Sometimes science hardly seems worth it. To find out about the hunting habits of a rare spider, scientists had to find spiders, examine their sex organs, and finally put them in death matches against each other.
Palpimanus gibbulus is commonly known by its cooler-sounding name: the spider-hunting spider. This arachnid lives in Spain and Portugal, where it finds out where other spiders are living, kicks in the door, and takes them out Van Damme style. Scientists wanted to find out about its hunting skills and its prey, but up until recently they were thwarted. For one thing, the spider doesn't build webs. Why would it? It's an assassin, not an engineer. It's also, like most monsters, nocturnal. In order to get enough spiders for a real tournament, researchers had to bring in another spider from Israel. Palpimanus orientalis looks just like P. gibbulus, except for its sex organs. As long as the spiders didn't fight with their junk, the scientists figured they were close enough to each other to count as the same species.
Once they had rounded up their herd of fighters, they went looking for opponents. They captured a number of other species of spiders, and then it was Thunderdome time. The scientists put a gibbulus or an orientalis in a petri-dish match with various other species of spider, to see what they would do. In well over half the repeated trials, the spider-hunting spiders caught all but one type of species. And they were capable of at least once catching every species offered to them. Nor did they hesitate when the other spider was twice their size. Most impressively, when they put gibbulus in with a jumping spider - which also eats other spiders - the gibbulus won nine times out of ten.
The researchers weren't satisfied, though, so they started giving gibbulus handicaps. They found that hair helps in a fight. When they glued together the tufts of hair on gibbulus' legs, they became less effective. The hairs there are sticky, and help incapacitate prey. They still didn't fall down easy, though. The gibbulus has extra-thick armor on its body, keeping it safe from the prey spider's bites. They also have a long reach, with massive front legs. These are, truly, the superspiders. It's lucky for us they hunt their own kind.
Via New Scientist.