Red fluorescence in marine fishes: Functions, mechanisms and consequences for visual communication on reefs

• Applicant: Professor Dr. Nicolaas K. Michiels
• Subject Area: Sensory and Behavioural Biology
• Term: from 2009 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 130047674

This project contradicts established views on marine fish color vision by attempting to prove my prediction that long-wavelength light (“red”) plays an adaptive role for coral reef fish, also at depths where red light from the sun cannot penetrate. This change of paradigm is inspired by our recent discovery of red fluorescence in reef fishes, which transforms incoming bluegreen light into red light independent of depth. Based on our initial observations, it is plausible that these fish can see red light and use it for intra- or inter-specific signaling. We also found preliminary evidence that the fluorescent pigments are possibly sequestered from microbial sources. These findings are new to science and warrant swift and in-depth investigation along two lines: (1) evaluation of the adaptive function and evolution of red fluorescence in marine fish including tests of the ability of the presumed signal receivers (of the same or other species) to perceive red, and (2) detailed histological, microscopical, microbial and molecular analyses of the sources of these pigments and the mechanisms that fish use to modulate their fluorescence intensity. We have carried out a series of pilot experiments to address the feasibility of many of these aspects.

• DFG Programme: Reinhart Koselleck Projects