“What is the meaning of life? … I’m afraid the answer is disappointingly simple: Mating. That’s it” written by the author Oliver Markus. Mating is essential for an organism’s evolutionary fitness in sexual species, but male fitness ultimately depends on sperm fertilizing eggs. Mating does not guarantee fertilization when females mate multiply and sperm from several males compete. Males therefore have to invest in sexual traits that attract females and in producing a large number of high-quality sperm. With limited resources, males cannot invest maximally into both type of traits. Hence, resource allocation to mating traits and sperm production should be optimized to achieve the greatest fitness. But what happens when there are rapid changes in the environment? For example, do males adjust their mating strategies based on cues about female availability? Increased expression of sexual traits is, however, not without costs as it may slow growth and decrease time for feeding. Do mated individuals age faster than virgins due to past reproductive effort? Finally, fitness also depends on survival. Does environmental stress alter resource allocation into reproduction and traits that affect survival? In this talk, I will present seven experimental studies that examine short-term male reproductive plasticity, the effects of cumulative reproductive effort on senescence, and the impact of environmental stress on fecundity and life-history trajectory.

Biography

I completed my bachelor’s degree in Taiwan, where I studied osmotic regulation and aerobic metabolism of euryhaline fish. I also gained practical experience working at fish farms and aquaculture research centres, where I learned how to modify rearing strategies by observing behavioural differences among fish. This experience sparked my interest in linking my physiology knowledge with the role that behaviour may play in stress adaptation. During my PhD, I spent most of my time observing fish reproduction and exploring the strategies that males employ to increase their success, while also contemplating the evolution of such capabilities. Meanwhile, I remain interested in how the environment may play a role in regulating fish behaviour, body conditions and life history.