Elachisina sp.

Albano, Paolo G., Steger, Jan, Bakker, Piet A. J., Bogi, Cesare, Bosnjak, Marija, Guy-Haim, Tamar, Huseyinoglu, Mehmet Fatih, LaFollette, Patrick I., Lubinevsky, Hadas, Mulas, Martina, Stockinger, Martina, Azzarone, Michele & Sabelli, Bruno, 2021, Numerous new records of tropical non-indigenous species in the Eastern Mediterranean highlight the challenges of their recognition and identification, ZooKeys 1010, pp. 1-95 : 1

Elachisina sp. Figure 12A-E

New records.

Israel • 1 spcm; north of Atlit; 32.7417°N, 34.9177°E; depth 31 m; 25 Apr. 2017; sand; grab; HELM project (sample NG30_8M) • 14 spcms, 1 sh; west of Rosh HaNikra Islands; 33.0725°N, 35.0923°E; depth 20 m; 1 May 2018; rocky substrate; suction sampler; HELM project (samples S13_1F, S13_1M, S13_2F, S13_3L); size of largest specimen: H 1.6 mm, W 1.3 mm • 9 spcms; same collecting data as for preceding; depth 19 m; 29 Oct. 2018; HELM project (samples S53_1F, S53_2F, S53_3F).

Additional material examined.

Elachisina robertsoni Kay, 1979: United States • 1 sh; Hawaii, Oahu, Maunalua Bay; BPBM 9754 (holotype).

Remarks.

The morphology of this species is unique among the native mollusks of the Mediterranean, which does not host any shallow water Elachisinidae . Therefore, we consider it a new non-indigenous species in the basin.

The only Indo-Pacific Elachisina we are aware of is E. robertsoni Kay, 1979, which indeed shares the general characters of our species. However, it can be readily distinguished by the thicker and fewer spiral cords, less rounded whorls and sigmoid, rather than strongly prosocline, aperture profile. Elachisina sp. is more similar to the West-African E. tenuisculpta ( Rolán and Gofas 2003), but the Israeli shells have more rounded whorls, a greater height/width ratio and smaller ratio between aperture and shell height.

Figures

Figure 12. Comparison between Elachisina sp. and Elachisina robertsoni Kay, 1979 A-E Elachisina sp., west of Rosh HaNikra Islands, Israel, HELM project (sample S 13 _ 3 L): front (A, B), side (C) and back (D, E) views F-H Elachisina robertsoni, BPBM 9754 (holotype), Maunalua Bay, Oahu, Hawaii: front (F), side (G) and back (H) views (photograph courtesy N. Young). Scale bars: 0.5 mm.