Reproductive Strategies of White Sands Pupfish (Cyprinodon tularosa) Inhabiting Stable and Stochastic Habitats

Authors: Adam Baca, Damon Peterson, Colleen A. Caldwell

Year: 2016 (xlviii)

Abstract

One of the fundamental theories in the evolution of mating systems is the interplay between mate choice and reproductive signaling. Reproductive signals such as bright coloration, body size, and agonistic behavior influence selection by female ma tes; however, these signals may not be an accurate means of judging the relative fitness of an individual. When such signals fail, animals may adopt a reproductive bet-hedging strategy where reproductive investment is based on the reliability of a given cue to compensate for variation in reproductive success across generations. The White Sands pupfish (Cyprinodon Tularosa) was used to test the hypothesis that mate choice strategies are influenced by environmental stability. Wild fish were collected from two locations on Salt Creek, White Sands Missile Range in the Tularosa basin of southcentral New Mexico. Each location was characterized by either highly variable flows marked by stream drying and extreme temperatures or stable flows with consistent diel patterns of water temperature. A series of camera monitored laboratory experiments characterized whether reproductive signals of male pupfish from chaotic vs. stable environments affected mate choice of female pupfish from the same environments. Detectable differences were observed between pupfish from stable versus chaotic stream environments in both the distribution of eggs among nest holding males. Additionally, reproductive effort, measured by total number of eggs produced, were significant ly different between fish originating in stable versus chaotic systems. These results suggest that reproductive investment may decrease as habitat stability decreases due to the breakdown of reliable reproductive signals and highlight the importance of understanding local adaptations and the importance of maintaining population structure integrity.