马氏珠母贝混养紫海胆对污损生物防除效果的研究

Study on the biological control effect of Pinctada martensi mixed culture with Anthocidaris crassispina on fouling organisms

利用我国南方紫海胆(Anthocidaris crassispina)与大亚湾马氏珠母贝(Pinctada martensi)进行不同比例混养,探讨了紫海胆对马氏珠母贝贝体和养殖网笼污损生物的防除效果,以及紫海胆和马氏珠母贝的生长状况。试验设混养组(PA3、PA6、PA9)和对照组(P),即在养殖马氏珠母贝30只/层的基础上,分别混养紫海胆3、6、9、0个/层;另设紫海胆单养组(A3、A6、A9),养殖密度分别为3、6、9个/层。试验结果显示:各混养组及P组间马氏珠母贝的存活率无显著差异(P>0.05),混养组紫海胆的存活率均接近100%,组间无显著差异(P>0.05);PA6、PA9组马氏珠母贝的特定生长率大于P组(P<0.05),而PA3组与P组之间差异不显著(P>0.05);就马氏珠母贝的壳长日平均增长率而言,PA3、PA9组与P组间无显著差异(P>0.05),但PA6组显著大于P组和PA3组(P<0.05);PA6、PA9组马氏珠母贝的肥满度显著大于P组(P<0.05),PA3组与P组间无显著差异(P>0.05);混养与单养各组之间紫海胆的存活率、壳长日平均增长率、肥满度均无显著性差异(P>0.05);PA3、PA6、PA9组网笼的污损生物量与P组相比分别减少了(52.5±12.4)%、(63.3±15.7)%、(70.5±13.1)%,马氏珠母贝壳表附着的污损生物量分别减少了(45.4±9.6)%、(62.9±7.5)%、(68.1±11.9)%,其中PA6、PA9组壳表附着污损生物量显著小于P组(P<0.05)。结果表明,混养紫海胆不仅不会影响马氏珠母贝和紫海胆的生长存活,而且能对养殖网笼和贝类壳表的污损生物起到很好的防除效果,紫海胆混养密度以6个/层为宜。

The fouling biological control effect of Anthocidaris crassispina on Pinctada martensi shell body and farmed cages,as well as the growth of the A.crassispina and P.martensi were studied through A.crassispina of southern China mixed culture with P.martensi in Daya Bay in different proportions.Mixed culture groups PA3,PA6,PA9 and control group P were set up.3,6,9 and 0 A.crassispina in each layer were mixed cultured with 30 P.martensi,respectively.3,6,9 A.crassispina single reared in each layer were marked as A3,A6 and A9 groups,respectively.There was no significant difference in survival rate(SR)of P.martensi between mixed groups and P group.The SR of purple sea urchin was almost 100%and no significant differences were observed in the multicultural groups(P>0.05).The specific growth rate(SGR)of P.martensi in PA6 and PA9 groups was significantly higher than that in P group(P<0.05),but there was no significant difference between PA3 and P groups(P>0.05).In terms of daily growth rate of shell length(LDR)of P.martensi,there was no significant difference among PA3,PA9 and P groups,but LDR of PA6 group was significantly higher than that of P and PA3 groups(P<0.05).Condition factor(CI)of P.martensi in PA6 and PA9 groups was significantly higher than that in P group(P<0.05),but there was no significant difference between PA3 and P groups(P>0.05).There were no significant differences in SGR,LDR and CI of purple sea urchins among mixed and single rearing groups(P>0.05).The fouling biomass on the cages of PA3,PA6 and PA9 decreased by(52.5±12.4)%,(63.3±15.7)%and(70.5±13.1)%compared with the control.The fouling biomass of shell surface attachment of P.martensi decreased by(45.4±9.6)%,(62.9±7.5)%and(68.1±11.9)%,respectively,and the fouling biomass of shell surface attachment of PA6 and PA9 groups was significantly lower than that of P group(P<0.05).The results showed that mixed culture of A.crassispina had no effect on the survival of pearl P.martensi and A.cras-sispina,but had a good control effect on the fouling organisms on the cage and shell surface of shellfish.The best choice was mixed culture of 6 A.crassispina per layer.