Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli and Crocetta, 2019

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 : 273-275

Okenia longiductis Pola, Paz-Sedano, Macali, Minchin, Marchini, Vitale, Licchelli and Crocetta, 2019

( Figure 2 (h))

Material examined

Cala Maset caves, Sant Feliu de Guíxols ( Spain), 41°47 ʹ 10”N, 3°2 ʹ 44”E, 23 September 2016, 1 m depth, 5 spcs, juveniles, adults and egg masses, L = 2–8 mm; 14 September 2017, 1 m depth, 7 spcs, adults and egg masses, L = 5–13 mm; 16 October 2017, 1 m depth,>20 spcs, adults and egg masses, L = 7–13 mm; Cala Ventosa, Sant Feliu de Guíxols ( Spain), 41°47 ʹ 5”N, 3°2 ʹ 52”E, 13 September 2017, 1 m depth, 2 spcs, adults and egg masses, L = 5 mm; Fòrum pools, Barcelona ( Spain), 41°24 ʹ 34.5”N, 2°13 ʹ 36.8”E, 23 November 2017, 2.3 m depth, 7 spcs, adults and egg masses, L = 5–10 mm.

External morphology

Body elongate, narrow, background colour light brown or white with irregular brown, black and white punctuations in adults. Papillae smooth, found scattered on dorsum and laterals. Rhinophores present a smooth front surface, lamellar in back. Discoidal branchial leaves.

Ecology

All specimens at each locality were found on the bryozoans Amathia verticillata (Delle Chiaje, 1822) , laying their egg masses.

Distribution

Recently reported in Italy and on the Mediterranean French coast ( Pola et al. 2019); Mediterranean Spanish coast: Catalonia ( Pola et al. 2019; this study).

Remarks

Pola et al. (2019) recently confirmed the differences between this species and O. zoobotryon (Smallwood, 1910) , previously recorded in the Mediterranean but originally described from the Islands of Bermuda. Morphological analyses in that study revealed differences in the reproductive system and the gill branches between these two species. Thus, according to Pola et al. (2019), previous records of O. zoobotryon in the Mediterranean are misidentifications of O. longiductis , and O. zoobotryon is only present in the western Atlantic.

Figures

Figure 2. Photographs of live Cephalaspidea species: (a) The alien Haloa japonica. (b) Haminoea orteai. (c) Egg mass of Haminoea orteai. (d) Philine catena. The Nudibranchia species: (e) Aegires palensis. (f) White morphotype of Aegires sublaevis. (g) Aldisa smaragdina on top of the sponge Phorbas topsenti. (h) Okenia longiductis on the bryozoan Amathia verticillata.