The Japanese sea star is a sea star

Sea star

Starfish or sea stars are echinoderms belonging to the class Asteroidea. The names "starfish" and "sea star" essentially refer to members of the class Asteroidea...

 originally from Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and recently introduced to Tasmania

Tasmania

Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

. Measuring 12 cm arm to arm it can vary in colour inscribed with blue and orange patterns. It is non-native in Australia but fortunately has not spread to the mainland.

On January 4, 2004 a huge migration

Animal migration

Animal migration is the relatively long-distance movement of individuals, usually on a seasonal basis. It is a ubiquitous phenomenon, found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The trigger for the migration may be local...

of sea stars went from Japan to Thailand in order to attract mates. This phenomenon happens around every 20 years.