I have no idea why they died!!

[fishgirl]

BACKGROUND: I have a 75 gal FOWLR with hermit crabs, emerald crabs, a cleaner shrimp, a Yellow Tang and a sebea clown. It has 90lbs of LR, a LS bed, a prizm protien skimmer and a couple of Rio powerheads. I add garlic extract and zoe vitamins.
LEVELS as of today: pH: 8.1, SG: 1.026, Temp: 86, 'trates: under 10.0, Ammonia: 0.
Everyone was doing fine and I decided to move my Humbug damsel and my yellow-tailed damsel (both I have had for about six years now and they have survived everything) from my 30 FO (which has the same pH, SG, and temp as the 75) to the 75 three days ago. Today I woke up to find them both dead on the bottom with no sign of disease. My tang, clown, and all my inverts are fine but my two damsels are dead.
The only thing I can think of is that they were killed by the tang or clown, although they are large and pretty fiesty. My tang never payed any attention to them, although I did notice the clown chasing them a little - nothing I was worried about at the time.
Any ideas as to what happened?!
Thanks in advance!

 

[beth]

I think you are probably right, either the clown or the tang did them in. It wouldn't take much more than a swat from the tang's swords to kill off the damsels in short order. They wouldn't even know what hit them.
That is really bad, especially since you've had them for long.

 

[fishgirl]

Thanks Beth, but now I'm worried about what kind of fish I can ever add to my tank.
I had a stunning flame angel for about a month over the summer; eating well, looking great, then one day just dead like my damsels now. My tang, clown, shrimp, and crabs have been great - so it can't be disease.
I want to have corals soon, and buying a big angel or a trigger woudl mess that up completely but I have to find someone who can hold thier own with my clown and tang who is also reef-safe! Any ideas??