Spanish Dancer

The Spanish Dancer is one of the largest of all nudibranchs. It is a strong swimmer (rare among nudibranchs). The species name, sanguineus, refers to its bright-red coloration, although there is also a yellow variant. This nudibranch has two modes of locomotion: crawling and swimming. When it crawls, the wide edges of the mantle (called "parapodia") are rolled up close to the body. But when it swims, the parapodia unfurl and are whirled through the water in a spectacular undulating motion (hence the widely-accepted name "Spanish Dancer").