bumble bee goby Help!!!!!!

[Ritt]

I got a bumble bee goby today. Think I have a serious problem. After thoroughly acclimating him to my tank he freaked out and started floating I thought he was dead but then I noticed his gills moving. Now he doesn’t seem to be able to swim to the bottom he just floats. What is wrong?

 

[CFC]

Is your tank Brackish or FW? Did you make sure that the goby was being kept in the same type of water as yours before you bought it?