Sea Stars: Asteroidea

Physical characteristics: Blue starfish have five arms and can be as large as 12 inches (30 centimeters) across. Adults are brilliant blue. The young are bluish green or purplish with dark spots.

Geographic range: Blue starfish live in the Indian and Pacific oceans.

Habitat: Blue starfish live on coral gravel in direct sunlight, in sand, and under rocks.

Diet: Blue starfish graze on waste and small animals.

Behavior and reproduction: Adult blue starfish hide during the day in coral and rocky crevices. They turn their stomachs inside out to feed on coral. Blue starfish use asexual reproduction, but scientists do not know the details.

Blue starfish have five arms and can be as large as 12 inches (30 centimeters) across. Adults are brilliant blue. The young are bluish green or purplish with dark spots. (Patricia Jordan/Peter Arnold, Inc.)

Blue starfish and people: Blue starfish are used in home aquariums and are the most commonly imported sea star.

Conservation status: Blue starfish are not considered threatened or endangered. ∎