In spiders, sex is not a part of pleasure. Or a perilous pleasure. On the male side of the operation, the vital prognosis is even engaged. Because these eight-legged wonders are formidable predators that do not recognize their conspecific. Any individual, insect or spider, of size to be devoured therefore becomes a potential prey. And as males are always smaller than females, they are up to them to take all the risks.
First well dose the approach. Few are the females ready to let himself come from. Some males use a bad cocktail of pheromones to sleep their mistrust. Others patting on the canvas to drown the noise of their arrival. Still others rely on the charm of their bridal dance or on their extreme discretion. “The approach phase can last hours before the aggressiveness of the female falls back and the male can finally insert his two copulatory bulbs into the genital slit of the female, describes Christine Rollard, arachnologist at the National Museum of Natural History from Paris. Sometimes he must even be content with one. “
Because time is pressing and it is once the act committed that the most difficult begins. For females, more than a source of genes, the male first represents a protein intake for the spawning exhaust. And as the males die, whatever happens, at the end of the season, the species does not have too much to lose there. Except that males, they, hear it otherwise. The approximately 50,000 species identified – bar crossed last week – offer a parade flourch against this sex cannibalism. The position, for jumping spiders and wolf spiders: males take advantage of their dance to stand above females, and can save without damage. The distance, for the tetragnathes, which remove the females thanks to their long chelars (mandible). The diversion of attention, for the admirable pisaurus, which offers to his lady of the Embassured prey occupants so until the end of the sexual act. The cunning, in the crab spiders, which take advantage of their dance to surround the legs of the predator. The discretion, for the nephiles: the males are so small that they manage to accomplish their work without aroupeting the attention of their partner. Non-exhaustive list.
Reminder wire
In Current Biology April 25, a team of Chinese, Singaporean and Slovenian researchers describes so far unknown behavior. During penetration, the male folds his legs before against the abdomen of the female. Then relaxes them abruptly once its fluid transmitted by releasing the hydraulic pressure of the first articulation. “Like a catapult”, summarizes Shichang Zhang, a lecturer at the University of Hubei, China. The researcher fell on the operation “by chance”, he admits, while he wanted to study the reproduction of the Philoponela Prominens. It must be said that the phenomenon is as wide as fast. “According to our calculations, the male leaped up to 82 centimeters per second, while it measures 3 millimeters. It’s like we skipped 530 meters in one second.” Respect.
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