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).
Size:
Up to 4 x 1.5 mm.
Colour:
Empty shell is brownish or grey, living ones seem nearly black.
Animal:
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:
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.
Distribution:
First described in 1963 and subsequently recorded from North Sea coasts (Distr. H. neglecta), Guernsey, and the western coasts of Scotland and Ireland.