Odostomia acuta

Jeffreys, 1848

Description (shell):
Shell a regular pointed cone, straight-sided in profile. There are 5-6 postlarval whorls, which are slightly swollen, each with a small subsutural shelf. Last whorl commonly angulated at the periphery (occupies about 60 % of the shell height). Sutures are channelled. Growth lines are nearly straight and only slightly prosocline. In a few shells spiral ridges occur in the throat under the outer lip. Aperture is a broad oval, not usually much flared at the base (occupies about 35-40 % of the shell height). The outer lip is slightly prosocline and a little flexuous. Umbilical groove is deep, umbilicus distinct. A prominent tooth arises at the very edge of the peristome at the level of the umbilicus.

Size:
Up to 5.5 x 2.75 mm.

Colour:
White or cream, sometimes tinged with brown or pink.

Animal:
The animal has rather stout, short tentacles with large eyes between their bases. The mentum is long, its lateral edges turning dorsally to form the sides of a groove which supports the proboscis when everted. There is a prominent tubular process on the extreme right of the mantle skirt. The front of the foot shows a medial bay and short lateral points; its posterior end is bluntly rounded. Pale cream with reddish brown marks on the mentum, the anterior end of the foot and its sides, as well as on the right projection of the mantle; tentacles pale.

Habitat:
The animals are not intertidal and live 20-80 m deep, perhaps with bryozoans.

Distribution:
Occurs in the Black Sea, the Mediterranean, and off European coasts as far north as the Lofoten Islands. Not in the southern North Sea (Distr. O. acuta).

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