Salinity of water acceptable for the culture of Macrobrachium rosenbergii:

Correct option is A

Correct Answer: (a) 3–4 ppt
Explanation:
→ Macrobrachium rosenbergii is primarily a freshwater prawn; juveniles and grow-out perform well in low salinity (around 3–4 ppt) which can improve growth and reduce stress compared with pure freshwater in some systems.
→ Larval stages require higher salinity in hatcheries, but culture ponds often use low-brackish conditions.
Information Booster:
→ Salinity management depends on lifecycle stage: hatchery larvae need brackish water, post-larvae acclimate to lower salinities for grow-out.
Additional Information (Other Options):
(b–d) Higher salinities are more typical for marine shrimp species (e.g., Penaeus), not ideal for routine M. rosenbergii grow-out.