I discussed this with Jan, and she thinks that it might be due to
spawn damage. This fish is the "female of choice" in the pond it would
seem, and I've seen signs of the fish getting busy lately, so that
could be.

On Jan's advice I'm going to bring the fish into the inside tank
containing just pond water and raise the salt .05% per day until it
reaches to .3%.

Since I first posted, the fish has been swimming around the pond,
which is encouraging. Unfortunately that makes it pretty tough to
catch! I've also noticed it's interested in eating, so maybe it's not
so far gone after all.

Thanks,

Dave