Freature: The Portia Spider

Spiders are pretty universally creepy. While I’m not really arachnophobic as I was when I was a kid, I will admit that spiders in general, especially the long-legged brown ones so common in temperate climates, give me the willies. There are some that are just cool to look at and don’t fill me with dread, including but not limited to garden spiders and jumping spiders. Speaking of jumping spiders, there’s one genus out there that is part cheetah, part Predator (the one from the movie) and part Spider-Man.

Image By Zeen

Spider-Man seems a bit redundant, I guess, but I didn’t use him without reason. I doubt portia spiders care much about fighting crime, but they are very intelligent. That’s why I said “Spider-Man.” Because Peter Parker is smart…


Anyway, jumping spiders in general have to be smart and fast because they are active hunters that go after fast-moving prey like files. This requires good reflexes, great eyesight (up to 10x better than other jumping spiders) and the ability to improvise, all things jumping spiders have. Portias up the bar a little, however, by hunting other  spiders. It’s the boogie-man’s boogie-man. As a result, they have developed a number of abilities all centered around eating food that eats things like them for food. In fact, some portias actually hunt spitting spiders, which is another species of spider-hunting-spider.

Imagine this; you are a cannibal who is an expert in hunting other humans. The portia is the guy who only hunts guys like you. Like a SEAL Team 6 cannibal with a web cannon in his butt and a poison face. Evolution works on the principle of “necessity is the mother of invention”, with natural selection making sure that the only spidators that live are the ones who can figure out how to not get eaten by their somewhat less lethal prey. If you hunt sheep, and the sheep kills you, then you probably won’t have kids. The crappy trend ends with you.

So what is in a portia’s repertoire? Well, for starters, there is their ability to mimic other spiders’ vibrations on web-builder’s homes. In case you weren’t aware, web building spiders come programmed with their own little bits of knowledge. They can tell if a vibration is caused by a drop of water, a struggling insect, or a potential mate. Portias figure out how to mimic the insect and spider vibrations to get the spider to come out of its home.

The best part is not just that they learn, and can retain, these disparate sets of skills, and can recognize which species to use which vibration on (unless they are just doing “terrified bug”), they also time it to coincide with the wind so that the prey is less likely to notice any discrepancies. They do all of this with a brain that is less than the size of a pinhead.

If that wasn’t crazy enough, they can also abstract to a degree. Let me explain; other visual predators, like other jumping spiders, often have to keep their eyes on the prize when they stalk, lest they forget what the hell they were going after. that sounds funny, but imagine if your brain was only as big as a spec of sand, and the cheeseburger you were about to eat was suddenly blocked from your view by a hat. For most really small animals, that’s game over. You’re still hungry, but as far as you’re concerned, that burger no longer exists. For portia, it does. They will stalk prey, attempting to sneak around it to cut it off or attack from another angle if it thinks it might be spotted, and can use roundabout routes that require them to move where they can’t see the prey, in some cases moving prey. Once they are in an advantageous spot, they strike.

Image By Eugene

This is one secret to their success when hunting other spider species that include arachnids on the menu. For instance, studies of portias hunting the spitting spiders show them stalking and striking from behind, much as you would if you wanted to take down a guy with a gun, because we’re all Bruce Willis.

However, if the spitting spider happens to be a mom with her egg sack, well then they just go ahead and run up to them, head-on. In the Bruce Willis analogy, imagine you know the guy has a gun, but his arms are full of grocery bags full of babies. He’s an easy target (and you’re a dick.) There’s no challenge for them. That there is problem solving behavior, and it’s amazing that something so small (a few millimeters in length) can be so smart.

Now, they are “slow” compared to bigger animals because they are working with limited resources. While a bigger animal like a wolf has access to millions of neurons when making a decision, the portias only have a few hundred thousand. Think of it this way; a 56k dial up modem can download the same 4 megabyte hi-res picture you accidentally took of your nostrils with you phone that one time as your high speed cable connection, it just takes much much longer because it lacks the bandwidth to do it faster. It’s the same principle here; the spider lacks the number-crunching power, so it takes longer.

The scary thing is, that it performs the same calculations as the wolf, except it’s working 3 dimensions because they live in trees and hunt prey of webs and stems, while the wolf only has to worry about a fairly level playing field. A study on the spiders showed that they can learn mazes through trial and error, (I found the study through this site) patiently processing all of the data from their experiences and determining the best route, and remembering the wrong turns they had made in the past.

While they lack the ability to truly extrapolate and infer what can’t be seen (like humans or crows), what they can do makes them the Teddy Roosevelt/Einstein hybrid of the arthropod world.

Image By Melvin Yeo

Now, there is nothing to worry about if you happen to be in the Western Hemisphere (and happen to be a sentient insect who just happens to be reading this, in which case, how weird is it being smaller than the words you’re reading?) because portias are exclusively found in the Indian Ocean area, stretching from Vietnam down through Myanmar and Indonesia, down to Australia. This should come as a surprise to no one, since that region of the world is where Nature decided to paint every living thing with garish colors and arm it with poison.

In case the pictures and descriptions weren’t enough to give the hypothetical bug-sapiens that was reading this nightmares, here are portias in action:

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