PLEASE Identify before I put in tank

[eric4usa]

I am cycling some live rock I bought from someone getting out of the hobby.
As I transfered from one rubbermaid to another, these guys were there in the bottom.
I still have the rock in cycle.
Good or Bad ? (fraid they might be mantis)
If they are mantis, I have 3 tangs , picasso trigger and a christmas wrasse, will they eat these little guys?

 

[marine fanatic]

Considering they came from your LR and from the pitcure, I would say they are copepods. Very good to have in your tank. Having an established pod population in your tank is both a good sign of a healthy system as well as a great food source for many of your tank critters.

 

[eric4usa]

Ok thanks.
I thought they looked like a praying mantis on the front.
I have kept them!

 

[bang guy]

They are Gammarus Amphipods. Good detritus consumers and excellent fish food.