- [Narrator] What does this look like to you?

Could it be moss or some kind of fungus?

Take a closer look.

This is actually an animal and it's called a bryozoan.

- They are a bit like corals.

It's like a skeleton and it has an animal inside it.

It's like sort of a worm shaped, U-shaped animal.

It's got a ring of tentacles and a mouth in the center, and each tentacle is lined in cilia and that creates water flow, so they're sort of bringing their food to them.

- [Narrator] Megan is one of the few bryozoan experts in the country, because not many people study this aquatic animal, much less know it exists.

- I think they're cool, so that's what got me into it.

- [Narrator] Bryozoans are colonial, meaning the individuals, called zooids, live together in a group and build elaborate homes out of calcium carbonate they pull in from the water.

Megan calls them apartment complexes.

- [Megan] So you can see the little apartment complexes.

The holes is where the animal comes out, and so you're looking at the skeleton - [Narrator] Although they seem like they'd be super obscure, bryozoans are fairly common.

They just take on so many different forms that people often don't know what they are.

- So this is a bryozoan, or a lot of bryozoans, and they're all growing on snail shells.

This is also a bryozoan, and the interesting thing about these is that they can sort of walk along the surface.

This is also a bryozoan, and as you can see, it's very branchy.

- [Narrator] This freshwater bryozoans shows up a lot in news reports as a mysterious blob.

- It just looks like a big booger, but if you look at 'em under the microscope in water, the tentacles will come out.

- [Narrator] There are more than 6,000 described bryozoan species, and scientists, including Megan, find more all of the time, but we don't know much about them or the role they play in ecosystems.

But according to Megan... - They exist, so we should know about them.

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