little something

[Al Vance]

every morning when the light turn on I watch.
I see these little things running on the sand. I seen an emerald crab eat one.
They are moving so fast though. Can't see when lights are on
What are they. Very Very small.

 

[dcantucson]

Small ones are likely copepods and the larger ones Amphipods. Both good things.

Copepod - Wikipedia, the free encyclopedia

http://saltaquarium.about.com/od/copepodamphipodprofiles/Copepod_Amphipod_Profiles.htm

 

[Bifferwine]

Yep, your tank is filled with beneficial little bugs. Pods are great food for corals and fish.

 

[Al Vance]

how did they get there?
I see my lfs sells them?
I thought for seahorses and mandarins

 

[Bifferwine]

They come in on the rocks. If you have macroalgae, you'll have them too. LFS sell them bottled for seahorse and mandarin foods, but the bottles contain thousands of them. If you have live rock, you have them in your tank naturally. But usually that's not enough to keep a mandarin or seahorse fed if they are only eating live foods.

 

[bjohanson1234]

They come in on the live rock.