Iuloboridae is a family of spiders widespread (almost) all over the world, with the exception of sub -Sasaharan Africa, which It includes almost 300 speciesall united by a very particular feature and that is not found in almost any other spider in the world: they lost the poison glands.
So how do they paralyze their prey and consume them in peace? A new study published on BMC Biology reveals their strategy: First they wrap them in their cobweb, then … they vomitand continue to cover it with gastric juices until it is ready to be digested.
Spiders without poison. The name of the family, uuloboridae, means “with a fatal bite”: one of the characteristics of these spiders is their ability to block the prey by biting it. However, it is only the first step of their predatory strategy: the next one is based on the way they build the spiderweb. Which is not as sticky as those of other spiders, but comes “combed“From the animal to make it like wool: in this way, The prey remains clinging to the canvas and cannot escape.
At this point the disgusting part is triggered: the uuloboridae they regurgic gastric juices on the aforementioned prey, and continue to do so until it has been “short” enough to be consumed without problems. The team of the University of Lausanne who studied these spiders has shown that they are without poison glands, and that their bagpipes are not quarries: almost all the other spiders have small cracks that allow the passage of the poison.
Lethal vomiting. The study also shows that the gastric juices of these spiders still contain some poison components, similar to those present in other actually poisonous spiders; And on the other hand, many poisonous spiders contain digestive enzymes in their poison. For the latter, according to the authors, The presence of gastric juices in the poison could be a way to protect itself: When they have finished the poison themselves and have to “recharge”, they have other ways to block and digest prey.
Survival techniques. Iuloboridae, on the other hand, should not worry about their poison reserves: they have the redirect all their efforts towards gastric juices and use only those to digest prey. This tactic, combined with the power of their cobweb, makes them extremely effective predatory even without having to use poison. The team now designs to deepen the composition of the gastric juices, to find out if they contain (as it happens in many spiders) neurotoxins capable of paralyzing preyor if the Uuloboridae really is enough the cobweb to immobilize their meal.
