ABS 2023
UV reflectance and its influence on social behavior in a livebearing fish (Girardinus metallicus)�� � �
Madeleine S Kwon, Jake D Roth, Gita R Kolluru. California Polytechnic University, San Luis Obispo, CA, United States

Ultraviolet (UV) reflective markings may be important in animal signaling, particularly in social species. We describe UV reflectance patterns obtained using digital imagery, in both male color morphs and both sexes of the small, freshwater, livebearing fish Girardinus metallicus. The most prominent reflectance occurs on the iridescent vertical bars which occur along the body and characterize the species. There is also a reflective area behind the eye, which is also described in other livebearers. G. metallicus is a social species that inhabits clear, shallow water, likely facilitating UV transmission. UV patterns have been shown to be used by fish for species and individual identification. To test whether UV reflectance influences social behavior in G. metallicus, we tested association preferences for conspecifics located behind UV blocking versus UV admitting filters. UV reflectance is an often overlooked component of animal signaling because it is invisible to humans. However, it may serve important functions in intraspecific communication, especially because it can be used as a private communication channel, visible to conspecifics but not predators.� �