Opalinata

Opalinata
Opalina ranarum, a species of Opalinea
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Clade: Stramenopiles
Phylum: Bigyra
Infraphylum: Placidozoa
Superclass: Opalinata
Wenyon, 1926 em. Cavalier-Smith, 1996 stat. n. 2006[1]
Classes[1]

Opalinata is a superclass of non-phagotrophic heterokonts that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea.[1]

Description[edit]

When Opalinata was first erected as a taxon in 1926, it was placed as the sole class in the group "Protociliata" and considered as primitive ciliates due to the fact that they move thanks to their numerous cilia and that they both present two nuclei.[2] They were distinguished because they perform syngamy by the complete fusion of uninucleated gametes, while the rest of ciliates, forming "Euciliata" (Ciliata + Suctoria), perform syngamy through their micronuclei alone while their macronuclei dissolve.[2]

The taxon Opalinata was revised in 1996 by Cavalier-Smith and placed in Opalozoa, and is now defined by the following synapomorphies: gut parasitism and the loss of peroxisomes and phagocytosis.[3]

Phylogeny[edit]

The cladogram below shows the relationships between Opalinata and the rest of Opalozoa.[1]

Opalozoa
Placidozoa
Opalinata

Opalinea

Blastocystea

Opalomonadea  

Nanomonadea

Placididea

Bikosea

Classification[edit]

The modern taxonomy of Opalinata is as follows:[1]

References[edit]

  1. ^ a b c d e Cavalier-Smith, Thomas; Scoble, Josephine Margaret (2012). "Phylogeny of Heterokonta: Incisomonas marina, a uniciliate gliding opalozoan related to Solenicola (Nanomonadea), and evidence that Actinophryida evolved from raphidophytes". European Journal of Protistology. 49 (3): 328–353. doi:10.1016/j.ejop.2012.09.002. PMID 23219323.
  2. ^ a b Wenyon, Charles Morley (1926). Protozoology : a manual for medical men, veterinarians and zoologists. Vol. 1. William Wood & Company. doi:10.5962/bhl.title.7465.
  3. ^ Cavalier-Smith, Thomas (1997). "Amoeboflagellates and mitochondrial cristae in eukaryote evolution: megasystematics of the new protozoan subkingdoms eozoa and neozoa". Archiv für Protistenkunde. 147 (3–4): 237–258. doi:10.1016/S0003-9365(97)80051-6. ISSN 0003-9365.