Life-history traits of batoids (Superorder Batoidea) in the Northeast Atlantic and the Mediterranean

Life-history traits provide a way to estimate the vulnerability of both individuals and populations of a species to disturbance (e.g., overexploitation, climate change). Life-history traits compilations for species of batoids in the Northeast Atlantic (NEA) and the Mediterranean Sea (MED) are scarce, outdated, and generally limited to a local or a regional scale. A literature review compiling values of 10 life-history traits describing the growth, reproductive and feeding strategies of 14 batoids in the NEA and the MED was performed. Via a principal components analysis (PCA) the main drivers of variance and (groups of) similar species were identified. Significant data gaps were revealed for natural mortality and lifespan, for most of the life-history traits of small-eyed ( Raja microocellata ), shagreen ( Leucoraja fullonica ), and sandy ( Leucoraja circularis ) ray, and specifically for the English Channel and Bay of Biscay. The common skate complex ( Dipturus batis complex ) and white ( Rostroraja alba ) skate were found to be different from the rest of the species due to their larger sizes, relatively slow growth, and late maturity, which may make them more vulnerable to overexploitation, while the Raja spp. and Leucoraja spp. rays tend to be smaller species growing at faster rates. Growth and reproductive life-history should be considered as vulnerability to disturbance proxies, be used to update/establish management measures (i.e. minimum size) and enhance the stock assessment predictive ability (i.e. length based-indicators). Future research should be directed towards filling important regional data gaps and providing robust estimation for unreported parameters, such as natural mortality.