Velutina velutina (O. F. Müller, 1776),
|Phylum:||Mollusca Linnaeus, 1758|
|Class:||Gastropoda Cuvier, 1795|
|Order:||Littorinimorpha Golikov & Starobogatov, 1975|
|Family:||Velutinidae Gray, 1840|
|Genus:||Velutina Fleming, 1820|
|Synonyms:||Velutina laevigata (O. F. Müller, 1777), Velutina laevigata (Linnaeus, 1758)|
Description. - Shell with 3 convex rounded whorls, deeply impressed suture and well developed calcareous layer and periostracum. Upper part of spire projects slightly above inflated last whorl which occupies almost entire shell. Protoconch small, white, uncovered by periostracum. Periostracum fibrous, yellowish or brown, tightly adherent to shell forming closely spaced discontinuous spiral crests. Intervals between crests are equal to or 2 times the crest thickness. Adult individuals with 22-30 crests on last whorl. Sculpture on calcareous layer of ir¬regular growth lines crossing spiral riblets. The ribs correspond to crests on per¬iostracum. Aperture broad, almost rounded, opaque-white on inside. Inner lip slightly turned back on outside.
Measurements. - Largest seen specimen: height 15 mm, length 26 mm, width 20 mm.
Remarks. - The species is separated from the closely related V. (V.) schneideri by a more strongly developed periostracum structure with 22-30 spiral crests on last whorl.
Distribution. - In the Arctic Region the species is circumpolar. In the Pacific it occurs in the Bering and northern parts of Okhotsk and Japan Seas as well as Gulf of Alaska. In accordance with MacGinitie (1959), the species is found in Monterey Bay (California) and in the Atlantic Ocean it is distributed to Cape Hatteras and Portugal.
Ecology. - The species occurs at depths from 0.5 to 408 m, most common at 20 to 150 m on mud, gravel and pebble mixture and muddy sand substrata, often in Laminaria and other algae as well as on ascidians.
- Gulbin V.V., Golikov A.N. A review of the prosobranch family Velutinidae in cold and temperate waters of the Northern Hemisphere. III. Velutininae. Genera Ciliatovelutina and Velutina