Red spotted worm

[Harold]

I found this creature squirming around in my mud puddle sample from last week. The video was shot at 100x, so whatever it is, it's pretty big. And yes, I know, it sounds like a cat Any ideas?

https://youtu.be/EdyAFe-3Tfw

[TonyT]

Aeolosoma

[EthanBCW]

Yes that's of the genus Aeolosoma. I used to have a whole jar full of them from a pot of rainwater outside.

[Harold]

Thanks. I'll be looking up that genus. Interesting critter to watch.

[Sphaerotilus]

A more common name is bristle worm. They are sometimes seen in wastewater treatment plants.