快猫短视频

Getting stung before sex may be a way for female scorpions to evaluate potential suitors.

During scorpions鈥� lengthy mating rituals, the male grabs the female鈥檚 pincers to lead her in a dance and then rubs his tail gland all over her, lathering her in its secretions. If the female doesn鈥檛 react by running away 鈥� or by attacking and eating him 鈥� he then places one to three stings into the willing female, before finally transferring his sperm.

Some experts believe the act 鈥� which is unique to scorpions 鈥� 鈥渄rugs鈥� the highly aggressive arachnids into submission. But the females鈥� lack of resistance suggests that they might appreciate these sexual stings and even use them to help assess a male鈥檚 qualities before accepting his sperm package, says at the National University of C贸rdoba in Argentina.

Female scorpions give birth to live young after gestation periods lasting up to 18 months and then carry them on their backs for several weeks. Unlike males, females only mate a few times in their lives 鈥� and for some species, only once. As such, female scorpions are highly selective in choosing a mate, says Oviedo-Diego.

To better understand the animals鈥� selection process, Oviedo-Diego and her colleagues collected 70 female and 130 male Urophonius achalensis scorpions, a common South American species, from the Andes mountains in Argentina. They placed random male-female pairs into a glass 鈥渕ating arena鈥� and watched them.

Faced with a female, 55 per cent of the males shook with excitement 鈥� the first stage of courtship 鈥� and 53 per cent of the courted females allowed the male to grab their pincers and start dancing. However, only one-third of the courted females stayed in the courtship to the end, with the male laying a sperm packet on the ground and pulling the female on top of it.

Females that stayed in the courtship remained mostly motionless while the male rubbed her body with his telson gland, a bulb near the tip of the tail that secretes fluid. In a previous , scientists blocked this gland so that it couldn鈥檛 secrete its chemical, and the females were more resistant to the male鈥檚 courtship. 鈥淪o we think this is a stimulating behaviour that makes the female more receptive,鈥� says Oviedo-Diego.

The females that continued with the courtship in the latest study also showed little resistance as the male inserted his stinger into one of her softer body regions, like the side of the abdomen. 鈥淒uring that moment, the female is very quiet,鈥� she says.

鈥淏ut that doesn鈥檛 mean that the female is passive,鈥� she adds. 鈥淪he is screening something there, like the quality of the male.鈥� She might, for example, be analysing the quality of his sting or his venom, or even his endurance over such a long, high-energy event.

It is a 鈥渃ompelling鈥� suggestion that fits with energetic displays of male fitness in birds, fish and other animals, says at the University of Aberdeen, UK.

鈥淚f you can sting a lot, and for quite a long time, then it鈥檚 indicating to the female that this male has a lot of energy to expend鈥� and it鈥檚 probably therefore a very fit male which will sire good offspring,鈥� he says.

Whether the male actually injects venom 鈥� or even pre-venom, which is less toxic 鈥� during these sexual stings remains to be determined, the researchers say.

鈥淪corpions have a bad reputation, but there are a lot of behaviours that are fascinating,鈥� says Oviedo-Diego.