Mantis or Pistol Shrimp?

[mseepman]

Oscar,

I just bought a pistol/goby pair for my "in progress" nano tank. They are very cool when in a pair.

It sounds to me like you have a pistol shrimp in there somewhere. Usually they are harmless to to most things except other shrimp, like cleaners, etc.

I would keep looking with the flashlight, but I wouldn't worry too much.