Polyculture is defined as the simultaneous cultivation or rearing of two or more species of plants or animals, and it is becoming increasingly popular in aquaculture. The polyculture system is adopted widely in the aquaculture sector due to its significant advantages such as minimizing the risk of species-specific diseases, an increase in overall yield, efficient use of resources, and the reduction in waste management strategies.
In the fish farming industry, Catla, Rohu, and Mrigal are the most commonly farmed fish in India. Catla (Catla catla) is a freshwater fish species that has a uniquely herbivorous feeding habit. Rohu (Labeo rohita) and Mrigal (Cirrhinus mrigala) are omnivorous fishes and contribute significantly to the fish production in the Indian subcontinent. The polyculture system that combines these three fish species has been found to be highly productive and profitable.
In the polyculture system, the optimal ratio of Catla to Rohu to Mrigal fish species depends on several factors such as the farming practices, fish health management policies, fish species’ preference, and environmental conditions. The general accepted ratio for these fish species in a polyculture system is 40:30:30, which means 40% Catla, 30% Rohu, and 30% Mrigal fish species. This ratio has been tested and proven in several studies and is widely used for commercial fish farming across India.
Catla fish play a significant role in the polyculture system as a herbivorous species by feeding mainly on submerged vegetation, which not only reduces the need for artificial feeding but also helps to maintain the ecosystem’s balance. Rohu and Mrigal consume both plant and animal feeds As such, they work together to make the polyculture system more balanced and sustainable.
In conclusion, the combination of Catla, Rohu, and Mrigal in a polyculture system has become a popular option among Indian fish farmers. The optimal ratio of these fish species that is most effective for a profitable and sustainable fish farming enterprise is a 40:30:30 ratio. The polyculture system is also a viable way to promote a healthy ecosystem while producing a higher quantity of fishes with a reduced carbon footprint.