Alvania canariensis ( d’Orbigny, 1840 )

Amati, Bruno, Appolloni, Massimo, Giulio, Andrea Di, Scuderi, Danilo, Smriglio, Carlo & Oliverio, Marco, 2020, Revision of the Recent Alvania scabra (Philippi, 1844) complex (Mollusca, Gastropoda Rissoidae) from the Mediterranean Sea with the description of a new species, Zootaxa 4767 (3), pp. 415-458 : 446-447

Alvania canariensis ( d’Orbigny, 1840)

( Figs 19A, B and E, F, K )

Rissoa canariensis d’Orbigny, 1840: 78 , pl. 6, figs 5–7

Other references.

Alvania canariensis ; Ponder, 1985: 140, fig. 91H; Moolenbeek & Hoenselaar, 1989: 216, 226, figs 1, 2 and figs 15-17; Albuquerque et al., 2009: 129, 4 unnumbered figs; Perna, 2013: 55, 2 unnumbered figs.

Type Material. Lectotype NHMUK 1854.9 .28.74 ( Moolenbeek & Hoenselaar, 1989: 216), type locality: Santa Cruz, Tenerife Is. (Canary Islands).

Material examined. Madeira: 4 sh (MO). Savage Islands: (Selvagem Pequena) Gran Piton, intertidal, ii.1975, 37 sh (BA). Canary Islands: (Tenerife) Candelara la Caleta, tidal pools, iii.1987, 122 sh (BA), Punta de Teno, 1 m depth 10 sh ( JT, JDO), 1977, 64 sh (MO); Los Gigantes, 10-35 m depth, xii.1994, 26 sh ( CS-PM); (Lanzarote) Playa del Pozo 1 m depth, 13.viii.1984, 4 sh (BA), Famara, beached: 5 sh ( JT, JDO); (Gran Canaria) Arguineguin, 29 m depth, vii.1985, 68 sh (BA); (La Gomera) intertidal, 31 sh (BA); (La Palma) Playa Salema, beached, 10 sh ( JT, JDO); (El Hierro) Mar de las Calmas, 10 m depth 10 sh ( JT, JDO); no further data, 6 sh (Monterosato coll. ex Mac Andrew coll., MCZR-M-22174).

Distribution. Known from Madeira, Savage Islands and Canary Islands.

Remarks. It is diagnosed in the Alvania scabra -complex by the more robust shell than in other species, the very convex and angled whorls, the robust labial varix, the large tubercles at the intersections, and the dark-colored protoconch nucleus (never this way in all other species).

Three shells from Gando Bay (Gran Canaria) (BA, MO) are somehow outliers in having a more slender and less angulate outline, a more delicate sculpture, smaller and less elevated tubercles at the intersections. Pending the availability of more material, we cannot decide if they represent a distinct species ( Figs 19 C-D). A shell in the Monterosato collection (ex Mac Andrew coll., MCZR-M-22174) ( Fig. 19E, F, K ) probably from Canary Islands, clearly differs from the most common A. canariensis morphotype (i.e. marked colouration, dark apex, tubercles less acute) by its very weak colouration with faded subsutural blotches, white apex with the coloured suture, and the acute tubercles. Pending more material, we also include this specimen within the rather wide range of variation of A. canariensis .

Historically A. canariensis has erroneously been reported as present in the Mediterranean Sea (e.g. Monterosato, 1872: 36; 1874: 262; 1875: 27; 1877: 35; 1878: 85). Some of these specimens have been checked in the Monterosato collection (MCZR) and have been identified as A. scabra and A. lucinae . More recently, Ponder (1985) erroneously reported A. scabra as present at Madeira, but it was actually a specimen of A. canariensis .

Figures

FIGURE 19. Alvania spp. A, B. Alvania canariensis (d’Orbigny, 1840), Candelara la Caleta, Tenerife, Canary Island (Spain), height 2 mm (BA). C, D. Alvania sp. aff. canariensis (d’Orbigny, 1840), Gando Bay, Gran Canaria, Canary Islands (Spain), height 1. 85 mm (BA). E, F. Alvania canariensis (d’Orbigny, 1840), Monterosato coll. ex Mac Andrew coll., MCZR-M-30074, Canary Islands (Spain), height 1.8 mm with original label. G, H. Alvania angioyi vanAartsen, 1982, Biscoitos, Terceira (Azores), 1 m depth, height 1.7 mm (JT, JDO). I–K. Alvania sp., Monterosato coll. ex Mac Andrew coll., MCZR-M-30074, Azores, height 2 mm. L–P. Alvania grancanariensis Segers, 1999, Maspalomas, Gran Canaria, Canary Islands (Spain) height 1.7 mm (L: JT, JDO), 1.7 mm (M: JT, JDO), 1.85 mm (N–P: JT, JDO).