I have to be honest with you here, chances of survival in my opinion is zero.
Once that bloat has set in there is no cure and internal organs are rapidly damaged & eventually shuts down.
Likely causes are severe bacterial infection or hexamite-like infestation. Angelfish generally carry this in their intestinal tract where it is in a natural balance. When the immunity of the fish is affected the balance is destroyed and the hexamite rapidly multiplies.
I'd suggest you break up the territory in the tank. Change the plant layout and ensure that there are suitable spawning areas on either end of the tank. Also ensure that both sites have plants in front of them.
Might also be worthwhile splitting the tank in half through plants, roots, etc.
Hi, sorry for a late reply. By the sounds of it your terrapin has a bacterial infection.
I am also a little bit concerned about the gravel in the tank as it is very possible that it may have swallowed some which will cause a blockage in its intestines. Either use sand or very fine gravel.
What lighting do you have in its tank and also are you coating the food in calcium powder? They also need a piece of cuttlebone (which they bite pieces out of) as an additional source of calcium. As for the lighting, I think it is UV-C (or UV-B)(can't remember which) which will stimulate the natural production of vitamin-D while they bask. There is also a commercial vitamin additive you can put in the water with each water change (which should be weekly).
Cl (pardon me but typing out your full name takes forever). What you said about domestic varieties would apply to Discus as well, and may well apply to loads of other species of fish.
Personally I don't have any view on which is better looking, domestic varieties or wild caught as both are equally beautiful as long as they are healthy and have the right look about them.
Just another thought. When do you stop breeding wilds? And no it is not a trick question. F1 would no longer be wild, and I would speculate that you will start seeing domestic traits sooner or later if you continue with subsequent generations.
Now we go into a whole different realm in terms of the ethics of breeding, in-breeding, crossing, out-crossing, line-breeding, etc., etc.