More than 60 marine non-indigenous species (NIS) have been removed from previous lists and 84 species have been added, bringing the total to 986 alien species in the Mediterranean [775 in the eastern Mediterranean (EMED), 249 in the central Mediterranean (CMED), 190 in the Adriatic Sea (ADRIA) and 308 in the western Mediterranean (WMED)]. There were 48 new entries since 2011 which can be interpreted as approximately one new entry every two weeks. The number of alien species continues to increase, by 2-3 species per year for macrophytes, molluscs and polychaetes, 3-4 species per year for crustaceans, and 6 species per year for fish. The dominant group among alien species is molluscs (with 215 species), followed by crustaceans (159) and polychaetes (132). Macrophytes are the leading group of NIS in the ADRIA and the WMED, reaching 26-30% of all aliens, whereas in the EMED they barely constitute 10% of the introductions. In the EMED, molluscs are the most species-rich group, followed by crustaceans, fish and polychaetes. More than half (54%) of the marine alien species in the Mediterranean were probably introduced by corridors (mainly Suez). Shipping is blamed directly for the introduction of only 12 species, whereas it is assumed to be the most likely pathway of introduction (via ballasts or fouling) of another 300 species. For approximately 100 species shipping is a probable pathway along with the Suez Canal and/or aquaculture. Approximately 20 species have been introduced with certainty via aquaculture, while >50 species (mostly macroalgae), occurring in the vicinity of oyster farms, are assumed to be introduced accidentally as contaminants of imported species. A total of 18 species are assumed to have been introduced by the aquarium trade. Lessepsian species decline westwards, while the reverse pattern is evident for ship-mediated species and for those introduced with aquaculture. There is an increasing trend in new introductions via the Suez Canal and via shipping.

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summaRY: The fauna of molluscs associated with deep subtidal Zostera marina beds (12-16 m) in southern spain (alboran sea) has been characterised in terms of micro-habitat preference, feeding guilds and biogeographical affinity. The species list (162 taxa) is based on sampling completed before the strong eelgrass decline experienced in 2005-2006, using different methods (small agassiz trawl covering 222 m 2 and quadrates covering 0.06 m 2 ) and different temporal scales (months, day/night). dominant epifaunal species are Jujubinus striatus, Rissoa spp. and Smaragdia viridis in the leaf stratum and Nassarius pygmaeus, Bittium reticulatum and Calliostoma planatum on the sediment. nevertheless, the infauna dominated the epifauna in terms of number of individuals, including mainly bivalves (Tellina distorta, T. fabula, Dosinia lupinus). The epifauna of both the sediment and leaf strata included high numbers of species, probably due to the soft transition between vegetated and unvegetated areas. The dominant feeding guilds were deposit feeders, filter feeders and peryphiton grazers, but ectoparasites (eulimids), seagrass grazers (Smaragdia viridis) and an egg feeder (Mitrella minor) also occurred, unlike in other eelgrass beds of europe. The molluscan fauna of these Z. marina beds is essentially derived from the local fauna, which includes many widely distributed species along european coasts, with a low representation of strictly mediterranean or strictly atlantic species. This fauna is richer than that found in other eelgrass beds of europe, and deserves important attention for conservation.Keywords: bivalves, gastropods, seagrass, biodiversity, alboran sea, biogeographical distribution.Resumen: Una comunidad altamente diversa de moluscos asociados a praderas de Zostera marina del mar de Alborán: preferencias de micro-hábitat, grupos tróficos y distribución biogeográfica. -La fauna de moluscos asociada a praderas infralitorales profundas de Zostera marina (12-16 m) del sur de españa (mar de alborán) ha sido caracterizada en relación a su micro-hábitat preferente, grupo trófico y distribución biogeográfica. el listado faunístico (162 especies) se obtuvo antes de la fuerte regresión sufrida entre los años 2005 y 2006, usando diferentes métodos (pequeño patín de agassiz que muestreaba 222 m 2 y cuadrantes que muestreaban 0.06 m 2 ) y escalas temporales (meses, día/noche). Las especies dominantes asociadas al estrato foliar son Jujubinus striatus, Rissoa spp. y Smaragdia viridis y al sedimento son Nassarius pygmaeus, Calliostoma planatum y Bittium reticulatum, entre otras. no obstante, la endofauna domina a la epifauna, incluyendo principalmente bivalvos como Tellina distorta, T. fabula y Dosinia lupinus. La epifauna asociada al sedimento y al estrato foliar tiene una gran riqueza de especies, probablemente debido a la suave transición entre zonas cubiertas y no cubiertas. Los grupos tróficos dominantes fueron los depositívoros, filtradores o ramoneadores, pero ectoparásitos (eulímidos) y consumidores de fanerógamas ma...