Johnson Erik S
Department of Biology University of Missouri St. Louis Missouri USA.
Whitney R. Harris World Ecology Center St. Louis Missouri USA.
Ecol Evol. 2025 Feb 19;15(2):e70735. doi: 10.1002/ece3.70735. eCollection 2025 Feb.
Livebearing fishes in the family Poeciliidae have been essential to testing life history theory. These species are remarkable because males internally inseminate females, and females give birth to free-swimming young, making these fishes amenable to investigating the evolution of a variety of life history traits, including the timing and nature of maternal reproductive investment, timing of maturity, strategies for maternal provisioning of embryos, and several other classic life history traits. However, researchers vary in the methods that they use to measure these traits, making it difficult to compare findings across studies. Here, I present a standardized approach to studying life history traits in livebearing fishes. I describe methods for preserving samples in the field, for collecting data on a standard set of life history traits, and for processing data in ways that will allow comparisons among studies. I highlight different options in preservation techniques and in data collection that are dependent on the specific questions being addressed. Finally, I argue for a standard approach moving forward to make it possible to complete large-scale comparative studies to reveal how life history traits have evolved in this important model system.
花鳉科的卵胎生鱼类对于检验生活史理论至关重要。这些物种很特别，因为雄性通过体内受精使雌性受孕，雌性产出能自由游动的幼鱼，这使得这些鱼类适合用于研究各种生活史特征的进化，包括母体生殖投资的时间和性质、成熟时间、母体为胚胎提供营养的策略以及其他一些经典的生活史特征。然而，研究人员在测量这些特征时所使用的方法各不相同，这使得跨研究比较结果变得困难。在此，我提出一种研究卵胎生鱼类生活史特征的标准化方法。我描述了在野外保存样本、收集一组标准生活史特征数据以及以允许进行研究间比较的方式处理数据的方法。我强调了保存技术和数据收集方面的不同选项，这些选项取决于所解决的具体问题。最后，我主张采用一种标准方法，以便能够完成大规模的比较研究，从而揭示在这个重要的模型系统中生活史特征是如何进化的。
