The effect of age on the sensitivity of zebrafish sperm against mercury exposure was investigated in the present study. Although results of the use of sperm from mature individuals for toxicity tests have been published, there is no information about the exact age of the fish in some cases, which can affect the results. During the experiments, pooled sperm was stripped from males of 7, 12, or 18 months of age, divided into 5 sub-groups, diluted with different concentrations of Hg (0, 0.5, 1, 2.5, and 5 mg/L Hg), and incubated for 240 min. The motility parameters of sperm (progressive motility (%), curvilinear velocity (VCL)) were measured by a computer-assisted sperm analysis system, at 30, 120, and 240 min of exposure. Regarding the age, significant differences were found in PMOT (p = 0.0267) as well as in VCL (p = 0.0004) among the three different age groups. The different concentrations of Hg also caused significant differences. The most significant differences in PMOT were between the 7- and 18-month-old groups; these differences were observed at 0.5, 1 and 2.5 mg/L Hg at 30 min, at 0.5 and 1 mg/L at 120 min, as well as at 0.5 mg/L at 240 min. In VCL the most significant differences were found between the 7- and 12-month-old groups; significant differences were found at each tested concentration at 30 min as well as at 0.5 and 2.5 mg/L at 240 min. According to the results, the age of zebrafish negatively influences the sensitivity of its sperm. This may concern not only toxicology tests but many techniques in fish breeding where the sperm is treated before use (cryopreservation, pressure shock, etc.).

本研究调查了年龄对斑马鱼精子对汞暴露敏感性的影响。尽管使用成熟个体的精子进行毒性测试的结果已经发表，但在某些情况下没有关于鱼的确切年龄的信息，这可能会影响结果。在实验过程中，从 7、12 或 18 个月大的雄性身上提取混合精子，分为 5 个亚组，用不同浓度的 Hg（0、0.5、1、2.5 和 5 mg/L Hg）稀释，并孵育 240 分钟。在暴露的 30、120 和 240 分钟时，通过计算机辅助精子分析系统测量精子的运动参数（进行性运动 (%)、曲线速度 (VCL)）。在年龄方面，PMOT 存在显着差异（p = 0.0267) 以及在 VCL ( p = 0.0004) 在三个不同的年龄组中。不同浓度的汞也造成了显着差异。PMOT 的最显着差异出现在 7 个月大和 18 个月大的组之间；这些差异在 30 分钟时为 0.5、1 和 2.5 毫克/升 Hg，在 120 分钟时为 0.5 和 1 毫克/升，以及在 240 分钟时为 0.5 毫克/升时观察到。在 VCL 中，在 7 个月大和 12 个月大的组之间发现了最显着的差异；在 30 分钟时的每个测试浓度以及 240 分钟时的 0.5 和 2.5 毫克/升时，都发现了显着差异。根据结果​​，斑马鱼的年龄对其精子的敏感性产生负面影响。这可能不仅涉及毒理学测试，还涉及鱼类育种中的许多技术，其中精子在使用前经过处理（冷冻保存、压力休克等）。