PDF(Pubmed)
Abstract：
Habitat fragmentation may cut off anadromous salmonids from parts of their potential native habitat and separate previously connected populations. Understanding the consequences of this is vital for fish management and prioritization of restoration activities. Here, we show that there is a significant difference in the body morphology, physiological stress response, and aspects contributing to aerobic capacity between juvenile anadromous brown trout, Salmo trutta, collected at a downstream site and an upstream site, separated by 2 km and several challenging stream sections, in a small unfragmented stream system in western Sweden. Following a standardized stress test, there were significant differences between fish from the upstream and downstream sites (plasma cortisol concentration, plasma osmolality, hematocrit, hemoglobin concentration, and mean corpuscular hemoglobin concentration). Plasma glucose concentration did not significantly differ between fish from the two sites. Fish from the upstream site had larger spleen mass, although there was no evidence of differences in ventricle mass or proportion of compact ventricular myocardium. These physiological differences indicate local variation in stress response and highlight the importance of considering local trait variation in river management. If a section of the river becomes fragmented or degraded, and there are differences in the juveniles in different parts of the river, the consequence for the population might be larger than the proportional loss of habitat.
摘要：
栖息地的碎片化可能会从其潜在的本地栖息地的某些部分中切断原始的鲑鱼，并将以前相连的种群分开。了解其后果对于鱼类管理和恢复活动的优先次序至关重要。这里,我们发现身体形态存在显著差异，生理应激反应，以及有助于幼年无缘褐鳟鱼之间有氧能力的方面，SalmoTrutta,在下游站点和上游站点收集，由2公里和几个具有挑战性的溪流部分隔开，在瑞典西部的一个小的未分散的河流系统中。在标准化压力测试之后，上游和下游位点的鱼之间存在显著差异(血浆皮质醇浓度，血浆渗透压,血细胞比容,血红蛋白浓度,和平均红细胞血红蛋白浓度)。两个地点的鱼之间的血浆葡萄糖浓度没有显着差异。上游的鱼有较大的脾脏肿块，尽管没有证据表明心室质量或紧凑型心室心肌比例存在差异。这些生理差异表明应激反应的局部变化，并强调了在河流管理中考虑局部性状变化的重要性。如果一段河流变得支离破碎或退化，河流不同部分的青少年有差异，对种群的影响可能大于栖息地的比例损失。
