Females of some funnel-web spider species play dead to attract male sexual mates. An article about this was published in Current Zoology.
Funnel spiders live all over the world, including the house spider. However, species that only live in Australia are considered dangerous – their venom can cause severe pain and even death if left untreated. Many funnel web spiders practice sexual cannibalism, in which the female kills and eats the male after intercourse. This developed many forms of adaptation, including sexual catalepsy, in which one of the sexual partners pretends to be dead during copulation.
Jihye Liu and colleagues conducted a series of experiments to find the nuances of this situation. Scientists were interested, including: the female controlled this situation herself, or the male somehow influenced her to protect himself. In the first experiment, a pair of spiders was allowed to mate naturally. In the second, the female was rocked in a test tube before the couple was allowed to mate, and in the third, the female was artificially brought into a death-like state using anesthesia. After the experiments, all the spiders were frozen and crushed for body chemistry analysis.
It turned out that the male did not send any signals that would cause a situation similar to death – therefore, the female did everything. The scientists also discovered that this allows the female to be selective – they only do so with males from whom they want to have offspring. In addition, females turned out to be quite capable of controlling the duration of the death-like state – as soon as mating was complete, they stood up and left.
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