Reproduction of both SIS species occurred in all ponds, their fry numbers, weight and biomass at harvest not being affected either by silver carp or by the bottom feeder species. The addition of silver carp in mrigal ponds had a negative effect on both adult SIS, while its addition to carp ponds had a weaker negative effect on mola and a positive effect on punti. Common carp favoured mola growth and reduced punti survival. Silver carp performance was not affected by the species of bottom feeder present. Common carp performance was not affected by silver carp. Mrigal harvesting biomass and survival were not affected by silver carp, but its harvesting weight, growth rate and yield decreased respectively by 29%, 42% and 39% in its presence. Large carp and total harvested biomass and yields were over 50% higher when silver carp was also present. In the presence of silver carp, large carp and total yields were 20% higher in common carp ponds, while in its absence they were somewhat higher in mrigal ponds. The FCR calculated considering only the large fish were 10% higher in mrigal ponds. FCR calculated including all species were somewhat higher in common carp ponds without silver carp, and 35% higher in mrigal ponds with silver carp. The observed results are explained and discussed considering the feeding habits of each species, the natural food web, and the ecological processes developing in the ponds.