Explain the concept of Composite Fish Culture System. Describe how different fish species are selected based on their feeding habits to maximize fish yield from a single pond. Discuss the major problem faced in this culture system and how it is overcome.

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Composite Fish Culture System Composite Fish Culture is a technique in which five or six different species of fish are cultured together in a single fish pond. The species are selected such that they do not compete for food among themselves due to their different feeding zones and food habits. Selection of Species Based on Feeding Zones: Surface Feeders: Species like Catla feed on the surface of the water, utilizing food available in the uppermost layer. Column Feeders: Species like Rohu feed in the middle zone (column) of the pond water. Bottom Feeders: Species like Mrigal and Common Carp feed at the bottom of the pond, consuming decaying organic matter and organisms dwelling on the pond floor. Weed Feeders: Species like Grass Carp feed specifically on aquatic weeds growing in the pond. Advantages of Composite Fish Culture: Complete utilization of available food in all zones of the pond without any inter-species competition. Significantly higher yield of fish compared to monoculture systems. Diverse fish species can be harvested simultaneously. Major Problem and Solution: Major Problem: A major drawback of this system is that many of these fish species breed only during the monsoon season. Even if fish seeds (spawn) are collected from the wild, they get mixed with unwanted species seeds, resulting in a lack of availability of good quality fish seed. Solution: This problem is overcome by using induced breeding through hormonal injections (pituitary gland extracts). This ensures the pure supply of desired fish seed in required quantities at any given time.