Description: As with all members of family Nassariidae (Dogwhelks or nassa mud snails), the coiled shell has a well-developed spire and a siphonal notch or canal but no anal notch (though this species has a narrow posterior notch near where the anal notch would be found). The outer shell is not highly polished and is usually sculptured. The widest part of the aperture is less than half the diameter of the shell. Has a horny operculum. The lowermost portion of the body whorl, including the siphonal canal, is set off from the rest of the shell by a deep groove and upturned for most species in the family (see photos above and below). Both axial ribs and spiral ridges are well developed on Hima mendica shells, creating a beaded appearance where they overlap. The axial ribs are larger than the spiral ridges. These beads are not evenly spaced. The outside of the shell is grayish-brown, often with one or more darker brown spiral bands (see above), and the inside of the shell is white without an orange callus. The 12 axial ribs are larger than the spiral ridges and extend all the way to the groove at the base of the body whorl. Shell length to about 2.2 cm and more slender than most other family members such as N. fossatus. Has about 8 whorls. Animal body is yellow or white, with a very long, extended siphon and pinpoint black eyes on long tentacles. The foot and siphon of at least this individual have a yellow or orange tinge.
How to Distinguish from Similar Species:Illyanassa obsoleta does not have the deep groove at the anterior end of the body whorl. Several Nassarius species have more than 20 axial ribs which are about the same size as the spiral ridges.
Geographical Range: Kodiak Island, Alaska to Isla Ascuncion, Baja California
Depth Range: Intertidal to 75m
Habitat: Sand, mud, rocks.
roving scavenger snails have a very long siphon.
Hermit crabs often inhabit their shells after the snail dies. On muddy
bottoms it pushes its way through the sediment with its long siphon
extended upwards into the water.
Kozloff, 1987, 1996 (As Nassarius mendicus)
General Notes and Observations: Locations, abundances, unusual behaviors:
Authors and Editors
Salish Sea Invertebrates web site provided courtesy of Walla