From FrugalReef

• Scientific Name: Elysia Crispata
• Also Known As: Butterflies of the sea, Lettuce Sea Slug, Lettuce Leaf Nudibranch and Green Lettuce Nudibranch
• Hardiness: Moderate.
• Reef Safe: Yes
• Disposition: Non-aggressive herbivore

The lettuce nudibranch is a beautiful shell less snail. It's colors can range from green to blue. Some specimens have red, orange, brown or yellow trim on it's folds and often appears to be spotted.

The lettuce nudibranch is an algae eater, but contrary to popular opinion will not eat hair algae. They will, however, happily consume Bryopsis. As a matter of fact, some sources indicate that the only algae they will eat is Bryopsis, leading to a very real possibility of starvation. As the nudibranch eats this algae, it will incorporate the chloroplasts into it's own skin and become photosynthetic.

Another major concern with these creatures is getting sucked into overflows and powerheads. They are very fragile, all powerhead and overflow intakes should be covered with a fine mesh to prevent this.