1.Center for Marine Ranching Engineering Science Research of Liaoning, Dalian Ocean University, Dalian 116023, China;2.Fisheries Seedlings Authority of Liaoning Province, Dalian 116015, China
Abstract: The postlarvae of Chinese shrimpFeneropenaeuschinensiswith body length of (1.00±0.03)cm were reared in net cages disposed in a pond at a rate of 150, 300, 450 and 600 ind./m2for 20 days from the 15th of May to the 4th of June in 2005. Then the shrimp had body length of (2.81±0.19)cm and survival of 70.2%±2.7% at a density of 150 ind./m2, (2.57±0.22)cm and 67.0%±2.8% at a density of 300 ind./m2, (2.15±0.20)cm and 37.6%±3.4% at a density of 450 ind./m2and (2.01±0.32)cm and 33.4%±4.1% at a density of 600 ind./m2. The Chinese shrimp postlarvae with body length of (0.99±0.03)cm were reared in net cages disposed in a pond at a rate of 150, and 300 ind. /m2for 20 days from 10 to 29 in May, 2009. The juveniles with body length of (2.78±0.23)cm and (2.55±0.21)cm were obtained, with survival rate of 70.4% ±3.5% and 69.5% ±3.4%. The sudden mortality of small (with body length of 1.0 cm)and large (with body length of 2.7 cm)shrimp juveniles was studied in coastal waters of Pikou(N39°18′ 22 ″ E122° 23 ′ 30″)from 3 to 4 in June, 2009 and from 4 to 5 in June, 2010. The survival rate was found to be 0% in the small juveniles and 51.7%±1.5% in the large juveniles in the 2009 experiment due to the poor weather, and to be 88.5%±4.4% in the small juveniles and 98.5%±3.5% in the large juveniles in the 2010 experiment under the good weather. In terms of 150 million shrimp juveniles being released into the northern Yellow Sea in 2010, 247.64 thousands yuan RMB, accounting for 13.6% of the total cost, would be saved if large shrimp juveniles were released.
2014, Vol. 29 
