Eubranchus prietoi Llera and Ortea, 1981

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 : 284-285

Eubranchus prietoi Llera and Ortea, 1981

( Figure 4 (c))

Material examined

Cala Maset caves, Sant Feliu de Guíxols ( Spain), 41°47 ʹ 10”N, 3°2 ʹ 44”E, 11 to 16 February 2018, 1.5–2 m depth, 13 spcs, adults and egg masses, L = 4–7 mm; 9 to 15 March 2018, 1.5 m depth, 13 spcs, juveniles, adults and egg masses, L = 6–10 mm; 30 March 2018, 1.5 m depth, 7 spcs, juveniles, adults and egg masses, L = 7–15 mm; 15 April 2018, 1.5 m depth, 2 spcs, adults, L = 8 mm; 7 May 2018, 0.7 m depth, 2 spcs, adults, L = 7 mm .

External morphology

Body elongate, narrow, with a black mark on the dorsum (corresponding to digestive gland seen by transparency), starting between the first couple of cerata and ending at the last group of cerata. Background colour beige with brown and white punctuation. Rhinophores long, equal. Cerata large and fusiform compressed at the middle, transparent with white to dark brown visible digestive gland, white tips.

Ecology

Specimens found during the day at the base of the hydrozoan Kirchenpaueria halecioides (Alder, 1859) , but actively crawling, mating and feeding on the colony at night. ‘C’-shaped egg masses were found on the hydrozoan.

Distribution

Ghana; Strait of Gibraltar ( García-Gómez 1987); France (Rudman 2020); Atlantic Spanish coast: Cantabria ( Ortea and Bacallado 1981); Mediterranean Spanish coast: Catalonia (this study).

Remarks

When active, the cerata are completely lateralised. Slugs are camouflaged from the pycnogonids also found on the hydrozoan colonies (X. Salvador pers. obs.). Specimens can be differentiated externally from other Eubranchus species by the insertion of the first cerata groupings and the visible black digestive gland on the dorsum between cerata ( Llera and Ortea 1981).

Family FACELINIDAE Bergh, 1889

Genus Godiva Macnae, 1954

Figures

Figure 4. Photographs of live Nudibranchia species: (a) The pelagic Phylliroe cf. bucephala. (b) Amphorina andra surrounded by hydrozoans of the genus Sertularella. (c) Eubranchus prietoi on the hydrozoan Kirchenpaueria halecioides. (d) The alien Godiva quadricolor. (e) Three specimens of Piseinotecus soussi and their egg masses. (f) Piseinotecus sphaeriferus on top of the hydrozoan Obelia sp. (g) Tenellia adspersa. (h) Trinchesia cuanensis on top of the hydrozoan Sertularella sp.