Apart from other creative ideas to protect themselves against the deadly female attack, the male spiders have come up with a new way of catapulting to protect themselves from death after mating. According to the researcher Zhang, on a human scale, the action is equivalent to a 5-foot-10 human leaping a third of a mile from their partner after sex.
These Male Spiders 'Catapult' Themselves To Avoid Getting Eaten By Female Spiders After Mating
Chinese researchers have described yet another disturbing sex habit of spiders. According to the researchers, some male spiders launch themselves at a great speed of their cannibalistic female partners to avoid becoming their meal after mating.
According to the new study, the way they make their egress is similar to the mechanism at play in catapults.
The spiders are communal orb-weaving spiders (Philoponella prominens), and they have active and potentially fatal sex lives.
Just like the praying mantises, the female spiders have an appetite for their male counterparts. However, to escape this deadly end, the 0.12-inch (3 mm) males of the species have developed an escape plan: They capitalize on an adaptation in the joint in their front two legs to launch themselves off the females, at speeds of nearly 3 feet (88.2 cm) per second.
The team’s research got published in Current Biology.
“Males can use super-fast actions with extraordinary kinetic performance to escape the female’s attack,” said Shichang Zhang, a behavioral ecologist at Hubei University, in an email to Gizmodo. “This may help scientists to consider the balance or trade-off between cost in physical strength and the benefit of paternity when studying sexual conflict.”
Apart from this, there are many other methods by which male spiders use sex to counter cannibalism. According to Zhang, these include nuptial gifts, pretending to be dead, cutting off their own genitals, and even mutilating the females. These are very freaky but definitely creative. However, this catapulting approach is new to researchers.
The lab team mated 155 pairs of spiders in the lab, in 152 of the encounters, the males catapulted to escape the death safely. The three males who did not do the behavior were captured, killed, and eaten by the females.
According to the researchers, this behavior of the males' ability attributes their sexual partners to a leg joint called the tibia-metatarsus.
The tibia-metatarsus (and all the leg joints in the spiders) are ensconced in sheathes called thecae, which increase the limbs’ elasticity. In the front two legs of the male spiders, the surface area of the thecae was much larger than on the other legs.
Also, the spider sex is quite different from that of humans. Their mating lasts for about 30 seconds and male spiders use an appendage called the palp to inject sperm into the female’s epigynum, a hard plate on the bottom of the abdomen.
The females’ eggs aren’t immediately fertilized. Instead, the female can store sperm and only release the egg for fertilization when it is ready. It can also squeeze the sperm out or kill them if the sperm (and the male who provided them) are found wanting.
“Mating is ended by the female; once [they] sense the aggressiveness of the female, males catapult off, but if a male can not sense the danger, it may not catapult before the female kills it,” Zhang said.
“Through the catapulting, male can escape female sexual cannibalism, and female can choose males with high quality, because the kinetic performance may directly correlate with male’s physical condition. Only those with good quality can catapult off far or can catapult for several times,” Zhang added.
Apart from this, the lab team also noted that the males employed a silk 'safety line' to dangle near the webs when the mating happened. This, researchers, believe as a means for the male to return in case they wanted to attempt mating again.
On a human scale, according to Zhang, the action is equivalent to a 5-foot-10 human leaping a third of a mile from their partner after sex. You know, just to be safe.