Meeting Abstract

P1.5  Wednesday, Jan. 4  Cuttlefish camouflage: using visual psychophysics approach with grayscale disk patterns to examine disruptive body patterning BIRK, M.A.*; ULMER, K.M.; CHIAO, C.-C.; CHUBB, C.; SIEMANN, L.; HANLON, R.T.; Univ. of North Carolina Wilmington; Marine Biological Laboratory, Woods Hole, MA; National Tsing Hua Univ., Hsinchu, Taiwan; Univ. of California, Irvine; Marine Biological Laboratory, Woods Hole, MA; Marine Biological Laboratory, Woods Hole, MA

Cuttlefish can change their color, intensity, and pattern to camouflage in any natural environment. This study sought to determine an “activation function” for the 11 skin components that make up disruptive body patterns, and whether their activations could be predicted based on different proportions of grayscale disks in the visual background. Ten cuttlefish (Sepia officinalis) were used in a behavioral assay to determine these “activation functions”. Four complementary pairs of visual patterns were designed with proportions of five grayscale disks varying in mean intensity, contrast, skewness, and kurtosis. All four pairs of disk patterns were tested on white, 50% gray, and black backgrounds. The patterns potentially provide the ability to determine the sensitivity of the cuttlefish to each of the five grayscale disks. Preliminary analyses indicate that cuttlefish were not differentially sensitive to the disk patterns on a gray or black background. Cuttlefish showed stronger disruptive body pattern on a white background with disk patterns that were low mean intensity, high-contrast, or all-black. These three disk patterns each have a large proportion of black disks, thus suggesting that cuttlefish are more sensitive to black objects than white or gray objects when the objects are placed on a light background. Further analyses suggest that activation functions of a few disruptive components can be derived from these data, although predicting body patterns of cuttlefish on any given background still remains elusive.