Amphorina andra Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin,, 2020

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 : 283-284

Amphorina andra Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin,

Martynov, 2020

( Figure 4 (b))

Material examined

Cala d’Aiguafreda, Begur ( Spain), 41°57 ʹ 49”N, 3°13 ʹ 41”E, 22 June 2013, 18 m depth, 1 spc., juvenile, L = 3 mm ( GROC 2009_2021); Balaruc-les-Bains ( France), 43°26 ʹ 28.8”N, 3°41 ʹ 3”E, 5 April 2014, 2 m depth, 2 spcs, adults, L = 10–15 mm; Barra de l’Arbre, Mataró ( Spain), 41° 31 ʹ 57.9”N, 2°28 ʹ 21.2”E, 1 May 2014, 20 m depth, 1 spc., juvenile, H = 2 mm; Punta del Romaní, L’Escala ( Spain), 42°6 ʹ 54”N, 3°10 ʹ 9”E, 12 April 2015, 4 m depth, 3 spcs, adults, L = 10–12 mm; Cala Maset caves, Sant Feliu de Guíxols ( Spain), 41°47 ʹ 10”N, 3°2 ʹ 44”E, 16 January 2018, 1 m depth, 2 spcs, adults, L = 10 mm; 16 January 2018, 1 m depth, 2 spcs, adults and egg masses, L = 10–12 mm; 22 January 2018, 0.7 m depth, 6 spcs, adults, mating and egg masses, L = 12–15 mm; 16 February 2018, 1.2 m depth, 2 spcs, adults, L = 8–10 mm; 9 March 2018, 0.6 m depth, 6 spcs, adults, mating and egg masses, L = 10– 15 mm; Punta d’en Bosch, Sant Feliu de Guíxols ( Spain), 41°45 ʹ 54”N, 3°0 ʹ 11”E, 17 April 2018, 1 m depth, 5 spcs, adults mating, L = 8–12 mm; Cova de l’infern ( Spain), 42°19 ʹ 2.75”N, 3°19 ʹ 12.74”E, 2 March 2019, 1 m depth, 3 spcs, adults and egg masses, L = 10–20 mm.

External morphology

Body elongate, narrow, background colour variable, typically white with black and orange marks, some specimens with completely white or orange colouration. Rhinophores and oral tentacles smooth and yellow, white apically. Cerata globular, with white and black marks, apical part yellow.

Ecology

Specimens found at a broad range of depths, always associated with hydrozoan colonies. The specimens of Sant Feliu were found inside a cave and associated with hydrozoans of the genus Sertularella , on which they often lay their egg masses. Active at night, mating and laying eggs. During the day they are found at the base of the hydrozoans. The egg mass is spiral-shaped, usually laid on rocks, but also on the hydrozoans upon which they feed.

Distribution

Italy and Croatia ( Korshunova et al. 2020); France (this study); Spain: Catalonia (this study).

Remarks

This species was recently described, but up to now it was considered a morphotype of Eubranchus farrani , now Amphorina farrani (Alder and Hancock 1845) . Amphorina andra is variable in body colour, from completely white or orange to a white with black spots and orange circles on the dorsum. Specimens found at deeper depths were typically small, whereas specimens found at very shallow depths, mostly in caves, were larger and found on hydrozoan colonies of the genera Obelia and Sertularella , among others. Populations observed in Croatia were in shallow waters, between 0 and 0.5 m ( Korshunova et al. 2020), as was the population studied in Sant Feliu, Catalonia ( Spain).

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.