Pedinellales

Pedinellales
Light micrograph of Pteridomonas danica
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Clade: Stramenopiles
Phylum: Gyrista
Subphylum: Ochrophytina
Class: Dictyochophyceae
Order: Pedinellales
Zimmermann, Moestrup & Hallfors 1985
Family: Actinomonadaceae
Kent 1880
Genera
Synonyms
As class
  • Pedinellea (ICZN) Cavalier-Smith, 1986
  • Pedinellophyceae (ICN) Cavalier-Smith, 1986
As subclass
  • Pedinellidae Cavalier-Smith, 1995
As order
  • Ciliophryida (ICZN) Febvre-Chevalier 1985
  • Ciliophryales (ICN) Cavalier-Smith, 1995
As suborder
  • Actinomonadineae Cavalier-Smith 2006[1]
  • Ciliophryineae Febvre-Chevalier ex Cavalier-Smith, 2006[1]
As family
  • Apedinellaceae Cavalier-Smith, 1995[2]
  • Cyrtophoraceae Pascher, 1911
  • Pedinellidae (ICZN) Pascher, 1910
  • Pedinellaceae (ICN) Pascher, 1910 orthog. emend. Cavalier-Sith, 1995[2]
  • Ciliophryidae (ICZN) Poche, 1913
  • Ciliophryaceae (ICN) Poche, 1913 orthog. emend. Cavalier-Smith, 1995[2]

Pedinellales (ICN) or Pedinellida (ICZN) is a group of single-celled algae found in both marine environments and freshwater.[3]

These are found in both freshwater and marine environments, and most genera are sessile, attached by posterior stalks. The flagellum is at the anterior of the cell, and the tentacles surround it, often capturing small prey drawn in by its current. The colored genera are Pedinella, Apedinella, Pseudopedinella, and Mesopedinella. Several more genera have lost their chloroplasts and feed entirely by phagocytosis. These are Parapedinella, Actinomonas, and Pteridomonas.

It also appears that certain heliozoa are actually derived pedinellids. Ciliophrys alternates between a mobile flagellate stage and a heliozoan feeding stage, where the body is contracted with extended axopods all over its surface, and the flagellum is curled up into a tight figure eight. The actinophryids, Actinophrys and Actinosphaerium, exist only in a heliozoan form with no flagellum and with more elaborate bundles of microtubules supporting their axopods. Their inclusion was argued by Mikrjukov and Patterson, who coined the term actinodine to refer specifically to this extended group.

Pedinellids were classified as heliozoans by some authors. The colored pedinellids were originally treated as a family of golden algae in the order Ochromonadales, promoted to an order Pedinellales by Zimmerman in 1984. Their relationship to the silicoflagellates became apparent some time later, and Patterson defined this rankless group for the two in 1994. Moestrup treated it as the class Dictyochophyceae, previously restricted to the silicoflagellates, while Cavalier-Smith defined a new class Actinochrysophyceae for them.

  1. ^ a b Thomas Cavalier-Smith; Ema E-Y Chao (April 2006). "Phylogeny and megasystematics of phagotrophic heterokonts (kingdom Chromista)". Journal of Molecular Evolution. 62 (4): 388–420. doi:10.1007/S00239-004-0353-8. ISSN 0022-2844. PMID 16557340. Wikidata Q28303534.
  2. ^ a b c Cite error: The named reference Cavalier-Smith 1995 was invoked but never defined (see the help page).
  3. ^ Lee RE (March 2018). "Heterokontophyta - Dictyochochyceae". Phycology (5 ed.). Cambridge University Press. p. 345. ISBN 9781107555655. Retrieved 28 August 2018.