海蜇—对虾—缢蛏—牙鲆综合养殖池塘的食物网分析

在面积6.7 hm^2,水深1.5～2.0 m的池塘中进行海蜇—中国明对虾—缢蛏—褐牙鲆综合养殖,在4—9月养殖周期内,采用碳氮稳定同位素法和IsoSource线性混合模型计算各种饵料对海蜇、中国明对虾、缢蛏和褐牙鲆的平均饵料贡献率,以探讨综合养殖池溏的营养级和池塘食物网结构。试验结果表明,海蜇的主要食物来源为投喂的轮虫;中国明对虾的食物来源为鳀鱼、虾夷扇贝下脚料和蜢虾;缢蛏的主要食物来源为底栖硅藻,其次为中国明对虾与褐牙鲆粪便;褐牙鲆的主要食物来源为中国明对虾,其次为虾夷扇贝下脚料和鳀鱼。海蜇的营养级为2.09～3.43,平均值为2.81;中国明对虾的营养级为3.11～4.04,平均值为3.72;缢蛏的营养级为2.37～2.94,平均值为2.62;褐牙鲆的营养级为2.63～3.83,平均值为3.42。综合分析发现,海蜇摄食浮游动物,缢蛏滤食底栖硅藻,中国明对虾和褐牙鲆摄食投喂的虾夷扇贝下脚料和鳀鱼,褐牙鲆也摄食部分中国明对虾,两者的粪便不仅为浮游单胞藻和底栖硅藻生长提供营养,还为缢蛏提供了饵料。上述研究结果为多品种海水综合养殖池塘的生态健康养殖提供科学依据。

Analysis of Food Web in a Jellyfish-Prawn-Shellfish-Flounder Polyculture Pond

In order to analyze the feeding habits of jellyfish Rhopilema esculentum , prawn Fenneropenaeus chinensis , shellfish Sinonovacula constricta and fish Paralichthys olivaceus , and to discuss the trophic levels and food web in sea water polyculture pond in Dandong, with an area of 6.7 hm^2 , the depth from 1.5 to 2.0 meters, during the aquaculture cycle which was from April to September, the δ 13 C and δ 15 N values of the four species of cultured animals and different feeds in sea water aquaculture pond were detected using carbon and nitrogen stable isotopes methods.The contribution proportions of different feeds to R. esculentum , F. chinensis , S. constricta and P. olivaceus were calculated using the IsoSource linear mixture model. The results showed that the rotifer was mainly food source to jellyfish R. esculentum;Engraulis japonicus , Themisto gracilipes and Patinopecten yessoensis wastes were mainly food source to F. chinensis;the benthic diatoms were mainly food source to S. constricta , and then was dejecta of F. chinensis and P. olivaceus;F. chinensis was mainly food source to P. olivaceus , and then were P. yessoensis waste and E. japonicus . Compared the trophic levels of the R. esculentum , F. chinensis , S. constricta and P. olivaceus , it was found that the trophic level of R. esculentum ranged from 2.09 to 3.43, averaged at 2.81, F. chinensis ranged from 3.11 to 4.04, averaged at 3.72, S. constricta ranged from 2.37 to 2.94, averaged at 2.62, P. olivaceus ranged from 2.63 to 3.83, averaged at 3.42. These results means that the food web in jellyfish-prawn-shellfish-flounder polyculture pond was as follow: jellyfish R. esculentum feeds on zooplankton, shellfish S.constricta filter feeding the benthic diatoms, prawn F. chinensis and fish P. olivaceus feeds on E. japonicus and P. yessoensis waste, P.olivaceus feeds on F. chinensis , the dejecta of F. chinensis and P. olivaceus was not only supplying nutrition to phytoplankton and benthic diatoms, but also was feeds to S. constricta . The results would supply the basic data for ecological healthy polyculture sea water pond.