Charles B. Miller

The Red Cap of Calanus, An International Bestseller

The red pigment cap on the posterior end of the oil sac of Calanus finmarchicus can be explained as an adaptation to reduce detection by predators. The oil sac should capture downwelling irradiance along its sides, guide it to the conical posterior end, and emit it as fish attracting sparkles. The sparkling is blocked by the red pigment. The poster shows results of an optical model of submarine light field distortion by these tiny lenses.