Society for the Exploration and Valuing of the Environment (SEVE), St. Philips, NL, A1M 2B7, Canada.
Department of Ocean Sciences, Memorial University, St. John's, NL, A1C 5S7, Canada.
Sci Rep. 2021 May 21;11(1):10691. doi: 10.1038/s41598-021-89805-0.
Recent efforts have been devoted to the link between responses to non-physical stressors and immune states in animals, mostly using human and other vertebrate models. Despite evolutionary relevance, comparatively limited work on the appraisal of predation risk and aspects of cognitive ecology and ecoimmunology has been carried out in non-chordate animals. The present study explored the capacity of holothuroid echinoderms to display an immune response to both reactive and anticipatory predatory stressors. Experimental trials and a mix of behavioural, cellular and hormonal markers were used, with a focus on coelomocytes (analogues of mammalian leukocytes), which are the main components of the echinoderm innate immunity. Findings suggest that holothuroids can not only appraise threatening cues (i.e. scent of a predator or alarm signals from injured conspecifics) but prepare themselves immunologically, presumably to cope more efficiently with potential future injuries. The responses share features with recently defined central emotional states and wane after prolonged stress in a manner akin to habituation, which are traits that have rarely been shown in non-vertebrates, and never in echinoderms. Because echinoderms sit alongside chordates in the deuterostome clade, such findings offer unique insights into the adaptive value and evolution of stress responses in animals.
最近的研究致力于探讨动物对非物理应激源的反应与免疫状态之间的联系，主要使用人类和其他脊椎动物模型。尽管与进化相关，但在非脊索动物中，对捕食风险评估以及认知生态学和生态免疫学方面的研究相对较少。本研究探讨了棘皮动物海参类对反应性和预期性捕食应激源产生免疫反应的能力。实验试验和一系列行为、细胞和激素标志物被用于研究，重点是体腔细胞（相当于哺乳动物的白细胞），这是棘皮动物先天免疫的主要组成部分。研究结果表明，海参类不仅能够评估威胁信号（例如捕食者的气味或受伤同类发出的警报信号），还能够在免疫上做好准备，可能是为了更有效地应对潜在的未来伤害。这些反应具有与最近定义的中枢情绪状态相似的特征，并在长时间的应激后逐渐消失，类似于习惯化，这些特征在非脊椎动物中很少出现，在棘皮动物中从未出现过。由于棘皮动物与脊索动物一起位于后口动物进化枝中，因此这些发现为动物应激反应的适应性价值和进化提供了独特的见解。
