Lecture 6

Question 1

describe how the anatomical characteristics unique to molluscs have been modified in cephalopods

Answer 1

foot has been modified into a circle of arms
head is now inline with visceral mass

muscular mantle surrounds body, has also been enlarged an thickened

closed circulatory system

Question 2

indicate the features of cephalopods that make them effective predators

Answer 2

highly developed nervous system and brain

advanced sight

tentacles with suckers

beak/radula

camouflage and stealth

jet propulsion

venom and toxins

sensory systems

Question 3

how does the structure of the cephalopod and vertebrate eyes illustrate the concept of convergent evolution

Question 4

describe some attributes to cephalopods that are indicative of a very complex nervous system

Answer 4

learning, memory, problem-solving, and advanced sensory processing.

large brain

highly developed ganglia

Question 5

cephalopoda

Answer 5

podos = foot

octopus, squids, nautilus, and ammonites

marine

foot has been modified into a circle of arms
head is now inline with visceral mass

muscular mantle surrounds body, has also been enlarged an thickened

closed circulatory system

~550 species - diversity has decreased over evolutionary time

spawned in the Cambrian era

shells are now internal and highly reduced

evolution of buoyancy control (during palenzoic/ cambrian explosion

SHELL
- center of shell is the oldest (start of life)
- expands out in a spiral
- divided into chambers that have nipples