Ordóñez-Grande Borja, Guerreiro Pedro M, Sanahuja Ignasi, Fernández-Alacid Laura, Ibarz Antoni
Department of Cell Biology, Physiology and Immunology, University of Barcelona (UB), 08028 Barcelona, Spain.
CCMAR-Centre for Marine Sciences, University of Algarve, 8005-139 Faro, Portugal.
Animals (Basel). 2020 Sep 1;10(9):1546. doi: 10.3390/ani10091546.
European sea bass is a marine teleost which can inhabit a broad range of environmental salinities. So far, no research has studied the physiological response of this fish to salinity challenges using modifications in skin mucus as a potential biological matrix. Here, we used a skin mucus sampling technique to evaluate the response of sea bass to several acute osmotic challenges (for 3 h) from seawater (35‱) to two hypoosmotic environments, diluted brackish water (3‱) and estuarine waters (12‱), and to one hyperosmotic condition (50‱). For this, we recorded the volume of mucus exuded and compared the main stress-related biomarkers and osmosis-related parameters in skin mucus and plasma. Sea bass exuded the greatest volume of skin mucus with the highest total contents of cortisol, glucose, and protein under hypersalinity. This indicates an exacerbated acute stress response with possible energy losses if the condition is sustained over time. Under hyposalinity, the response depended on the magnitude of the osmotic change: shifting to 3‱ was an extreme salinity change, which affected fish aerobic metabolism by acutely modifying lactate exudation. All these data enhance the current scarce knowledge of skin mucus as a target through which to study environmental changes and fish status.
欧洲海鲈是一种海洋硬骨鱼，能够栖息在盐度范围广泛的环境中。到目前为止，尚无研究以皮肤黏液作为潜在生物基质的变化来探究这种鱼类对盐度挑战的生理反应。在此，我们采用皮肤黏液采样技术，评估了海鲈对几种急性渗透挑战（持续3小时）的反应，这些挑战包括从海水（35‰）到两种低渗环境，即稀释的半咸水（3‰）和河口海水（12‰），以及一种高渗环境（50‰）。为此，我们记录了分泌的黏液量，并比较了皮肤黏液和血浆中主要的应激相关生物标志物以及渗透相关参数。在高盐度条件下，海鲈分泌的皮肤黏液量最大，皮质醇、葡萄糖和蛋白质的总含量也最高。这表明如果这种状况持续一段时间，会出现加剧的急性应激反应并可能导致能量损失。在低盐度条件下，反应取决于渗透变化的幅度：转移到3‰是一种极端的盐度变化，它通过急性改变乳酸分泌来影响鱼类的有氧代谢。所有这些数据都丰富了目前关于皮肤黏液作为研究环境变化和鱼类状态的一个靶点的稀缺知识。
