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Many cephalopods, the group in which scientists classify octopi,
squid, cuttlefish and nautiluses, can change color, body texture, and shape. If those methods of camoflage don't work,
they can still "disappear" in a cloud of ink, which they use as a smoke-screen or decoy. Cephalopods are flippin' sweet because
they have three hearts that pump blue blood, they're jet powered, and they're found in all oceans of the world, from the tropics
to the poles, the intertidal to the abyss. Cephalopods have inspired legends and stories throughout history and are thought
to be the most intelligent of the invertebrates. Some cephalopod species can squeeze through the tiniest of cracks. They have
eyes and other senses that rival those of humans.
The class Cephalopoda, which means "head foot", are mollusks and
therefore related to things like scallops, oysters, clams, snails slugs,tusk shells, andchitons. Some of these mollusks,
like the don't even have a head, much less something large enough to be called a brain. *cough*Like Gabriel*cough* Yet
cephalopods have well-developed senses and large brains. Most mollusks are protected by a shell and many of them are not very
mobile. Although the older nautiluses had an external shell, the trend in cephalopods is to internalize and reduce the shell.
The shell in cuttlefish, when present, is internal and is called the cuttlebone *giggle*, which is sold in many pet shops
to supply calcium to birds. Squid also have a reduced internal shell called a pen. Octopi lack a shell completely.
 Nautilus pompilus.
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Most cephalopods eat things wth shells like crabs, lobsters, and clams. They breathe through gills
so they can only lve in water. Cephalopods like octopi propel themsleves through the water using a kind of jet propulsion.
Scientists noted that many cephalopods excrete in a way similar to dogs. A female cephalopod lays thousands
of eggs at a time and for about six months she does not eat, but spends all of her time protecting the eggs from other sea
creatures. Like Pacific salmon, cephalopds only reproduce once in their life. After her eggs hatch, the female
dies. The babies float to the water's surface, where they live for about six weeks. At this point, they are large
enough to survive life in the ocean depths.
Surprisingly in light of their ability to change color, most cephalopods are probably color blind.When camouflaging themselves, they use their chromatophores to change brightness and
pattern according to the background they see, but their ability to match the specific color of a background probably
comes from cells such as iridophores and leucophores that reflect light from the environment. Evidence of color
vision has been found in only one species, the Sparkling Enope Squid.
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