Warning: include(_inc/header.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 9

Warning: include(_inc/header.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 9

Warning: include(): Failed opening '_inc/header.php' for inclusion (include_path='.:/opt/cpanel/ea-php82/root/usr/share/pear') in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 9

Welcome to The Cephalopod Page


The Cephalopod Page is the personal web page of Dr. James B. Wood and has been online since 1995. James is an Assistant Research Scientist at the Bermuda Institute of Ocean Sciences. Questions and suggestions are always welcome( ) but please browse the website and read the FAQ (Frequently Asked Questions) first.

Bathypolypus arcticusIntroduction to Cephalopods


A 33 MB video (which takes a while to download even on a fast connection) of a Octopus macropus escaping out of a 2.5 cm hole. This is part of Ray Deckel's fall independent research project at BIOS.

Many cephalopods, the group in which scientists classify octopuses, squid, cuttlefish and nautiluses, can change color faster than a chameleon. They can also change texture and body shape, and, and if those camouflage techniques don't work, they can still "disappear" in a cloud of ink, which they use as a smoke-screen or decoy. Cephalopods are also fascinating 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. Cephalopods can do all these things and more.

The class Cephalopoda, which means "head foot", are mollusks and therefore related to bivalves (scallops, oysters, clams), gastropods (snails and slugs), scaphopoda (tusk shells), and polyplacophorans (chitons). Some of these mollusks, like the bivalves, don't even have a head, much less something large enough to be called a brain! 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 ancient nautilus has 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, which is sold in many pet shops to supply calcium to birds. Squid also have a reduced internal shell called a pen. Octopuses lack a shell altogether.

Nautilus pompiliusCephalopods are found in all of the world's oceans, from the warm water of the tropics to the near freezing water at the poles. They are found from the wave swept intertidal region to the dark, cold abyss. All species are marine, and with a few exceptions, they do not tolerate even brackish water.

Cephalopods are an ancient group that appeared some time in the late Cambrian period several million years before the first primitive fish began swimming in the ocean. Scientists believe that the ancestors of modern cephalopods (Subclass Coleoidea: octopus, squid, and cuttlefish) diverged from the primitive externally-shelled Nautiloidea (Nautilus) very early - perhaps in the Ordovician, some 438 million years ago. How long ago was this? To put this into perspective, this is before the first mammals appeared, before vertebrates invaded land and even before there were fish in the ocean and upright plants on land! Thus, nautilus is very different from modern cephalopods in terms of morphology and life history.

Cephalopods were once one of the dominant life forms in the world's ocean. Today there are only about 800 living species of cephalopods (compare that with 30,000 living species of bony fish, see FishBase). However, in terms of productivity, some scientists believe that cephalopods are still giving fish a run for their money.
Warning: include(_inc/resources.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 34

Warning: include(_inc/resources.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 34

Warning: include(): Failed opening '_inc/resources.php' for inclusion (include_path='.:/opt/cpanel/ea-php82/root/usr/share/pear') in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 34

Warning: include(_inc/footer.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 36

Warning: include(_inc/footer.php): Failed to open stream: No such file or directory in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 36

Warning: include(): Failed opening '_inc/footer.php' for inclusion (include_path='.:/opt/cpanel/ea-php82/root/usr/share/pear') in /home/onebreat/thecephalopodpage.org/MarineInvertebrateZoology/index.php on line 36