Elysia leucolegnotes are often found clustered together in small pools left by the ebb of the mangrove tide. When the pools are nearly dry, they will burrow into crab holes or mud to escape heat. Each pool can hold up to 100 of them.
Elysia tomentosa are found in offshore underwater coral reefs. They are olive green, covered with white hairs of different lengths with a distribution of orange and black dots, forming a protective camouflage that blends with their habitats. The lateral foot margin and olfactory horn of Elysia tomentosas are orange, and as they age they become darker and their body length extends to about 40 millimeters, Wan said.