Revision of deep-water species in Granulina (Gastropoda: Granulinidae) from Mauritania and Western Sahara Author Elm, Laura-Marie Von 9FB99C0B-AA0A-4AA8-8465-1EAFCC65B366 Thüringerstrasse 3, 26180 Rastede, Germany. laura-marievonelm@kabelmail.de Author Hoffman, Leon E2B27F54-29C5-46AA-9437-ABA84D54DDF3 Senckenberg am Meer, Südstrand 40, 26382 Wilhelmshaven, Germany. leon.hoffman@senckenberg.de text European Journal of Taxonomy 2024 2024-03-18 925 268 291 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2467/10969 journal article 10.5852/ejt.2024.925.2467 2118-9773 10837829 B09375C0-6E28-4E2D-BB7C-26E1753171E2 Granulina crassa Smriglio, Gubbioli & Mariottini, 2000 Figs 1 , 3 Granulina crassa Smriglio, Gubbioli & Mariottini, 2000: 55 , figs 2, 9–12; type locality: off Mauritania , 80– 100 m . Smriglio et al . (2000) reported 14 type specimens, of which some empty shells from off Mauritania ( 80– 100 m ) and off Western Sahara ( 50 m ) without further details. The holotype was deposited in Bologna Zoology Museum (MZB14030). Thirteen paratypes were retained in private collections. Material examined (509 shells) MAURITANIA – Banc d’Arguin • 5 shells; 20.3667° N , 17.6667° W ; depth 200 m ; 28 Oct. 1978 ; CANCAP stn 3.120; sandy clay with shells; van Veen grab; RMNH .MOL.351803 • 12 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.351804 • 3 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.351805 • 28 shells ; 19.35° N , 16.9333° W ; depth 200 m ; 31 Oct. 1978 ; CANCAP stn 3.154; sandy clay with shells; van Veen grab ; RMNH.MOL.351806 • 60 shells; 19.94° N , 17.48° W ; depth 151 m ; 22 May 1988 ; Tyro Mauritania I stn B5; SaM • 2 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 • 40 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 • 1 shell; Baie du Levrier ; 20.8169° N , 17.0186° W ; depth 13 m ; 31 Oct. 2010 ; MSM16– 3 stn GeoB14780; bottom grab in muddy silt; SaM • 1 shell; southern Banc d'Arguin ; 19.7967° N , 17.2034° W ; depth 105 m ; 6 Nov. 2010 ; MSM16–3 stn GeoB14850; box core in muddy silt; SaM . – Timiris mud wedge • 2 shells; 19.5506° N , 16.9731° W ; depth 100 m ; 8 Nov. 2010 ; MSM16– 3 stn GeoB14866; box core in silty sand; SaM . – Banda Mound Complex • 1 shell; 17.6699° N , 16.6736° W ; depth 505 m ; 14 Nov. 2010 ; MSM16–3 stn GeoB14898; bottom grab in muddy silt; SaM . – off Nouakchott • 3 shells; 17.045° N , 16.7783° W ; depth 202 m ; 11 Feb. 1977 ; M44 stn 133–KG613; box core; SMF • 5 shells ; 17.045° N , 16.7783° W ; depth 208 m ; 11 Feb. 1977 ; M44 stn 133–KG615; box core; SMF • 1 shell ; 17.0817° N , 16.775° W ; depth 312 m ; 12 Feb. 1977 ; M44 stn 135–KG625; box core; SMF • 25 shells ; 17.0967° N , 16.73° W ; depth 127 m ; 17 Feb. 1977 ; M44 stn 193–KG626; box core; SMF • 5 shells ; 17.0967° N , 16.73° W ; depth 126 m ; 17 Feb. 1977 ; M44 stn 193–KG627; box core; SMF • 72 shells; off Nouakchott ; 17.2783° N , 16.4483° W ; depth 87 m ; 13 Feb. 1982 ; M60 stn 77–KG960; box core; SMF • 85 shells ; 17.2783° N , 16.4483° W ; depth 88 m ; 13 Feb. 1982 ; M60 stn 77–KG961; box core; SMF • 55 shells ; 17.2783° N , 16.4483° W ; depth 87 m ; 13 Feb. 1982 ; M60 stn 77–KG965; box core; SMF . 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 WESTERN SAHARA – off Cap Blanc • 62 shells; 21.325° N , 17.37° W ; depth 81 m ; 25 Feb. 1977 ; M44 stn 235–KG649; box core; SMF • 1 shell; 21.7683° N , 17.4333° W ; depth 125 m ; 20 Feb. 1982 ; M60 stn 88–KAD268; SMF . – North of Dakhla • 39 shells; 25.0000° N , 15.5167° W ; depth 53 m ; 21 Feb. 1975 ; M36 stn 94–KG2; box core; SMF • 1 shell ; 25.18333° N ; 15.80333° W ; depth 87 m ; 22 Feb. 1975 ; M36 stn 95–KG6; box core; SMF . Remarks Smriglio et al . (2000) indicated a holotype height of 1.9 mm ; our set indicates a maximum height of 2.1 mm . The species is the smallest member of the four coffin-shaped species from Mauritania . It has very weak labial denticles that occasionally may be absent, even though these specimens may be subadult. Granulina crassa lacks an (ab-)apical rostration. The species is known from empty shells in the latitudinal range 17.0– 25.2° N . The full bathymetric range is 13–505 m ; it is commonly found on the lower shelf at depths of 80–210 m in silty sand.