Pyrgulina craticulata (Issel, 1869)

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

Pyrgulina craticulata (Issel, 1869) Figure 28A-I

New records.

Israel • 1 sh; north of Atlit; 32.7820°N, 34.9466°E; depth 10 m; 21 Sep. 2016; sand; grab; HELM project (sample NG10_1F) • 3 spcms; Ashqelon; 31.6868°N, 34.5516°E; depth 12 m; 30 Apr. 2018; offshore rocky reef; suction sampler; HELM project (samples S12_2F, S12_3F) • 17 spcms, 1 sh; same collecting data as for preceding; depth 11 m; 31 Oct. 2018; HELM project (samples S58_1F, S58_1M, S58_2F, S58_3F); size: H 1.5 mm, W 0.7 mm (illustrated specimen) • 2 spcms; Ashqelon; 31.6891°N, 34.5257°E; depth 25 m; 2 May 2018; offshore rocky reef; suction sampler; HELM project (sample S16_2F) • 1 spcm; same collecting data as for preceding; depth 28 m; 31 Oct. 2018; HELM project (sample S59_2F) • 2 spcms; west of Rosh HaNikra Islands; 33.0704°N, 35.0926°E; depth 12 m; 29 Oct. 2018; rocky substrate; suction sampler; HELM project (samples S52_2F, S52_3F) • 1 spcm; west of Rosh HaNikra Islands; 33.0725°N, 35.0923°E; depth 20 m; 1 May 2018; rocky substrate; suction sampler; HELM project (sample S13_3F) • 2 spcms; same collecting data as for preceding; depth 19 m; 29 Oct. 2018; HELM project (sample S53_1F).

Additional material examined.

Pyrgulina craticulata : EGYPT • 1 sh; Sinai (Red Sea), Gulf of Aqaba, Strait of Tiran, Jackson Reef; 28.0167°N, 34.4667°E; depth 2-3 m; 31 Oct. 1985; sand and coral substrate; T. Bratcher leg.; LACM 1985-111.4.

Madagascar • 3 shs; Antsiranana Province, south of Nosy Be, out from Hellville (= Andoany); 13.4500° S, 48.2500°E; depth 14 m; 5 Apr. 1989; coral heads and gorgonians; J.H. McLean leg.; LACM 1989-55.1.

Maldives • 1 sh; North Male Atoll, 2 km north of Baros Island; 4.3167°N, 73.4167°E; depth 25-35 m; 10 Feb. 1983; gravel; leg. A.J. Ferreira; LACM 1983-9.7.

Thailand • 1 sh; Phuket Province, east side of Kaew Yai Island; 7.7450°N, 98.3083°E; depth 0-3 m; 24-26 Mar. 1985; coral; J.H. McLean leg.; LACM 1985-5.17 • 1 sh; same collecting data as for preceding; LACM 1985-5.18 • 6 shs; Phuket Province, southern tip of Phromthep Cape; 7.7583°N, 98.3217°E; depth 0 m; 24 Mar. 1985; boulder beach with coral; J.H. McLean leg.; LACM 1985-6.4 • 4 shs; Phuket Province, east of Phuket, near Pee-Pee (= Phi Phi) Island, Hin Hmusang Rock; 7.7917°N, 98.5500°E; depth 15 m; 15 Feb. 1985; sand; A.J. Ferreira leg.; LACM 1985-14.2.

Spiralinella incerta (Milaschewitsch, 1916): Israel • 1 sh; north of Atlit; 32.7820°N, 34.9466°E; depth 10 m; 21 Sep. 2016; sand; grab; HELM project (sample NG10_1F) • 1sh; north of Atlit; 32.7422°N, 34.9181°E; depth 30 m; 20 Sep. 2016; sand; grab; HELM project (sample NG30_2F) • 2 shs; Ashqelon; 31.7002°N, 34.5498°E; depth 21 m; 18 Sep. 2016; sand; grab; HELM project (sample SG20_2F) • 1 sh; Ashqelon; 31.7101°N, 34.5406°E; depth 31 m; silty sand, 90 cm below sediment surface; gravity corer; HELM project (sample SC30_1_90L) • 1 sh; west of Rosh HaNikra Islands; 33.0704°N, 35.0926°E; depth 12 m; 1 May 2018; rocky substrate; suction sampler; HELM project (sample S14_4F); size: H 1.5 mm, W 0.7 mm (illustrated shell).

Remarks.

Issel (1869) described Odontostomia craticulata based on an illustration of a shell from the Red Sea by Savigny (1817: pl. 3, fig. 39); the syntype from the Savigny collection (MNHN-IM-2000-34095) was later figured by Bouchet & Danrigal (1982) and is shown on the MNHN website (https://science.mnhn.fr/institution/mnhn/collection/im/item/2000-34095?listIndex=15&listCount=44; last accessed 26 July 2020). As Odontostomia is considered an unjustified emendation of Odostomia ( MolluscaBase 2020), a genus with very different conchological characters from P. craticulata , we follow the opinion of Peñas et al. (2020) and use the combination Pyrgulina craticulata (Issel, 1869).

Pyrgulina craticulata has been reported only from the Red Sea so far, however, a search of previously uncatalogued lots of pyramidellid shells in the LACM collection by one of us (PILF) yielded specimens from Madagascar, the Maldives and Thailand, confirming that this species has a much wider distribution in the Indian Ocean. Shells of P. craticulata seem indistinguishable from the illustration of Chrysallida tribulationis (Hedley, 1909), a taxon recorded from Australia and the western Japan Sea ( Hedley 1909; Higo et al. 2001). In the light of a possible distribution of P. craticulata also in the West Pacific, we recommend an assessment of potential synonymy between C. tribulationis and P. craticulata .

Here, we provide the first records of P. craticulata for the Mediterranean Sea. Several living specimens were found on hard substrates off southern and northern Israel, suggesting it is established in the region. In terms of shell size, shape and type of ornamentation, this species closely resembles the native Spiralinella incerta (Figure 28J-N ), but has pronounced spiral cords in the interspaces of the axial ribs (Figure 28I vs. 28N) which enable a reliable segregation of these two species. In addition, the axial ribs are spaced more closely in S. incerta than in P. craticulata .

Figures

Figure 28. Comparison between Pyrgulina craticulata (Issel, 1869) and Spiralinella incerta (Milaschewitsch, 1916) A-I Pyrgulina craticulata, Ashqelon, Israel, HELM project (sample S 58 _ 3 F): front (A, B) and back (C, D) views, aperture and details of the sculpture on the base (E), top view (F), detail of the protoconch-teleoconch transition (G), apical view of the protoconch (H) and detail of the sculpture of the body whorl (I) J-N Spiralinella incerta, west of Rosh HaNikra Islands, Israel, HELM project (sample S 14 _ 4 F): front (J, K) and back (L, M) views, detail of the sculpture of the body whorl (N). Scale bars: 0.5 mm (A-D, J-M); 0.2 mm (E, F, I, N); 0.1 mm (G, H).