Mathger, LM, C-C Chiao, A Barbosa, and RT Hanlon. 2008. “Color matching on natural substrates in cuttlefish, Sepia officinalis”. J Comp Physiol. 194: 577-585

Cuttlefish are known to be able to adjust their color pattern based on their immediate environment. The goal of the experiment was to provide quantifiable data to justify this notion. In order to do so, the researchers developed natural substrates which were used to elicit three common color change responses in the cuttlefish. Once these changes had been observed, the reflectance of both the background and the color pattern present on the cuttlefish were calculated. The researchers also measured the reflectance of the chromatophores present in the cuttlefish and determined overall, that the reflectance of the animal and its chromatophores closely mimics the reflectance of the background indicating that the cuttlefish does indeed adjust its appearance in order to blend in with its surroundings.

The cuttlefish express three different pattern variations known as uniform, mottled, and disruptive. In order to conduct the experiment, eight cuttlefish were obtained. Four of the cuttlefish were euthanized and dissected and the spectral reflectance of the chromatophores was obtained. Sand substrates of different colors and grain textures were created so as to elicit one of the three color patters of the cuttlefish. The substrates, except for two which were artificially dyed, underwent spectral analysis. The cuttlefish were placed in the presence of the substrate outdoors and the cuttlefish’s pattern reflectance was measured in 6 different locations and the substrate was measured in 10 locations at various areas around the cuttlefish. In order to determine the amount of discrepancy between the color reflectance of the background and the cuttlefish, the researchers normalized the reflectance spectrum to its maximum. This was done to compensate for any variation due to outside factors.

When the chromatophores of the euthanized cuttlefish were analyzed, three different colors were found. Yellow, orange, and brown were found on the dorsal side of the cuttlefish and on the ventral, the yellow and the orange were observed. When the animal was placed in a substrate, there was some variation between the reflectance of the background and of the cuttlefish itself. However, it was clear that the reflectance of the animal fell into the range of the background reflectance. When the cuttlefish were placed in the artificial sand environment, the cuttlefish did not adjust its color to its environment. However, the match between the reflectance of the cuttlefish and its background was much smaller with the natural substrates.

The conclusion that was reached after conducting their experiment – namely, that the cuttlefish adjusts its color pattern based on its natural surrounding environment, closely reflects the discussions in lecture. Based on the material presented in class, the cuttlefish is able to change its pattern rapidly as it passes over patches of sand or rock with different patterns thereby able to blend into its environment so as, for example, to escape from predators and hunt for prey.