Pod Explosion, or Something Else?

[Bongo Shrimp]

So I'm going around to each of my tanks before I go to bed tonight. The lights are out and I'm using a flashlight. When I got to my seahorse tank, I found THOUSANDS AND THOUSANDS of these little shrimp like creatures "flicking" around the tank. They are very tiny, smaller than a grain of rice and instead of swimming smoothly through the water like tiger pods do, they flick around in quick jerky movements.

Now I'm not really worried about this because the seahorses will just eat them, but I'm at a loss as to how they got there and exploded seemingly over one day's time. I can assure you that they weren't there last night.

The only thing I can imagine them being is mysis shrimp larvae. The only thing is, is that I have never fed live mysis to the tank. The only place they could have come from, assuming they are mysis larvae, is from the frozen mysis cubes I feed daily. The tank almost looks like I just fed it with a cube of cyclopeeze because there are all these tiny things floating around. I've never seen anything like this.

Is it possible if one of the frozen shrimp had eggs that they hatched in the tank?

If not, then what are these things?

Here is a video and some pics I took with my digital microscope. The video is a bit glitchy (no it isn't your computer) so bear with me because it wasn't really meant to shoot video.

Video

I'm really at a loss here...

 

[mmotown]

Those are shrimp. What kind I don't know but good!!!!!

 

[lordofthereef]

I have a ton of those too in my nano. Dunno where they came from. Haven;t added anything to the tank in a few months but one night I saw a bazillion of them.

 

[Luis A M]

Bongo,they are definitely Mysis.They come with LR,plants and such.They don´t broadcast eggs nor have free larvae.
The commercial frozen mysids are from cold FW.