I collected Diamond's ashes today from his Veterinary Surgeon. His remains were separately cremated by the Animal Welfare League. I intend to scatter them in his garden when a couple of his closest human friends can come around to participate.
So far I haven't informed the fish, although they seem to have guessed that something has happened. Their chief concern seems to be that they are fed regularly twice a day. Diamond would notify me if I was late. Perhaps they miss him jumping around when I sprinkle their special goldfish pellets, although he hadn't been agile enough to do much of that for a while.