190 likes | 415 Views
Echinoderms. Phylum Echinodermata , from the Greek for spiny skin. Phylum Echinodermata – spiney-skinned animals. includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids reverted back to radial symmetry tube feet and water vascular system. Echinoderms.
E N D
Echinoderms Phylum Echinodermata, from the Greek for spiny skin
Phylum Echinodermata –spiney-skinned animals • includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids • reverted back to radial symmetry • tube feet and water vascular system
Subphylum Asterozoa • Classes • Asteroidea (sea star) • Ophiuroidea (brittle stars)
Subphylum Echinozoa Classes • Echinoidea (sea urchin and sand dollar) • Holothuroidea (sea cucumber)
Subphylum Crinozoa • Crinoidea (feather stars and sea-lillies)
Characteristics Adult echinoderms possess radial symmety
Class Asteroidea Sea star
Brittle star Class Ophiuroidea
Sea urchin Class Echinoidea
Class Echinoidea Sand-dollar
Sea cucumber Class Holothuroidea
Feather star Class Crinoidea
Characteristics • Echinoderms' larvae are ciliated, free-swimming organisms that are bilaterally symmetrical
Characteristics • echinoderms do not possess an external skeleton. • a thin skin covers an endoskeleton made of tiny calcified plates and spines • Echinoderms possess a unique water vascular system, a network of fluid-filled canals that function in gas exchange, feeding, and secondarily in locomotion • echinoderms possess a complete digestive tube • Many echinoderms can regenerate. Some sea stars are capable of regenerating lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star. • the seastar can insert its stomach through the opening of a bivalve and release gastric juices, digesting the prey alive during feeding