There are more than 600 species of starfish/kloc-0, and more than 300 species of fossils, which are widely distributed in sandy seabed, soft mud seabed, coral reefs and oceans of various depths.
Starfish are carnivores and can feed on all kinds of invertebrates, especially shellfish, crustaceans, polychaetes and even fish.
Starfish breathe and excrete mainly through skin gills, tube feet and body surface. Dermatobranchial cleft is a tumor in which epithelial cells inside and outside the body wall protrude outwards and body cavity fluid also flows into it.