Phylum Mollusca. Ch. 12. General Ideas Phylum Mollusca. Members are called Mollusks Example Species: Slug Squid Scallops Octopus Snails. Phylum Mollusca Characteristics. Over 100,000 Species Many are marine, some are freshwater, and some live in moist land environments
Open Circulatory System
Closed Circulatory System
Only some mollusks, such as squid.
Blood is confined to blood vessels as it moves through the body.
Mollusks that move quickly, such as octopi, need more energy than slow-moving mollusks, and the closed circulatory system quickly deliver nutrients and oxygen.
"There once was an oysterWhose story I tell,Who found that some sandHad got into his shell.It was only a grain,but it gave him great pain.For oysters have feelingsAlthough they're so plain.Now, did he beratethe harsh workings of fateThat had brought himTo such a deplorable state?Did he curse at the government,Cry for election,And claim that the sea shouldHave given him protection?'No,' he said to himselfAs he lay on a shell,Since I cannot remove it,I shall try to improve it.
Now the years have rolled around,As the years always do,And he came to his ultimateDestiny - stew.And the small grain of sandThat had bothered him soWas a beautiful pearlAll richly aglow.Now the tale has a moral,for isn't it grandWhat an oyster can doWith a morsel of sand?What couldn't we doIf we'd only beginWith some of the thingsThat get under our skin.” - Unknown
and tentacles to eat