| Mate choice plays a vital role for driving speciation and evolution,which is the most important selection behavior among various social behaviors.Animals can assess qualities of mates by collecting various information,and then make mate choice strategies to improve their success rates of reproduction and the fitness of offspring.Compared with female mate choice,relatively little is known about male mate choice.Meanwhile,several studies have shown that environmental factors can influence individuals‘ behaviors and alter their personality traits.However,there are few studies on whether environmental factors will affect individual mate choice.In order to understand the impact of environmental factors on mate choice and personality traits,we used invasive Western mosquitofish(Gambusia affinis Baird & Girard,1853)as our model organism in this study.We asked whether seasonal fluctuation,predation risk and social factors affect this species‘ mate choice and personality traits combining with laboratory research and field work,we also introduced computer animations technology to simulate live mates during this study.Furthermore,we tried to reveal G.affinis adaptive strategies of mate choice under different contexts.Our main results are as follows:(1)The validity of computer animations technology in the behavioral study of G.affinis was verified by measuring behavioral characteristics(mate choice and personality traits)at five sample sites across China.Secondly,boldness and activity of male and female individuals showed significant behavioral consistency,also shoaling tendency of male has significant behavioral consistency.Dichotomous mate choice tests showed: female focal fish showed significant mating preferences for large body males with the increase of boldness/activity,while males with highly shoaling tendency showed stronger mating preferences for those females with highly activity.Our present results indicate that there are more complex mate choice patterns in nature.(2)Based on seasonal population dynamic monitoring of invasive G.affinis in Ankang area,Shaanxi Province,China,we found that the sex ratio of this population showed ?male-bias‘ structure,the number of juvenile reaches the peak in summer,and the seasonal change of population is congruent with ?boom and bust‘ population cycle succession mode.In addition,the effects of seasonality on individual personality traits are not consistent.Female individuals showed overall mating preferences for lager males,especially in spring and summer these preferences were significant.The seasonal change of mate choice reflects an adaptive plasticity of mate choice,which is affected by opportunity of mate choice,we speculated these results showed a trade-off between behavior and life-history strategies.(3)By introducing predator computer animations to simulated changes of mate choice in G.affinis when facing predators in nature.We found that wild-caught G.affinis significantly altered their mate choice decisions when encountered co-occurring predator(Channa argus),while laboratory-reared individuals responded most to co-evolved predator(Lepomis cyanellus),which reflects the innate mechanism and learning effects are involved.This effect is more pronounced in those individuals with highly boldness and larger body,and females stronger than males.Probably due to individuals with these phenotypes may face greater predation risk.(4)By exploring the influence of social factors on male mate choice,the results showed that males with higher mate choice copy tendency were more likely to respond to the presence of competitors by showing ?audience effect‘ in male mate choice,suggesting that male mate choice copy may indeed be part of social responsiveness syndrome.In conclusion,our study mainly investigated the effects of environmental factors on mate choice and personality traits of invasive G.affinis,reflecting an adaptive plasticity of this species‘ mate choice,also revealed a trade-off between behavior and life-history strategies.In addition,this study aims to develop and improve the theoretical connotation of ?mate choice‘ in behavioral ecology,and to explore the theoretical mechanism of rapid expansion of this invasive species in China,which is of great theoretical and scientific value for improving the invasion status of G.affinis and protecting the endangered indigenous species.Meanwhile,it has certain guiding significance for the application of ethology in the animal husbandry,endangered wildlife conservation and biological invasion. |
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