外源Sr^(2+)在大麻哈鱼胚胎耳石上的沉积

Exogenous Sr^(2+) sedimentation on otolith of chum salmon embryos

为探明外源Sr2+在大麻哈鱼耳石上的沉积状况,本研究利用电子显微探针技术(EPMA)对大麻哈鱼发眼卵后期胚胎进行50、100、200、400 mg·L-1Sr2+48 h浸染试验,经12和100 d暂养后检测其在耳石上的沉积.结果表明:不同浓度Sr2+均在大麻哈鱼耳石上产生明显的深红色标记环.同一剂量组锶峰区均值和极值不稳定,但最小锶峰极值也能达到对照组水平的35.1倍,整体上锶峰随浸染浓度增加而增大.经100 d暂养后,锶峰没有减弱迹象.检测结果还表明,锶在大麻哈鱼耳石上的沉积是逐渐进行的,有明显的滞后现象,高峰后能恢复到正常水平.这些特点符合对放流标记技术的要求,表明可以利用外源Sr2+对大麻哈鱼耳石进行标记.

To explore the exogenous Sr^2＋sedimentation on otolith of chum salmon embryos,chum salmon embryos were exposed to culture water contained Sr^2＋at Sr^2＋concentration of 50,100,200 or 400 mg·L- 1for 48 h to imitate Sr^2＋sedimentation. After a culturing period of 12 d and 100 d,the otoliths of the chum salmon were taken to detect exogenous Sr^2＋sedimentation with electroprobe microanalyzer（ EPMA）. The results showed that obvious deep red strontium signatures were produced in the otolith of chum salmon at different concentrations of Sr^2＋. The mean and extreme values of peak strontium area were not stable for the same Sr^2＋dose,but the lowest of all the peak values was 35. 1 times as much as that of control. Overall,the strontium value increased with the increase of Sr^2＋concentration. The strontium peak had no signs of abating after a culture period of100 d. The results also showed that strontium was gradually deposited in the otolith,and had obvious hysteresis to immersion. Strontium sedimentation could also return to a normal level after the peak. These characteristics accorded exactly with the requirement of discharge tag technology,which indicated that exogenous Sr^2＋was suitable in the marking of salmon otolith.