Fish otolith marking with the alizarin dye is a commonly used tool in sustainable fishery management. However, the reported effects of this dye on fish health are rather controversial and are possibly linked to differences in the composition of different brands of Alizarin red S (ARS). Laboratory experiments designed to elucidate effects of different concentrations of theoretically the same ARS as indicated by the CAS (Chemical Abstracts Service) number on fish at different development stages were carried out. The acute toxicity of ARS to Salmo trutta was found to be concentration- and fish developmental stage-dependant. Our study results showed that S. trutta sensitivity to ARS varies depending on its developmental stages as follows: fry (50-days after hatching) > alevins (30-days after hatching) > alevins (1-day after hatching). One of the tested ARS brands (purchased from VWR International LLC (Matsonford Road, USA)) was found to be several times more toxic to fish than another (purchased from Sigma-Aldrich (St. Louis, USA)), although according to the certificates of analysis, the tested substances were identical. Survival and growth of the S. trutta fry, which was marked with different ARS brands and stocked in the same natural stream, was investigated for two consecutive years. The results obtained indicate remarkable differences (p < 0.05) in the effects produced by the tested ARS brands, thus confirming our laboratory findings. The performed elemental analysis of the tested ARS dyes revealed significant differences in chemical impurities that these dyes contain. This study has, for the first time, expressed concern about the probable long-term impact of some ARS brands on the marked fish and their potential to bias the results of the studies dealing with ARS-marked fish.

用茜素染料标记鱼耳石是可持续渔业管理中常用的工具。然而，据报道这种染料对鱼类健康的影响颇具争议，可能与不同品牌的茜素红 S (ARS) 成分的差异有关。实验室实验旨在阐明不同浓度的理论上相同的 ARS，如 CAS（化学文摘社）编号所示，对不同发育阶段的鱼类的影响。发现ARS 对Salmo trutta的急性毒性与浓度和鱼类发育阶段有关。我们的研究结果表明，S. trutta对 ARS 的敏感性取决于其发育阶段，如下所示：鱼苗（孵化后 50 天）> alevins（孵化后 30 天）> alevins（孵化后 1 天）。一种经过测试的 ARS 品牌（购自 VWR International LLC（美国马特森福德路））被发现对鱼的毒性是另一种（购自 Sigma-Aldrich（美国圣路易斯））的几倍，尽管根据分析证书，测试的物质是相同的。连续两年对标有不同ARS品牌并在同一自然流中放养的S. trutta鱼苗的生存和生长情况进行了调查。所得结果表明差异显着（p< 0.05) 测试的 ARS 品牌产生的效果，从而证实了我们的实验室发现。对测试的 ARS 染料进行的元素分析揭示了这些染料所含化学杂质的显着差异。这项研究首次表达了对某些 ARS 品牌可能对标记鱼的长期影响以及它们可能对处理 ARS 标记鱼的研究结果产生偏见的担忧。