Euspira pallida (Broderip & Sowerby, 1829)

Common name(s): Pallid moon snail, closed moon snail, northern moon shell, pale northern moon snail

Synonyms: Lunatia pallida, Polinices palidus, Natica clausa     Euspira pallida
Phylum Mollusca 
Class Gastropoda 
Order Mesogastropoda 
Suborder Taenioglossa 
Euspira pallida, about 1.5 cm shell height, caught by otter trawl at 80 m depth in San Juan Channel. Was occupied by a hermit crab.
(Photo by: Dave Cowles )

Description:  As with all moon snails, this shell is round and bulbous. In this species the umbilicus is open into just a slight slit (photo) (or sometimes absent) and the operculum is thin, horny, and translucent brown. The snail has 4 or 5 whorls at its maximum size of about 5 cm height. Color gray-brown, cream, or whitish. According to Harbo (1997) the operculum is calcarious. The snail's partly translucent body is cream-colored with dark brown spots and blotches. While still globular like a moon snail, it is slightly less spherical and its spire is slightly more pointed that that of Polinices lewisii.

How to Distinguish from Similar Species:  Natica clausa has a closed umbilicus and is browner (some consider it the same species). Polinices lewisii gets well above 5 cm height, is cream-colored, pink, or beige, has 5-6 whorls, and the umbilicus is completely covered with a large callus that spreads over much of the columella region of the body whorl.

Geographical Range:  Circumpolar in the Arctic Ocean; in the NE Pacific extends southward to northern California.

Depth Range:  Subtidal down to 2000 m.

Habitat:  Sandy bottoms.

Biology/Natural History:  Although moon snails can close up completely within their shells, they can also expand very greatly until their body, several times larger than the shell, wraps around the shell like a snowplow as they push their way through the sand searching for bivalve prey. Moon snails also lay their eggs in a distinctive, curled collar leading to the name "necklace snail" in England. The egg mas of this species has tiny protuberances.



Dichotomous Keys:
  Kozloff, 1987, 1996

General References:
  Byersdorfer and Watson, 2010
  Harbo, 1997
  Lamb and Hanby, 2005
  Morris, 1966 (as Polinices pallidus)

Scientific Articles:

Web sites:

General Notes and Observations: Locations, abundances, unusual behaviors:

A view of the nearly sealed umbilicus, plus the aperture Photo by Dave Cowles, August 2023

Authors and Editors of Page:
Dave Cowles (2023):  Created original page
CSS coding for page developed by Jonathan Cowles

Salish Sea Invertebrates web site provided courtesy of Walla Walla University