Sea Stars and Sea Urchins
Sea Stars (also called starfish) and Sea Urchins both belong to the group of spiny-skinned animals called echinoderms. They move using their many hydraulically operated tube-feet and have a mouth in the middle of the underside of their radially symmetrical body. Often the sea urchins found on the beach have lost their spines.
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Sea Urchin Amblypneustes (Echinodermata: Echinoidea) Sea urchins of this type have spines that break off easily leaving a “sea egg”. Notice that this is a radially symmetrical animal with the mouth in the middle of the underside and with the outer shell divided into five equal segments. Sea urchins are omnivorous scavengers or algae-eaters using their beak-like teeth which are self-sharpening. |
