Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
Ripley's Aquarium of Canada, Toronto, Ontario, Canada.
Zoo Biol. 2021 Sep;40(5):472-478. doi: 10.1002/zoo.21631. Epub 2021 Jun 14.
Magnesium is involved in a variety of physiological processes in marine animals and is known to be deleterious in both excess and deficiency. The effects of magnesium concentration ranging from 700 mg/L (low), 1344 mg/L (control), and 2000 mg/L (high) on size and pulse rate in upside-down jellyfish (Cassiopea andromeda) medusae were examined in two separate 28-day trials. Exposure to low magnesium resulted in significantly (p < .05) higher pulse rates and decreased bell diameter and also produced oral arm degradation. Exposure to high magnesium resulted in significantly (p < .05) lower pulse rates and decreased bell diameter as well as oral arm cupping. In both low and high magnesium, almost all specimens changed color from pale blue on Day 1, to brown by Day 28, suggesting a loss of zooxanthellae. The decrease in bell diameter and color change was more pronounced and occurred more rapidly in low magnesium. The results of both trials demonstrate the deleterious effects of high and low magnesium on C. andromeda and emphasize the importance of monitoring magnesium concentration to maintain healthy display animals in public aquaria.
镁参与海洋动物的各种生理过程，已知过多和过少都会产生有害影响。在两个单独的 28 天试验中，研究了浓度范围为 700mg/L（低）、1344mg/L（对照）和 2000mg/L（高）的镁对倒立水母（Cassiopea andromeda）水母体大小和脉搏率的影响。低镁暴露导致显著（p<0.05）更高的脉搏率和减少钟形直径，还导致口臂退化。高镁暴露导致显著（p<0.05）更低的脉搏率和减少钟形直径以及口臂凹陷。在低镁和高镁中，几乎所有标本的颜色都从第 1 天的淡蓝色变为第 28 天的棕色，表明虫黄藻丧失。钟形直径的减小和颜色变化在低镁中更为明显且发生得更快。两次试验的结果都表明，高镁和低镁对 C. andromeda 的有害影响，并强调监测镁浓度以维持公共水族馆中健康展示动物的重要性。
