We found this relatively rare and largish nudibranch (approximately 7 cm or 3″) in less than 1 metre (3 ft) of water in broad daylight on the algae covered reefs of Maui’s West side. Although this particular animal is an obvious bright red with yellow margins, the species comes in darker and lighter varieties. They are occasionally mistaken for the Dendrodoris nigra or Black Dendrodoris. Please see Cory Pittman and Pauline Fiene’s Sea Slugs of Hawaii for more complete information.