Getting Fry To Survive

[Garp]

I have two convicts that have produced small fry about 4 or 5 times. They guard them and protect them very well from two Jack Dempseys but eventually they all die. What can I do to enable at least a few to survive?

 

[vancouver]

Remove them... the parents are probably too stressed trying to defend them from the JDs, so they eat them.