Marine Species Identification Portal : Alvania subsoluta

(Aradas, 1847)

Description (shell):
Shell very similar to that of the other Alvania species but the costae and outer lip are orthocline and the diameter of the protoconch exceeds 400 µm (A. subsoluta-protoconch). Whorls without peripheral flattening. The shell is semitransparent and has about five whorls. Last whorl occupies 66 % of shell height, aperture 40 %. The numbers of costae and of spiral ridges are so similar to those of Alvania abyssicola that they cannot be used as diagnostic features. A. subsoluta can usually be separated from Alvania abyssicola on the basis of the direction in which costae and outer lip lie, the angle of the latter to the shell axis in particular being very different in the two species.

Size:
Up to 3.5 x 2 mm.

Colour:
White or cream (A. subsoluta-photo;A. subsoluta-variations).

Habitat:
Animals recorded in British Isles are collected from muddy bottoms at depths of about 200 m.

Distribution:
Not only rare but it is restricted in distribution. It has been found between the Mediterranean and the north of Norway (Distr. A. subsoluta).

Alvania subsoluta