Skip to main content Accessibility help

An Epibiont on the Red-Water Ciliate Mesodinium Rubrum

  • David W. Crawford (a1)


Spherical, opaque bodies (5–10 µm diameter) were frequently observed adhering to cells of the marine ciliate Mesodinium rubrum, particularly towards the end of red-water blooms in Southampton Water. Transmission electron microscope sections revealed these structures to be of biogenic origin, and packed with an amorphous, lipid-like material. No diagnostic features were observed to confirm their identity.

The phototrophic ciliate Mesodinium rubrum (Lohmann) forms recurrent red-tides each summer and autumn in the Southampton Water estuary, UK (Williams, 1980; Soulsby et al., 1984). During a study of the impact of these blooms on the estuary, live cells were routinely observed microscopically. Frequently, but predominantly later in the bloom, numerous individuals posessed spherical, colourless, but opaque bodies, apparently attached or adherent to the outer cell membrane. Cells observed prior to the bloom, or at other times of the year, were never observed o possess such structures.

Cells bearing these bodies were photographed live, or after preservation in Lugol's iodine, using the phase contrast optics of an Olympus BH2 photomicroscope.



Hide All
Foissner, W. & Foissner, I., 1984. First record of an ectoparasitic flagellate on ciliates: an ultrastructural investigation of the morphology and the mode of attachment of Spiromonas gonderi nov. spec. (Zoomastigophora, Spiromonadidae) invading the pellicle of ciliates of the genus Colpoda (Ciliophora, Colpodidae). Protistologica, 20, 635648.
Grain, J.Puytorac, P. De & Groliere, C.A., 1982. Quelques précisions sur l'ultrastructure et la position systématique du cilié Mesodinium rubrum, et sur la constitution des symbiontes chloroplastiques. Protistologica, 18, 721.
Johnson, T.W., 1966. Chytridiomycetes and Oömycetes in marine phytoplankton. Nova Hedwigia, 10, 579588.
Kazama, F., 1972. Development and morphology of a chytrid isolated from Bryopsis plumosa. Canadian Journal of Botany, 50, 499505.
Lindholm, T., 1985. Mesodinium rubrum - a unique photosynthetic ciliate. Advances in Aquatic Microbiology, 3, 148.
Oakley, B.R. & Taylor, F.J.R., 1978. Evidence for a new type of endosymbiotic organisation in a population of the ciliate Mesodinium rubrum from British Columbia. BioSystems, 10, 361369.
Reynolds, C.S., 1973. The seasonal periodicity of planktonic diatoms in a shallow eutrophic lake. Freshwater Biology, 3, 89110.
Soulsby, P.G., Mollowney, M., Marsh, G. & Lowthion, D., 1984. The role of phytoplankton in the dissolved oxygen budget of a stratified estuary. Water Science and Technology, 17, 745756.
Taylor, F.J.R., 1983. Some eco-evolutionary aspects of intracellular symbiosis. International Review of Cytology, supplement 14, 128.
Taylor, F.J.R., Blackbourn, D.J. & Blackbourn, J., 1969. Ulnfrastructure of the chloroplasts and associated structures within the marine ciliate Mesodinium rubrum (Lohmann). Nature, London, 224,819821.
Taylor, F.J.R., Blackbourn, D.J. & Blackbourn, J., 1971. The red-water ciliate Mesodinium rubrum and its ‘incomplete symbionts’: A review including new ultrastructural observations. Journal of the Fisheries Research Board of Canada, 28, 391407.
White, A.W., Sheath, R.G. & Hellebust, J.A., 1977. A red tide caused by the marine ciliate Mesodinium rubrum in Passamaquoddy Bay, including pigment and ultrastructure studies of the endosymbiont. Journal of the Fisheries Research Board of Canada, 34, 413416.
Williams, P.J.Leb., 1980. Phytoplankton in Southampton Water. In The Solent Estuarine System. NERC Publications, series C, no. 22, 7375.

An Epibiont on the Red-Water Ciliate Mesodinium Rubrum

  • David W. Crawford (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed