Phylum Mollusca
*General Characteristics:
-Includes: Snails, chiton, clams, and squids.
-Body of two parts: head-foot and visceral mass.
-Mantle that secrets a calcareous shell and covers the visceral mass.
-Mantle cavity functions in excretion, gas exchange, elimination of digestive waste, and release of reproductive products.
-Bilateral symmetry.
-Trochophore larvae.
-Coelom reduced to cavities surrounding the heart, nephridia, and gonads.
-Open circulatory system in all but class Cephalopoda.
-Radula usually present and used in scraping food; supported by the odontophore and have been lost in bivalves.
-Triploblastic.
-Bivalves and Gastropods are the most successful molluscans as cephalopod species numbers dwindle.
-They are both marine, freshwater, and terrestrial animals.
-Body of two parts: head-foot and visceral mass.
-Mantle that secrets a calcareous shell and covers the visceral mass.
-Mantle cavity functions in excretion, gas exchange, elimination of digestive waste, and release of reproductive products.
-Bilateral symmetry.
-Trochophore larvae.
-Coelom reduced to cavities surrounding the heart, nephridia, and gonads.
-Open circulatory system in all but class Cephalopoda.
-Radula usually present and used in scraping food; supported by the odontophore and have been lost in bivalves.
-Triploblastic.
-Bivalves and Gastropods are the most successful molluscans as cephalopod species numbers dwindle.
-They are both marine, freshwater, and terrestrial animals.