Lettuce Sea Slug
Elysia crispata is known in the hobby as Lettuce Nudibranchs and Lettuce Sea Slugs. They are sarcoglassans, a type of slug that sucks the chlorophyll out of algae and uses it to achieve their attractive green color. This species is also able to use the chlorophyll to create sugar from solar energy just like plants do. This process is called kleptoplasty, and gives them their final common name of Solar Slugs. For their size they consume more algae than their snail and hermit crabs counterparts. However, sea slugs have particular care requirements that make them unsuitable for most reef tanks. They are prone to gathering at drains and intakes.Because of this, Koralia/Vortech styled powerheads pose a danger to them. Maxi Jet style powerheads, with an extended arm and fine strainer are better suited. Similarly, wide overflow slots and drains without somewhat fine mesh are likely to be traps for the sea slug. They do not mind high flow levels, but high velocity will often send them adrift, and it is stressful to them. They are non-toxic, but do utilize chemicals from the algae they consume to make them unpalatable to most fish species.
The lettuce nudibranch derives its green color from the chloroplast in the algae it consumes and uses it not only for camouflage, but to create sugar which it can use to digest as well. Lettuce Sea Slugs aren't 100% macroalgae safe, but there are many species of algae that can be kept with them. If you have a planted tank and are considering a lettuce sea slug feel free to contact us with questions you may have about compatibility.