2Phylum characteristics More species of mollusca than any other group in the ocean, 110,000 living species.Bilateral symmetryComplete digestive tract.Respiration may be surface exchange, gills or lungs.Nervous system is cephalized; gangliaSoft body protected by a calcium carbonate shell which is secreted by a mantle.
6Class Gastropoda Largest group of mollusca Torsion Larvae start as bilateral but because of torsion become asymmetric.Many have an operculumGanglion and eyesDioecious or hermaphroditic. Sperm-darts
7Who are they? (conch, abalone, murex, cowrie, cones)
8Class Cephalopoda ‘Head-foot’ Most complex brain of all invertebrates. 90+ tentaclesBeak inside buccal cavityMay have internal shell or lack shell entirely. Only 1 in this class has an exterior shell.Chromatophores