What freshwater fish is the cleanest and healthiest?

Among clean freshwater fish, giant salamander is the first, giant salamander generally needs to be cultured in running water, followed by mandarin fish and perch, the third should be carp and crucian carp, which eat feed and biology, the fourth should be tilapia and snakehead, which have mixed feed, the fifth should be grass carp, which mainly eats aquatic plants, and the sixth should be catfish, which can survive in sewage. People in China generally don't eat catfish in the past.