The nutritional relationship of Anemonia Sulcata (pennant) and its dinoflagellate symbiont

High resolution autoradiography in the optical and electron microscopes has been used to define the nature of the nutritional relationship between Anemonia sulcata and its algal symbiont. Grain counts from these autoradiographs have been examined quantitatively, and the results compared with those obtained from an in vitro analysis of the excreted products of the symbionts. These investigations clearly indicate that a system of carbon translocation between the alga and the host does exist in situ, and that over 60 % of the carbon fixed in photosynthesis is transferred to the host under the conditions of these experiments.