Specificity in the Convoluta Roscoffensis/Tetraselmis Symbiosis
Convoluta roscoffensis is an intertidal acoel turbellarian (fflatworm1) that is locally abundant on sandy beaches of the Brittany coast of France and nearby Channel Islands. It is a conspicuous member of the beach fauna, for two reasons: first, the animals are green, due to the presence of algal symbionts of the genus Tetraselmis (=Platymonas, Prasinocladus) in their tissues (Parke & Manton, 19 67); and, secondly, they are gregarious, forming large dark-green patches on the surface of the beach at low tide (Holligan & Gooday, 1975). The details of the life cycle of C. roscoffensis was established by Keeble & Gamble (1907). The adult animals reproduce exclusively sexually and the fertilized eggs are deposited, within a common gelatinous capsule, in the sand. The algal symbionts are not transmitted directly into the eggs and the association is reestablished at each generation of C. roscoffensis when recently-hatched juveniles feed on free-living algae in the interstitial water. The symbiosis appears to be obligate for C. roscoffensis; all adult animals are green in the field and, in the laboratory, aposymbiotic juveniles die within a few weeks of hatching.
KeywordsBiomass Respiration Photosynthesis Beach Peri
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- Doonan, S.A., Douglas, A.E. & Gooday, G.W. (1980). Acquisition of algae by Convoluta roscoffensis. In: Endo-cytobiology Endosymbiosis & Cell Biology, Volume 1 (W. Schwemmler & H.E.A. Schenck, editors) pp. 293–304 Walter de Gruyter, Ber1in.Google Scholar
- Douglas, A.E. (1983a). Uric acid utilization in Platymonas convolutae and symbiotic Convoluta roscoffensis. J. mar. biol. Ass. UK, 50, 199–208.Google Scholar
- Keeble, F. & Gamble, F.W. (1907). The origin and nature of the green cells of Convoluta roscoffensis. Quart. J. microscop. Sci. 51, 167–219.Google Scholar
- McFarlane, A.E. (1982b). Ultrastructural & Immunological Studies of the Symbiosis between Convoluta roscoffensis and Prasinophycean Algae. Ph.D. Thesis, University of Bristol.Google Scholar
- Meyer, H., Provasoli, L. & Meyer, F. (1979). Lipid biosynthesis in the marine flatworm Convoluta roscoffensis and its algal symbiont Platymonas convolutae. Biochim. Biophys. Acta, 573, 464–480.Google Scholar
- Smith, D.C. (1981). The role of nutrient exchange in recognition between symbionts. Ber. Deutsche Bot, Ges., 94, Supplement 517–528.Google Scholar
- Smith, D.C. & Douglas, A.E. (1987). The Biology of Symbiosis Edward Arnold.Google Scholar