Meeting Abstract

33.4  Sunday, Jan. 5 08:45  Dynamic Polarization Signaling in Swordtails Alters Female Mate Preference CALABRESE, G.M.*; BRADY, P.; GRUEV, V.; CUMMINGS, M.E.; University of Texas at Austin; University of Texas at Austin; Washington University in St. Louis; University of Texas at Austin gina.maria.calabrese@gmail.com

Polarization of the light field—and visual sensitivity to it—is pervasive across aquatic and terrestrial environments. While documentation of invertebrate use of polarized light is widespread, evidence of polarization-mediated signaling in vertebrates is currently lacking. Here we provide evidence that vertebrates use polarized reflectance in communication. Combining videopolarimetry and polarization-manipulated mate choice trials using the northern swordtail, Xiphophorus nigrensis, we found sexually dimorphic polarized reflectance, polarization-dependent mate choice behavior, and differential polarization signaling across social contexts. Our videopolarimetry measurements reveal that courting males adjust contrast in polarization patterning in social conditions by increasing within-body contrasts but decreasing body-to-background contrasts relative to asocial conditions. Use of polarization cues in mate choice contexts may provide aquatic vertebrates with enhanced detection of specific display features (e.g., movements or angular information), as well as a dynamic signaling mechanism that may enhance detection by intended viewers while minimizing detection by others.