ZOO 2700 Study Guide - Final Guide: Bioluminescence, Ecdysone, Monoplacophora
Document Summary
Describe how viscoelastic mucus is used during digestion in many molluscs. Discuss how the different molluscan groups might have evolved: different niches and ecological advantages produced the changes in shells and morphology. For instance, the aplacophorans probably lost their shells because they did not need it. The cephalopods internalized their shells, which allowed them to squeeze into very tight places, either to hide from predators or chase prey into small spaces. Gastropods got a shell that allowed them to retreat into and hide. Inhalation: circular muscles relax and radial muscles contract and hyperextend the mantle wall: can hold more water than during slow jetting ii. iii. Increase in diameter creates a negative pressure that draws water in through peripheral inhalant siphons. Is the fourth pair down from the dorsal side: how do cephalopod suckers work (i. e. generate suction forces and break the seal)? a.
