It utilizes different ecological niches in the pond.
Explanation
Composite Fish Culture, or polyculture, is an aquaculture system where multiple species of fish are reared together in a single pond. The selection of species is based on their non-competitive feeding habits to ensure efficient utilization of resources.
- It focuses on a single high-yield species. is incorrect: This system involves the simultaneous culture of five or six different fish species, rather than a single species (monoculture).
- It utilizes different ecological niches in the pond. is correct: The primary advantage of this system is the utilization of different ecological niches within the pond. For instance, Catla are surface feeders, Rohu feed in the middle zone, and Mrigal and Common Carp are bottom feeders. This stratification ensures that food resources in all zones of the pond are consumed without inter-species competition, leading to higher yields.
- It eliminates the dependence on fish seed. is incorrect: The system does not eliminate dependence on fish seed. In fact, a major constraint of composite fish culture is the lack of availability of good quality stock (seed) during the breeding season.
- It requires minimal water management. is incorrect: This method requires scientific management, including monitoring of water quality, stocking density, and supplementary feeding, to sustain the high biomass of multiple species.
Key Takeaway: Composite Fish Culture maximizes production by stocking compatible species that inhabit distinct water levels (surface, column, and bottom), thereby utilizing the entire aquatic ecosystem efficiently.