Please help ID

[ags]

About six months ago I set up a buddy of mines tank. Since then he added about 200lbs of Fla LR. The other day I was looking through his tank and in a super small crevice I see a bunch of brine shrimp looking bugs swimming and darting around really fast. The space was so tight I could not get a more detailed look but they looked like tiny microscopic brine shrimp but much faster. This is an extremely crude description but hopefully someone can tell me what they are.

 

[banshee]

My guess is Mysis shrimp...a good thing.

 

[ags]

Do the mysis shrimp come out during the day as well? These were out mid-afternoon. Thanks for the help.

 

[bang guy]

If you have no predators they'll come out all the time. In one of my refugiums they even cruise along the water surface.