questions: asked about the ideal pond construction, pond type, optimum size, depth required for carp polyculture in india. 
 answers: 1. nursury pond: size: 100 - 500 m2 , depth: 1.0 - 1.5 m, 2. rearing pond: size: 500 -1000 m2 , depth: 1.5 - 2.0 m, & 3. stocking pond: size: 1000-2000 m2 , depth: 1.5 ¿ 2.5 m. rectangular pond are suitable for netting purpose but square shaped pond are economical. side slope of the pond should be maintained at the time of the excavation.