Pentasters

A small number of dinoflagellates contain an internal skeleton. One of the best known species is perhaps Actiniscus pentasterias, in which each cell contains a pair of siliceous five-armed stars surrounding the nucleus. This species was originally described by Ehrenberg.[1] Although the description is incomplete and without illustrations, Ehrenberg described the skeletal elements but mentioned that the living cell was colorless and non-motile. Ehrenberg subsequently diagrammed the silicified skeletal elements (pentasters) from geological deposits in various parts of the world.[2]These can be found as microfossils. Pentasters were studied from the Cenozoic South Pacific by Dumitrică http://deepseadrilling.org/21/volume/dsdp21_25.pdf [3] Tappan [4] gave a survey of dinoflagellates with internal skeletons. This included the first detailed description of the pentasters in Actiniscus pentasterias, based on scanning electron microscopy.

The ultrastructure of Actiniscus pentasterias was investigated.[5]

References

  1. ↑ Ehrenberg, C. G. 1841. Uber noch jetzt zahlreich lebende Tierarten der Kreidebildung und den Organismus der Polythalamien. Abh. K. Akad. Wiss. Berlin 1839:81-174, pls. 1-4.
  2. ↑ Ehrenberg, C. G. 1854. Mikrogeologie das Erden und Feslen schaffende Wirken desunsichtbaren kleinen selbstandigen Lebens auf der Erde. Leopold Voss, Leipzig, 374 pp., pls. 1-40.
  3. ↑ Dumitrică, P., 1973: Cenozoic endoskeletal dinoflagellates in southwestern Pacific sediments cored during Leg 21 of the DSDP. In: Burns, R.E. et al., Deep Sea Drilling Project, Washington, Initial Reports, v.21, p.819-835, pl.1-5.
  4. ↑ Tappan, H. 1980. The Paleobiology of Plant Protists. Freeman and Company, San Francisco, 1028 pp.
  5. ↑ Hansen, G. 1993. LIGHT AND ELECTRON MICROSCOPICAL OBSERVATIONS OF THE DINOFLAGELLATE ACTINISCUS PENTASTERIAS (DINOPHYCEAE) J. Phycol. 29, 486-499 (1 993)
This article is issued from Wikipedia - version of the 4/7/2012. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.