Why is my right ball bigger than my left ball?
Asymmetries in reproductive anatomy: insights from promiscuous songbirds
Asymmetric patterns in the morphology and/or use of bilateral organs involved in reproduction is a common occurrence in animals, from the asymmetric size of the fighting claws of fiddler crabs to the wide range in asymmetry type or alternate usage of the double intromittent organ of phallostethid fishes and reptiles. In birds, testes asymmetry is a common phenomenon, with a left bias in size and shape being the predominant pattern. We are investigating the degree of asymmetry in testes size and several additional primary reproductive traits in male birds, using the Australian Maluridae as a case study. In this family, species exhibit a right bias in testes size despite a left-bias ancestral state. Our aim is to assess direct and indirect roles of sperm competition and side-correspondent development at the inter- and intraspecific level.
In this late lunch talk, I will present some results on reproductive organ asymmetry in the Australia Maluridae. Currently, our results are a little confusing. My hope is that the CEES hive mind will join me in thinking about the patterns we observe concerning asymmetry in avian reproductive traits. Let’s get together and think about the question – Why is my right ball bigger than my left ball?