Elysia crispata, or the lettuce sea slug, has a ruffled exterior that is reminiscent of a head of iceberg lettuce, especially when it takes on a greenish hue. These lettuce-like folds are actually ...

One of the most widespread sacoglossan genera is Elysia, or lettuce sea slug — so named because of the green coloration from its stolen chlorophyll food source coupled with its frilly exterior.