Granulina crystallina Smriglio, Gubbioli & Mariottini, 2000

Elm, Laura-Marie Von & Hoffman, Leon, 2024, Revision of deep-water species in Granulina (Gastropoda: Granulinidae) from Mauritania and Western Sahara, European Journal of Taxonomy 925, pp. 268-291 : 276

Granulina crystallina Smriglio, Gubbioli & Mariottini, 2000

Figs 1 , 2E

Granulina crystallina Smriglio, Gubbioli & Mariottini, 2000: 55 , 58, figs 3, 13–16; type locality off Mauritania (80–90 m).

Smriglio et al. (2000) reported 22 specimens, of which some empty shells from off Mauritania (80–90 m) without further details. The holotype was deposited in the Bologna Zoology Museum (MZB14031). Twenty-one paratypes were retained in private collections.

Material examined (48 shells)

MAURITANIA – off Banc d’Arguin • 11 shells; 20.3667° N, 17.6667° W; depth 200 m; 28 Oct. 1978; CANCAP stn 3.120; sandy clay with shells; van Veen grab; SaM • 3 shells; 18.9833° N, 16.8333° W; depth 203 m; 30 Oct. 1978; CANCAP stn 3.140; sandy clay with shells; van Veen grab; RMNH.MOL.351807 • 7 shells; Arguin mud wedge ; 20.4569° N, 17.6795° W; depth 142 m; 24 Oct. 2010; MSM16 –3 stn GeoB14706; box core in muddy silt; SaM; box core in muddy silt; SaM • 1 shell; 19.94° N, 17.48° W; depth 151 m; 22 May 1988; Tyro Mauritania I stn B5; RMNH.MOL.351808. – off Nouakchott • 1 shell; off Nouakchott; 17.0967° N, 16.73° W; depth 127 m; 17 Feb. 1977; M44 stn 193–KG626; box core; SMF • 3 shells; 17.045° N, 16.7783° W; depth 199 m; 11 Feb. 1977; M44 stn 133–KG616; box core; SMF .

WESTERN SAHARA – off Cap Blanc • 22 shells; 21.325° N, 17.37° W; depth 81 m; 25 Feb. 1977; M44 stn 235–KG649; box core; SMF .

Remarks

Smriglio et al. (2000) indicated a holotype height of 2.4 mm; our set indicates a maximum height of 3.1 mm. The species is a largest member of the four coffin-shaped species from Mauritania. It has weak labial denticles, a clear angular outline and it shows a weak (ab-)apical rostration.

The species is known from empty shells in the latitudinal range 17.0– 21.4° N. It is commonly found on the lower shelf at depths of 52–210 m in silty sand.

Figures

Fig. 1. Location map of the known species of Granulina Jousseaume, 1888 found off Mauritania and Western Sahara. All investigated stations are shown by white circles; specimens of Granulina were only found at locations indicated by colour symbols. Granulina cerea Smriglio, Gubbioli & Mariottini, 2000 is presented as yellow squares, G. crassa Smriglio, Gubbioli & Mariottini, 2000 as red diamonds, G. crystallina Smriglio, Gubbioli & Mariottini, 2000 as blue triangles and G. nofronii Smriglio, Gubbioli & Mariottini, 2000 as green circles. Bathymetric data from GEBCO, contours at 500 m intervals.

Fig. 2. Granulina Jousseaume, 1888 from Mauritania. A–D. Granulina cerea Smriglio, Gubbioli & Mariottini, 2000, off Banc d’Arguin, CANCAP/3.120. A–B. Shell. A. Ventral view, height 2.8 mm, width 1.7 mm. B. Micro-sculpture above second columellar fold, see arrow in A. C–D. Shell, ventral view and side view, height 2.6 mm, width 1.6 mm, tumidity 1.3 mm. E. Granulina crystallina Smriglio, Gubbioli & Mariottini, 2000, off Nouakchott, M44/193–KG626, ventral view, height 3.1 mm, width 2.0 mm. F–G. Granulina nofronii Smriglio, Gubbioli & Mariottini, 2000, MSM16–3/GeoB14714. F. Ventral view, height 2.3 mm, width 1.4 mm. G. Ventral view, height 2.5 mm, width 1.6 mm