【摘要】 为了探究耳石锶标记技术在鮻（Liza haematocheila）增殖放流中的应用,以体长1 cm左右的鮻幼鱼为研究对象,将其养殖海水中Sr²⁺质量浓度分别调至50、100、200、400 mg·L^-1,以自然海水(Sr²⁺质量浓度为7.9 mg·L^-1)为对照组,人为改变鮻幼鱼生存环境中Sr²⁺质量浓度48 h。待标记鮻幼鱼长至10 cm左右,采集鮻耳石样品,并利用X射线电子探针微区分析仪（EPMA）对耳石样本进行分析。耳石EPMA面分析结果显示,所有标记组鮻耳石均出现明显的"高锶标记环",并且整个实验期间标记组与对照组鮻的存活率未出现显著性差异（P>0.05）。结果表明,耳石锶标记技术作为鮻小规格苗种大规模标记的方法是可行的、安全的。耳石EPMA线性分析结果显示,鮻耳石中的Sr/Ca峰值和Sr/Ca显著变化阶段均值与水体中Sr/Ca是呈线性变化的,而鮻耳石高锶标记环的宽度与水体中Sr/Ca是呈对数关系变化的。综合实验结果,50 mg·L^-1 Sr²⁺的标记浓度完全可以实现小规格鮻苗种大规模标记的需求。更多还原

【Abstract】 To explore the method of strontium marking on the otolith of Liza haematocheila during the process of proliferation and release, juveniles with a total length of about 1.0 cm were immersed at four different concentrations(50, 100, 200, 400 mg·L^-1) of Sr²⁺ for 48 h to detect the Sr sedimentation effect. And juveniles immersed in natural seawater(concentration of Sr²⁺ was 7.9 mg·L^-1) were set as the control treatment. When the juveniles grew to about 10.0 cm in body length, otoliths of L. haematocheila were collected and analyzed by x-ray electron probe microanalysis（EPMA）. The EPMA mapping analysis showed that the “high strontium marking ring” appeared in otoliths of L. haematocheila in all marked treatments, and there was no significant difference in survival rates between four marked treatments and the control treatment（P>0.05）. These results suggested that the method of strontium marking on the otolith of L. haematocheila was feasible and safe to be used in large umber of small-size juveniles. The peak value or average value of Sr/Ca ratio during stages of Sr/Ca ratio significantly changed in otoliths varied linearly with the concentration of Sr²⁺ in water, and the correlation coefficient of linear equation was 0.999 or 0.987. While the width of the high strontium marking ring varied logarithmically with the concentration of Sr²⁺in water, and the correlation coefficient of logarithmic equation was 0.967. The reasons for these phenomena might be related to the time-lag characteristics of Sr²⁺ deposition in fish otoliths, which needed further study. Based on the results of our experiment, the marking concentration of 50 mg·L^-1 Sr²⁺ could meet the requirement of large number of small-size juveniles being marked. The otolith gradually became larger with the growth of individual fish, and smaller scale of surface analysis detection might be used for the EPMA mapping analysis, these might result in strontium markers to be thin and fuzzy. In order to keep the clear strontium markers of adult fishes when they were juveniles, the scale of surface analysis must be increased, especially for the part where the marking ring was located. Due to the fact that “high strontium marking ring” appeared in the vicinity of 200 mm from otolith core in our study, the large scale of surface analysis detection should be used to detected the scope of 100-300 mm from otolith core of adult L.haematocheila,who was marked when it was a juvenile with a total length of about 1.0 cm.更多还原