In the semi-intensive fresh water prawn culture, post larvae are stocked at:

Correct option is B

Correct Answer: (b) 4–20 /m²
Explanation:
→ Semi-intensive culture targets moderate stocking to balance growth and carrying capacity; 4–20 PL/m² is the recommended range for Macrobrachium systems.
→ This density allows natural productivity plus supplementary feeding without excessive competition.
Information Booster:
→ Exact stocking within this range depends on input level, aeration and water exchange.
Additional Information (Other Options):
(a) Low (extensive); (c),(d) correspond to intensive systems with high input/aeration.