I think I found the dead clown withing 12 or fewer hours of death. I removed the fish to a bucket of water, I was too busy to deal with it immediately. It was not until the following day that I get out to my garden dig a big hole. By then the slime coat had begun to come off. I doubt there was much "stink" left behind. I also did a major water change after I remove the fish.
We are now over a month since the death, There have been a few more big water changes since. Still neither of the two remaining big clowns will use the cave so far. I spotted one of them peering into the cave, but it would not go in.
Because I started so late in life with fish and because of subsequent family and then health issues I was never able to do what I would have loved to, visit Brazil and the Big Bend of the Rio Xingu. I have never been able to observe any of the fish I keep as they live in the wild. So I am totally unqualified to comment on their behavior there.
But just the way people who are missing one of their senses, blindness, deafness etc, learn to cope with what they do have, I have spent a lot of time observing my fish in tanks. No matter how hard we try, we can never give out fish an environment that comes even almost like nature. Imo, the result is that there are some obvious difference between the behavior of fish in the wild and in tanks.
Because this house has no basement, my tanks are spread out all over living spaces. At my peak I had 3 tanks in my bathroom, 9 in my bedroom and another 5 in the adjacent room which used to be a "library room." I also used to have another 9 in the fish space in our semi-detached guest building and storeroom.
Up until the most recent yeat I have done 50%+ weekly water changes on all tanks and cleaned whatever needed to be at the time. I am surrounded by tanks and I watch my fish on and off all day long. I am pretty observant and I can tell you a lot about how the species I keep behave in their tanks. I have digital and mechanical testing equipment and I stay on top of my parameters. The point is I have spent a lot of time watching my fish over the years.
So I know the water in the clow tank is good and there is not rsidiual evidence of the one that passed in the water. That cannot explain what I am seeing as far as I am concerned. The other thing I have noticed is the big one was the tank boss. The other two slightly smaller would occasionally challenge for the top spot. But I never saw those two fighting each other. Since the big one passed i have caught the other two going at it. I also often notice the two hiding behind the big log and touching each other as clowns do. It appears to me they are somewhat arguing about who is top dog. But they do not seem to put their hearts into the squabble the way it all went when the three (including the dead one) fought for a few months to establish the pecking order that lasted for about 15 years.
This sort fo thing is exactly why I love this hobby. After almost 23 years I am still learning and still observing how fish behave in tanks. It is not the same as they do in the wild for the most part. It is not radically different but it is not the same as in the wild. Part of this has to do with the fact that every tank is different as is how we as keepers may set them up, build a scape and then select the fish that go into it.