Blue Spot Jawfish DEAD in <24 hours

[DVNO]

Yesterday i went to my LFS and bought a mystery wrasse and a blue spotted jawfish. the mystery wrasse is doing great, but the blue spotted jawfish is dead.
He was tumbling around on the sand swimming sporatically and did not appear to have good balance. in addition, he had some discolored spots on his body. as he died, he gasped repeatedly. this sucks because no other fish has died in this tank. all the others are totally fine.
Does anyone have experience with BSJ? any ideas?
thanks folks.

[mustang2021]

sounds like maybe his internal organs may have been damaged better said his swim blater wich regulates the fishes abbility to swim normaly when this fish was at the pet store did it have this problem or did this become an issue when you intoduced it to the display