FAQ
A contribution of The Cephalopod Page
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Rick Villa and I have been corresponding for a while now. Here is one of his many interesting messages.
Dear James, How are you? It has been a while since we last communicated. We have the octopus residing in our tank finally! It has gotten pretty well adjusted. My tank has an undergravel filter, and the octopus has dug its den underneath a piece of coral all the way to the filter plate. I keep filling it back up with gravel but it digs the hole again. However, it has not gone underneath the filter plate as you warned, because the coral is in the middle of the tank. I hope this does not ruin the functionality of the filter; the octopus hole is close to the power head intake hole in the filter plate, I wonder if flow of water through the undergravel bed is affected negatively? Water will take the path of least resistance - the areas away from the power head which have more gravel may become anoxic over time. Because of problems such as this as well as octopuses getting under the undergravel filter plate, I don't recommend undergravel filters for octopus tanks. The octopus seems happy. It has lots of places to hide in. It has a voracious appetite. It will snatch goldfish in a heartbeat. We have given it some fiddler crabs which it takes with alacrity. Also, clams from King Soopers, although you have to open them for it. Recently, I did an interesting experiment that I had read about in a Cousteau book a long time back. I bought a small goldfish bowl and put a cork at the mouth, the cork with a hole in it. Inside the bowl, I put a fiddler crab, corked it up and offered it to the octopus. The octopus saw the crab and immediately went for it, trying to cover it with its mantle. It met with the glass wall which threw it off. It tried repeatedly to grab the crab, which was moving aware of the attack, but could not. It gave up, and started crawling in the front glass of the aquarium, sweeping past the fish bowl and not doing much about it. It was conscious of the fact that we were watching it, I think. So we left it alone and watched it from where it could not see us. It then attacked the bowl again, and started feeling around it. It found the cork and put a tentacle in the hole. It touched the crab but could not retrieve it. It kept feeling around trying to attack it, changing color constantly. It also kept moving away form the bowl and then returning to it. Then, it came back and attacked it form the top. This whole process went on for about an hour. Suddenly, it seemed to get hold of the cork, and it pulled on it. The cork went shooting upward, and the octopus held on to it for an instant, and then let it float. It then went into the bowl and neutralized the crab. It stood in there for a while, and then tried to get out but could not find the gaping hole on top. It started to move about brusquely, sort of panicking, then it found the outlet and went to its cave to eat its meal. We tried this again a couple of days later, and it took less than 5 minutes to open the cork top in the same manner. However, it somehow failed to go into the fishbowl and was swimming around it, never going into it from the top, trying to get the crab but still meeting the glass bowl. I finally pushed the crab out and let the octo take it after about an hour. While there seems to be no doubt the octopus is quite an intelligent problem solving creature, I was surprised how the second time around it simply did not get the crab after opening the bowl. This was pretty surprising. However, we had a lot of fun doing this experiment. I have to think of some more experiments of this sort to try out. |
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| Water will take the path of least resistance - the areas away from the power head which have more gravel may become anoxic over time. Because of problems such as this as well as octopuses getting under the undergravel filter plate, I don't recommend undergravel filters for octopus tanks. Dr. James Wood |