Oxygen Uptake and Osmotic Balance of Atlantic Salmon in Relation to Exercise and Salinity Acclimation
Oxygen Uptake and Osmotic Balance of Atlantic Salmon in Relation to Exercise and Salinity Acclimation
复制标题
大西洋鲑鱼的摄氧量和渗透平衡与运动和盐度驯化的关系
DOI：
--
复制
发表时间：
2018
影响因子：
3.7
通讯作者：
F. Oppedal
中科院分区：
文献类型：
--
作者：
M. Hvas;T. Nilsen;F. Oppedal
鱼鳃在生理上要求苛刻的情况下，其中有利于气体交换的条件可能会损害渗透平衡，特别是当血液和水生环境之间存在大的梯度时，会受到呼吸系统的损害。因此，在等渗水中的鱼应该较少受到呼吸系统损害的限制，这应该会提高有氧性能。为了研究这一假设，大西洋鲑鱼适应淡水，近等渗的咸水或海水，并在一个大型游泳隧道呼吸计，以评估代谢率，游泳能力和血液学参数进行测试，每组10个。氧摄取率和临界游泳速度之间的治疗相似。然而，渗透压和血浆[离子]之前和之后的游泳试验，并随后恢复不同。海水中的鱼在游泳试验中经历了显著更大的渗透干扰，其在疲劳后3小时进一步增加，而在较低盐度中的鱼接近完全恢复。游泳试验增加了血浆皮质醇水平，这可能会调节增加气体转移，促进有益的离子调节，在低和高盐度。游泳也增加了红细胞压积和血红蛋白浓度，恢复后恢复到对照水平，表明通过脾脏收缩募集红细胞。这些结果表明，大西洋鲑鱼不引起一个明确的盐度最佳的代谢和运动优势。尽管如此，在海水中游泳会带来更大的压力调节挑战，这可能会对重复游泳挑战产生影响。因此，大西洋鲑鱼装备精良，以尽量减少潜在的限制，呼吸系统的妥协有氧性能，更是在咸水和淡水。
The fish gill is subject to an osmorespiratory compromise in physiologically demanding situations where conditions that favour gas exchange may compromise osmotic balance, especially when large gradients between the blood and the aquatic environment are present. Fish in isosmotic water should therefore be less restricted by an osmorespiratory compromise, which should improve aerobic performance. To investigate this hypothesis, Atlantic salmon were acclimated to freshwater, near isosmotic brackish water or sea water, and tested in groups of 10 in a large swim tunnel respirometer to assess metabolic rates, swimming capacity and haematological parameters. Oxygen uptake rates and the critical swimming speed were similar between treatments. However, osmolality and plasma [ions] before and after swim trials, and subsequent recovery differed. Fish in sea water experienced a substantially larger osmotic disturbance in the swim trials, which had increased further 3 hours post-fatigue, while fish in lower salinities were approaching full recovery. Swim trials increased plasma cortisol levels, which may modulate increased gas transfer and facilitate beneficial ion regulation in both low and high salinities. Swimming also increased haematocrit and haemoglobin concentration that returned to control levels after recovery, suggesting recruitment of erythrocytes via splenic contraction. These results show that Atlantic salmon do not elicit a clear salinity optimum in terms of metabolic and locomotory advantages. Although, swimming in sea water imposes larger osmoregulatory challenges which may have implications for repeated swim challenges. Hence, Atlantic salmon are well-equipped to minimize the potential restrictions of an osmorespiratory compromise on aerobic performance, and more so in brackish and freshwater.