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 of the phylum
Bigyra, and is the sister group to
Sagenista.
Opalozoans are non-photosynthetic
heterokonts 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 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 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
opalinids,
proteomyxids and
plasmodiophorids.
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
******Order
Pseudodendromonadida
*****Superorder
Borokiae
******Order
Borokida
****Subclass
Rictidia
*****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
*** Superclass
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**** 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