Effects of larval density on hematological stress indices in salamanders.
Effects of larval density on hematological stress indices in salamanders.
复制标题
幼虫密度对蝾螈血液应激指数的影响。
DOI：
10.1002/jez.557
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
J. Maerz
中科院分区：
文献类型：
--
作者：
A. K. Davis;J. Maerz
在具有复杂生命周期的动物中，幼年环境的质量对于塑造个体的长期适应性非常重要。幼虫密度是决定两栖动物幼虫环境质量的一个主要因素，高密度会导致生长速度降低，变态时尺寸较小，并可能产生长期的变态后效应。一个很少研究的幼虫密度的影响是它对变态后个体的生理应激的影响。我们使用了血液学的方法，涉及特定的白色血细胞类型（中性粒细胞和淋巴细胞），与皮质酮协变的计数，估计压力水平在最近变态斑点蝾螈（Ambystoma maculatum），饲养在三个不同的幼虫密度在户外围隔。在重复的治疗，包括12，25，或50幼虫，存活率是，正如预期的那样，最低和最小的变态在最高密度的围隔。此外，从高密度处理幸存的蝾螈有显着较高的中性粒细胞淋巴细胞比率，表明高水平的应激激素（皮质酮）。这一趋势不是由于密度相关的身体状况差异，因为这些不随密度而变化。此外，估计的应力水平是相似的，无论蝾螈变态早期或晚期，这表明密度对应力的影响是持久的，即使一旦实现密度已通过死亡率或早期变态减少。这些结果可能对理解两栖动物种群动态很重要，因为对其他脊椎动物类群的研究表明，高血液压力指标导致脊椎动物生长减少，存活率降低，疾病易感性增加。
In animals with complex life cycles, the quality of juvenile environments is important in shaping the longer-term fitness of individuals. Larval density is a major factor governing quality of larval environments in amphibians, with high densities leading to reduced growth rates, smaller size at metamorphosis, and potentially long-lasting postmetamorphic effects. A little-studied effect of larval density is its impact on physiological stress of postmetamorphic individuals. We used a hematological approach, involving counts of specific white blood cells types (neutrophils and lymphocytes) that covary with corticosterone, to estimate stress levels in recently metamorphosed spotted salamanders (Ambystoma maculatum) that were reared in three different larval densities in outdoor mesocosms. In replicated treatments consisting of 12, 25, or 50 larvae, survival was, as expected, lowest and size at metamorphosis smallest in the highest density mesocosms. In addition, surviving salamanders from high-density treatments had significantly higher neutrophil to lymphocyte ratios, indicative of high levels of stress hormones (corticosterone). This trend was not a result of density-related differences in body condition as these did not vary with density. Further, estimated stress levels were similar regardless of whether the salamanders metamorphosed early or late, suggesting that the density effect on stress is long-lasting even once realized density has been reduced through mortality or early metamorphosis. These results may be important in understanding amphibian population dynamics, since research on other vertebrate taxa demonstrates that high hematological stress indicators lead to reduced growth, survival, and increased disease susceptibility in vertebrate animals.
影响因子：
4
作者：
Krain, LP;Denver, RJ
通讯作者：
Denver, RJ
DOI：
10.1016/j.cbpb.2004.12.007
发表时间：
2005-08-01
影响因子：
2.3
作者：
Crespi, EJ;Denver, RJ
通讯作者：
Denver, RJ