Velutina schneideri Friele, 1886,

Phylum:Mollusca Linnaeus, 1758
Class:Gastropoda Cuvier, 1795
Order:Littorinimorpha Golikov & Starobogatov, 1975
Family:Velutinidae Gray, 1840
Genus:Velutina Fleming, 1820

Description. Shell broadly ear-shaped, with 2.5 convex rounded whorls and deeply impressed suture. Spire projects slightly above last whorl. Protoconch one-whorled, uncovered by periostracum. Last whorl moderately convex. Peri¬ostracum yellow or light brown, less developed than calcareous layer, occasion¬ally obsolete on spiral surface. Sculpture of frequently disposed growth lines crossing spiral ribs. The latter not only present on periostracum but also on calcareous layer. Riblets vary greatly in number and frequency. Last whorl usually with 12-22 riblets with intervals near shell edge exceeding their width by 2-4 times. Aperture roundly oval, with thickened edge because of periostracum. Calcareous lining of aperture bluish-white, opaque.
Measurements. Largest seen specimen: height 8.8 mm, length 15.5 mm, width 13.5 mm.
Remarks. - Because of great variability most investigators consider this species synonymous with V. (V.) velutina. In typical V.(V.) schneideri, riblets are delicate and disposed at intervals 4-5 times their width and not exceeding 20 in number; occasionally they are not well developed. Specimens morphologically similar to V.(V.) velutina have wider riblets, and intervals exceed the width 2-3 times. Periostracum usually is better developed. The shape of penis easily distinguish the species. In V.(V.) schneideri it is wide and flattened at the base, terminating into a pointed long flagellated appendage. In V.(V.) velutina, penis is in form of a broad cylinder bordered by wide folds at the end.
Distribution. Greenland, the Norwegian, Barents, Kara, Laptev and East Siber¬ian Seas as well as North Kurile Strait. Since many authors unite V. (V) schneideri with V.(V.) velutina, the area of distribution of V.(V.) schneideri given in the present paper is apparently provisional.
Ecology. The species occurs at depths from 7 to 350 m, most common at 100¬150 m, and prefering muddy sand with stone substrata.



Literature

  • 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

Author: Zakharov Denis V. / 13.02.2017
Last edit: Zakharov Denis V. / 07.03.2017

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