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So You Want a New Pet?

So You Want a New Pet?


Can you name an animal that is dainty as silk but devious besides? Probably not. From their pictures, we might imagine that octopuses are solid, scary and, like the majority of marine creatures, not too intelligent. The scary part of the picture is correct, especially if one is a crab or shrimp or abalone. Nevertheless octopuses are typically as insubstantial as a lady’s negligee and smart, smart, smart.

Imagine that you want a pet octopus. Let’s see what these animals can do. Such creatures are found in all oceans of the world. Mostly they are quite small. The most popular species for raising in captivity is the common octopus (O. vulgaris) which has an arm span of about 25 cm. There are big species too. Giant octopus live off the west coast of Canada and the United States. No one knows how big Octopus dofleini actually gets. One specimen found in 1957 weighed 272 kg and had an arm span of 9.6 m. More typically mature specimens vary from 15 to 23 kg with an arm span of about 2.5 m.

Your mother, I am quite sure, does not want a big specimen in her house. To please her we will look at smaller species. They are just as talented as the giants. If you were to pick up your pet, you would find that it is pretty floppy. It has no bones, you know. All it consists of really is a head with eight arms attached. Watch out for the mouth. It has a vicious beak much like a parrot’s. The prominent eyes are actually much like yours. If you watch the animal perform its under-water ballet in the large tank your dad may graciously provide, you will notice that the iris in the octopus eye always remains horizontal no matter what the orientation of the creature. This eye motion, called counter-rolling, allows your pet to keep track of what direction is down.

One thing that you might not want to mention to your mother, is how hard it is to keep an octopus anywhere the octopus does not want to be. These are incredible escape artists. If you want to keep them out of a container under water, they will find a way to get in. If you want to keep them confined somewhere, they will most certainly escape. An article by Gilbert Voss (National Geographic December 1971 p. 791) informs us that octopuses have escaped from covered tin cans, securely tied wooden boxes and even steel strongboxes. Dr. Voss recounts the story of Billie, an octopus with a 37 cm armspan. Her body was about the size of a tennis ball and she was confined in a clear plastic box with only one hole, 1 cm in diameter. Billie was not pleased with this turn of events. She soon located the hole. One arm after another, suitably compressed, emerged through the hole. Next she slid her head through, distorting the shape of her eyes in the process. The first escape took twenty minutes but by week’s end she managed it all in less than two minutes. (See photos pp. 788-789 in same article.)

How was this animal able to achieve such a task? The experts believe it is pure and simple intelligence. Considerable research on the behaviour of the common octopus has been carried out in Italy. Not only do these animals learn quickly to avoid hazards like mild electric shocks, but other specimens watching the training process, learn even faster than the individuals which are learning by doing. Scientists Graziano Fiorito and Pietro Scotto in 1992 in the journal Science (256: 545-7) describe the case of a spectator octopus watching from an adjacent tank. The spectator learned to make the correct choice after only four observations. The actual trainee on the other hand took sixteen tries to make the correct choice. The ability to learn by watching is so impressive that the authors call it the first step toward forming abstract ideas (concepts). (See also National Geographic December 1992 in Geographica.)

Other talents of your new pet are just as fascinating as body flexibility. On their skin are cells which contain one or other of various colours. Special muscles close or open these cells. If all are closed, the animal is white. If some are partly opened, the animal will be a pale blend of whatever colour cells are open. If all are open, the animal assumes a dramatic dark hue. We have all heard “Can a leopard change its spots?” Well in the case of the octopus, it can and quickly too. Almost instantaneously an octopus can display dramatic false eyes, or stripes to spots. It can also produce a spectacular “passing cloud” display where washes of colour flush across the body. These talents serve partly to confuse predators which might fancy an octopus for lunch. Also many experts believe the colour displays reflect the animal’s mood. Bright colours indicate an upbeat, happy or curious octopus while pale ones reflect fear. Another feature which adds to the beauty of a happy octopus is a further layer of cells under the skin. This layer of platelike prismatic cells, when suitably oriented, serves to reflect light, thereby conferring a shimmery irridescence on the creature. It definitely adds to the richness of the colour display. Aren’t you glad you chose such a beautiful and talented pet?

Besides colour changes for camouflage, octopuses can make their skin bumpy or smooth. Another method of avoiding capture is to squirt into the water an inky liquid. Some species know how to do this so that the cloud represents the size and shape of the fleeing animal. A photo in the National Geographic (December 1971 p. 793) shows a moray eel pursuing an empty black cloud of ink while the real octopus, now white and bumpy to blend into the background, quietly exits the scene.

In all these situations the octopus displays a split second ability to analyze the situation and respond appropriately. But octopus talents don’t end there. If they are not occupied in catching dinner, or avoiding being dinner, then they prefer to hide in a crevice or some kind of protective container. If a home is not available, the animal will build one with whatever debris is available. But these animals are not good housekeepers. The area immediately in front of the home is littered with shells of various victims. These animals may be messy but the female is an excellent mother. First she lays her eggs in a protected spot. The eggs hang in vertical clusters from a common strand. Eating little or nothing, the female stays by her eggs for long periods (7 weeks for the common octopus and 6 months for the giant octopus). She guards them and waves her arms to keep oxygen filled water moving past them. The article in December 1971 National Geographic describes how a mother octopus released her mature young from their eggs rather than allow a scientist to capture them (for research purposes). Many mothers die once their eggs have hatched. At any rate few of these animals live more than four years.

Plainly octopus intelligence and talents are astonishing. Other animals with which the octopus shares some characteristics, such as the snail and the clam, display no comparable intelligence or any smarts at all. Neither do any other creatures which lack back bones. Fred Bavendam in his 1991 article on the giant octopus (National Geographic March pp. 86-97) estimates that the octopus is just as smart as the house cat (p. 91). So which would you rather have at your house, an octopus or just a plain puss?

While you ponder the benefits of one pet over the other, you might pause to wonder how the octopus got so smart. It can’t have been through gradual development. Other than a tiny group of similar animals (squid, octopus, cuttlefish and nautilus), no animals which lack backbones, display any thinking skills. In addition, the intelligence needs to be supplemented by other skills such as camouflage and flexibility. The octopus survives only because it has the advantage of all these talents all at the same time. Without a doubt all these skills were conferred on the octopus. This animal is wonderfully designed. Nevertheless I personally wouldn’t want one for a pet. How about you? Tell your mother that Moxie recommends cats.

May 1997

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