Is the temperature-size rule mediated by oxygen in aquatic ectotherms?
Is the temperature-size rule mediated by oxygen in aquatic ectotherms?
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DOI：
10.1016/j.jtherbio.2014.12.003
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发表时间：
2015-12-01
影响因子：
2.7
通讯作者：
Verberk, Wilco C. E. P.
中科院分区：
文献类型：
--
作者：
Hoefnagel, K. Natan;Verberk, Wilco C. E. P.
温度是影响体型、生长速度和成熟度等关键性状的重要环境因素。在高温下饲养的外胚层通常生长较快，但最终尺寸较小，这一现象被称为温度-大小规则(TSR)。在对氧气的需求很高的高温下，氧气可能成为一种有限的资源，特别是在水中，因为水下的氧气摄取比空气中的氧摄取更具挑战性。因此，在水生外温动物中，TSR很可能是通过温度对氧可获得性和需氧量的影响来调节的。为了区分温度和氧气的直接影响，采用析因设计测定了不同温度和氧气条件下饲养的水生体表温度和氧气条件下的生长速度和最终大小。生长可以用修正的Von Bertalanffy生长函数来描述。温度和氧气都影响成熟和生长的年龄。生长对温度的反应取决于氧气条件(温度和氧气的交互作用)。只有在低氧条件下，当氧气最大限度地限制时，我们才发现经典的TSR。此外，当比较温度不同但氧气需求和供应平衡相似的处理时，高温既增加了生长速度，又增加了最终的大小。因此，氧气的影响可能会解开水生外温体中TSR的生活史之谜。(C)2014爱思唯尔有限公司。保留所有权利。
Temperature is an important environmental factor that influences key traits like body size, growth rate and maturity. Ectotherms reared under high temperatures usually show faster growth, but reach a smaller final size, a phenomenon known as the temperature-size rule (TSR). Oxygen may become a limiting resource at high temperatures, when demand for oxygen is high, especially in water as oxygen uptake is far more challenging under water than in air. Therefore, in aquatic ectotherms, the TSR might very well be mediated by temperature effects on oxygen availability and oxygen demand. To distinguish between the direct effects of temperature and oxygen mediated effects, growth rate and final size were measured in the aquatic ectotherm Asellus aquaticus (Linnaeus, 1758) reared under different temperature and oxygen conditions in a factorial design. Growth could be best described by a modified Von Bertalanffy growth function. Both temperature and oxygen affected age at maturity and growth. Growth responses to temperature were dependent on oxygen conditions (interactive effect of temperature and oxygen). Only under hypoxic conditions, when oxygen was mast limiting, did we find a classic TSR. Moreover, when comparing treatments differing in temperature, but where the balance between oxygen demand and supply was similar, high temperature increased both growth rate and final size. Thus effects of oxygen may resolve the life-history puzzle of the TSR in aquatic ectotherms. (C) 2014 Elsevier Ltd. All rights reserved.