Welcome to another episode of 8 minutes of Eww! I am your host Ms. Mallory, the Curious Conservationist and self-proclaimed grossologist.
Today we are learning all about the creepy cool science behind the 8-legged, web-walking acrobat known as the spider. But don’t press sto. because even if these creatures give you the heebie jeebies, the science behind them just may turn your Eww into Ooooh.
Let’s get started.
Have you ever found yourself exploring a dark place and walked through a spiderweb?
I don’t know about you, but when I walk through a spider web, I immediately become a ninja— trying to karate chop my way through the invisible threads.
But what’s crazy is spider silk may seem thin and frail, but it’s one of the strongest fibers on earth, more durable and elastic than any natural or synthetic fiber— including Kevlar, which is used to make bulletproof vests— And it’s six times stronger than high-grade steel— per weight, of course.
The only substance found to be stronger than the strongest of spider silk are the teeth of limpets- a type of aquatic snail with a cone-like shell. I’m pretty sure you’ve seen one if you have ever been near a tidepool.
Incredibly, spider silk doesn’t start out as the thread that we see, but as a droplet of liquid protein. As it passes through the spider’s silk spinning organs— or spinnerets— and makes contact with air, it becomes a solid. Crazy cool, right?
Spider silk is so amazingly complex that humans still can’t replicate it. And trust me, we want to replicate spider silk. It’s a flexible, durable, lightweight and incredible strong building material. Imagine what our buildings, our bridges or even our clothes would look like if made from spider silk.
Unfortunately, movies and stories have made spiders out to be super gross and creepy, but they are perfectly designed for what they do.
Spiders have two body segments. The front segment is the cephalothorax, which holds the spider’s eyes, fangs, stomach, brain, venom glands- which we will get to later, legs and little leg-like things that help hold prey called pedipalps.
The second part of the spider is called the abdomen. The abdomen is where many of the important organs of the spider live. We’re talking about the digestive tract, reproductive organs, lungs and spinnerets.
Have you ever wondered what the inside of a spider looks like? It's pretty fascinating. Many assume a spider’s insides would look similar to that of a human’s, but it is soooo different.
Let’s start with the circulatory system, humans and other vertebrates - or animals with a backbone- have a closed circulatory system, our blood moves from the heart and lungs to the rest of the body through veins and arteries. A spider’s circulatory system is open, they don’t have veins to transport their blood. In fact, they don’t even have true blood. A blue tinted fluid that acts like blood is pumped throughout the body by a long tubular heart that lines the back of the abdomen where the backbone would be if it had one.
Wait. Spiders don’t have backbones?
Nope. Spiders are arachnids, which are 8 legged arthropods. An arthropod is an animal with jointed legs and an exoskeleton, meaning their protective skeleton is on the outside of their bodies unlike ours which is on the inside of our bodies. In order to grow, spiders and other arthropods will shed their entire exoskeleton all at once, a process called molting.
But even though spiders have a lot of things that are different from us, we actually have something in common- being hairy. But spider hairs are soooo much cooler than ours.
If you think Spiderman’s spidey senses are cool, then prepare to be blown away by spider hair.
You see, humans rely a lot on their sense of sight to learn about the world around them. Spiders, on their other hand, rely mainly on their sense of touch- hair touch that is. All the information they need about the world around them can be gathered by sensory hairs covering their body. No joke. Different types of hair relay different types of information. For example, some sensory hairs can tell the spider what the air temperature is or if a storm is approaching. Meanwhile other types can help some species climb walls, recognize chemicals, and even detect air-borne vibrations from the wing beats of an approaching meal. . or the presence of a predator.
But, personally, I think the coolest hairs a spider can possess are ones found on American tarantulas — called urticating hairs. When threatened, the hairy spider (yes, tarantulas are spiders) will brush their back legs rapidly across the back of the abdomen, sending up a cloud of the barbed hairs into the eyes, nose or mouth of a potential predator. The spider escapes while its pursuer is distracted by an eyeball full of microscopic splinters.
But you may be asking yourself, why wouldn’t the tarantula just use its venom and bite the bully. Well, because that venom is very important to a spider— it’s the only way a spider can eat. Imagine you didn’t have teeth to chew your food, instead (like the spider) you had a straw-like mouthpiece to slurp up their meals. So how would you eat your pizza without teeth? Well, you would have to turn you pizza into a pizza smoothie. And that is exactly what spiders do with their saliva. Important enzymes in the spider’s saliva not only paralyze its prey, but will also start digesting it from the inside out, turning the insides of the fly into a slurpable soup.
Now this saliva uses up a lot of energy to make. And that energy comes from food the spider eats. So if the spider uses a lot of venom to protect itself, that means the spider has less venom to catch flies, replenish their energy and make more venom. Let’s think about this a different way. Imagine you worked all summer to save enough money to buy the coolest collectible of your life. And you can’t wait to put it on your shelf. However, as soon as your little brother or sister sees it, they want to play with it. Well, are you going to hand over your new prized possession? Of course not! I mean you just worked your tail off for over a month to get this thing and you know they would break it in a matter of minutes. You are going to try to trick them into wanting any other toy in your room before you let their chocolate covered hands touch our new treasure. Well, same for a spider. It doesn’t want to use the precious venom it’s worked so hard to make unless it absolutely has to.
So remember, no spider wants to bite you. However, a defensive spider will bite if it feels there is no other option, so it's best to admire all spiders with our eyes and not our hands.
Well, aspiring grossologists, my time is about done. But I want to hear what you think now that you have learned the science behind the spider. Ask an adult to send me a message with your thoughts on the MsMalloryAdventures website or on instagram. Because I hope the next you see a spider your “ewwwww” becomes an “ooooh!”
Thanks for joining me, everyone. See you next time.
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