Teleost fish providing parental care: individual and intergenerational costs and consequences of nest predation pressure

Predation pressure is an important ecological variable which can influence the morphology, behaviour, physiology and survival of prey species. A particular focus has been given to individuals engaged in reproduction because traits or behaviours associated with reproduction often make individuals more prone to predation. For many taxa, reproduction also involves specialized parental care behaviours. Under these circumstances, individuals engaged in parental care may not be directly threatened by predators, but guard vulnerable offspring. However, parental care often imposes physiological and energetic costs on parents which can influence their survival. In this thesis, I tested whether variation in nest predation pressure had consequences for parents, as well as offspring. I used a teleost fish that provides male-only parental care as a model (smallmouth bass, Micropterus dolomieu). I used six populations which differed in predation pressure to test a number of hypotheses. First, I tested whether variation in nest predation pressure influenced parental care behaviour. I found that males from populations with increased nest predation pressure were more often engaged in antipredator behaviours relative to males from populations with lower predation pressure. Second, I tested whether variation in nest predation pressure influenced the cost of providing care. Traditional energetic approaches (i.e., lipid analysis) showed that energy status declined during parental care for all populations but individuals from populations with increased predation pressure did not lose relatively more energy stores. An in-situ approach (i.e., electromyogram telemetry) showed that males from the populations at the opposite extremes of predation pressure differed in overall swimming activity. Third, I tested whether variation in predation pressure influenced indicators of performance in parental males. I found that males from all six populations had similar indicators of swimming performance, a proxy for parental care. Finally, I tested whether nest predation pressure influenced the antipredator behaviour of offspring. Here, I found that offspring from all populations were similarly able to avoid an introduced nest predator. From a physiological perspective, offspring from the site of highest predation pressure had lower active metabolic rates and recovered more quickly from a simulated predator attack compared to offspring from the population with the lowest predation pressure.