Data from: Sizing ocean giants: patterns of intraspecific size variation in marine megafauna

What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the world’s oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans.

全球体型最大的海洋巨型动物群（marine megafauna）物种所能达到的极限体型究竟是多少？这一问题看似简单，实则答案复杂难解。诸多体型最为庞大的物种都栖息于全球各大海洋之中。对于其中多数物种而言，其种群稀有性、栖息环境偏远，再加上测量这些巨型个体的实操流程复杂繁琐，均使得获取精准的体型测量数据难上加难。关于这些物种极限体型的不准确记载在学术文献与大众媒体中随处可见。此外，这些动物的种内体型变异（intraspecific variation）如何与性别、种群结构、环境以及人类活动的影响相关联，这一问题至今尚未得到足够重视。本研究针对动物界中25种海洋巨型物种的体型展开综述与分析。针对各分类群，我们整理了多个演化支（clades）下已知体型最大的海洋物种的体型记录。同时，我们还分析了各物种的种内体型变异，并确定了各物种已知的最大个体。在数据允许的前提下，我们进一步分析了种内体型变异的空间与时间分布格局。我们还提供了不同体型测量指标之间的异速生长缩放方程（allometric scaling equations），以供其他研究者参考使用。在部分案例中，由于数据匮乏，我们无法完整开展上述分析，对此我们会专门指出相关研究的不足以及数据收集过程中存在的障碍。总体而言，我们发现种内体型分布存在显著差异，其偏态分布从强烈左偏到强烈右偏均有覆盖。我们提供了多组异速生长方程，可通过更易获取的测量数据估算物种的总长度与体重。在部分案例中，我们还量化了显著的地理体型变异，以及可能由人类活动导致的体型下降趋势。