I have included some of my science note booking work, so you can learn more about Cephalopods -  Cuttlefish, Octopuses, Squid and Nautiluses.

Cephalopods (sef’ uh loh podz), a group made up of Cuttlefish, Octopuses, Squid, and Nautilus, are considered (scientifically speaking) mollusks, however they do not really fit in this group.  Nor are they truly fish or herps either, so this is the only spot they even kind of fit into.

What is a Cephalopod?  Well, most Cephalopods have special cells called chromatophores, but a Nautilus does not.  One distinguishing feature that all Cephalopods have are tentacles.  A octopus (obviously)  has eight arms, while Cuttlefish and Squid have ten, and Nautilus can have anywhere between 38 and 90 arms!  While Cephalopod means “Head foot”, Cephalopod’s tentacles are called arms, even though they aren’t actually arms.

Those arms each have a personal set of suckers, and they use those suckers for eating.  Pray, what do they eat with?  In the center of all those waving tentacles  is a beak.  Some Cephalopods are poisonous, while most eat crustaceans and other mollusks.  They use this beak to crush their prey’s shell.

Besides these amazing features, Cephalopods have other surprising aspects.  For example, their body is smaller, but they have three hearts that pump blue blood!  Cephalopods moving in a similar way that jellyfish do.  They open and close their arms and are pushed forward.  Some also move in a similar way that sea horses do, by grabbing and pulling.  With all this, Cephalopods can produce ink!  They use this ink to confuse predators.  If they are bothered, the shoot out the ink in a great black cloud while they propel themselves to safety.

Cuttlefish, despite their sleepy look, are dangerous nighttime predators.  Well, at least if your a gastropod, another kind of mollusk, or smaller bethnic animal.  They are usually colored a kind of mottled brown, white, grey, and other neutral colors.

Believe it or not, Cuttlefish DO have a shell!    Rather than having an exoskeleton, like a crustacean (these don’t actually have a shell) or a shell like an oyster’s or conch’s, Cuttle fish have their shell under their skin, called a internal shell (or in un-scientific terms, a cuttlebone, but it is not a bone, it is a shell).

Why is a Cuttlefish a deadly hunter?  It is a poisonous animal!  Under the eight arms around it’s mouth, it’s beak will inject a toxin that will kill it’s prey (lobsters, crabs, shrimp, snails, scallops, etc.).  A Cuttle fish is a master at hiding because of it’s chromatophores.  It has two tentacles under each eye, stored in a pouch, which come out and seize the prey of the Cuttlefish so that the Cuttlefish can eat it's meal.

Squid are fascinating creature that can grow from a couple of inches or to as much as 40 feet.  The one I really like is called the Giant Squid, whose members grow up to forty feet!

Giant squid were first thought of as fables.  People on land insisted that no squid could grow that big.  The sailors (especially whalers) said that it attacked ships and whales, and that they had found scars around sperm whales’ mouths that were the size of dinner plates.  Finally in the late 1800’s, a shoal of Giant Squid washed up on a beach, and so the myth was proved.

A Woodcut of the Fabled Giant Squid.  No Date or Artist.

Study of Giant Squid remains shallow, due to the fact that Giant Squid are designed for deep ocean water with lots of pressure.  Going into warm, pressure-free water causes it to die fast.  Scientists are doing their best however, and discoveries are being made - slowly.

Octopuses can change colors, like all most other Cephalopods.  How?  It has special cells called chromatophores.  These chromatophores  produce pigments (chemicals that have color) which can be manipulated to change the color of the Cephalopod’s skin.  Octopods are masters: they even can change textures!

Some octopuses (also called octopods) will change colors with their feelings.  They might turn white when they are frightened, red when their angry, etc.  Most use their chromatophores for just camouflage.

Octopus's brains are HUGE!!!  Their brains are close to ours, in fact, scientists estimate that they feel pain the same way we do, so there are laws that say that you can’t operate on an octopus without anesthesia.  Octopuses have been known to climb on ships and out their tanks and even play with objects like pill bottles!

Fiction.

Camouflaged Octopus.