This is a website aimed to educate people about sea slugs.

The Sea Slug Diet

Sea slugs can have a variety of diets depending on the species, some are herbavores meaning that they eat plants like algae and some are carnivores, in fact some are known to eat other sea slugs. In special cases the sea slug: Elysia chlorotica can photosynthesize

Here is a picture of a sea slug canabalizing another sea slug:

Original image here