The first colonization of the Genus Amphistegina and other exotic benthic foraminifera of the Pelagian Islands and south-eastern Sicily (central 'Mediterranean Sea)

A detailed study of the marine sediments collected on the inner shelf of some of the selected areas of the central Mediterranean Sea has been carried out in order to verify the presence of exotic benthic foraminiferal species. Since 2000, the coastal marine environments of the Pelagian Islands and of Sicily (central Mediterranean) have been increasingly colonized by exotic species (i.e. fishes and algae) originating both from the Atlantic Ocean and the Red Sea. The studied areas (Pelagian Islands and SE Sicily) are located in the middle of the Mediterranean Sea. Therefore, they represent an ideal place to understand how exotic species, coming from different Oceans, may have colonized ecological niches in the Mediterranean Sea. The objective of this study is to evaluate the colonization of benthic foraminiferal species which have migrated from the Atlantic Ocean and the Red Sea into the Mediterranean. The study shows that two species of Amphistegina (lessonii and lobifera) have massively colonized the Pelagian Islands. Furthermore, two ecomorphotypes of Amphistegina (A. cf. lessonii and A. cf. papillosa), never described up to now, have been found attached to exotic green algae, of Indo-Pacific origin. In the study area, Amphisteginids are so abundant that they can account for up to 90% of the total assemblage. In addition to Amphistegina, other exotic benthic foraminifera, such as Amphisorus hemprichii, have colonized the central Mediterranean Sea. The migration might have been through the Suez Canal, as a Lessepsian invasion. Alternatively, other species, such as Sorites orbiculus might have colonized the Mediterranean Sea from the Atlantic Ocean, migrating through the Gibraltar gateway and/or from the Red Sea, via the Suez Canal. (C) 2014 Elsevier B.V. All rights reserved.