Variation in the visual habitat may mediate the maintenance of color polymorphism in a poeciliid fish

PLoS One. 2014 Jul 2;9(7):e101497. doi: 10.1371/journal.pone.0101497. eCollection 2014.

Abstract

The conspicuousness of animal signals is influenced by their contrast against the background. As such, signal conspicuousness will tend to vary in nature because habitats are composed of a mosaic of backgrounds. Variation in attractiveness could result in variation in conspecific mate choice and risk of predation, which, in turn, may create opportunities for balancing selection to maintain distinct polymorphisms. We quantified male coloration, the absorbance spectrum of visual pigments and the photic environment of Poecilia parae, a fish species with five distinct male color morphs: a drab (i.e., grey), a striped, and three colorful (i.e., blue, red and yellow) morphs. Then, using physiological models, we assessed how male color patterns can be perceived in their natural visual habitats by conspecific females and a common cichlid predator, Aequidens tetramerus. Our estimates of chromatic and luminance contrasts suggest that the three most colorful morphs were consistently the most conspicuous across all habitats. However, variation in the visual background resulted in variation in which morph was the most conspicuous to females at each locality. Likewise, the most colorful morphs were the most conspicuous morphs to cichlid predators. If females are able to discriminate between conspicuous prospective mates and those preferred males are also more vulnerable to predation, variable visual habitats could influence the direction and strength of natural and sexual selection, thereby allowing for the persistence of color polymorphisms in natural environments.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cichlids / physiology
  • Ecosystem*
  • Female
  • Light
  • Male
  • Pigmentation*
  • Poecilia / physiology*
  • Predatory Behavior*
  • Sexual Behavior, Animal*
  • Visual Perception

Grants and funding

This work was funded by a NSF CAREER grant (1137624) to JACU and the College of Arts and Sciences at Syracuse University to JACU and JLHG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.