Pest or not???

[bubbasguppies]

So my GSP is looking ok extended but it's growth rate is pretty slow. I looked at it with a magnifying glass and saw what looked like a growth on the outer skin...maybe sponge...no idea....so I dipped it in CoralRX Pro. During the dip this lil critter came off.....so I snagged it and put it into another container.....is this a pistol shrimp baby? If so what kind and is it reef safe?

Thanks everyone...

 

[ReeferMaddness843]

Looks like Gammaridea amphipod to me. It’s a good guy

 

[bubbasguppies]

oops...i meant mantis shrimp