Halfbeak Project
We study sexual selection using halfbeak fish as a model. Halfbeaks are small, live-bearing freshwater fish from Southeast Asia. These fish show overt competitive behaviours, display sexual ornaments and multiple mating is common. These attributes make halfbeaks an ideal model for assessing pre- and post-copulatory sexual selection and trade-offs among sexually selected traits.
Our ongoing projects examining sexual selection in halfbeaks include:
Mate Choice
We study mate choice in female and male halfbeaks. We also ask how social and environmental conditions influence mate choice. Our recent work focuses on the role that female ornaments play during male mate choice.
Competition
We study how halfbeaks compete for resources and mates. Both sexes engage in 'beak locking' where adults interlock their elongated jaws and 'wrestle' for social dominance. We investigate physiological and morphological correlates of social domiance in halfbeaks.
Cognition
Halfbeaks have a semi-transparent head that allows brain size to be measured externally. This affords us a relatively easy and minimally invasive way to assess how behaviours are related with brain size on live halfbeaks.
Postcopulatory sexual Selection
We examine how sperm quality is influenced by male social dominance, diet and access to females. We also assess how female ovarian fluid influences sperm quality and condition-dependent cryptic female choice.
Field WOrk
We study halfbeak behaviour in the field with our collaborator Nalini Puniamoorthy at the National University of Singapore. Using a range of field locations across Singapore, we study how ecological variables influence social and sexual behaviours in halfbeaks.
