Ophioderma rubicundum
Otherwise known as a Ruby brittle star, ophioderma rubicundum is a species of brittle star. Ruby brittle stars consist of a central disc with five slender red legs ringed with cream colored bands. A brittle star has arms that are supported by vertebral ossicles (plates made from calcium carbonate.) These ossicles allow the brittle star's arms to move. The plates are moved by a type of connective tissue called mutable collagenous tissue, which is controlled by the nervous system. Unlike a sea star, whose arms are relatively inflexible, the brittle star's arms can have a graceful, snakelike quality, which allows them to navigate quickly through and squeeze into tight spaces, such as in coral complexes.