Hyalocylis striata (Rang, 1828)

Salvador, Xavier, Fernández-Vilert, Robert & Moles, Juan, 2022, Sea slug night fever: 39 new records of elusive heterobranchs in the western Mediterranean (Mollusca: Gastropoda), Journal of Natural History 56 (5 - 8), pp. 265-310 : 290-291

Hyalocylis striata (Rang, 1828)

( Figure 5 (b))

Material examined

Cala Sa Tuna , Begur ( Spain), 41°57 ʹ 38”N, 3°13 ʹ 52”E, 9 February 2019, 1 m depth, 1 spc ., adult, L = 6 mm; Montiel , Tamariu ( Spain), 41°54 ʹ 55.9”N, 3°12 ʹ 46.3”E, 13 March 2019, 1 m depth, 4 spcs, adults, L = 6–10 mm; 14 March 2019, 1 m depth, 3 spcs, adults, L = 6–10 mm .

External morphology

Shell wide, short, striated, conical, translucent. Parapodia large, transparent. Statocysts visible between shell and parapodia.

Ecology

Found in open waters close to the surface and around other pelagic pteropod and salp species.

Distribution

Cosmopolitan. In the Mediterranean Sea, it is commonly reported in the eastern part ( Koukouras 2010; OBIS 2021) and from the Italian coast ( OBIS 2021). This species was recorded in Spanish Mediterranean waters by the study of Cervera et al. (2004) but only in remote areas tens of miles from the coast. This is the first report in the vicinity of the Mediterranean Spanish coast and the first record for Catalonia.

Remarks

As for C. virgula , almost all records in the Mediterranean Sea are based on shells of specimens caught with plankton nets in open waters and at great depths ( OBIS 2021). Our specimens were found from February to March along with the massive arrival of pelagic zooplankton.

Family PERACLIDAE Tesch, 1913

Genus Peracle Forbes, 1844

Figures

Figure 5. Photographs of live Pteropoda species: (a) Creseis virgula. (b) Hyalocylis striata. (c) Peracle reticulata. (d) Pneumodermopsis canephora. Runcinida: (e) Runcina ornata. Sacoglossa: (f) Aplysiopsis elegans. (g) Caliphylla mediterránea. (h) Cyerce graeca.