Cerithiopsis 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

Cerithiopsis sp. Figure 10

New records.

Israel • 1 sh; Shiqmona Beach; 32.8259°N, 34.9555°E; beached; 4 Jan. 2008; size: H 3.5 mm, W 1.2 mm.

Remarks.

This beautiful species has almost eight teleoconch whorls bearing two strong spiral cords with oblong tubercles at the intersection with prosocline axial ribs. Interspaces between spiral cords are approximately as large as the cords themselves, and interspaces between the axial ribs are double the size of the ribs. A third smooth thick cord delimits the rather flat base and is visible above the suture throughout most of the teleoconch. The protoconch is smooth with very fine and extremely short axial riblets just below the suture; it is multispiral but broken in our specimen in which only the last two whorls are preserved. The slender shape, the two strong spiral cords and the smooth flat base distinguish it at once from all native Mediterranean species suggesting it is a new non-indigenous species in the basin.

Among Indo-Pacific cerithiopsids, Synthopsis lauta Cecalupo & Perugia, 2013, described from Vanuatu, is among the few similar species we were able to trace. However, the interspace between the spiral cords is broader, the tubercles on the first spiral cord of the last whorl are larger than those on the second cord, and the teleoconch is shorter with just six whorls. Additionally, the color pattern with white tubercles, yellowish interspaces, deep brown suture and violet protoconch is strikingly different from the one of our shell. We have some reservations that S. lauta , as well as our specimen, belong to the genus Synthopsis Laseron, 1956 that was described as bearing three tuberculate spiral cords on the whole teleoconch ( Laseron 1956). Pending a molecular phylogeny of the family, we consider this feature important at the genus level. Therefore, we assign our specimen to the nominotypical genus Cerithiopsis , in the wait of a better understanding of cerithiopsid systematics. The specimen identified as Horologica gregaria Cecalupo & Perugia, 2012 and illustrated in the recent revision of Cerithiopsidae from South Madagascar ( Cecalupo and Perugia 2014b: fig. 8G) is also similar to ours; that specimen, however, has a distinct basal spiral cord which is absent in our specimen. The latter character, the prominence of the tuberculate spiral cords and the evident but rather flat third cord also raise some doubts that the specimen from South Madagascar is conspecific with the H. gregaria originally described from the Central Philippines ( Cecalupo and Perugia 2011). Last, the Sudanese specimen of Horologica cf. taeniata Cecalupo & Perugia, 2013 illustrated by Cecalupo and Perugia (2016: fig. 1P-S) shares the general features of our shell but can be distinguished by the first spiral cord that tends to split into two separate cords, and by the color pattern of white teleoconch and orange base.

Figures

Figure 10. Cerithiopsis sp., Shiqmona Beach, Israel: front (A, B), side (C) and back (D) views, protoconch oriented to highlight the transition to the teleoconch (E, F), microsculpture (G). Scale bars: 1 mm (A-D); 0.2 mm (E, F); 0.4 mm (G).