Alvania subsoluta ( Aradas, 1847 )

Oliver, Joan Daniel, Gofas, Serge, Urgorri, Victoriano, Díaz-Agras, Guillermo & Templado, José, 2022, Rissoidae gastropods of the outer continental shelf and slope off Galicia (NW Spain), Zootaxa 5196 (1), pp. 1-45 : 13

Alvania subsoluta ( Aradas, 1847)

( Fig. 6 )

Material examined. (6 empty shells and 6 with soft parts in 4 samples): SPAIN • 1 sh; 43° 57.030′N, 008° 54.795′W to 43° 57.248′N, 008° 54.133′W; 1191– 1132 m; 08–15 SeP. 2002; DIVA-Artabria I AT-1000 • 1 sh; 43° 58.84′N, 008° 15.625′W to 43° 59.621′N, 008° 14.285′W; 233–237 m; 15–24 Jul. 2008; A SELVA EBS-20 • 1 sh; 43° 32.89′N, 009° 30.88′W to 43° 33.79′N, 009° 29.60′W; 1211– 1207 m; 15–30 SeP. 2008; DIVA-Artabria II EBS-10 • 6 sPc + 3 sh; 42° 45.9′N, 009° 41.68′W to 42° 47.00′N, 009° 42.12′W; 1499– 1373 m; 15–30 SeP. 2008; DIVAArtabria II EBS-27 .

Remarks. This species ranges from Norway to off Morocco, also in the Mediterranean, usually in a wide bathymetric range of 200–2000 m ( Bouchet & Warén 1993; Warén 1996). In the Mediterranean it has been recorded from 200 down to 700 m in depth, probably as a Pleistocene subfossil ( Gaglini 1991; Oliverio et al. 1992). Records from the Canaries ( Bouchet & Warén 1993; Hoenselaar & Goud 1998) are extremely scanty and need confirmation. The record from shallow water in Madeira is based ( Segers et al. 2009) on the misidentification of Alvania spreta ( Watson, 1873) . Alvania subsoluta resembles A. testae from which it mainly differs by having a paucispiral protoconch ( Figs. 6d–f ).

The shells studied show some variability being characterized by their square reticulate sculpture. The interspaces bear a micropattern of very thin spiral lines ( Fig. 6h ). Paucispiral protoconch bearing also delicate spiral lines ( Figs. 6f–e ). Few shells with soft parts remains were found in a sample from muddy bottom with gravel deeper than A. testae and A. cimicoides (at 1400–1500 m).

Figures

FIGURE 6. Alvania subsoluta (Aradas, 1847) (DA-II (08):EBS-27). a Shell (2.7 mm); b Shell (2.3 mm); c Shell (2.1 mm); d–e Protoconch from a; f Lateral view of the protoconch from c; g Detail of the microsculpture of protoconch; h Detail of the microsculpture of teleoconch.