Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA, United States of America.
Department of Biology, Washington University in St. Louis, St. Louis, MO, United States of America.
PeerJ. 2023 Feb 2;11:e14749. doi: 10.7717/peerj.14749. eCollection 2023.
Overexposure to ultraviolet radiation (UVR) emitted by the sun can damage and kill living cells in animals, plants, and microorganisms. In aquatic environments, UVR can penetrate nearly 47 m into the water column, severely impacting many marine organisms. Jellyfish are often considered resilient to environmental stressors, potentially explaining their success in environmentally disturbed areas, but the extent of their resilience to UVR is not well known. Here, we tested resiliency to UVR by exposing benthic polyps of the moon jellyfish, sp., to UVA and UVB-the two types of UVR that reach Earth's surface-both separately and in combination. We quantified asexual reproduction rates and polyp attachment to hard substrate, in addition to qualitative observations of polyp health. There were no differences in asexual reproduction rates between polyps exposed to isolated UVA and polyps that received no UVR. Polyps reproduced when exposed to short term (∼7-9 days) isolated UVB, but long-term exposure limited reproduction and polyp attachment to the substrate. When exposed to both UVA and UVB, polyps were unable to feed and unable to remain attached to the substrate, did not reproduce, and ultimately, experienced 100% mortality within 20 days. Although many studies only examine the effects of UVB, the combination of UVA and UVB here resulted in greater negative impacts than either form of UVR in isolation. Therefore, studies that only examine effects of UVB potentially underestimate environmentally relevant effects of UVR. These results suggest that polyps are unsuccessful under UVR stress, so the planula larval stage must settle in low-UVR environments to establish the success of the polyp stage.
过度暴露于太阳发出的紫外线辐射（UVR）会损害和杀死动物、植物和微生物中的活细胞。在水生环境中，UVR 可以穿透近 47 米深的水柱，严重影响许多海洋生物。水母通常被认为对环境胁迫具有弹性，这可能解释了它们在环境受到干扰的地区成功生存的原因，但它们对 UVR 的弹性程度尚不清楚。在这里，我们通过将 sp. 的底栖水螅暴露于 UVA 和 UVB（到达地球表面的两种 UVR 类型），单独和组合，来测试对 UVR 的弹性。我们量化了无性繁殖率和水螅附着在硬基质上的能力，以及对水螅健康的定性观察。暴露于单独的 UVA 下水螅的无性繁殖率与未接受 UVR 的水螅没有差异。水螅在短期（约 7-9 天）暴露于单独的 UVB 下会繁殖，但长期暴露会限制繁殖和水螅附着在基质上。当暴露于 UVA 和 UVB 时，水螅无法进食，无法附着在基质上，无法繁殖，最终在 20 天内 100%死亡。尽管许多研究仅检查 UVB 的影响，但这里 UVA 和 UVB 的组合产生的负面影响大于单独的任何一种 UVR 形式。因此，仅检查 UVB 影响的研究可能低估了 UVR 的环境相关影响。这些结果表明，水螅在 UVR 胁迫下无法成功生存，因此浮游幼虫阶段必须在低 UVR 环境中定殖，才能建立水螅阶段的成功。
