Hydrobia neglecta

Muus, 1963

Description (shell):
Shell more slender than in Ventrosia ventrosa , with apex less sharp, whorls less tumid; spire slightly cyrtoconoid in profile (H. neglecta-drawing).

Up to 4 x 1.5 mm.

Empty shell is brownish or grey, living ones seem nearly black.

Body differs from Hydrobia ulvae and Ventrosia ventrosa in tentacle pigmentation, with black pigment in cone-shaped areas set less than their own length away from tentacle tips;H. ulvae has rings of pigment,H. ventrosa has, at most, a darkish streak on dorsal surface near the tip. The structure of the penis may also be used to distinguish H. neglecta; it lacks the flagellum of H. ventrosa , and the recurved anterior end is angulate rather than smoothly sickle-shaped as inH. ulvae.

Habitat similar to that of Ventrosia ventrosa , though appears to be less tolerant of salinities below 10 รค and seems to favour the presence of Potamogeton and Zostera.

First described in 1963 and subsequently recorded from North Sea coasts (Distr. H. neglecta), Guernsey, and the western coasts of Scotland and Ireland.