The blue starfish is a fascinating nocturnal sea organism. Also called the blue sea star comet, sea star or blue Linckia sea star, this creature has five arms and radial symmetry. Although they’re known as starfish, they’re not really fish, but are actually sea stars. Amazingly, they can grow a new leg after one of their legs is chopped off. Even more incredible is that a totally new sea star can develop from just about any portion of the one that is broken off.
These sea stars have tubular feet and elongated arms with identical internal organs on each arm. They’re known for their long, thin blue and orange rays with parallel sides. The blue starfish's mouth lies in the middle of its oral side and its anus is located on the top (aboral) side. A vascular system lets its suckers expand and contract, which causes these sea stars to move extremely slowly.
Color and Size
The bodies of blue starfish are bright or light blue with occasional red or purple spots, although they can also be pink, green, yellow or red. Their color, which is derived from a blue pigment (linckiacyanin) and yellow carotenoids, depends on the combination and exact ratio of the pigments of a particular sea star. A mature blue starfish can grow up to 12 inches long.
Geography and Life Span
Blue starfish originate from Bali and are now mostly found in the Great Barrier Reef, off the coast of Queensland in northeastern Australia. Because today there’s just one Great Barrier Reef and this reef is dying, they also live in other areas. Blue starfish live up to 10 years.
Food and Predators
Blue starfish are scavengers that continually search for food and mostly eat algae. They also consume organic matter found on the bottom of the sea, as well as sponges, mollusks, ascidians and bryozoans. Using their tube feet, they can pry apart bivalves and then insert their stomachs for digesting soft mollusks. Several predators, such as puffer fish, sea anemones and harlequin shrimp, eat blue starfish.
Sea stars reproduce by releasing their gametes into the water to be fertilized by gametes from the opposite sex. The female releases significant amounts of eggs into the water. Within only a couple of days, fertilized eggs can develop into feeding larvae when a male and female spawn close to each other. Although sea stars stay in their home reef when mature, when they become larvae, they disperse.