Hentzia mitrata
Behold, The Jumping Spider
Out of the entire animal kingdom, spiders are by far my favorite creatures. They are fascinating in their diversity and super abilities. Case in point: jumping spiders (family Salticidae). Jumping spiders make up about 13% of all spider species in the world.
Jumping spiders are active hunters. You'll usually find them out during the day time, because they rely on their acute vision to track down their prey. Once they spot something that piques their interest, they go on the prowl, and they are highly adapted for the hunt. Jumping spiders have actually been known to chase a laser pointers, probably thinking they are a possible prey item. But, they don't just take off running toward their target with reckless abandon; no, jumping spiders are far to intelligent for that. Instead, they will study their prey, stalk it, and plan the best route to get the jump on it. They have even shown an ability for abstract thought by locating prey that is out of their line of sight. Apparently, they are able to visualize where their target is located and reason through the best path to get there. These little guys are like the Nikola Tesla of spiders! But their superiority over other araneid species doesn't end there. Salticids display a whole new set of super abilities once they have caught up with their desired meal.
You're Not Watching Me! I'm Watching YOU!!
Super Vision!
Like most spiders, jumping spiders have eight eyes arranged in four pairs. There are usually four eyes on top of the head that give them great peripheral vision (like, almost 360 degrees!) and four more that face straight forward. Take a look at the two largest eyes in the middle of this spider's face.
You're looking into two of the most highly evolved eyes in the entire class of Arachnids! With their tubular shaped design, these two eyes have the ability to bend and flex within the spider's head to help it look around (check this video out). In addition to that, they have even evolved a mechanism that gives them depth perception! These wonders of the arachnid world have four layers of sensory cells. Two of the layers are used to see light in the UV spectrum. The other two allow the spider to see the visible spectrum. Why does an eyeball need two layers of receptor cells to detect light, you ask? Prepare to be amazed! As light passes through the lens of the eyeball, it is focused onto one of the two layers. This layer is able to render a crisp, clear image. The other layer receives and out-of-focus image the gets rendered as blurry. Scientists think that the spiders are able to compare the clear image to the blurry image and figure out how far away an object is by judging how fuzzy the out-of-focus image is. This depth of vision is paramount to the jumping spider's survival strategy and the use of its next super power.
BUNGEE Jumping Spider
The Ability To Leap Tall Flowers In A Single Bound!
Jumping spiders, as the name insinuates, also have super jumping abilities. Some are able to leap over 50 times the length of their own body! How do they achieve such a feat? They have their own built-in hydraulic fluid. Spider blood, called hemolymph, is not used to transport oxygen like human blood does. Instead, the spider is able to pump their hemolymph around their body. Pushing the fluid down into their legs, causes them to extend with a force great enough to propel the spider toward its prey or away from predators. But these spiders rarely leap before they look. Before takeoff, a jumping spider will tether itself to its platform just in case it misses its target. Wanna see the whole process in action? Take a look at this quick video from National Geographic.
Salticids are the perfect specimen to learn about for anyone that is ready to jump into the beautiful world of spiders. They are some of the most interesting creatures on the planet, and even the most arachnophobic among us have to admit that they are just gosh darned cute little spiders!