Jul 26, 2019 · Freshwater fish such as grass carp (Ctenopharyngodon idella), Nile tilapia (Oreochromis niloticus), and grey mullet (Mugil cephalus) have relatively lower dietary protein requirements than carnivorous fish. Local freshwater fish farmers prefer to use unconsumed food, agricultural by-products or leftovers from household kitchens as feed in order