I don't know if anyone's tried that...but I think someone on here had put a hermit crab inside one of those "candy machine" plastic things with the tight cover on top with the octopus successfully opening it. However, according to biologists, some octo's can do it and some don't which leads into further studying on their learning abilities.
Im guessing not many have done it on here because a jar of normal size would probably be more appropriate with a vulgaris or GPO to figure out.
kashmir could get a fiddler out of a water bottle with the top screwed on... took a while but he figured it out. started with the top just barely on and then as he figured that out i slowly started to tighten it every now and then
As I understand it, the original experiment was carried out in the wild and went something like this:
1. A researcher using SCUBA located and developed a rapport with one particular Octopus (I vaguely recall that it was in the Mediterranean) by feeding it shrimp.
2. One day the researcher showed the octo the shrimp, put the shrimp in a jar, closed the jar with a cork, and gave the jar to the octo. The octo took several minutes to figure out how to open the jar and then ate the shrimp.
3. The experiment was repeated several days later and the octo opened the jar almost immediately; possibly demonstrating memory or the ability to learn an artificial task.
4. On a subsequent repetition of the experiment the researcher showed the shrimp to the octo whereupon the octo swam into the jar and waited for his meal!
At the Feiro Marine Life Center, where I volunteer, we would give our smaller GPO (tip to tip arm-span ~ 4 or 5 feet) a squid in an old peanut butter jar with a plastic screw top lid. The first try took her about five minutes; subsequently she would remove the lid in under a minute. Unfortunately, as I mentioned in my earlier post, after being fed one crab she completely lost interest in squid - in or out of the jar. We also tried the jar on our larger GPO (5 or 6 feet tip to tip) and she also managed to figure it out but there was no repetition after we learned how difficult it was to retrieve the empty jar from her den. [Her tank is almost five feet deep.]
P.S. It's just not practical for us to try putting a one pound or larger crab in a jar!
At the New England Aquarium they put a large crab in a latched box and the GPO there opens it to get the crab. If the octopus gets the hang of it they put in different boxes with different latches and mix up which box is put in. I've heard that sometimes they put a box inside another box, each with a different latch. It's very interesting to watch becuase they put the closed box in there and the octopus comes over, completly covers the box with his body, and then a couple minutes later when he crawls away you see an empty, open box.
As far as the jar trick goes though, I've never seen an octopus do that.