短波紫外线辐照对近江牡蛎眼点幼虫存活及附着的影响

Effects of Ultraviolet-C on the larvae survival rate and settlement rate of Crassostrea ariakensis

近江牡蛎(Crassostrea ariakensis)是海洋中主要污损生物之一,对海上养殖设施以及海洋工程装备存在较大的影响。波长短能量大的短波紫外线(UV-C,波长200~280 nm)辐照能够损伤贝类幼虫的DNA和蛋白质结构,影响其存活和附着,可用于防治生物污损。本研究选用二倍体近江牡蛎附着变态期的眼点幼虫为研究对象,采用单一变量法,研究不同强度和剂量UV-C的眼点幼虫致死响应,以及不同UV-C辐照频率和辐照距离下眼点幼虫的附着率差异性。研究结果表明,10 W短波紫外线灯辐照试验中部分处理组和对照组在观测时间段内存在显著差异(P<0.05),24 h后所有处理组试验单元内无存活幼虫,此时对照组存活率为(26.3±1.9)%;20W短波紫外线灯辐照试验中处理组和对照组在所有观测时间段的存活率均存在显著差异(P<0.05),24 h后所有处理组试验单元内没有存活幼虫,此时对照组存活率为(22.3±1.3)%;辐照频率达5 min/h时,平均附着率从(12.83±1.17)%降低至(3.31±0.69)%,显著地降低了附着率;装置距离网衣15和20 cm对附着率的辐照效果无显著差异,与对照组相比均能有效减少附着。本研究可为UV-C防治生物污损的装备设计提供参考。

Crassostrea arakensis is one of the main fouling organisms in the ocean,which has a significant impact on marine aquaculture facilities and marine engineering equipment.Short wavelength and high-energy ultraviolet radiation(UV-C,200-280 nm)can damage the DNA and protein structure of shellfish larvae,affecting their survival and attachment.They can be used to prevent biological fouling.This study selected the larvae of Crassostrea arakensis as the research object.The single variable method was used to study the lethal response of larvae under different intensities and doses of UV-C,as well as the differences in attachment rates of larvae under different UV-C irradiation frequencies and distances.The research results showed significant differences(P<0.05)between some treatment groups and the control group during the observation period in the 10 W shortwave UV-C irradiation experiment.After 24 hours,there were no surviving larvae in all treatment groups in the experimental units,and the survival rate of the control group was(26.3±1.9)%;In the 20W UV-C irradiation test,there was a significant difference in survival rates between the treatment group and the control group at all observation periods(P<0.05).After 24 hours,there were no surviving larvae in all treatment groups in the experimental units,and the survival rate of the control group was(22.3±1.3)%;when the irradiation frequency reached 5 minutes/h,the average adhesion rate decreased from(12.83±1.17)%to(3.31±0.69)%,significantly reducing the adhesion rate;There was no significant difference in the irradiation effect of the attachment rate between the distance of 15 and 20 cm,and both groups were able to reduce attachment compared to the control group effectively.This study can provide references for the design of equipment for UV-C prevention and control of biological fouling.