Marine Species Identification Portal : Nassarius incrassatus

(Ström, 1768)

Description (shell):
Shell solid, tall, conical, with up to eight tumid whorls; periostracum confined to grooves between striae. Sculpture of strong, slightly flexuous costae, strap-like spiral striae, and fine growth lines. Costae more prominent than spiral striae on all whorls, 12-15 on whorls of spire; last whorl with strong labial varix. Penultimate whorl with eight to ten spiral striae; without marked reticulation. A deep spiral channel runs from base of siphonal canal to umbilical region of columella, below it a boss with up to 12 thin spiral striae. Aperture oval, with slight anal sinus and short, deep, markedly oblique siphonal canal. Outer lip arises at about 45° to last whorl, curving without inflection to tip of siphonal canal; thickened internally in mature shells, with seven teeth below labial varix. Inner lip spread widely over parietal region of last whorl; toothed or ridged in both columella and parietal regions in mature shells (N. incrassatus-drawing).

Size:
Up to 12 x 6 mm.

Colour:
Buff or light tan, often with brown bands below sutures and at base of last whorl; labial varix and columella white, siphonal canal with dark brown mark on roof.

Animal:
Like that of Nassarius reticulatus , yellowish with black speckling, mainly on the siphon and foot.

Habitat:
Common near LWST in silted areas of rocky shores, below stones and in crevices; more abundant in shallow sublittoral, extending to 200 m.

Distribution:
Distributed from Mediterranean to northern Norway and Iceland; common in the North Sea (Distr. N. incrassatus).

Nassarius incrassatus