Spanish Dancer (Hexabranchus sanguineus)

Reaching sizes of at least 16 inches (40 cm), the Spanish Dancer (Hexabranchus sanguineus) is the largest nudibranch and one of the largest sea slugs on the planet.

Like most nudibranchs, the Spanish Dancer is brightly colored and does not blend in well with its surroundings. This bright coloration, similar to that of the poison dart frogs and many other species, serves as a warning to potential predators that the Spanish Dancer does not taste good and may even make a predator sick. Though this species spends most of its time crawling along the reef surface, it will swim when threatened, violently flapping its external gills and other appendages and displaying its brightest warning colors. This behavior reminded some observers of a flamenco dancer, earning the Spanish Dancer its common name.

via //photo 1: Mauritius100 //photo 2: manaphoto

Source: underthevastblueseas