Vitrinella aff. Vitrinella sp. 1 (sensu Blatterer 2019)

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

Vitrinella aff. Vitrinella sp. 1 (sensu Blatterer 2019) Figure 14

New records.

Israel • 1 sh; Ashdod; 31.8697°N, 34.6473°E; depth 24 m; Sep. 2019; soft substrate; grab; APM DAN project (sample 10B); size: H 0.4 mm, W 0.7 mm.

Remarks.

This tiny gastropod defeated all our attempts to identify it. It consists of a protoconch and a teleoconch of ~ 1.5 whorls each. Sculpture is absent, except for two spiral ridges that run on the shoulder and on the base. A third ridge runs periumbilically (Figure 14E ). Broad umbilicus, roundish aperture. Our shell closely resembles the Vitrinella sp. 1 illustrated by Blatterer (2019: plate 127, fig. 12a-j) from the Dahab region in the northern Red Sea, which, however, apparently bears fine spiral threads in the umbilicus (fig. 12e, and unpublished figures). SEM images of our shell show that its surface is taphonomically altered; additionally, Blatterer’s specimens look slightly more mature, reaching 2 teleoconch whorls. The significance of these features should be re-assessed upon a satisfying revision of these tiny gastropods from the Indo-Pacific province. Another similar shell is illustrated by Janssen et al. (2011, plate 19, figs. 3a-b), which apparently has less conspicuous or absent spiral ridges as long as can be judged from the optical illustrations provided. It is worth mentioning that gastropods belonging to the family Clenchiellidae D.W. Taylor, 1966 share the small size, low spire, wide umbilicus and presence of strong spiral keels we observed in our specimen ( Ponder et al. 2014); the latter, however, lacks the numerous finer spiral cords that characterize clenchiellids. Additionally, these gastropods occur in mangrove swamps or adjacent habitats in tropical estuaries, a kind of habitat that does not occur in Israel. The shell shape and sculpture (in particular the strong spiral keels) distinguish it at once from native Mediterranean species. The extreme similarity with the shell illustrated in Blatterer’s book suggests that the species belongs to a Red Sea clade and is here considered a new non-indigenous species in the Mediterranean Sea.

Figures

Figure 14. Vitrinella aff. Vitrinella Vitrinella sp. 1 (sensu Blatterer 2019), Ashdod, Israel, APM DAN project (sample 10 B): apical (A, B), umbilical (C, D), front (E) and side (F) views, protoconch (G) and back view (H). Scale bars: 0.3 mm (A-F, H); 0.1 mm (G).