Someone, I've found under microscope. Who is it?

[Obriy]

I have some algae starting to grow in my tank and decided to put to use my kids' microscope. This was on a small white thread-like particle attached to a rock. There are actually many of them.
Can anyone name this guy?

 

[WalkerLoves_TheOcean]

I am going to take a wild guess, but that looks like a detritus worm. I could be very wrong though. Someone more knowledgeable should hop on soon.

 

[DaJMasta]

Yeah, some kind of small nematode. I don't know if they're that well documented in marine aquaria, but they are certainly common in mature sandbeds and algaes.