Lettuce sea slug

The lettuce sea slug is a soft-bodied mollusc with a frilled, leaf-like body that looks like a loose head of curly lettuce. It comes in a striking range of colours, making each encounter on the reef a little different.

Also known as: common lettuce slug, elysia crispata, elysia crispata mörch, 1863, lettuce slug

This slug is often mistaken for a nudibranch, another group of soft-bodied sea slugs, but it is not closely related to them. The tightly ruffled, lettuce-like edge of its body, rather than the finger-like gills nudibranchs often show, is the clearest way to tell it apart.

This sea slug has a soft body covered in ruffled, leaf-like flaps called parapodia, giving it a frilly, lettuce-like look. Colour varies widely between individuals: it can be green, blue, pale with red lines, or pale with yellow lines. It grows up to 15 cm long.

This slug feeds on several kinds of algae rather than sticking to just one species, giving it more food options if its usual algae become scarce. After eating, it keeps some of the algae's chloroplasts alive inside its own body, using them to keep making energy from sunlight for over a month.

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  Black-banded sea slug

  Cyerce nigricans

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  Leaf sheep

  Costasiella kuroshimae

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  Sea slugs

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