Obtusella intersecta (S. Wood, 1857 )

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 : 30

Obtusella intersecta (S. Wood, 1857)

( Fig. 18 )

Material examined. (46 empty shells and 29 with soft parts, in 9 samples): SPAIN • 1 sPc + 1 sh; 43° 40.192′N, 008° 43.760′W to 43° 40.943′N, 008° 42°.366′W; 207–212 m; 08–15 SeP. 2002; DIVA-Artabria I EBS-200 • 1 sh; 43° 26.703′N, 008° 30.669′W to 43° 27.452′N, 008° 29.612′W; 103– 102 m; 10–20 SeP. 2003; DIVA-Artabria I EBS-100 • 5 sh; 43° 29.412′N, 008° 28.362′W to 43° 29.779′N, 008° 28.240′W; 110–111 m; 17–28 SeP. 2004; VERTIDOS GA-AT-110 • 1 sPc; 43° 32.026′N, 008° 37.520′W to 43° 32.806′N, 008° 35.993′W; 150–151 m; 17–28 SeP. 2004; VERTIDOS GA-AT-150 • 25 sPc + 15 sh; 42° 30.391′N, 009° 19.517′W to 42° 29.428′N, 009° 17.924′W; 147–148 m; 17–28 Sep. 2004; VERTIDOS AG-EBS-150 • 1 sPc; 42° 29.455′N, 009° 17.472′W to 42° 31.292′N, 009° 19.660′W; 149– 147 m; 17–28 SeP. 2004; VERTIDOS AG-AT-150 • 2 sh; 42° 31.176′N, 009° 23.380′W to 42° 32.132′N, 009° 24.151′W; 242–248 m; 17–28 SeP. 2004; VERTIDOS AG-EBS-250 • 1 sPc + 2 sh; 42° 15.780′N, 009° 10.500′W to 42° 17.100′N, 009° 10.630′W; 149–150 m; 17–28 SeP. 2004; VERTIDOS CH-EBS-150 • 20 sh; 43° 58.84′N, 008° 15.625′W to 43° 59.621′N, 008° 14.285′W; 233–237 m; 15–24 Jul. 2008; A SELVA EBS-20 .

Remarks. This species is common in the outer part of the continental shelf off Europe from Iceland and Norway to Morocco (absent from the Baltic and eastern shores of North Sea) and the Mediterranean Sea ( Bouchet & Warén 1993; Gofas & Oliver 2011).

Shells with soft parts were found in samples from 147 to 212 m and were specially abundant in the sample AG-EBS-150 collected at 150 m in a muddy sand bottom. These shells were very small, just over 1 mm, and globose ( Figs. 18a, d ). Sculpture of closely spaced spiral striations crossed by growth lines ( Fig. 18c ). Flattened protoconch ( Figs. 18b, e ). High magnification reveals minute spirals in the embryonic whorl ( Figs. 18f–g ).

Figures

FIGURE 18. Obtusella intersecta (S.V. Wood,1857) (VE:AG-EBS-150). a–c Shell (1.0 mm), lateral view of its protoconch and microsculpture of the teleoconch; d–e Shell (0.9 mm) and microsculpture of its protoconch; f–g Embryonic protoconch and detail of its microsculpture.