鮻幼鱼的耳石锶标记

Otolith strontium marking of juvenile Liza haematocheila

为探明鮻(Liza haematocheila)幼鱼耳石锶标记的安全与有效性,本研究通过不同浓度(20~100 mg·L^(-1))六水氯化锶(SrCl_(2)·6H_(2)O)浸泡1、2和3 d对鮻幼鱼进行耳石标记,之后,将不同标记的幼鱼转入自然海水中续养90 d。结果表明:标记结束时,所有标记组Sr/Ca比值均与对照组无显著差异;在续养90 d时,除标记ST1-20标记组未出现高Sr/Ca比值区外,其他标记组均在离耳石核心1.1~1.3 mm区域出现显著高于对照的Sr/Ca比值,且续养90 d时其锶标记效果仍可见;在整个实验期间,标记组体长、体质量、肥满度和死亡率均与对照组无显著性差异;选择40 mg·L^(-1)六水氯化锶标记1 d(ST1-40)和20 mg·L^(-1)六水氯化锶标记2 d(ST2-20),之后,续养36、38 d时两个标记组肌肉中锶含量均恢复到对照水平。综上所述,鮻幼鱼的耳石锶标记方法具有有效、稳定、安全的特点;在实验中,较实用的标记方法为添加外源锶40 mg·L^(-1)标记1 d和添加外源锶20 mg·L^(-1)标记2 d。

To clarify the safety and effectiveness of otolithic strontium markers in juvenile Liza haematocheila,otolith marking was carried out through soaking in different concentrations(20-100 mg·L^(-1))of strontium chloride hexahydrate(SrCl_(2)·6H_(2)O)for 1,2,and 3 d.After that the marking juvenile fish were transferred to natural seawater for 90 d of continuing rearing.The results showed no significant difference in Sr/Ca ratio between the all marking groups and the control groups.After these fish were reared for 90 d,there was no significant difference in Sr/Ca ratio between the marked ST1-20 marking groups and control groups,while the Sr/Ca ratio of the other marking groups in area 1.1-1.3 mm away from the otolith core was significantly higher than that of the control groups.After being reared for 90 d,the effect of the Sr-marking was still visible.During the experiment period,there were no significant differences in body length,body weight,fullness and death rate between the marked groups and the control groups.For the groups,after 40 mg·L^(-1)Sr-marking for 1 d and 20 mg·L^(-1)Sr-marking for 2 d,the muscle strontium content in the two marked groups gradually returned to the control level at 36 and 38 d.Our results suggested that the otolith Sr-marking method for juvenile Liza haematocheila could be effective,stable,and safe.The better marker groups are ST1-40 and ST2-20.