Hi Nehpets, you might want to read up on the 30 day syndrome. I have fry approaching the 30 day mark and asked a well know breeder (you guys know Cary S.) about preventing it. He suggested keeping the water, tank and filters very clean. So I have been doing large daily water changes, wiping the tank sides and bottom and rinsing the filters weekly.
Regarding the fry pictured that appears to be nerve damage (at least in an adult). Was it perhaps handled roughly when netting or removing the parents?
Pat