Sexual selection – selection arising from variance in mating success – is an evolutionary force that frequently drives the evolution of exaggerated ornamental traits. However, sexual selection is not the only explanation for ornamental trait evolution, especially in females. A key goal of evolutionary biology is to characterize the scope for selection and quantifying the relative importance of evolutionary forces such as sexual selection.
In this project, I will be addressing these key evolutionary questions in a pipefish with a unique ornamental trait. Pipefish have male pregnancy, which has resulted in stronger sexual selection on females than in males. In a native New Zealand pipefish, Stigmatopora nigra, females have a flat and wide abdomen with distinct stripes, a trait that is unique among pipefishes. The trait is only expressed in females, and this sexual dimorphism has resulted in the assumption that the female ornament experiences sexual selection, but this hypothesis has yet to be. Here, I will