Erythropsidinium

Erythropsidinium agile, from here.

Belongs within: Gymnodiniales.

Erythropsidinium is a genus of marine phagotrophic dinoflagellates found in warm and temperate waters, characterised by the possession of a complex ocelloid and a contractile tentacle-like structure called a piston (Gómez 2008).

Characters (from Gómez 2008): Cell body globular, gymnodinioid, 70-120 µm in length (excluding piston), ~45-60 µm in width. Cell body mostly occupied by hyposome; episome less than 1/4 size of hyposome. Ocelloid present at left side of cell in ventral view; ocelloid composed of one or several hyaline lenses (hyalosome) and a highly pigmented region (melanosome). Nucleus ellipsoidal, usually located at right side of cell. Piston projecting from posteroventral invagination in hyposome; piston length highly variable, tending to be inversely proportional to thickness; piston may be enlarged in distal and/or proximal parts and with intermediate knobs; end may be capitate, with flattened thickening or papillae; distal end may show a terminal stylet. Contour of cell body may show an anterior lamella or horn; lamella (if present) pointed, arising from a lanceolate peduncle. Chromatophores absent.

Erythropsidinium Silva 1960 [=Erythropsis Hertwig 1884 non Lindley ex Schott & Endlicher 1832] FT93
    |--E. agile (Hertwig) Silva 1960 [=Erythropsis agilis] S73
    |--E. cochlea (Schütt) Silva 1960 [=Pouchetia cochlea] S73
    |--E. cornutum (Schütt) Silva 1960 [=Pouchetia cornuta] S73
    |--E. extrudens (Kofoid & Swezy) Silva 1960 [=Erythropsis extrudens] S73
    |--E. hispidum (Kofoid & Swezy) Silva 1960 [=Erythropsis hispida] S73
    |--E. labrum (Kofoid & Swezy) Silva 1960 [=Erythropsis labrum] S73
    |--E. minus (Kofoid & Swezy) Silva 1960 [=Erythropsis minor] S73
    |--E. pavillardii (Kofoid & Swezy) Silva 1960 [=Erythropsis pavillardii] S73
    |--E. richardii (Kofoid & Swezy) Silva 1960 [=Erythropsis richardii] S73
    `--E. scarlatinum (Kofoid & Swezy) Silva 1960 [=Erythropsis scarlatina] S73

*Type species of generic name indicated

REFERENCES

[FT93] Fensome, R. A., F. J. R. Taylor, G. Norris, W. A. S. Sarjeant, D. I. Wharton & G. L. Williams. 1993. A classification of living and fossil dinoflagellates. Micropaleontology Special Publication 7: i-viii, 1-351.

Gómez, F. 2008. Erythropsidinium (Gymnodiniales, Dinophyceae) in the Pacific Ocean, a unique dinoflagellate with an ocelloid and a piston. European Journal of Protistology 44: 291-298.

[S73] Sournia, A. 1973. Catalogue des espèces et taxons infraspécifiques de Dinoflagellés marins actuels publiés depuis la révision de J. Schiller. I. Dinoflagellés libres. Beihefte zur Nova Hedwigia 48: 1-92.