Impact of Female Mating Status on Male Courtship Behaviour in a Sexually Cannibalistic New Zealand Fishing Spider

The evolution of male courtship rituals has traditionally been attributed to female mate selection, but may also hinge on male investment strategies in sexually cannibalistic species. In many spiders, males perform energetically costly courtship rituals to increase acceptance by females and minimise the risk of sexual cannibalism. However, due to sperm competition, males may invest less energy when courting already mated females, therefore driving evolutionary trade-offs between the risks of sexual cannibalism and energetic loss. Here, we investigated how female mating status influences male courtship investment in the New Zealand nurseryweb (fishing) spider, Dolomedes minor. Using laboratory experiments, we compared male courtship responses toward unmated and previously mated females. Contrary to expectations, we found that female mating status did not significantly affect male courtship duration or sequence structure, but that its primary effect was an increased latency to initiate courtship. This delayed initiation may indicate that males are expressing pre-copulatory choosiness in the face of potentially irreversible mating costs, such as genital mutilation, hesitating to commit to courtship with previously mated females rather than reducing investment once courtship has begun. Our observations also provide the first detailed ethogram and network of Dolomedes male courtship, highlighting the importance of vibrational and visual signals. These results provide a foundation for exploring additional communication modalities, such as chemical and tactile signals, and highlight the need to consider the limitations of laboratory setups when extrapolating findings to natural conditions.