Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for the spatio-temporal dynamics of biological invasions, their invasive , and the magnitude of their impacts. However, with the exception of first on a country level or wider regions, observations of species presence tend remain unpublished, buried in scattered repositories or in the personal databases experts. Through an initiative to collect, harmonize and make such unpublished for marine alien and cryptogenic species in the Mediterranean Sea available, a dataset comprising 5376 records was created. It includes records of 239 alien cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries the Mediterranean Sea. In terms of records, the most reported Phyla in order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. most recorded species was Caulerpa cylindracea, followed by Siganus luridus, sp. (cf. gigas or angulata) and Pterois miles. The dataset includes from 1972 to 2020, with the highest number of records observed in 2018. the records of the dataset, Dictyota acutiloba is a first record for the Sea. Nine first country records are also included: the alga Caulerpa var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner Urocaridella pulchella from Israel; the sponge Paraleucilla magna from and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan vermiformis and the polychaetes Prionospio depauperata and aberans from Malta.