Alvania zetlandica ( Montagu, 1816 )

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 zetlandica ( Montagu, 1816)

( Fig. 7 )

Material examined. (9 empty shells and 10 with soft parts, in 11 samples): SPAIN • 1 sPc (juv) + 2 sh; 43° 48.421′N, 008° 51.453′W to 43° 49.160′N, 008° 51.091′W; 599–607 m; 10–20 SeP. 2003; DIVA-Artabria I DRN-600 • 6 spc (4 juv) + 12 sh (4 juv); 43° 48.587′N, 008° 51.402′W to 43° 49.545′N, 008° 51.197′W; 610– 598 m; 10–20 SeP. 2003; DIVA-Artabria I EBS-600 • 1 sh; 43° 51.873′N, 008° 53.683′W to 43° 53.120′N, 008° 53.301′W; 802– 788 m; 10–20 Sep. 2003; DIVA-Artabria I EBS-800 • 1 sPc; Polygon delimited by Points 44° 10.000′ N, 009° 00.000′ W /44° 10.000′ N, 008° 35.000′ W/44° 00.000′ N; 009° 00.000′ W/44° 07.000′ N; 008° 35.000′ W; 480–600 m ; SARRIDAL (2006–2007) SARRI-2 • 1 sPc; Polygon delimited by Points 44° 10.000′ N, 009° 00.000′ W /44° 10.000′ N, 008° 35.000′ W/44° 00.000′ N; 009° 00.000′ W/44° 07.000′ N; 008° 35.000′ W; 417–668 m; SARRIDAL (2006–2007) SARRI-4 • 6 sh; 44° 11.652′N, 008° 58.152′W to 44° 11.539′N, 008° 57.574′W; 908–1106 m; 15–24 Jul. 2008; A SELVA DRN-7 • 25 sh; 44° 08.65′N, 008° 55.305′W to 44° 08.771′N, 008° 55.104′W; 581– 566 m; 15–24 Jul. 2008 ; A SELVA DRN-7 C • 2 sh; 44° 09.896′N, 008° 39.581′W to 44° 10.129′N, 008° 39.494′W; 438–459 m; 15–24 Jul. 2008 ; A SELVA DRN-11 • 1 sPc; 44° 07.309′N, 008° 48.289′W to 44° 07.488′N, 008° 48.047′W; 445– 438 m; 15–24 Jul. 2008; A SELVA DRN-11-5 • 1 sh; 44° 07.495′N, 008° 46.999′W to 44° 07.675′N, 008° 45.225′W; 416– 407 m; 15–24 Jul. 2008 ; A SELVA AT-11-2 • 1 sPc; 4211.73′N, 009° 26.19′W to 42° 11.73′N, 009° 25.63′W; 445– 326 m; 14–25 Feb. 2009 ; FORSAGAL DRC-6.

Remarks. It is a common species of the continental slope in the north Atlantic, from Norway to Cape Verde Islands and in the Canary Islands ( Bouchet & Warén 1993; Hoenselaar & Goud 1998; Hoffman et al. 2011), also present in the western Mediterranean ( Gofas & Oliver 2011). Shells with soft parts were found in samples from 350 to 600 m in sandy bottoms, and some empty shells down to 1000 m depth. The strong sculpture of the shells forms knobs at the intersection of axial ribs and spiral cords ( Fig. 7a ). Microsculpture of indistinct granulose spiral threads closely spaced ( Figs. 7e–g ). Multispiral protoconch sculptured with irregular dashes forming spiral threads adapically ( Figs. 7b–c ). Embryonic protoconch exhibiting a delightful reticular sculpture ( Fig. 7d ).

Figures

FIGURE 7. Alvania zetlandica (Montagu, 1815) (SA: SARRI-2). a Shell (2.9 mm); b Protoconch; c Detail of the protoconch/ teleoconch transition; d Detail of the microsculpture of the embryonic protoconch; e–f–g Details of the microsculpture of the teleoconch.