MOBS 1.0: A database of interspecific variation in marine organismal body sizes

Motivation

Body size is a fundamental trait influencing an organism's life history, ecology, physiology and evolutionary dynamics. While extensive body-size databases exist for terrestrial vertebrates, equivalent datasets for marine animals are lacking, even though they include a much larger number of species. This data gap hinders comparative and macroecological analyses that rely on body-size data to uncover evolutionary and ecological patterns and processes in marine ecosystems. The Marine Organismal Body Size (MOBS) Database aims to address this deficit by providing standardised body-size data for marine animals, enabling deeper investigations into marine biodiversity and informing conservation and ecological theory.

Main Types of Variables Contained

The MOBS Database includes maximum linear dimensions of marine animals, specifically height, length, width and diameter. Additional fields include species taxonomy (linked to AphiaIDs in the World Register of Marine Species), notes about measurements and data sources.

Spatial Location and Grain

The dataset is global in scope, encompassing marine species across all oceanic regions, but does not itself contain geographic data. Integrations with databases like the Ocean Biodiversity Information System (OBIS) can yield spatially resolved analyses.

Time Period and Grain

Modern, extant species.

Major Taxa and Level of Measurement

MOBS focuses on marine animals (kingdom Animalia), covering 30 marine phyla. The database currently contains data for 85,204 species (40.4% of valid marine animal species in WoRMS), with seven phyla surpassing 75% coverage. Measurements are reported at the species level, with some records including multiple observations to account for intraspecific variations.

Software Format

The MOBS Database is available in csv format and is hosted on GitHub for public access (https://github.com/crmcclain/MOBS_OPEN).