Abstract

Fishes are characterized by a great diversity of reproductive strategies that often make fecundity evaluation difficult. Unlike marine fishes, a single consensual concept of terminology and definitions is lacking for freshwater fish fecundity. Several approaches are known from scientific literature for evaluating fecundity in batch spawning fishes of indeterminate fecundity and asynchronous oocyte maturation. These methodological differences impose a bias on the outputs of comparative studies of fecundity. For both theoretical and practical reasons, accurate fecundity data are required to inform the decision-making process in terms of environmental policy and the related applications for the control of non-native species and the conservation management of native species and ecosystems. The main aim of the present study was to review briefly the existing fecundity-evaluation methods, to test among-method compatibility, and to develop a new approach that aims to make fecundity evaluation more systematic and transparent. A simulated ‘test’ dataset demonstrated considerable variability in the results obtained from the various existing approaches. The literature review and our analyses revealed a need for standardization. Thus, a new approach is proposed here that is based on multiple sampling throughout the reproductive cycle; provides greater overall detail of the species’ reproductive traits and permits inter-population comparisons.

摘要

鱼类的特点是繁殖策略多种多样，这往往使繁殖力评估变得困难。与海洋鱼类不同，淡水鱼繁殖力缺乏统一的术语和定义概念。从科学文献中已知几种方法用于评估不确定繁殖力和异步卵母细胞成熟的分批产卵鱼的繁殖力。这些方法论差异对生育力比较研究的结果产生了偏见。出于理论和实践的原因，需要准确的繁殖力数据来为环境政策和非本地物种控制以及本地物种和生态系统保护管理的相关应用方面的决策过程提供信息。本研究的主要目的是简要回顾现有的繁殖力评估方法，测试方法之间的兼容性，并开发一种旨在使繁殖力评估更加系统和透明的新方法。模拟的“测试”数据集表明从各种现有方法获得的结果存在相当大的可变性。文献综述和我们的分析表明需要标准化。因此，这里提出了一种基于整个生殖周期多次采样的新方法；提供物种繁殖特性的更多整体细节，并允许进行种群间比较。模拟的“测试”数据集表明从各种现有方法获得的结果存在相当大的可变性。文献综述和我们的分析表明需要标准化。因此，这里提出了一种基于整个生殖周期多次采样的新方法；提供物种繁殖特性的更多整体细节，并允许进行种群间比较。模拟的“测试”数据集表明从各种现有方法获得的结果存在相当大的可变性。文献综述和我们的分析表明需要标准化。因此，这里提出了一种基于整个生殖周期多次采样的新方法；提供物种繁殖特性的更多整体细节，并允许进行种群间比较。