Critter found in filter

[sleeper]

Found this guy while cleaning out my TUNZE comline filter today. Any ideas, I have no idea if he is the only one. Usually where is one, there's a hundred you don't see. He is pretty good size though. That's my index finger I agitate the water with towards the end of the video.
https://www.dropbox.com/s/pq6mbuzx8yxhd8b/Video Sep 05, 4 02 37 PM.mov?dl=0

 

[Tradevg]

Looks like a pod...

 

[brandon429]

gammarus agreed. the first reefing question I ever asked in my life was for that animal, in 96, to professor about why the school tank was crawling with those things. the fascination never ended. he showed me how those rascals burrow, live in the live rock crevices, are fish food, contribute in bulk to working the top layers of sand, produce gametes for food webs in the tank, on and on, one bug/one group of bugs.

 

[Flippers4pups]

Amphipod.

 

[sleeper]

Guess I should have thrown him back. I'm assuming he's not the only one.