Is the sun important to nudibranchs?

Eventhough nudibranchs are animals, the sun is still very important to some of them.  There are a few species of nudibranchs that have developed the ability to live in a symbiotic relationship with the photosynthetic micro-organisms known as zooxanthellae.  These zooxanthellae live within the outer layers of the nudibranch and when they harvest the energy from the sun, the nudibranch in turn harvests that energy from the zooxanthellae.  These nudibranchs have been given the nickname “Solar Powered Nudibranchs.”