The incredibly bright colors of this starfish may be a warning that it contains toxic chemicals. If carried with bare hands for any length of time, it causes numbness. A mosaic of raised yellow ridges covers its red upper surface and it has a soft texture. The mosaic sea star feeds mostly on sponges, and these may be the source of its toxins. When the females spawn, the fertilized eggs are retained and brooded on the underside of the body.