Actinophrys

Actinophrys is a genus of heliozoa, amoeboid unicellular organisms with many axopodial filaments that radiate out of their cell. It contains one of the most common heliozoan species, Actinophrys sol.^[2] It is classified within the monotypic family Actinophryidae.^[3]

Actinophrys
Actinophrys undergoing multiple plasmotomy
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Stramenopiles
Phylum:	Gyrista
Subphylum:	Ochrophytina
Class:	Raphidomonadea
Order:	Actinophryida
Suborder:	Actinophryina
Family:	Actinophryidae Dujardin, 1841
Genus:	Actinophrys Ehrenberg, 1830[1]
Type species
Actinophrys sol (Müller, 1773) Ehrenberg, 1830[1]
Species
A. sol A. pontica A. salsuginosa A. tauryanini
Synonyms
Trichoda Müller 1773 nomen oblitum Peritricha Bory de St.Vincent 1824 nomen dubium non Stein 1859

Characteristics

Actinophrys species belong to an informal group known as heliozoa, which are unicellular eukaryotes (or protists) that are heterotrophic (also known as protozoa) and present stiff radiating arms known as axopodia.^[3][4] In particular, Actinophrys species are characterized by axonemes consisting of double interlocking spirals of microtubules. Their axonemes end on a large central nucleus. They are also characterized by the siliceous material present in their cysts.^[2]

Systematics

Actinophrys was described in 1830 by German naturalist Christian Gottfried Ehrenberg, with the type species Actinophrys sol. The species originally belonged to a genus named Trichoda, described earlier by Otto Friedrich Müller and later declared obsolete.^[1] In 1824, Bory de St. Vincent transferred that species to a new genus Peritricha but, without any new observations to justify the change, it fell out of use.^[2]

Species

There are currently four accepted species of Actinophrys.^[2]

• Actinophrys sol (Müller, 1773) Ehrenberg, 1830^[1] (=A. difformis Ehrenberg, 1830; A. marina Dujardin, 1841; A. stella Perty, 1852; A. oculata Stein, 1854; A. tenuipes Claparède & Lachmann, 1858; A. fissipes Lachmann, 1859; A. longipes Lachmann, 1859; A. tunicata Lachmann, 1859; A. limbata Lachmann, 1859; A. paradoxa Carter, 1864; A. picta Leidy, 1879; A. alveolata Schewiakoff, 1893; A. subalpina West, 1901; A. vesiculata Penard, 1901)
• Actinophrys pontica Valkanov, 1940^[5]
• Actinophrys salsuginosa Patterson, 2001
• Actinophrys tauryanini (Mikrjukov, 1996) Mikrjukov & Patterson, 2001

References

1. Ehrenberg, Christian Gottfried (1830). "Beiträge zur Kenntniss der Organisation der Infusorien und ihrer geographischen Verbreitung, besonders in Sibirien" [Contributions to the knowledge of the organization of the infusoria and their geographical distribution, especially in Siberia]. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin (in German): 1–88. doi:10.5962/bhl.title.143632.
2. Mikrjukov, Kirill A.; Patterson, David J. (2001). "Taxonomy and phylogeny of Heliozoa. III. Actinophryids" (PDF). Acta Protozoologica. 40: 3–25.
3. Cavalier-Smith, Thomas; Scoble, Josephine Margaret (2013). "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.
4. Gast, R.J. (2017). "Centrohelida and Other Heliozoan-like Protists". In Archibald, J.; Simpson, A.; Slamovits, C.; Margulis, L.; Melkonian, M.; Chapman, D.; Corliss, J. (eds.). Handbook of the Protists. Cham, Switzerland: Springer International. pp. 1–17. doi:10.1007/978-3-319-32669-6_28-1. ISBN 978-3-319-32669-6.
5. Valkanov A (1940). "Die Heliozoen und Proteomyxen. Artbestand und sontige kritische Bemerkung". Archiv für Protistenkunde. 93: 225–254.