Millar Zachary, Kecheliev Dimo, Wolvin Sophie, LePage Véronique, Lumsden John S
Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Ripley's Aquarium of Canada, Toronto, Ontario, Canada.
Zoo Biol. 2023 Sep-Oct;42(5):661-667. doi: 10.1002/zoo.21770. Epub 2023 Apr 26.
Magnesium chloride in high concentration is used for euthanasia of jellyfish to limit overpopulation and for predatory species consumption, but its use could lead to magnesium bioaccumulation and subsequent negative effects in consumers. Two species of scyphozoan jellyfish (Cassiopea andromeda and Aurelia aurita) were subjected to freezing (control), or magnesium chloride baths (144 g/L), with subsequent 30 min baths (one or two) in fresh artificial saltwater and submitted for inductively coupled plasma analysis to determine tissue concentration. Frozen jellyfish consistently yielded the lowest magnesium concentrations, while magnesium chloride euthanized individuals contained the highest concentrations in both species. C. andromeda displayed a significantly higher (p < .05) magnesium absorption capacity than A. aurita in both trials. Single and double baths significantly decreased magnesium concentrations (p < .05) in both species, however, magnesium remained consistently elevated compared to frozen specimens. This study demonstrated species-specific magnesium accumulation in jellyfish posteuthanasia and that rinsing was an effective method to limit excessive magnesium that could be deleterious to animals in public display aquaria. Magnesium concentrations of tissue and receiving water should be tested if magnesium chloride euthanasia is utilized for dietary supplementation in small bodies of water.
高浓度的氯化镁被用于水母的安乐死，以控制水母数量过多以及供捕食性物种食用，但这种使用方式可能会导致镁的生物累积，并对食用者产生后续负面影响。两种钵水母纲水母（仙女杯根口水母和海月水母）分别接受冷冻处理（对照组）或置于氯化镁浴（144克/升）中，随后在新鲜的人工海水中浸泡30分钟（一次或两次），并送去进行电感耦合等离子体分析以确定组织中的浓度。冷冻处理的水母镁浓度始终最低，而经氯化镁安乐死处理的个体在两个物种中镁浓度均最高。在两项试验中，仙女杯根口水母的镁吸收能力均显著高于海月水母（p < 0.05）。单次和两次浸泡均显著降低了两个物种中的镁浓度（p < 0.05），然而，与冷冻样本相比，镁浓度仍持续升高。本研究证明了水母安乐死后镁的物种特异性积累，并且冲洗是一种有效方法，可限制可能对公共展示水族箱中的动物有害的过量镁。如果在小水体中使用氯化镁安乐死来进行饮食补充，应检测组织和接收水体中的镁浓度。
