Fish commonly raised by polyculture are

Options

A. labeo rohita
B. catala catla
C. mystus singhala
D. both 1 & 2

Answer

### Step-by-Step Solution:

1. **Understanding Polyculture**:
- Polyculture is an aquaculture practice where multiple species of fish are raised together in the same environment, such as a pond. This method has been practiced for thousands of years, originating in China.

2. **Purpose of Polyculture**:
- The main goal of polyculture is to maximize the use of resources and minimize competition among fish species. Different fish species have varying feeding habits, which allows them to coexist without competing for the same food sources.

3. **Feeding Habits**:
- In a polyculture system, fish are selected based on their different feeding habits. For example:
- Some fish feed on aquatic vegetation.
- Others may feed on small aquatic organisms.
- Some may consume phytoplankton.

4. **Common Fish Species in Polyculture**:
- The most commonly raised fish species in polyculture systems include:
- **Labeo rohita (Rohu)**: A fish that feeds on detritus and phytoplankton.
- **Catla catla (Catla)**: A surface feeder that primarily consumes plankton.
- **Labeo (Lebiu)**: Another species that can be included based on its feeding habits.

5. **Conclusion**:
- Therefore, the fish commonly raised by polyculture are Labeo (Lebiu), Rohu, and Catla. The answer to the question is both Labeo and Rohita, as well as Catla.

### Final Answer:
- The fish commonly raised by polyculture are **Labeo (Lebiu), Rohu, and Catla**.

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