Hydrobia ulvae

Hydrobia ulvae 50 cm.
Made for FIMUS.

Supervised by Kathe Rose Jensen, SNM.

The Laver Spire Shell or Mudsnail, is a European species of very small aquatic snail with gills and an operculum, a gastropod mollusk in the family Hydrobiidae. This species occurs on the coasts of the Baltic Sea, the White Sea the Eastern Atlantic and the western Mediterranean Sea. It has a deep brown colour, the opening is oval, and it is the size of a wheat grain. As you can see, the shell has 5-7 very weakly convex whorls, that are regularly increasing but not always regularly rounded. The lip is attached to the last whorl. The width of the shell is 2.5–3 mm, and the height is 4-5.5 mm. Hydrobia ulvae is a widespread and abundant member of the benthic fauna of estuarine habitats and coastal brackish and salt waters, and is very common in brackish water and saltwater, in estuaries and salt marshes, where it tolerates salinity 1.0-3.3 %.