Corbula erythraeensis H. Adams, 1871

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

Corbula erythraeensis H. Adams, 1871 Figure 45A-K

New records.

Israel • 1 spcm; Ashqelon; 31.7002°N, 34.5498°E; depth 21 m; 18 Sep. 2016; sand; grab; HELM project (sample SG20_4F) • 3 spcms; Ashqelon; 31.7487°N, 34.4960°E; depth 41 m; 27 Apr. 2017; sandy mud; grab; HELM project (sample SG40_8M); sizes: L 2.9 mm, H 2.5 mm (illustrated specimen 1, Figure 45A-C ); L 3.8 mm, H 3.1 mm (illustrated specimen 2, Figure 45D, E ) • 2 spcms; Soreq desalination plant; 31.94°N, 34.69°E; depth 17-22 m; 10 May 2009; soft substrate; grab; Soreq project; size: L 1.9 mm, H 1.5 mm (Figure 45J, K ).

Additional material examined.

Corbula erythraeensis : Egypt • 1 sh; Bay of Safaga; 26.8142°N, 33.9653°E; depth 39 m; 31 Oct. 1994; mud; scuba diving; M. Zuschin leg.; ref. Oliver and Zuschin (2000), sample 94/4/b; NHMW-MO-106107; size: L 3.5 mm, H 2.5 mm (illustrated shell, Figure 45F-H ) • 1 v; same collecting data as for preceding; NHMW-MO-106100; size: L: 2.3 mm, H: 1.6 mm (illustrated valve, Figure 45I ).

Corbula gibba (Olivi, 1792): Israel • 271 spcms; Ashqelon; 31.7492°N, 34.4964°E; depth 41 m; 27 Apr. 2017; sandy mud; grab; HELM project (sample SG40_8M) • 300 spcms, 11 shs, 10 vv (5 right, 5 left); Soreq desalination plant; 31.94°N, 34.69°E; depth 17-22 m; 10 May 2009; soft substrate; grab; Soreq project.

Remarks.

Corbula erythraeensis is widespread in the northern Red Sea where it has been recorded from the gulfs of Suez ( MacAndrew 1870; Oliver 1992) and Aqaba at Eilat ( Edelman-Furstenberg and Faershtein 2010), as well as the northern Bay of Safaga (Egypt) ( Zuschin and Oliver 2003); outside the Red Sea, its distribution ranges eastward to Pakistan ( Huber 2010). Here we report the first findings of this species from the Mediterranean. Corbula erythraeensis was found sympatrically with the common native Mediterranean Corbula gibba but was always present in very low numbers. No empty shells have been found so far. While being similar in appearance to the morphologically variable C. gibba , C. erythraeensis has a convex anterior dorsal margin of the right valve (usually concave in C. gibba , particularly in smaller specimens), a more inflated umbonal region, a regular concentric sculpture on the left valve ( Oliver 1992), and its color always is whitish-yellowish ( C. gibba frequently has a rosy pattern). Juvenile individuals are more wedge-shaped than those of C. gibba .

Figures

Figure 45. Comparison between Corbula erythraeensis H. Adams, 1871 and Corbula gibba (Olivi, 1792). A-E Corbula erythraeensis, Ashqelon, Israel, HELM project (sample SG 40 _ 8 M): A-C Specimen 1: left (A) and right (B) valve outer views, sculpture of the anterior left valve (C) D, E Specimen 2: left (D) and right (E) valve outer views. F-H Corbula erythraeensis, Bay of Safaga, Egypt, NHMW-MO- 106107: left valve outer (F), ventral (G) and dorsal (H) views. I Corbula erythraeensis, same collecting data as for preceding, NHMW-MO- 106100: left valve outer view J, K Corbula erythraeensis, Soreq desalination plant, Israel, Soreq project: left (J) and right (K) valve outer views L, M Corbula gibba, same collecting data as for A-E: left (L) and right (M) valve outer views N, O Corbula gibba, same collecting data as for J-K: left (N) and right (O) valve outer views. Scale bars: 1 mm (A, B, D, E, F-I, L, M); 0.5 mm (C, J, K, N, O).