Numerous new records of tropical non-indigenous species in the Eastern Mediterranean highlight the challenges of their recognition and identification Author Albano, Paolo G. https://orcid.org/0000-0001-9876-1024 Department of Palaeontology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria pgalbano@gmail.com Author Steger, Jan Department of Palaeontology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria Author Bakker, Piet A. J. Naturalis Biodiversity Center, Darwinweg 2, 2333, CR Leiden, The Netherlands Author Bogi, Cesare Gruppo Malacologico Livornese, c / o Museo di Storia Naturale del Mediterraneo, via Roma 234, 57127, Livorno, Italy Author Bosnjak, Marija Department of Palaeontology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria & Croatian Natural History Museum, Demetrova 1, Zagreb, Croatia Author Guy-Haim, Tamar National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108001, Israel Author Huseyinoglu, Mehmet Fatih Faculty of Maritime Studies, University of Kyrenia, Karakum, Girne, Turkish Republic of Northern Cyprus Author LaFollette, Patrick I. Malacology Section, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, CA 90007, USA Author Lubinevsky, Hadas National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108001, Israel Author Mulas, Martina https://orcid.org/0000-0001-9228-786X National Institute of Oceanography, Israel Oceanographic and Limnological Research (IOLR), Haifa 3108001, Israel & The Leon H. Charney School of Marine Sciences, University of Haifa, 199 Aba Khoushy Ave., Mt. Carmel, Haifa 3498838, Israel Author Stockinger, Martina Department of Palaeontology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria Author Azzarone, Michele Department of Palaeontology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria Author Sabelli, Bruno Museo di Zoologia dell'Universita di Bologna, via Selmi 3, 40126, Bologna, Italy text ZooKeys 2021 2021-01-13 1010 1 95 http://dx.doi.org/10.3897/zookeys.1010.58759 journal article http://dx.doi.org/10.3897/zookeys.1010.58759 1313-2970-1010-1 45DF30C9AEB448AAAC32BBE77CB7191D D317557D854C577289AA424187C079D2 Arcuatula perfragilis (Dunker, 1857) Figure 32 New records. Israel • 1 spcm; Palmachim; 31.9574°N , 34.6645°E ; depth 36.2 m; 2 May 2018; soft substrate; box-corer; Shafdan project (sample 24(C)); size: L 13 mm, H 5.3 mm • 1 spcm; Palmachim; 31.9737°N , 34.6767°E ; depth 35.4 m; 2 May 2018; soft substrate; box-corer; Shafdan project (sample 29(A)). Remarks. This species was first recorded in Israel in 1960 from Bat Yam with living individuals ( Barash and Danin 1973 ). Further living individuals were recorded in the 1960s and early 1970s from Israel and Egypt (Bardawil Lagoons) ( Barash and Danin 1971 , 1973 , 1977 ). Since then, however, no further living individuals were found, questioning the persistence of its populations in the Mediterranean. We report here the recent finding of two living individuals, suggesting that the species indeed still occurs in Israel. Figure 32. Arcuatula perfragilis (Dunker, 1857), Palmachim, Israel, Shafdan project. Left valve outer view. The pink hue is due to staining with eosin solution. Photograph courtesy S. Bartolini. Scale bar: 2 mm.