Schultz E T, Conover David O
Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000, USA, , , , , , US.
Oecologia. 1997 Feb;109(4):516-529. doi: 10.1007/s004420050112.
This study focuses on the seasonal accumulation and depletion of somatic energy in the Atlantic silverside (Menidia menidia), an annual estuarine fish. Previous research revealed that northern silversides are subject to strong size-dependent winter mortality, while southern fish suffer no appreciable winter mortality. To examine whether there was geographic differentiation in allocation strategies, we compared temporal patterns of energy storage and utilization among three populations along this gradient in seasonality. The comparative design used monthly or biweekly samples of fish collected in the wild, as well as samples of fish from each population reared in a common environment, where genetic differences can be clarified. Somatic energy stores were quantified via gravimetric analysis of neutral storage lipids and lean tissue. Analysis revealed that small individuals maintained relatively low levels of lipid reserves, which may account for their lower survival in winter. Wild fish in the north rapidly accumulated large somatic reserves, which were depleted over the winter and then increased again during the subsequent spring breeding season. In wild southern fish, relatively small reserves accumulated slowly until breeding commenced in the spring. The common-environment comparison of somatic storage patterns revealed a genetic basis for among-population differences in reserve accumulation rates, but no differences in the amount of reserves stored. We conclude that the overwinter depletion of somatic reserves has a significant selective impact on energy accumulation and allocation strategies in seasonal environments.
本研究聚焦于一年生河口鱼类大西洋银汉鱼（Menidia menidia）体细胞能量的季节性积累与消耗。先前的研究表明，北方银汉鱼在冬季会遭受强烈的体型依赖性死亡，而南方的鱼在冬季没有明显的死亡情况。为了研究在能量分配策略上是否存在地理差异，我们比较了沿着季节性梯度的三个种群之间能量储存和利用的时间模式。比较设计使用了在野外每月或每两周采集的鱼类样本，以及在共同环境中饲养的每个种群的鱼类样本，在这种共同环境中可以厘清遗传差异。通过对中性储存脂质和瘦组织进行重量分析来量化体细胞能量储存。分析表明，小个体维持相对较低水平的脂质储备，这可能是它们冬季存活率较低的原因。北方的野生鱼类迅速积累大量的体细胞储备，这些储备在冬季被消耗，然后在随后的春季繁殖季节再次增加。在南方的野生鱼类中，相对较小的储备缓慢积累，直到春季开始繁殖。体细胞储存模式的共同环境比较揭示了种群间储备积累速率差异的遗传基础，但在储存的储备量上没有差异。我们得出结论，体细胞储备的越冬消耗对季节性环境中的能量积累和分配策略有显著的选择性影响。
