title: Fairy wrasses perceive and respond to their deep red fluorescent coloration.
abstract: Fluorescence enables the display of wavelengths that are absent in the natural environment, offering the potential to generate conspicuous colour contrasts. The marine fairy wrasse Cirrhilabrus solorensis displays prominent fluorescence in the deep red range (650-700 nm). This is remarkable because marine fishes are generally assumed to have poor sensitivity in this part of the visual spectrum. Here, we investigated whether C. solorensis males can perceive the fluorescence featured in this species by testing whether the presence or absence of red fluorescence affects male-male interactions under exclusive blue illumination. Given that males respond aggressively towards mirror-image stimuli, we quantified agonistic behaviour against mirrors covered with filters that did or did not absorb long (i.e. red) wavelengths. Males showed significantly fewer agonistic responses when their fluorescent signal was masked, independent of brightness differences. Our results unequivocally show that C. solorensis can see its deep red fluorescent coloration and that this pattern affects male-male interactions. This is the first study to demonstrate that deep red fluorescent body coloration can be perceived and has behavioural significance in a reef fish.
authors.affiliation: Animal Evolutionary Ecology Group, Faculty of Sciences, University of Tübingen, Auf der Morgenstelle 28 E, Tübingen, Germany mail@tobiasgerlach.com.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gerlach
authors.affiliation: Animal Evolutionary Ecology Group, Faculty of Sciences, University of Tübingen, Auf der Morgenstelle 28 E, Tübingen, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Sprenger
authors.affiliation: Animal Evolutionary Ecology Group, Faculty of Sciences, University of Tübingen, Auf der Morgenstelle 28 E, Tübingen, Germany.
authors.forename: Nico K
authors.initials: NK
authors.lastname: Michiels
mesh_terms: D000378:Agonistic Behavior; D000818:Animals; D003116:Color; D005453:Fluorescence; D008297:Male; D010473:Perciformes / Q000502:physiology*; D010858:Pigmentation; D014796:Visual Perception
keywords: fish coloration; marine visual ecology; private channel; red fluorescence; signalling; visual communication