Use of ultraviolet cues in female mate preference in the sailfin molly, Poecilia latipinna

Abstract

Photopigments that allow for ultraviolet (UV) vision occur in numerous fish species. In several species that also reflect short wavelengths, there is an indication that UV cues are important in forms of social signaling including mate choice. The sailfin molly, Poecilia latipinna, is closely related to species that use UV-reflective structures in mate selection, but it is unknown whether P. latipinna possess UV-reflective structures and whether the perceived presence or absence of these structures influences mating decisions. We detected prominent UV features on males and fewer, smaller reflective areas on females and then tested the role of these markings in mate preference. We focused on female preference, as male ornamentation and signals in the visible spectrum are known to influence female mating decisions. Using a two-choice paradigm, we exposed sexually receptive females to males whose visual appearance was manipulated by filters that either transmitted the full spectrum or blocked UV wavelengths. Female mollies significantly preferred males viewed under full spectrum, whereas male controls had no preference for females in UV-present or UV-absent light environments. While the ubiquity of these markings across both sexes may suggest additional roles for UV communication (i.e., shoaling), our results suggest that female P. latipinna take into account information transmitted in the UV markings when making visual mate choice decisions.