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

• Main Authors: McClain, Craig R., Balk, Meghan A., Benfield, Mark C., Branch, Trevor A., Chen, Catherine, Cosgrove, James, Dove, Alistair D. M., Gaskins, Leo C., Helm, Rebecca, Hochberg, Frederick G., Lee, Frank B., Marshall, Andrea, McMurray, Steven E., Schanche, Caroline, Stone, Shane N., Thaler, Andrew D., Helm, Rebecca R.
• Format: Dataset
• Language: unknown
• Published: 2021
• Subjects: Cetorhinus maximus; Mirounga leonina; Hexanchus griseus; Architeuthis dux; Dermochelys coriacea; Manta birostris; Marine; Modern; Physeter macrocephalus; Mola mola; megafauna; Tridacna gigas; Regalecus glesne; Odobenus rosmarus; Balaenoptera musculus; Bathynomus giganteus; Carcharodon carcharias; Xestospongia muta; Somniosus microcephalus; Syrinx aruanus; Enteroctopus dofleini; Giganteus
• Online Access: https://zenodo.org/record/4531448; https://doi.org/10.5061/dryad.411mv

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. Sizing Ocean Giants Data and ScriptsBalaenoptera musculus and Physeter macrocephalus data were provided by the International Whaling Commission (IWC). These data are not included in sizingoceangiants.zip, and must be obtained from IWC directly.sizingoceangiants.zip