This yellow nudibranch is one of the more colorful species of a group of creatures commonly referred to as sea slugs. These soft-bodied animals are common on the reef, where they forage for sponges, tunicates, and other small invertebrates. The fuzzy growths on top of the nudibranch are its gills, which it uses to extract oxygen from the water. Nudibranchs are known for their amazing colors and striking forms. Currently, over 2,300 different species of nudibranchs are known to exist.