The pervasive effects of lighting environments on sensory drive in bluefin killifish: an investigation into male/male competition, female choice, and predation

Abstract

Sensory drive predicts that the conditions under which signaling takes place have large effects on signals, sensory systems, and behavior. The coupling of an ecological genetics approach with sensory drive has been fruitful. An ecological genetics approach compares populations that experience different environments and asks whether population differences are adaptive and are the result of genetic and/or environmental variation. The multi-faceted effects of signaling environments are well-exemplified by the bluefin killifish. In this system, males with blue anal fins are abundant in tannin-stained swamps that lack UV/blue light but are absent in clear springs where UV/blue light is abundant. Past work indicates that lighting environments shape genetic and environmental variation in color patterns, visual systems, and behavior. Less is known about the selective forces creating the across population correlations between UV/blue light and the abundance of blue males. Here, we present three new experiments that investigate the roles of lighting environments on male competition, female mate choice, and predation. We found strong effects of lighting environments on male competition where blue males were more likely to emerge as dominant in tea-stained water than in clear water. Our preliminary study on predation indicated that blue males may be less susceptible to predation in tea-stained water than in clear water. However, there was little evidence for female preferences favoring blue males. The resulting pattern is one where the effects of lighting environments on genetic variation and phenotypic plasticity match the direction of selection and favor the expression of blue males in swamps.

A perspective on sensory drive

“…There was also some evidence that female mating preferences differed among populations as well. Mitchem et al. (2018) presented three new studies showing that 1) predation risk of different colour morphs likely varies due to lighting environment, 2) the outcome of male/male competition varies due to lighting environment, but 3) unlike previous studies, female mate choice did not vary due to lighting environments.…”

“…Such patterns can be generated by local adaptation, adaptive phenotypic plasticity, or a combination of the two. Echoing the approach of Cummings and Endler (2018) is the contribution from Mitchem et al. (2018) summarizing a body of work on bluefin killifish and presenting three new studies on components of sensory drive.…”

“…4. Phenotypic plasticity as a function of the sensory environment may be common, particularly for organisms that have a high probability of experiencing multiple environmental conditions ( Mitchem et al. 2018 ).…”

“…2017 ; Cummings and Endler 2018 ; Gunderson et al. 2018 ; Mitchem et al. 2018 ; Yohe and Brand 2018 ).…”

“…Three main themes emerge in this column: the effects of signaling environments on signals and receiving systems ( Cummings and Endler 2018 ; Gunderson et al. 2018 ; Mitchem et al. 2018 ), the potential for sensory drive in sensory modalities other than vision and acoustics ( Cronin 2018 ; Yohe and Brand 2018 ), and the inferences concerning sensory drive that can be drawn by understanding the neurobiology underlying signal reception, perception, and discrimination ( Gunderson et al.…”