Range: Cosmopolitan Habitat: Moss, freshwater waterways, marine sediment, and more Size: About 0.04 inches (1mm) long Diet: Decaying plant material, algae, fungi, nematodes, protozoans, and water bears Threats: Snails, mites, insect larvae, crustaceans, and other small arthropods Life span: Up to two years

Transcript:

Today on Animal Fact Files we’re talking about water bears. Don’t be tardy to new videos, be sure to subscribe; and thank you to dillon lee for today’s request. Although you’ve probably never seen a water bear, you’ve likely been around them.

These little creatures are also known as moss piglets because a vast majority of them spend their lives inhabiting moss. Yes, that green squishy vegetation covering the rocks behind the shed in your backyard, it’s likely teeming with water bears. Water bears are also known as tardigrades which means “slow stepping”. Considering water bears have eight legs they use for getting around, this seems like an apt description. Though, to be fair, some water bears do swim. There are the water bears who live in moss and then there are some who are found in freshwater and even marine water sediment, Basically they live just about anywhere that is wet and has food.

Water bears eat decaying plant material, algae, fungi, nematodes, protozoans, and even each other from time to time. In turn, they’re consumed by snails, mites, insect larvae, crustaceans, and other small arthropods because, well, water bears are freaking tiny. Imagine a pencil, or hold one up if you have one nearby, most water bears could easily fit on the tip of that pencil. To get a good look at a water bear, one would have to use a microscope.

Water bears don’t really look or act exactly like any other known animals; as such, they’re classified into their own phylum. Now, we’ve briefly talked about what a phylum is in the past, but to make sure everyone is up to speed, it is the highest classification after kingdom. So, the animal kingdom is all the animals like… ever, and phylum is just the next step down. For example, horseshoe crabs, moths, and tarantulas all belong to the same phylum: arthropoda. Considering the vast differences present in all the arthropods we know of, it just goes to show how different water bears are from anything else. Though, we ought to note that water bears are thought to be most closely related to arthropods.

One example of a similarity between arthropods and water bears are that they both shed their exoskeleton, and it’s not unheard of for females to lay their eggs in their sheddings. Since there are more than a thousand described water bear species, and there are thought to be thousands more awaiting discovery, we can’t exactly narrow down their breeding habits to something simple, but, generally speaking, water bears are separated into males and females, the females lay eggs and the males may either fertilize them internally or externally after they have been laid by the female. All in all, they don’t usually live for more than a few months under excellent conditions, but when are conditions ever completely perfect?

Probably the most well known aspect of water bears are their ability to survive just about anything. Water bears are able to enter cryptobiotic phases in which they’re basically dead, but they can come back to life once conditions are more favorable. Pfft. Water bear. More like, Juliet bear slug thing... I have no idea what I’m talking about.

Some of the extreme conditions water bears can survive include, extremely cold temperatures, like, almost absolute zero cold when molecules stop moving kind of cold, high levels of radiation, heights of more than three and a half miles, depths of almost three miles, freaking space. This may be a contributing factor as to why water bears are found worldwide. And not like, mostly world wide, like, world wide worldwide, as in, they live in Antarctica, and that might be the most impressive fact about water bears there is.

For more facts on water bears, check out the links in the description. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.