Fred is toast.
The water in his specimen container was pretty badly fouled this morning, and it wasn't from the nori... (peeeeeeeee-yew!) There is no suction from his foot, and when I jiggle the container, an off-color substance is coming out from under his shell. I'm guessing that's Fred.
I tested my tank water this morning, everything looks pretty darn good.
I am super glad my wife saw him (I didn't) and we got him isolated before he croaked. At least he didn't have the opportunity to foul the tank. I have visually observed all of my inverts and none seem to be having any problem. Asterea Snails, Margarita Snails, Stomatella Snails, Sexy Shrimp and Emerald Crabs seem to be doing fine. None of my zoos or shrooms look any different than normal.
Dunno if Abalone are hard to keep or not. I have some thoughts about this one that I would like to take an opportunity to share. This may sound a bit like Monday Morning Quarterback, but so be it.
When I purchased Fred from my LFS, the worker there had to exert an enormous effort to pull him off the glass. And when I say he pulled, he really did pull. There is a possibility that poor Fred never had a chance because that action had injured him before he even went in the bag. I know my tank water is good, and there is plenty of algae to eat, so he definitely didn't starve.
Since recounting this story privately to several people, every one with Abalone experience say this was handled poorly by the LFS and they may have indeed damaged this animal. This was before we noticed anything wrong with Fred, mind you. In fact, I think it was Skip who told me his LFS will not sell these critters if they don't come off the glass easily. A book I read also talked about using a plastic card to gently break the suction rather than just pulling.
At some point I will probably try another Abalone. I think they are cool, and really not overly expensive. (Less than $10.) If I have problems then, I'll be done. But I will be better informed on how NOT to remove one from the tank, and next time I won't let my lack of experience stop me from saying something... like... "How you're handling that animal is wrong." I almost said something at the time and didn't, now I wish I had.
Live and learn...