“…In addition to the reduction in water quality, there was also a reduction in the productivity performance as stocking density increased. This has been observed in several species, such as Horabagrus brachysoma , Oreochromis niloticus , Trichogaster trichopterus , Pterophyllum scalare, Carassius auratus and Heros severus , due to the behaviour alterations that lead to aggression for feed or territories at high stocking densities (Abe et al, ; Barcellos, Nicolaiewsky, Souza, & Lulhier, ; Gonçalves Júnior, Pereira, Matielo, & Mendonça, ; Gonçalves Júnior, Mendonça, Pereira, Matielo, & Amorim, ; Sahoo, Giri, Chandra, & Sahu, ; Syarifuddin & Kramer, ).…”