Right: aeolid nudibranch Pteraeolidia “farms” colonies of brown single-celled algae (zooxanthellae) in its cerata (stolen from cnidarian prey). Julia and Berthelina are remarkable sacoglossan “snails” with bivalve shells. Convergent evolution! Mimicry among dorid nudibranchs and polyclad flatwormscan you tell which is which?