Abnormal asteroids from the seas around India

Echinoderms as a rule are pentamerous and therefore most of the asteroids have only five arms. However, some of the asteroids like Luidia maculata, Acanthaster planci and others always have more than five arms. In some of the asteroids like Pentaceraster regulus and Protoreaster lincki. the number of arms may be less than five or more than five due to freak formation at the time of development