The Spanish Dancer (Hexabranchus sanguineus) is one of the largest and most well known nudibranch species. This species is spectacular to find and its common name arises from its resemblance to a Spanish person dancing when it can be seen swimming in the water column. The Spanish Dancer belongs to the family Hexabranchidae and there are only two species known to occur in this family; the other being Hexabranchus morsomus. This species can be found throughout the tropical waters of the world and has been recorded from New Caledonia, Japan, Malaysia, China, Vietnam, Indonesia, Africa, the Red Sea, Hawaii, Fiji, Papua New Guinea and Australia. In Australia it can be found from central Western Australia around the north to Fish Rock on the New South Wales mid north coast.
This species is known to feed on a variety of sponges and lays a bright pink egg rosette that is rather large and easy to recognise. This species is easily recognised by its bright red mantle, in areas like the Red Sea this species is a spectacular deep bright red colour. This species has the ability to produce distasteful and toxic chemicals in its body that ensure that fish cannot feed on it.
The Spanish Dancer (Hexabranchus sanguineus) grows to a maximum size of approximately 52 cm in length.