Help ID this critter?

[0utworld]

Hi all,

I noticed 3 of these guys on my glass and my frag plugs. They're round/triangular shaped, around 1mm in size, and not transparent or similar to copepods and amphipods. It moves like a bug so this rules out nudis, snails, and worms.

I managed to capture some footage under 100-200x magnification.

Please let me know what you all think this is. Thanks in advance!

 

[0utworld]

Don't think the video is working, here's the YouTube link

 

[taricha]

ostracod probably.