Department of Microbiology & Ecology, University of València, Avenue Dr. Moliner, 50, E-46100 Burjassot, Spain.
Department of Microbiology & Ecology, University of València, Avenue Dr. Moliner, 50, E-46100 Burjassot, Spain.
J Therm Biol. 2014 May;42:15-24. doi: 10.1016/j.jtherbio.2014.02.016. Epub 2014 Mar 4.
The temperature-size rule (TSR) is a well-established phenomenon to describe the growth response of ectotherms to temperature by which individuals maintained at low temperatures grow more slowly, but attain a larger size upon maturity. Although there are adaptive and non-adaptive theories about the plasticity of body size in response to temperature, these cannot be applied to all ectotherms, and little is known about the changes in growth and development rates through ontogeny. The ostracod species Heterocypris bosniaca, an inhabitant of freshwater temporary ponds, was used to examine the growth and development rates of its nine growth stages and female fecundity at four different temperatures (15°C, 20°C, 25°C and 30°C). The development rate of this species accelerates with increasing temperature, reaching a maximum value at 25°C. The growth factor has a reverse-TSR in younger instars, and the typical TSR is followed only in the last two moults, resulting in non-monotonic response of adult size to temperature. Fecundity (total offspring per female) was not directly related to adult size and was generally higher at lower temperatures. Our results agree with recent research showing that the TSR may vary during ontogeny, and may not be a general trend in ostracod species from temporary waters. Indeed, adult carapace size seems to follow the pattern of a thermal reaction norm, probably influenced by the reduction of oxygen bioavailability at low temperature and the drastic increase in metabolic demand at the upper extreme of the thermal gradient.
温度-体型法则（TSR）是一个成熟的现象，用于描述变温动物对温度的生长反应，即在低温下生长缓慢的个体，在成熟时会达到更大的体型。尽管有关于体型对温度可塑性的适应性和非适应性理论，但这些理论不能适用于所有变温动物，而且对于个体发育过程中生长和发育速度的变化知之甚少。作为淡水临时池塘的居民，介形虫物种 Heterocypris bosniaca 被用来研究其九个生长阶段的生长和发育速度以及四个不同温度（15°C、20°C、25°C 和 30°C）下的雌性繁殖力。该物种的发育速度随温度的升高而加速，在 25°C 时达到最大值。生长因子在年轻的龄期具有反向 TSR，只有在最后两次蜕皮中才遵循典型的 TSR，从而导致成年体型对温度的非单调响应。繁殖力（每个雌性的总后代）与成年体型没有直接关系，通常在较低温度下更高。我们的研究结果与最近的研究一致，即 TSR 可能在个体发育过程中发生变化，并且可能不是来自临时水域的介形虫物种的普遍趋势。实际上，成年甲壳大小似乎遵循热反应规范的模式，可能受到低温下氧气生物利用度降低和热梯度上限代谢需求急剧增加的影响。
