The chemosensory toolkit of the cursorial spider Pisaura mirabilis.

Chemical sensing is essential for animals to locate food, avoid predators, and find mates. Like many arthropods, spiders rely on chemosensory inputs, but their toolkit remains largely unknown. Here, we investigate the basics of chemosensing in the cursorial spider Pisaura mirabilis. Using electron microscopy, we identified two types of chemosensory sensilla. Tip-pore sensilla occur on legs and pedipalps of both sexes, while wall-pore sensilla are found on walking legs of adult males only. Tip-pore sensilla are classified as contact chemosensilla, while wall-pore sensilla are classified as odor-detecting sensilla. Our behavioral studies confirm that males are attracted to female odor. The distribution of these sensilla types supports their functions: tip-pore sensilla occur mainly at the tips of the legs, whereas wall-pore sensilla occur closer to leg bases, not contacting the substrate. These findings expand our knowledge of chemosensing in spiders and have implications for research on arthropod chemical ecology.