While diving in various parts of the reef, mainly shallow, you may see some ruffle like slugs. These are lettuce sea slugs. They resemble a type of lettuce, hence the name lettuce sea slug. They are usually of a green color, with some also having some blueish colors at times. If observed carefully, you can also spot a rainbow like colouration on their appendages.
These sea slugs are also called “sola slugs” because when they eat green algea they do not digest all the chloroplast and stores them in their ruffles or fleshy appendages. With this storage, the Lettuce sea slug is able to generate its own food.
Not much is known about the Lettuce sea slug’s mating habits. However, they do lay eggs upright on flat algae. The eggs take roughly about 15 days to hatch. Some of them will undergo various phases, where they will either stay on that reef or be carried away to other reefs via currents. Their diet has an array of various species of algae and the chloroplast actually work the same in their appendages as if it were one type of algae they feed on. What is beautiful about these slugs is the glow effect you can get when photographing them. These are very common on the shallow reefs in St. Lucia. Their life span is about 3-6 months!