Maximiadi Maria Michailidis Nikolas Mitsou Eleni Nicolaidou Artemis Petović Slavica Prado Patricia Santín Andreu Teneketzis Konstantinos Thasitis Ioannis Tirelli Valentina Trkov Domen Troplini Erion Tsiamis Konstantinos Vannucci Andrea

In the present article, new records are given for 18 species (6 native, 9 alien and 3 cryptogenic), belonging to 5 Phyla (i.e. Chlorophyta, Cnidaria, Annelida, Mollusca and Chordata), from 8 Mediterranean countries: Spain: A large population of Polycerella emertoni reported from the Ebro Delta, the presence of Spinimuricea klavereni is confirmed for the first time in the Catalan coast; Italy: the new record of Cryptonome turcica extends its distribution to the western Mediterranean Sea, the findings of Mawia benovici constitute the southernmost record of this species in the Adriatic Sea; Slovenia: second record of the alien seaslug Cuthona perca in the Mediterranean Sea; Montenegro: Styela plicata communities were recorded in Boka Kotorska Bay; Albania: the native great torpedo ray Tetronarce nobiliana recorded for the first time in Albanian waters; Greece: first record of Lagocephalus sceleratus in the Greek side of the Adriatic, the records of Cassiopea andromeda and Pterois miles are first records of these species from the Ionian Sea, the colonial ascidians Aplidium coeruleum and Didemnum protectum are recorded for the first time in the Eastern Mediterranean, an extremely abundant population of Melibe viridis is found in Messolonghi lagoon, the record of Synchiropus sechellensis is the range expansion of this species in Greek Seas, Acetabularia caliculus is recorded for the first time from Greece; Cyprus: first records of Callionymus filamentosus and Haminoea cyanomarginata from the island; Turkey: the presence of Berthellina citrina in the Mediterranean is confirmed. http://epublishing.ekt.gr | e-Publisher: EKT | Downloaded at 02/11/2019 03:06:07 | 674 Medit. Mar. Sci., 19/3, 2018, 673-689 Introduction Although it covers a small fraction of the world ocean, Mediterranean Sea is considered to have a rich biota due to its diverse geological, physical and biological characteristics (Bianchi & Morri, 2000). However, this biota is continuously reshaped by factors, such as, anthropogenic activities, climate change and alien invasion. Fragile species and habitats may be adversely affected by these stressors, whereas some native and alien species may benefit. Biological records are important, as they supply ecological information, such as habitat integrity, distribution of species, population densities and interaction between species. Monitoring the biodiversity is needed not only for scientific interest, but also for management and policy issues. Mediterranean Marine Science gives the opportunity to the researchers to publish a collective article concerning new records and range expansions of both native and alien species in the Mediterranean. The contributors are co-authors in this collective article, their names appearing in alphabetical order and contributing authors are cited at the beginning of each record. In this specific collective article, the new records are listed by countries, arranged from west to east. The locations of the records are approximately shown in Figure 1 and related information is given in Table 1. The records are explained in detail in relevant subchapters. In total, 18 species (6 native, 9 Fig. 1: Locations of records of new species in the Mediterranean Sea presented in “New Mediterranean Biodiversity Records (November 2018)”. Numbers of locations are given in