Nutrition of algal-invertebrate symbiosis. I. Utilization of soluble organic nutrients by symbiont-free hosts

The uptake and utilization of organic compounds, known to be present in the photosynthetic products excreted by algal symbionts, has been examined in an aposymbiotic anemone, Aiptasia pallida, and newly hatched, symbiont-free larvae of the turbellarian, Convoluta roscoffensis. Results indicate that these compounds are rapidly assimilated by the hosts, and subsequently metabolized to provide both energy, and a source of stable cell constituents. The role of these metabolic patterns in intact associations is discussed, and the data is further related to the general phenomenon of dissolved nutrients in seawater, and their significance to the nutrition of marine invertebrates.