外源Sr2+在大麻哈鱼胚胎耳石上的沉积

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^-1Sr²⁺ 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Sr^2+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Sr^2+对大麻哈鱼耳石进行标记.

Exogenous Sr2+ sedimentation on otolith of chum salmon embryos.

To explore the exogenous Sr²⁺ sedimentation on otolith of chum salmon embryos, chum salmon embryos were exposed to culture water contained Sr²⁺ at Sr²⁺concentration of 50, 100, 200 or 400 mg·L^-1 for 48 h to imitate Sr²⁺ sedimentation. After a culturing period of 12 d and 100 d, the otoliths of the chum salmon were taken to detect exogenous Sr²⁺ sedimentation with electro probe 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 Sr²⁺ 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 Sr²⁺ concentration. The strontium peak had no signs of abating after a culture period of 100 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 Sr²⁺ was suitable in the marking of salmon otolith.