Actiniscus pentasterias (Ehrenberg) Ehrenberg 1854

A&B = Side view (A&C, arrow=extrusomes(docidosomes)), B = One of the pentasters in the cell; C = Apical view middle focus; D = Squashed cell with pentasters and nucleus. A-C = A living cell. (DIC)


Life-form: Solitary

Size: Length 30-40 µm, width 35-40 µm.

Resting spore:


Distinctive features: Gymnodinioid cell with two siliceous internal skeletons (=pentasters). Prominent bundle of extrusomes (docidosomes)

Similar species:

Distribution: Subtropical to cold temperate waters. Even in arctic freshwater lakes

Hansen, G. 1993b. Light and electron microscopical observations of the dinoflagellate Actiniscus pentasterias (Dinophyceae). J. Phycol. 29: 486-499.

Hansen, G. & Larsen, J. 1992. Dinoflagellater i danske farvande. In: Thomsen, H. A. (ed.) Plankton i de indre danske farvande. Havforskning fra Miljøstyrelsen, Copenhagen, p. 45-155.

Steidinger, K. A. & Tangen, K. 1996. Dinoflagellates. In: Tomas, C. R. (ed.) Identifying marine diatoms and dinoflagellates. Academic Press, Inc., San Diego, p. 387-584.

  Copyright © 1996-2006, Mats Kuylenstierna & Bengt Karlson All rights reserved.
Last modified on 15 September, 2006

Swedish Meteorological and Hydrological Institute

Department of Marine Ecology, Göteborg University, Sweden