Solitary Confinement: Surprising Post-Copulatory Behaviour of an Australian Species of Wishbone Spider (Mygalomorphae: Anamidae: Aname).

Among invertebrates, spiders are regarded as a model group for sexual selection studies. However, our understanding of their mating behaviour is highly biased towards species in the infraorder Araneomorphae. Knowledge of the mating systems of mygalomorph spiders (infraorder Mygalomorphae) remains rudimentary at best. Here, we report on the mating behaviour of a recently described Australian wishbone spider (Anamidae: Aname inexpecta) from south-western Western Australia. In doing so, we present the first detailed observations of mating behaviour of a member of the family Anamidae and describe a remarkable, novel male sexual behaviour for mygalomorph spiders ('burrow plugging'). This behaviour involves the male collecting soil with his chelicerae and placing it over the entrance to the female's burrow, sealing the entrance before actively guarding the plugged retreat. We provide some of the first insights into post-copulatory mate guarding in burrowing mygalomorph spiders, contributing to our understanding of mating systems in a group where such studies are rare.