I may have the bad Isopods again

Cliff notes: Borbonius anthias is dead and being eaten by some kind of pods.

Story: Thursday morning I saw my borbonius anthias in the morning for his breakfast.  He was out and full of color.  He was eating like normal, no issues.  He has almost doubled in size since I got him at the end of November.  I would definitely say he was the most active healthy fish in the tank.  There are no fish that pick on him, though he and the flame angel will chase each other off on occasion.

Thursday night, no sign of the anthias.  He is normally the last fish to bed, and first fish up in the am.  Always healthy, and always out.  I am a bit worried about him not being there.  Friday, still hasn't shown up.  Tonight I finally find his body down being dragged into the pistol shrimp's cave under the rock.  I had looked at the mouth of the cave for him before and the body wasn't there, so I know the pistol shrimp just got it under there tonight.  I highly doubt the pistol shrimp is the culprit, but just scavenging.  At this point I am not understanding how a fish with no signs of stress or disease just dies in an afternoon, but then I see them, two small Pod animals going in and out of the flesh.  I did notice that they had long antennae though, so I am not sure if they are Copepod, Isopod, or amphipodes? As far as I know any of the three would likely eat a carcass as they are all omnivores. 

So I have a few concerns.  I am wondering if these guys are possibly isopods, because that is the only thing I can think of that would have brought that healthy fish down in less than a day.  They are the size of the isopod I pulled off the sailfin months ago, but I don't know where they would have come from because I would assume that they would have killed other fish between the time I pulled the one off the sailfin and now if they were infact still in the system. 

Here is a shot of the one I pulled off the Sailfin months ago:



These look almost just like that, but I cant get pictures or pull them from the system because of where they are at.  The only reason I think these may be different, is that I see long antennae on these where the above photo I do not see the antennae. 

Any ideas?  If these are Isopods, I need to start getting the fish out of the tank before they kill others. 

It really sucks that they picked my favorite/ way most expensive fish to kill (assuming they killed him), but I would like to help the others out before they fall victims as well.  Thanks :(

First pic----- yep, bad. Gotta get them off. Second pic- doesn't look bad to me. Looks like an amphipod of sorts. I'd be worried if I found that on the fish but not just in the tank.

On a side note. I had a local store call me the other day asking about ways to get rid of parasites. They've had an infestation recently and are battling this and want to make sure their fish are clean before they sell them.

Adam