Preferred Wavelengths of Visible Light for Juvenile Atlantic Menhaden

Juvenile Atlantic menhaden (Brevoortia tyrannus) from Chesapeake Bay tributaries were tested for preferred wavelengths of visible light. Fish were subjected to test gradients from 460 to 660 nm at 20 nm intervals in a test trough, and light-and dark-acclimated fish were tested at three light intensities (0.1, 0.2, and 0.4 µEm^-2 s^-1). These fish exhibited a preference (P < 0.05) for 460-540 nm wavelengths in all tests, and a concentration in the 460-500 nm wavelengths at the higher light intensities (0.2 and 0.4 µEm^-2 s^-1). Knowledge of these preferred light wavelengths can be helpful for increasing commercial fishery catches and lowering the industrial impingement rates in water intake systems.