The Lettuce Sea Slug (Elysia crispata) is a sacroglossan (not a nudibranch, but closely related) sea slug found in tropical areas of the Western Atlantic Ocean and in the Caribbean. It grows to be 5cm long, and participates in the same kleptoplasty shenanigans as most other sacroglossans- it retains the algae it eats and uses its photosythesis as a second food source! With frills pictured above and its ability to photosythesize, it’s no wonder it’s called the Lettuce Sea Slug (although additionally, many are coloured green)!