BIOL 1604 Lecture Notes - Lecture 10: Bivalvia, Melanin, Cephalopod
Document Summary
Body plan: head-foot plus visceral mass, mantle. Dorsal body wall forms a pair of folds (mantle) enclosing the mantle cavity. It is modified into gills or lungs and secretes the shell (the shell is absent in some) Ventral body wall specialize das a muscular foot used chiefly for locomotion. Surface epithelium usually ciliated and bearing mucous glands and sensory nerve endings. Circular, diagonal and longitudinal muscles in the body wall. Nervous system composed of paired cerebral, pleural, pedal and visceral ganglia. Sensory organs of touch, smell, taste equilibrium, and vision (in some) No asexual form monoecious and dioecious forms. Larva trochophore or veliger, some with direct development. One or two kidneys (metanephridia) opening into the coelom-pericardial cavity and usually emptying into the mantle cavity. Gas exchange by gills, lungs, mantle, or body surface. Open circulatory system (except cephalopods) of heart, blood vessels and sinuses; respiratory pigments in blood. Rasping, protusible, tonguelike organ with tiny chitinous teeth.
