Cause of death?

[pletlibo]

Hey guys I’m a new reefer. I recently purchased a small clownfish and royal gramma to put into my 20g quarantine. I purchased them from a store that was about a 2 hour drive away, and I made sure they packed them well. From acclimation, the royal gramma would just lay on its side. I read that this was rather normal behavior for stressed grammas, so I didn’t panic. But today, I saw him die. He was breathing laying on his side, then he swam around frantically, and stopped. I have no idea what caused his death. My parameters are all good. Could it just be stress? I’ve attached pictures of the body.

 

[sfin52]

How did you accumulate them.

 

[Big G]

Sorry for your loss. Did you see the fish eat while at the store?

 

[pletlibo]

I didn’t see him eat unfortunately, and to acclimate I floated them for 20 minutes and then drip acclimated them. However when pouring him out of the bag the gramma got stuck for a couple of seconds which likely contributed to lots of stress on the fish.

 

[DLHDesign]

Sorry for your loss.

First pic looks like there's a white stringy poop; was that actually there, or is that just a result of the camera? If so, there's a chance that the fish had some kind of intestinal parasite. If the fish hadn't been eating in the store due to that, the basic stress of a tank move could have pushed it over the edge. So even though you may have done everything right in the transfer to the QT, the problem pre-existed anything you did.
Asking a shop to show you a fish eating before purchase is always a good idea. A good LFS won't hesitate to do so, either. If they give you any push-back on that, then they are not a vendor you should be buying from anyways. When I first got into the hobby, I was worried that the LFS would be offended or something - but that's not been the case at the good shops.

 

[sfin52]

Well that rules out acclamatio