Reduction of Cypris Larval Settlement on a Flat Plate under Light Emission with a Central Wavelength of 940 nm

Abstract

We examined the effect of infrared light emission （central wavelength of 940 nm） on the settlement of cypris larvae on the surface of a flat plate reached by light. Only 8.5 ± 3.9 % (n=3) of individuals settled on the surface. The radiant intensity at the center and the edge 5 cm from the center were estimated to be 58.3 and 34.2 W m⁻², respectively. Those results indicate that cypris larvae can move spontaneously to avoid infrared light that reaches down with a radiant intensity of approximately more than 34.2 W m⁻².