starfish or sea stars are star-d echinoderm asteroidea

animal invertebrate wildlife organism coral underwater reef insect seafood reptile fish food leaf arthropod starfish sea stars star-shaped echinoderms belonging class asteroidea echinodermclass echinoderm live ocean floor deep water shallow intertidal zone low high tide five arms large sunflower star pycnopodia helianthoides largest: fully grown arm-span metre bit larger famous crown- -thorns lives polyps kingdom: animalia phylum: echinodermata superclass: asterozoa class: asteroidea