What is the smallest animal in the world? Hi! Welcome to Curious Kids Every Day. I'm Josh. How are you doing today? It's so good to hear from you. Hey, what is the smallest animal you have ever seen? Animals come in all shapes and sizes. Even within types of animals, there can be big size differences. Like dogs. I've seen some really big dogs. And some really, really tiny dogs too. But animals can be much, much smaller than even tiny dogs, right? Can you think of an animal that's smaller than a dog? What is the smallest animal in the world? Have you ever wondered what is the smallest animal in the entire world? Well, I looked it up and I was pretty surprised. You want to find out today? Now, you've never seen the smallest animal in the world. Do you know why? It's because it's so small, you can't see it without a microscope. We're going to learn a new term today. Are you guys ready for this? The smallest animal in the world is called... Mixobolus shekel. Can you say Mixobolus shekel? Mixobolus shekel. Mixobolus shekel. It basically just looks like a tiny little egg. Do you want to know how small it is? Mixobolus shekel is only a few micrometers long. Do you know what a micrometer is? Well, one millimeter is a thousand micrometers. So do you know what a millimeter is? One millimeter is about the size of a grain of sand. So picture a teensy tiny grain of sand. It takes a thousand micrometers to be the size of one grain of sand. So every grain of sand is a thousand micrometers. So imagine if you only had like five or seven micrometers. That's the size of Mixobolus shekel. That is incredibly tiny. And that's why you can't see it without a microscope. Even though Mixobolus shekel is so small, it's still an animal. It's actually a parasite. Have you ever heard of a parasite before? A parasite is a creature that lives inside another animal and gets what it needs to survive from that host. In this case, it lives inside certain fish. Mixobolus shekel is extremely simple compared to most animals. It doesn't have many of the parts that animals usually have, like a heart or a brain. But it still is classified as an animal because of how it grows and how it reproduces. Most animals use oxygen to make energy. Dogs do it, fish do it, bugs do it, lizards do it. But Mixobolus shekel is different. It doesn't use oxygen the same way most animals do. Inside most animal cells are tiny structures called mitochondria. These are like little power plants that use oxygen to make energy. But Mixobolus shekel does not have that normal mitochondria. Instead, it has very simplified parts and gets energy directly from the animal it lives inside. That's what makes it a parasite. Mixobolus shekel forms tiny structures called spores. And a spore is like a little small protective capsule. These spores help it move from one fish to another and survive long enough to find a new host. Mixobolus shekel, that's still kind of hard to say. Mixobolus shekel is a very simple creature because it's very, very small. It's so simple in fact that it needs the help of other creatures to get the energy it needs to survive and reproduce. I'm glad Mixobolus shekel sticks to fish. I don't think I'd want one near me. So the next time somebody asks you, what's the smallest animal you've ever heard of? Now you can tell them, Mixobolus shekel, the parasite that lives inside a fish. Did you know that some individual cells in your body are actually bigger than Mixobolus shekel? That means this whole animal can be smaller than just one tiny part of your body. Wow. Alright, let's have a quick quiz. What tool do you need to see Mixobolus shekel? You need a microscope and is a micrometer bigger or smaller than a millimeter? A micrometer is smaller. It takes 1,000 micrometers to make one millimeter. And remember, a millimeter is about the size of a grain of sand. What kind of animal is Mixobolus shekel? It's a parasite. And where does Mixobolus shekel live? Well, it's a parasite, so it lives inside other animals, like fish. Let's play true or false. True or false, you can see the smallest animal in the world with your eyes. No, that's false. You need a microscope. True or false, a micrometer is bigger than a millimeter. True or false, a micrometer is bigger than a millimeter. That is false, a micrometer is smaller than a millimeter. True or false, Mixobolus shekel is an animal. Yep, that's true. True or false, parasites live completely on their own without other animals. That is false. What makes it a parasite is that it lives inside of an animal and feeds on its host. Would you rather look at tiny things with a microscope or look at far away things with a telescope? I enjoy looking through microscopes and telescopes, but if I had to choose just one, I'd have to go with a telescope. I would love to look through a really, really powerful telescope and see things really, really far away in outer space. That would be cool. Alright, let's play a round of what am I? What am I? I am smaller than a millimeter. There are 1000 of me in one millimeter. And only a few of me are the size of a Mixobolus shekel. What am I? I am a micrometer. Today we learned that the smallest animal in the world is something called Mixobolus shekel. It's so tiny that you need a microscope to see it. Isn't it wild to think that there are things around us all the time that we can't see unless we looked at it in a microscope? What an amazing world we live in. What kind of question do you think we'll ask tomorrow on Curious Kids every day? I can't wait to find out so until then keep asking questions and stay curious kids. And we've got some birthdays today. Today is Cali's birthday. Cali's is from Minnesota and Cali's is turning five. Happy birthday Cali's. Alex is from Scotland and Alex is turning five. Alex is from Scotland and Alex is turning seven. Happy birthday Alex. Elena is from Florida and Elena is turning five. Happy birthday Elena. Adam is from Connecticut and Adam is turning eight. Happy birthday Adam. Luca is from Illinois and Luca is turning nine. Happy birthday Luca. Layla is from China and Layla is turning five. Happy birthday Layla. Abigail is from Georgia and Abigail is turning seven. Happy birthday Abigail. And Gabe is from Washington and Gabe is turning five. Happy birthday Gabe. To all the grown-ups listening, if you're Curious Kid once their birthday mentioned on the show, please visit supportcuriouskids.com and join the Curious Kids Club. That's supportcuriouskids.com. See you tomorrow.
