A spanish dancer nudibranch (
Hexabranchus sanguineus), gracefully undulates through the nighttime water off one of Maui's coastal reefs. This nudibranch has two very different modes of locomotion: crawling and
swimming. When it crawls, the wide edges of the mantle
are rolled up close to the body. When the animal swims however, the red edges unfurl, and are whirled through the water in a spectacular
undulating motion, propelling the animal forwards.
