Even though echinoderm has cute appearance, you should near be mistaken by thinking that all echinoderms are weak animals. They are predators. The tube feet of sea star will be used to grip the prey such as oysters and clams.
There are some species of sea star living in all the world’s oceans, from tropical habitats to the cold seafloor. The five-arm varieties are the most common, hence their name, but species with and even 40 arms exist.