Animal Kingdom I The final class contains squids and octopodes, Class Cephalopod
ID: 201920 • Letter: A
Question
Animal Kingdom I The final class contains squids and octopodes, Class Cephalopoda. These are marine animals that are excellent swimmers and predators. Their foot is divided to form their tentacles. They have two tentacles and eight arms. They are also extremely intelligent and have well developed senses suchr as the eyes. They move by jet propulsion and eject ink from an ink sac for hunting as well as to escape from predators. They can change their skin color very quickly as a form of protection. Members of this class have a small internal shell as well. They even have a parrot like beak that they use to inject venom into their prey Cuttlefish are another member of the Class Cephalopoda. They also have an internal shell and can eject ink as a form of protection from predators (sharks, large fish, and other cuttlefish). They can change their skin color as a form of protection as well. Unlike squids and octopi, cuttlefish have a cuttlebone that is made of calcium carbonate. They use it to control buoyancy and can sink quickly by changing the gas to liquid ratio in the bone. They are carnivores and eat crabs, shrimp, small mollusks, fish as well as other cuttlefish. They kill their prey with a venomous bite from their beak and are nocturnal. (Some squids are nocturnal and most octopi are nocturnal.) 18. How does the cuttlefish differ from squids and octopi?
Explanation / Answer
Cuttlefish have cuttlebone - buoyancy organ, which is unique to the family Sepiidae. Squids and octopi do not have cuttlebones. Cuttlebone is primarily composed of aragonite (Crystal form of calcium chloride) and forms the internal shell of cuttlefish.