Sex-specific covariation among life-history traits of yellow perch (Perca flavescens)

Questions: How do life-history traits covary among populations? Do two-trait models show different patterns of covariation than multi-trait models? Is covariation different for males and females? Is covariation among traits within populations (many generations) different to that among populations (one generation)? Organism: A sexually dimorphic medium-sized freshwater fish, yellow perch (Perca flavescens). Study system: Over 70 lakes in central North America. Methods: Fish older than young-of-the-year were collected using standardized autumn surveys. Mean life-history traits were calculated for each population by sex. Conclusions: Life-history traits generally covaried in the predicted manner among populations. Traditional two-trait comparisons resulted in similar conclusions as more complex models of covariation. Male and female patterns of covariation differed substantially for relationships between growth and age/size at maturation, moderately for lifespan and age at maturation, but were similar for size at maturation and maximum size. The relationships between female growth rate and maturation depended on the cause of variability in growth rates. Slow-growing populations matured young and small in warm lakes but old and large in cold lakes. Patterns of covariation in life-history traits were similar for temporal and spatial variability in traits.