Fig. 3. (A) Mean rock size of S1–S6 as percentage of nine cuttlefish's average White square area (381.32 mm²). (B) Percentage of sand coverage of S1–S6. (C) Relative mean intensity of S1–S6. Unit represents percentage of average photon catch of each substrate relative to photon catch of a white surface (see text for photon catch calculation). (D) Root-mean-square (RMS) contrasts of S1–S6. (E) Number of lighter rocks of S1–S6. Lighter rocks are defined by Weber contrasts greater than 1 (see text for the Weber contrast calculation).