三疣梭子蟹和凡纳滨对虾混养系统的氮磷收支的研究

Study on Nitrogen and Phosphorus Budget in Polyculture Systems of Litopenaeus vannamei and Portunus trituberculatus

利用海水池塘陆基实验围隔，研究三疣梭子蟹（Portunustrituberculatus）和凡纳滨对虾（Litopenaeusvannamei）不同混养系统的N、P的收支、利用率和养殖效果等。结果表明：投喂饵料（包括对虾饲料与蓝蛤）是围隔中N、P的主要来源，分别占N总输入量的79．77％～91．53％和P总输入量的94．31％～98．43％；其次为水层中带人的N、P，分别占到N总输入量的7．06％～16．22％和P总输入量的1．12％～4．53％；由于放养的养殖生物个体太小，对整个养殖系统中N、P的贡献极小。在支出项目中，N、P的支出主要在底泥积累中，分别占N总支出量的40．29％～65．89％和P总支出量的76．11％～86．54％，其次为养殖生物和水层积累，其中N在水层中输出的比例较大，而吸附、渗漏的较少，而P在水层中输出的比例较小，吸附、渗漏的较多。研究表明，各混养组梭子蟹N的利用率均显著高于单养蟹组（P〈0．05）。综合养殖结果和各系统N、P利用率数据表明，在本研究中，三疣梭子蟹和对虾混养的最佳配比为三疣梭子蟹6只／rn2，凡纳滨对虾45尾／m2。

Nitrogen （N） and phosphorus （P） budget in different polyculture systems of Portunus tritu- berculatus with Litopenaeus vannamei were studied. The polyculture systems were established as enclo sures in seawater ponds. The results showed that the feed was the main nitrogen and phosphorus input, accounting for 79.77 % -91.53 % and 94. 31% -98.43 %, respectively; while that contributed by seawater accounted for 7.06%-16.22% and 1.12G-4. 53% input of nitrogen and phosphorus, respectively. The major nitrogen and phosphorus output came from sediments, which accounted for 40. 29 % -65.89% and 76.11%-86. 54% of total of total nitrogen and phosphorus output, respectively. The biomass harvested removed away 8. 7%-24. 44% and 14. 11G-18. 90% of total nitrogen and phosphorus input, respective-ly. The utilization efficiency of nitrogen in polyculture systems was higher than monoculture systems. The polyculture system yielding the best culturing benefit was consisted of at 6 crabs/m2and 45 shrimps/m2.