Fig. 1

Lighting conditions of spectral and intensity experiments. In the spectral experiment, juvenile Megalops atlanticus were kept in lighting conditions of different spectra but identical irradiance (500 µW s⁻¹ cm⁻²). The ‘blue’ condition (a) and ‘red’ condition (b) were centered on 420 nm light and 590 nm light, respectively. In the intensity experiment, M. atlanticus were kept in lighting conditions of different irradiances but identical spectra. The ‘bright’ condition (c) and ‘dim’ condition (d) consisted of 2.5 mW s⁻¹ cm⁻² and .325 µW s⁻¹ cm⁻² white light, respectively. Insets: emission spectra and irradiance values for each condition, y-axes are normalized irradiance (μW s⁻¹ cm⁻²)