Vitreolina cf. philippi (de Rayneval & Ponzi, 1854)

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

Vitreolina cf. philippi (de Rayneval & Ponzi, 1854) Figure 16E, F

New records.

Israel • 4 spcms; Ashqelon; 31.6891°N, 34.5257°E; depth 25 m; 2 May 2018; offshore rocky reef; suction sampler; HELM project (samples S16_1F, S16_2F); size: H 2.6 mm, W 0.9 mm.

Additional material examined.

Vitreolina philippi (de Rayneval & Ponzi, 1854): GREECE • Crete, Plakias; 35.1796°N, 24.3957°E; depth 5 m; 24 Sep. 2017; Posidonia oceanica rhizomes; suction sampler (sample Rh.05_5M).

Remarks.

This Vitreolina is extremely similar to the native V. philippi , but the animal is whitish with a yellowish digestive gland (Figure 16E, F ), in contrast to the peculiar color pattern of typical V. philippi with a white background and red dots (Figure 16D ). Vitreolina is known to be gonochorous ( Warén 1984) but it is unclear if this different color pattern, never reported from the Mediterranean, can be related to sex. We suspect that this could be another new Lessepsian species for the Mediterranean Sea, because we observed several Mediterranean-Red Sea species pairs that are morphologically extremely similar. If we are correct, the occurrence and distribution of this species in the Mediterranean may be difficult to trace, because empty shells, the most easily collected, are virtually indistinguishable from the native V. philippi .

Figures

Figure 16. Hemiliostraca clandestina (Mifsud & Ovalis, 2019), and comparison between Vitreolina philippi (de Rayneval & Ponzi, 1854) and Vitreolina sp. A-C Hemiliostraca clandestina, Ashqelon, Israel, HELM project (sample S 16 _ 1 F): front (A), side (B) and back (C) views. D Vitreolina philippi (de Rayneval & Ponzi, 1854), Plakias, Crete, Greece (sample Rh. 05 _ 5 M): front view. E, F Vitreolina cf. philippi, Ashqelon, Israel, HELM project (S 16 _ 2 F): front (E) and side (F) views. Scale bars: 0.5 mm.