A project undertaken at The University of Sydney, and supervised by Dr Camilla Whittington.
While pregnancy is usually associated with females, some animals exhibit male pregnancy. This trait is very rare in vertebrates but is present in a group of fishes called syngnathids, which includes seahorses, pipefishes, pipehorses, and seadragons. These fish offer us the unique opportunity to examine the biology and evolutionary origins of embryo incubation in male animals. This study will allow us to understand the mechanisms that enable male seahorses to incubate developing embryos, using an Australian native species, the pot-bellied seahorse Hippocampus abdominalis, as a model.
Seahorse fathers incubate their embryos inside a brood pouch, made of fused skin outgrowths, which is located on the tail. We now know that male seahorses also have placentae that transport molecules between the father and the developing embryos. However, compared to mammals, the biology of seahorse pregnancy is not well-understood. Our project will explore the fundamental biology of placentation and pregnancy in male seahorses. We will particularly focus on the mechanisms by which nutrients are transported across the placenta. This project will provide important new knowledge about the function and evolution of the seahorse placenta, one of the only examples of a male placenta in a vertebrate.