...

Modern classification

The modern taxonomy of Opalozoa, down to order level, is as follows: * Subphylum Opalozoa ** Infraphylum Bikosia *** Class Bikosea ****Subclass

Bicosidia Bicosidia is a subclass of Bikosea, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major l ...

*****Superorder

Cyathobodoniae Cyathobodoniae is a subclass of bicosoecids, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a ...

******Order Bicoecida ******Order

Anoecida Anoecida is an order of bicosoecids, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major ...

******Order

Pseudodendromonadida Pseudodendromonadida is a subclass of bicosoecids, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The gr ...

*****Superorder Borokiae ******Order Borokida ****Subclass

Rictidia Rictus is a genus of Bikosea, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line ...

*****Order

Rictida Rictus is a genus of Bikosea, a small group of unicellular flagellates, included among the heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line o ...

** Infraphylum

Placidozoa Placidozoa is a recently defined non-photosynthetic lineage of Heterokonts. Phylogeny Taxonomy Infraphylum Placidozoa Cavalier-Smith 2013 * Superclass Wobblata Cavalier-Smith 2006 stat. n. 2013 (paraphyletic) ** Class Placididea Moriya, Nakay ...

*** Superclass

Wobblata Wobblata is a paraphyletic grouping of all placidozoans except Opalinata. It unites the classes Placididea, Nanomonadea and Opalomonadea. Description Members of this group are ancestrally aerobic phagotrophic biciliates. They have tubular mitoch ...

/nowiki>paraphyletic.html" ;"title="paraphyletic.html" ;"title="/nowiki>paraphyletic">/nowiki>paraphyletic">paraphyletic.html" ;"title="/nowiki>paraphyletic">/nowiki>paraphyletic/nowiki> **** Class Placididea ***** Order Placidida [=Placidae ] **** Class Nanomonadea ***** Order Uniciliatida **** Class Opalomonadea *** Superclass Opalinata **** Class Opalinea ***** Order Proteromonadida ***** Order Opalinida **** Class

Blastocystea ''Blastocystis'' is a genus of single-celled heterokont parasites belonging to a group of organisms that are known as the Stramenopiles (also called Heterokonts) that includes algae, diatoms, and water molds. Blastocystis consists of several ...

***** Order Blastocystida *Opalozoa incertae sedis: ** '' Pendulomonas'' ** Bordnamonadidae

Phylogeny

The cladogram below shows the internal relationships of Opalozoa.

References

{{Taxonbar, from=Q21445839, worms=582466 Placidozoa