On the cover The sacoglossan sea slug Elysia timida – these slugs are the only animals known to perform photosynthesis using plastids they sequester from their algal food source, in this case the green alga Acetabularia. The stolen plastids (kleptoplasts) can remain photosynthetically active for months in the cytosol of the animals’ cells. 

[Authors: Jan de Vries and Steffen Köhler (CAi Düsseldorf)]