Granulina cerea 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 : 270-271

Granulina cerea Smriglio, Gubbioli & Mariottini, 2000

Figs 1 , 2A–D

Granulina cerea Smriglio, Gubbioli & Mariottini, 2000: 54–55 , figs 1, 5–8; type locality: off Mauritania.

The holotype was deposited in the Bologna Zoology Museum (MZB14033). Smriglio et al. (2000) reported four shells from off Mauritania without further location details. Three paratypes were retained in private collections.

Material examined (388 shells)

MAURITANIA – off Banc d’Arguin • 5 shells; 18.9833° N, 16.8333° W; depth 203 m; 30 Oct. 1978; CANCAP stn 3.140; sandy clay with shells by van Veen grab; RMNH.MOL.351801 • 9 shells; 19.35° N, 16.9333° W; depth 200 m; 31 Oct. 1978; CANCAP III stn 3.154; sandy clay with shells; van Veen grab; RMNH.MOL.351802 • 89 shells; 19.94° N, 17.48° W; depth 85–151 m; 22 May 1988; Tyro Mauritania I stn B5; dredge; SaM • 4 shells; Arguin mud wedge; 20.2353° N, 17.6029° W; depth 111 m; 24 Oct. 2010; MSM16-3 stn GeoB14703; box core in muddy silt; SaM • 1 shell; Baie du Levrier ; 20.8801° N, 16.9922° W; depth 14 m; 31 Oct. 2010; MSM16–3 stn GeoB14782; box core in muddy silt; SaM • 4 shells; Arguin South 3 Canyon ; 19.7381° N, 17.1465° W; depth 483 m; 7 Nov. 2010; MSM16–3 stn GeoB14858; bottom grab; SaM. – Timiris Mud wedge • 1 shell; 19.5117° N, 16.8618° W; depth 52 m; 8 Nov. 2010; MSM16–3 stn GeoB14865; box core in muddy silt; SaM • 2 shells; 19.5506° N, 16.9731° W; depth 100 m; 8 Nov. 2010; MSM16–3 stn GeoB14866; box core in silty sand; SaM. – off Nouakchott; SMF • 61 shells; 17.045° N, 16.7783° W; depth 202 m; 11 Feb. 1977; M44 stn 133–KG613; box core; SMF • 43 shells; 17.045° N, 16.7783° W; depth 208 m; 11 Feb. 1977; M44 stn 133–KG615; box core; SMF • 108 shells; 17.045° N, 16.7783° W; depth 199 m; 11 Feb. 1977; M44 stn 133–KG616; box core; SMF • 46 shells; 17.0967° N, 16.73° W; depth 127 m; 11 Feb. 1977; M44 stn 193–KG626; box core; SMF • 3 shells; 17.0967° N, 16.73° W; depth 126 m; 11 Feb. 1977; M44 stn 193–KG627; box core; SMF • 2 shells; 17.0967° N, 16.73° W; depth 124 m; 17 Feb. 1977; M44 stn 193–KG629; box core; SMF .

WESTERN SAHARA – North of Dakhla • 2 shells; 25.1833° N, 15.8033° W; depth 87 m; M36 stn 95–KG6; 22 Feb. 1975; box core; SMF .

Remarks

Smriglio et al. (2000) indicated a shell height of 2.3 mm; the shells in our material show a height range for adult shells of 2.3–2.8 mm. The species is a member of the four coffin-shaped species from Mauritania. It has weak labial denticles, an angular outline and it lacks an (ab-)apical rostration.

All species reported by Smriglio et al. (2000) as well as all other NE Atlantic and Mediterranean species investigated in this study show a micro-sculpture (ab-)apically, near the columellar folds, the parietal area and the outer lip. Smriglio et al. (2000) stated that his specimens did not show any micro-sculpture, even at high magnification using a SEM. We note that the outline of a micro-sculpture is visible in some of their SEM images and colour photographs.

The species is known from empty shells in the latitudinal range between 17.0° N and 25.2° N. The full bathymetric range is 14–483 m; it is commonly found on the lower shelf at depths of 80–210 m in silty sand.

Gofas (1992: fig. 14) shows a small (height 2.15 mm) specimen from a depth of 50 m off Gorée Island ( Senegal) under the name Granulina sp. which could belong to G. cerea . If confirmed, then this would extend the southern distribution range significantly.

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