BIOL 111 Lecture Notes - Lecture 13: Cephalopod, Nudibranch, Peripheral Nervous System

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Irene Gregory- Eaves

Document Summary

2nd largest animal phylum terrestrial or aquatic. Modes of nutrition reproduction response to the environment. Variations on an ancestral molluscan body plan. Mollusk body plan: foot, mantle, visceral mass. 11mollusk body plan1. foot3. visceral mass2. mantlemouthanusheartgillsshellradulamantle cavity10mollusk body plan1. foot3. visceral mass2. mantlefootvisceral mass contains gills (aquatic); acts as lung (terrestrial)mantle cavityclass polyplacophora many plates . Water flows in mantle cavity and then across gills that act as filters for food foot used as anchor and for digging. Ex: scallop large adductor muscles to close shell. Mantle lined eyes can detect motion and light. 14class bivalvia two valves reduction of head hinged shell enlargement of footfoot mantle cavity modified by siphons enlargement of gill. Most diverse class (70,000 species) terrestrial or aquatic. More complex head and eyes internal or external fertilization. Either dioecious or hermaphroditic but can produce only sperm or eggs at one time. Coiling of visceral mass they undergo torsion then elongation and coiling.