Gymnosphaerid

Gymnosphaerida
Scientific classification Edit this classification
Domain: Eukaryota
Supergroup: Rhizaria
(unranked): incertae sedis
Phylum: Cercozoa (?)
Subphylum: Filosa (?)
Class: Granofilosea (?)
Family: Gymnosphaeridae
Poche 1913
Genera
Synonyms
  • Axoplasthelida Febvre-Chevalier 1984
  • Axoplastheliales
  • Gymnidae
  • Hedraiophryidae
  • Wagnerellidae Poche 1913

The gymnosphaerids are a small group of heliozoan protists found in marine environments. They tend to be roughly spherical with radially directed axopods, supported by microtubules in a triangular-hexagonal array arising from an amorphous central granule.

Genera

There are only three genera, each with a single species: Gymnosphaera albida, Hedraiophrys hovassei, and Actinocoryne contractilis.

Classification

Gymnosphaerids were originally considered centrohelids, which also have microtubules in a triangular-hexagonal array, but are set apart from the others by the structure of the central granule and the mitochondria, which have tubular cristae. The two groups have been treated as separate orders (Axoplasthelida and Centroplasthelida) in a common class, but this has lost support. Instead the gymnosphaerids may be allied with the desmothoracids, and on account of this have been placed in the Cercozoa, but this is somewhat tentative.

References

  1. ↑ Febvre-Chevalier C (1981). "Preliminary study of the motility processes in the stalked heliozoan Actinocoryne contractilis". Biosystems. 14 (3–4): 337–343. doi:10.1016/0303-2647(81)90040-X. PMID 7337812.