Color Experiment

On Tuesday April 27, we went back to Hopkins to conduct our first experiment. Judit let us use the lab's baby Two-Spot Octopuses (Octopus bimaculoides) which were about 2cm long. This made things much easier for us because they were less likely to leap out of their containers and make a run for it, like the Red Octopus had tried to demonstrate for us during our previous visit. After picking an octopus, we scooped it out of its tupperware home and put it in a clear plastic container half filled with sea water (which you can see behind the colored paper in the picture below). The little guy must have been a little surprised, because he let out a cloud of ink that was bigger than he was. We let it adjust to the new environment for about ten minutes, and began our experiment.

We used ten different colors of construction paper, which we had laminated to prevent from getting too damp. These were placed under the container one at a time and left for two minutes to allow the octopus to get used to the change and let us observe its color changing behavior. We decided to stick to describing the overall color of the octopus, as the variety of patterns it displayed could confuse our results.

Since the table top we were working on was black, we used the black paper as the control for our experiment. With this background color, we observed that the little octo was a dark reddish brown color and did not changeat all during the two minutes.

We decided it would be best to alternate between dark and light colored paper, so we chose white as the next background. The moment we placed the container over the paper, the octopus immediately turned pale. We were a little surprised by how quick the change was! As the time passed, we noticed that the octopus would flash reddish brown if we made a sudden movements.

The next color we tested was brown. We noticed that the octopus adjusted quickly to the new background again; this time, it turned completely brown, and would gradually fluctuate between dark and light shades.

Then we tried the pink paper. After the brown shades we observed with the previous color, the pale red skin of the octopus was easy to notice.

With the orange background, the octopus turned brown and remained so with little change. Halfway through the time limit for the color, it surprised us by turning completely orange. If the test environment had some clutter to hide among, we would have had a hard time spotting the little guy.

On the green paper our little friend became reddish brown and sometimes turned a pale brown yellow color. It would also flash different shades of brown from time to time.

Then we tried the red paper. The octopus was first orange but changed to a dark reddish brown.

On the blue paper, the octopus seemed a little hesitant. It remained a pale orange tan color, but would sometimes pulsate with an earthy brown color.

With the yellow paper, the octopus was initially brown but changed to pale orange. Its skin closely matched the color of the paper, and would likely be an effective disguise in the wild.

The final color we tried was purple. The octopus was a brownish red color for the entire two minute time period, but occaisonally the sides of its body would remain brownish red, while the top of it would change to a pale brown.

We noticed that the octopus would occasionally show multiple colors at once. Its most frequent patten was to make the center of its body pale with a crusty appearance, while its sides turned dark brown. While displaying this pattern, it would try to remain still and sometimes sink to the bottom of the container.

Because young octopuses only have a fraction of the fully developed chromatophores they will have as adults, we were only able to observe basic color change and patterns. It would be interesting to try this same experiment on an adult Two-Spot to see if mature chromatophores allow more complex responses.

We decided it would be fun to film the octopus and share our point of view, but unfortunately an assortment of technical difficulties prevented us from getting footage of the first half of our experiment from the camera to a computer. Bummer! Luckily we filmed with two cameras, so here's a short video of the cute little octopus, starting with the green paper. Enjoy!