Spiders have a bad reputation, but jumping spiders don't deserve all the scorn that's heaped on the Araneae order. Neither do the other spiders, but jumping spiders in particular are cute, cuddly and fascinating creatures.
They also differ from their fellow spiders in a number of unique ways, so read on to learn more about these hippity-hoppity spiders.
1. Jumping Spiders Belong to a Big Family
Jumping spiders are members of the Salticidae family, and it's not an overstatement to say that a reunion among members of that family would need a pretty big space. There are 610 recognized extant and fossilized genera and more than 5,800 described species of jumping spider according to a 2015 paper published in the Journal of Arachnology. This makes jumping spider the largest family of spiders in the world. (And you thought your family was big.) It also means that jumping spiders come in a variety of colors, shapes and sizes.
2. Jumping Spiders Are Everywhere
Well, almost everywhere. The 2015 paper from the Journal of Arachnology referenced above also notes that jumping spiders can be found in just about every habitat in the world, save for extreme polar regions. So the only way to get away from jumping spiders is to go to Arctic or to Antarctica. Jumping spiders mostly reside in tropical areas, but they will hang out in chillier climates as well. In face, in 1975, a researcher from the British Museum of Natural History found jumping spiders on the slopes of Mount Everest.
3. Jumping Spiders Don't Have Super Legs
It'd be easy to think that these tiny creatures have insanely muscular legs given their ability to leap up to 50 times their own body length. This is not the case, however. Instead, jumping spiders rely on segmented legs and blood flow to make their crazy jumps. When they're ready to jump, the spiders cause an extreme change in hemolymph pressure (the spider equivalent of blood pressure) by contracting the muscles in the upper region of their bodies. This forces the blood to their legs, and this causes the legs to extend rapidly. This quick and sudden extension of their legs is what propels them in the direction they're aiming.
OK, so maybe not all of them are cute, but jumping spiders are still a charismatic bunch. (Photo: Anders Johansson/flickr)
4. Jumping Spiders Aren't Reckless Acrobats
Just because they make daredevil leaps doesn't mean jumping spiders have a death wish. Jumping spiders spin a quick line of silk that they use as a dragline. This allows the spiders to stabilize their landing in addition to acting like a sort of safety net if they need to stop in mid-jump. A 2013 study published in the Royal Society journal Interface captured the difference between using a dragline and not using one in the video below.
5. Jumping Spiders Don't Use Webs to Hunt
Well, why would they? Their jumping abilities are how they catch their prey. They find a target, extend their legs and launch after their meal, which is typically small insects. A little bit of venom and it's dinnertime. One species, the Bagheera kiplingi, eats plant matter, while another species eat nectar. Some jumping spiders, however, go for more dangerous game by turning the tables on would-be predators. Regal jumping spiders have been known to attack and eat small frogs and lizards. And if you're worried about jumping spiders hunting you, don't worry. They can't produce enough venom to hurt us.
6. Jumping Spiders Can Be Trained to Jump on Command
Researchers at the University of Manchester trained a regal jumping spider to jump on command to better understand the species' jumping abilities. They filmed the spider, nicknamed Kim, and her jumping techniques. For close range jumps, as an example, Kim favored faster, lower trajectory jumps. This uses more energy, but results in shorter flight times, upping the odds of catching a target. With these new insights, researchers hope they can improve the jumping skills of tiny robots.
7. Jumping Spiders Have Eyes Like Galilean Telescopes
The eyes of jumping spiders of a decidedly odd arrangement. Two smaller eyes bracket two large eyes that rest in the center of their rectangular heads. Those two main eyes are what function like telescopes. Their eyes are basically just immobile lenses, and a long tube extends down from those eyes. This tube is filled with a liquid of some kind that we don't totally understand, but it causes light to bend, essentially functioning as a second lens. The eyes themselves collect and focus light while this liquid spreads it out. This process allows the spiders to see a massive amount of of detail, despite their tiny size. Additionally, the spiders' retinas can swivel on their own, allowing the spider to look around without moving its head.
8. Jumping Spiders May Not Have Ears, but They Hear Very Well
But how do they hear? Sensory hairs along their bodies take in vibration of sound waves, and that action sends signals to the spiders' brains. Researchers discovered this by accident in 2016. They were studying the spiders' eyes, but their method for doing so demonstrated that vibrations sent neurons firing, even vibrations that originated some 10 feet away.
9. Jumping Spiders Sing and Dance to Woo Mates
While their various spider senses are obviously good for hunting and avoiding danger, those same senses are also good for mating. Male spiders attempt to dance their way into a potential mate's heart, wriggling and writhing in special ways. Additionally, each male spider "sings" its own special song, sending buzzes, scrapes, clicks and taps on the ground, and the vibrations travel along the ground and into the female's legs and are picked up by her sensory hairs. The males have to sing and dance like no one is watching, however, because if the female is unimpressed, she will sometimes devour the male.
10. Peacock Spiders Take the Mating Game to Another Level
Peacock spider (Maratus volans), a species belonging to the jumping spider family, bring something extra special to the mating dance. In addition to the special footwork, peacock spiders flash their colorful flap-like extensions like fans to get a female's attention.