The Serpent Starfish is a tremendous scavenger that makes a great addition to any tank. They come in colors of black, brown, gray, green, and a combination. Their flexible arms are smooth and they can move very quickly. These starfish are nocturnal and like to spend the day hiding in rockwork. Often times, they will keep their body buried while extending out their arms to sense for food. During the night they will come out of the rockwork to search for food. They are tremendous scavengers and will feed on waste in an aquarium. Serpent Stars prefer lots of rockwork to hide in. More than one can be kept in each aquarium and they do a superb job of controlling excess waste in your aquarium. They are a must for any reef tank.Starfish are intolerant of sudden changes in oxygen levels, salinity and pH of the water, and cannot tolerate copper-based medications. The drip acclimation method is highly recommended for all Sea Stars due to their intolerability to changes in water chemistry. It should never be exposed to air while handling.Echinoderms are central disc organisms that use tube feet or spines to move their bodies. The Ophiuroidea Class is made up of Starfish that have a flat and smooth central disc with five spined arms. These spines vary from species to species and can be short, long, thick, or thin, and come in different colors. Some "arms" will lack spines altogether. Each arm is composed of top-side plates that allow for excellent flexibility and quickness, but have a downside of easily breaking. These arms will regenerate over time. The mouths of these creatures is on the underside of the central disc. This Class of Stars is nocturnal and do most their feeding at nighttime. During the day these Stars like to hide beneath rock, or in crevices and caves.