Some male spiders catapult to flee their mates to avoid being eaten, study finds

Some types of male spiders will catapult themselves into the air, attempting to flee their mate before she eats them, researchers have found.

The lengths that males of the orb-weaving spider Philoponella prominens will go to to avoid being eaten include throwing themselves into the air, faster than cameras can detect.

In a never before seen performance, the eight-legged creatures use a joint in their first pair of legs to push off the female in an extremely rapid action.

This involves flinging themselves away from their partners at speeds recorded at up to 88 centimetres per second (cm/s).

The study, published in the journal Current Biology, suggests that the female spiders may even judge the male’s suitability as a mate based on how well it can pull off this escape.

“We found that mating was always ended by a catapulting, which is so fast that common cameras could not record the details clearly,” said researcher Shichang Zhang of Hubei University in Wuhan, China.

Researchers say the reason for this manoeuvre is simple - male Philoponella prominens spiders need to avoid being eaten by females in an act of sexual cannibalism.

In the study, the males who were not seen catapulting away from their mate were promptly captured, killed, and eaten by their female partner.

The researchers also prevented some males from catapulting. They unfortunately also met the same fate.

Using high-resolution video cameras, the researchers were able to calculate an average peak speed of about 65 cm/s.

Overall, speeds ranged from about 30 cm/s to almost 90 cm/s, with the spiders also accelerating at an average of about 200 m/s2.

“We observed that males that could not perform the catapulting were cannibalised by the female,” said Dr Zhang.

“It suggests that this behaviour evolved to fight against female’s sexual cannibalism under strong predation pressure of females. Females may use this behaviour to judge the quality of a male during mating.

“If a male could not perform catapulting, then kill it, and if a male could perform it multiple times, then accept its sperm.”