Persistence of Functional Chloroplasts in <Emphasis Type="Italic">Elysia viridis</Emphasis> (Opisthobranchia,Sacoglossa)

SEVERAL species of sacoglossan mollusc retain in the cells of their digestive diverticula large numbers of chloroplasts derived from their food plants (mostly siphonaceous algae). These associations are capable of photosynthesis^1–4. In freshly collected Elysia viridis (Montagu) (which obtains chloroplasts from Codium fragile (Sur.) Hariot) the net rate of fixation is approximately 40% of that in the intact seaweed and the chlorophyll content, g^?1 fresh weight, is similar in animal derived material and seaweed (Trench, Boyle and Smith, in preparation). This report describes an experiment showing that E. viridis can retain functional chloroplasts for at least 3 months when starved in the light and at least one month when starved in the dark.