BILD 3 Lecture Notes - Lecture 15: Simian, Craniate, Thumb
Document Summary
Includes snails and slugs, oysters and clams, and octopuses and squids. Most molluscs are marine: though some inhabit fresh water and some are terrestrial. Molluscs are soft-bodied animals: but most are protected by a hard shell. Molluscs: trochophore larvae as part of life cycle, body plans with three main parts. A mantle: there are four major classes of molluscs. Marine; shell with eight plates; foot used for locomotion; radula; no head. Marine, freshwater, or terrestrial; asymmestrical body, usually with a coiled shell; shell reduced or absent in some; foot for locomotion; radula. Marine and freshwater; flattened shell with two valves; head reduced; paired gills; no radula; most are suspension feeders; mantle forms siphons. Marine; head surrounded by grasping tentacles, usually with suckers; shell external, internal, or absent; mouth with or without radula; locomotion by jet propulsion using siphon made from foot. Chitons: class polyplacophora is composed of the chitons. Oval-shaped marine animals encased in an armor of eight dorsal plates.
