Fish glowing red

Plenty of reef creatures fluoresce red, even where seawater absorbs red sunlight

A lot of reef creatures could be in the red.

RED FIN AND ALL A wrasse fish appears one color under full natural lighting (top) but is red when seen through a filter that blocks everything but the red fluorescence (bottom). Michiels et al. BMC Ecology

RED ZONES A triplefin reef fish fluoresces red as patches on its body absorb blue wavelengths of light and release the energy as a red glow.