Octopus--Beautiful AND Intelligent

E. Norbert Smith, Ph.D.
Email: DocGater@aol.com
Website: www.NorbertSmith.com

Let me share a personal story about a pet octopus I once had. But first, here is some background from Dr. James B. Wood's Cephalopod page, which he has kindly allowed me to use in this article.

Many cephalopods, the group in which scientists classify octopuses, squid, cuttlefish and nautiluses, can instantly change color. Like chameleons and many fish, their skin contains chromatophores that cause the color change. Fish and chameleons change color more slowly, because their chromatophores are controlled by hormones. In contrast the chromatophores of cephalopod mollusks are controlled by the nervous system. It is the neural control that facilitates their rapid color change.

In addition to instant changes in skin color, they can also change the texture of the skin and body shape rapidly. In addition to chromatophores the skin of octopuses is covered with small neutrally controlled erectile pimple-like structures called skin papillae. In the natural environment they are extremely excellent at camouflage and often difficult to detect unless they move. As every school child knows if those camouflage techniques don't work, they can still "disappear" in a cloud of somewhat toxic 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 propelled by forcefully expelling water and they're found in all oceans of the world; from the tropics to the poles--the intertidal regions to the deepest 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 image forming eyes and other senses that rival those of humans. Cephalopods can do all these things and more. While most mollusks have a hard 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. There are only eight hundred or so living species of cephalopods; compare that with thirty thousand living species of bony fish.

Now here is a true personal story about a pet octopus I once had. While attending Southwestern Oklahoma State University, I built a 379 liter (100-gallon) refrigerated salt water aquarium and kept a small octopus, crabs, starfish, beautiful sea anemone and other tide pool critters...not an easy task for one living in western Oklahoma.  I collected all the tide pool animals and several kinds of marine algae while on a family vacation along the rugged coast of Maine . I brought them and several New England ferns to Oklahoma in the family car in ice chests replete with aeration provided by a battery operated air pump. I purchased the octopus from a west coast biological supply house. The tank was divided by a vertical glass petition and on several occasions the octopus would get to the other side and devour the crabs.  Lacking a skeleton, it squeezed through the narrow 2-3 millimeter space alongside the petition!

I often read my university assignments in a recliner next to the aquarium.  Without fail, as soon as I was seated the octopus would leave its rock cave and paste itself on the glass next to me apparently out of curiosity watching me study.  I knew it was watching attentively, because the slightest hand or head movement by me would elicit a rapid color changes around his eyes and head.  Remember, the chromatophores of octopuses and other cephalopods are controlled neurally, unlike the much slower responding hormonally controlled chromatophores of chameleons and fish. They can also instantly change their texture from smooth to rough by raising small pimple-like structures all over their body as show in the photograph above.  Mating in octopuses and several other cephalopods is triggered by color changes in the female.  The male can read the female's mood by her color.  Wouldn't that save a lot of money spent on wine and dinner?  And to think some consider cephalopods primitive.  I disagree and miss my octopuses still.