17 Elysia viridis. Host alga Cladophora rupstris. Dorset, England.

17 Elysia viridis. Host alga Cladophora rupstris. Dorset, England.

© M. Storey. Coenocytic Cladophora has large multinucleate cells (right) containing large masses of cytoplasm for E. viridis to extract suctorially. Some E. viridis feed on it but, wherever Codium fragile subsp. fragile is available, Cladophora is ignored.

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