Lioberus ligneus (Reeve, 1858)

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

Lioberus ligneus (Reeve, 1858) Figure 33A-D

New records.

Cyprus • 2 shs; Turkish Republic of Northern Cyprus, southern tip of Karpaz Peninsula; 35.6809°N, 34.5785°E; depth 1 m; 29 Jul. 2019; mixed substrate with sand, rocks and Cystoseira ; P.G. Albano leg. (sample NCY7H); NHMW-MO-112930/LM/0173; size of the largest shell: L 30.2 mm, H 15.0 mm.

Israel • 1 spcm; Carmel Head; 32.8232°N, 34.9431°E; depth 12 m; 21 Apr. 2020; in a small patch of Galaxaura rugosa and Cystoseira sp.; M. Mulas leg. (sample SK2); SMNH MO83605; size: L 17.6 mm, H 10.0 mm.

Additional material examined.

Lioberus ligneus : Egypt • 19 vv; Red Sea, Suez; Jousseaume coll.; MNHN • 1 sh; Sinai (Red Sea), Dahab, dive site “Islands”; 28.4789°N, 34.5126°E; beached; Nov. 2007; H. Blatterer leg. • 1 v; same collecting data as for preceding; 2012 • 1 v; Sinai (Red Sea), Dahab, dive site “Lagoon”; depth unspecified; 2008; H. Blatterer leg. • 1 v; same collecting data as for preceding; 2009.

Lioberus agglutinans (Cantraine, 1835): Portugal • 1 v; Algarve, Canal of Olhão; depth 3-7m, MNHN • 2 vv; Algarve, Tavira, Pedra do Barril; depth 25 m; MNHN • 1 sh, 1 v; Algarve, Sagres, Ponta da Baleeira; depth 17-23 m; MNHN • 1 spcm; Algarve, Tavira, off Cabanas; depth 14 m; MNHN • 2 shs; Algarve, Olhão, Ilha da Barretta; depth unspecified; MNHN.

Tunisia • 1 sh, 8 vv; Gulf of Gabès, NW Boughrara Gulf; depth 10-15 m; MNHN • 11 spcms, 42 vv; Gulf of Gabès, Djerba, Ajim Canal; depth 10-32 m; MNHN.

Remarks.

We here report Lioberus ligneus for the first time from Israel and Cyprus. The Israeli live-collected specimen comes from a patch of Galaxaura rugosa and Cystoseira sp. whereas the two empty but fresh shells from Cyprus were found attached vertically to Cystoseira shoots. These findings suggest that this species indeed prefers vegetated habitats in the shallow subtidal. This species has been previously reported from Lebanon based on shells collected in 1999-2000 ( Crocetta et al. 2013), suggesting that it has likely occurred undetected throughout the Levantine Basin for long. The distinction of L. ligneus from the native Mediterranean Lioberus agglutinans (Cantraine, 1835) is not straightforward because both species share the elongated appearance, sculpture limited to concentric striae, and brown color. Moreover, they are morphologically variable. A fairly consistent character of L. ligneus in the samples we inspected from the Red Sea is the darker internal color, often shading into violet. The group would deserve a taxonomic revision to unambiguously distinguish its species.

Figures

Figure 33. Comparison between Lioberus ligneus (Reeve, 1858) and Lioberus agglutinans (Cantraine, 1835). A, B Lioberus ligneus, NHMW-MO- 112930 / LM / 0173, Karpaz Peninsula, Turkish Republic of Northern Cyprus, Cyprus: right valve outer (A) and left valve inner (B) views C, D L. ligneus, Dahab, Egypt (H. Blatterer coll.): right valve outer (C) and left valve inner (D) views E, F Lioberus agglutinans, Olhao, Ilha da Barretta, Algarve, Portugal: right valve outer (E) and left valve inner (F) views G, H L. agglutinans, Tavira, off Cabanas, Algarve, Portugal: right valve outer (G) and left valve inner (H) views. Scale bars: 5 mm.