With the availability of risk free (parasite free) pellets, I don't use fish at all.
Any fresh fish can contain parasites, even some frozen fish can (some parasites from lakes that freeze over can go into stasis when frozen, and return when thawed). Fish fillets can have questionable nutritional value as a staple, and even the most piscivores species get nutrition from other sources.
There is a study showing that as dovii become adults they eat less and less fish, and more and more insects in nature.
A management plan for the sport fishery of Parachromis dovii (Pisces: Cichlidae)(Gunther 1864) in Hule lake, Costa Rica
Any fresh fish can contain parasites, even some frozen fish can (some parasites from lakes that freeze over can go into stasis when frozen, and return when thawed). Fish fillets can have questionable nutritional value as a staple, and even the most piscivores species get nutrition from other sources.
There is a study showing that as dovii become adults they eat less and less fish, and more and more insects in nature.
A management plan for the sport fishery of Parachromis dovii (Pisces: Cichlidae)(Gunther 1864) in Hule lake, Costa Rica