Life History Perspectives on Voltinism
Patterns of voltinism are well documented in many crustaceans and other invetebrates, and these studies provide diverse insights into species biology, population ecology, and drivers of the evolution of voltinism. This chapter examines voltinism across crustacean taxa, with a focus on mysids as an informative model taxon that exhibits a broad range of life pattern diversity. Voltinism, which describes the number of generations per year for population or species, can be measured as generation time and is shaped by multiple environmental factors, including temperature, latitude, salinity, and depth. Generation time also varies with important biological traits, such as body size, life span, and maturation size and age. I discuss the relationships between voltinism and life history strategies, and the influence of voltinism on adaptative plasticity of species and their populations. Many factors shape evolution of voltinism, including fitness components such as survival, reproduction, and dispersal, as well as tradeoffs among age and size at maturity, reproductive investment, and lifespan. I highlight the importance of voltinism for population modeling in crustaceans, and for understanding regional differences in voltinism. Studies comparing and contrasting voltinism will be critical to better understand how climate change, strong habitat modifications, pollution, and invasive species will impact crustacean populations and their dependent communities.