δ13C and δ15N in Micropterus Salmoides largemouth bass and their scales: a freshwater environmental proxy

富山位于日本中部，由于海拔3000米，短距离内变化，以及丰富的水系，具有各种独特的地理环境。测定了8个坝湖和2个池塘中大口黑鲈（Laremouth Bass）肌肉的δ 13 C和δ 15 N，结果表明，各采样点大口黑鲈肌肉的δ 13 C和δ 15 N的平均值具有较大的变异性，但各采样点的标准差较小。坝湖的同位素组成可分为两组，作为平均海拔和坝水冲洗率的函数。这表明，大口黑鲈的同位素比值反映了每个调查的水圈环境和食物链的特点。此外，大口黑鲈鳞片和肌肉的δ 13 C，R2= 0.98; δ 15 N，R2= 0.95的相关性也很高，这表明更容易分析的鳞片可以代替肌肉样品用于全球水圈环境的监测和比较。

Toyama is located in central Japan and features a variety of distinct geographical environments, a result of the 3000-m elevation that changes over short distances, and abundant water systems. We determined δ13C and δ15N of the lipid-extracted muscles of largemouth bass, a top aquatic predator, from eight dam lakes and two ponds.The mean δ13C and δ15N values for the lipid-extracted muscle of largemouth bass from all sampling locations showed large variability, but there were only small standard deviations at each sampling location. The dam lakes could be divided into two groups by their isotopic compositions, as a function of mean altitude and flushing rate of the dam water. Thissuggests that the isotope ratios for largemouth bass express the characteristics of each investigated hydrosphere environment and food chain. Moreover a very high correlation of isotopic values （δ13C, R2= 0.98; δ15N, R2= 0.95) was found between largemouth bass scales and lipid-extracted muscles, suggesting the more easily analyzed scales can replace muscle samples for the monitoring and comparison of hydrosphere environments throughout the world.