Species: Littorina subrotundata

Newcomb Periwinkle

Species

Encyclopedia of Puget Sound

Shell thin, turbinate with four or five rounded whorls; apex sub-acute, last whorl somewhat inflated, subrimate, with or without three or four longitudinal brown bands; aperture ovate, outer lip thin, inner lip appressed to the columella and somewhat thickened; suture deep; epidermis greenish. Operculum with nucleus subcentral with two and one-half whorls (Hemphill 1877).

Articles:

Newcomb's Littorine Snail (Littorina subrotundata)

August 01, 2013

This article was originally published by the Washington Department of Fish and Wildlife as part of its annual report Threatened and Endangered Wildlife in Washington.

Littorina subrotundata (Carpenter, 1864) Salt Marsh Periwinkle. Photo courtesy of L. Schroeder. Source: www.PNWSC.org.

Classification

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Neotaenioglossa

Family

Littorinidae

Genus

Littorina

NatureServe

Source:
ELEMENT_GLOBAL.2.109396

Classification

Informal Taxonomy

Animals, Invertebrates - Mollusks - Other Mollusks

Formal Taxonomy

Animalia - Mollusca - Gastropoda - Neotaenioglossa - Littorinidae - Littorina - (fide Reid and Golikov, 1991) (Turgeon et al., 1998).

Ecology and Life History

Habitat Type Description

Marine

Migration

false - false - false - Typical snail-like crawl; subject to passive dispersal by occasional floods, inadvertant transport by birds or animals, or human activities in their aquatic habitat.

Non-migrant

false

Locally Migrant

false

Food Comments

Presumably feeds on SALICORNIA vegetation by rasping the surfaces to remove small particles for digestion. Other vegetation may also be acceptable.

Reproduction Comments

Egg masses of 15-40 eggs per mass are laid in June and July in moist locations where they will be submerged during most high tides. The early egg masses are light in color and tough in texture and become darker and softer as they age. The larvae emerge from these egg masses and crawl away as fully formed juvenile snails (pers. obs.). Hatchlings occur in midJuly with increasing abundance through late July and early August.

Ecology Comments

Its optimal distribution within its ecosystem is at, or slightly above, mean high tide so that its is submerged in sea water only a few hours per year. In the past, sawmill waste has had a devastating effect on its habitat and, consequently, on the species itself (Keen 1970 and Jones 1977).

Length

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

2010-04-13

Global Status Last Changed

1991-05-07

Distribution

Conservation Status Map

Global Range

H - >2,500,000 square km (greater than 1,000,000 square miles) - H - This common cold-water North Pacific marine gastropod has a southernmost limit in North America in Humboldt Bay, California; but occurs from there north to the Gulf of Alaska and from there westward throughout the Aleutian Island chain, the Pribilof and Commander (Komandor) Islands, over to the east coast of Kamchatka, and in Russia south to the Kurile Islands (Reid, 1996). In the U.S. it is currently known only from Humboldt Bay, California; Coos Bay, Oregon; and Gray's Harbor, Washington (Jones, 1977; Taylor, 1981); but more localities undoubtedly exist and it was initially incorrectly thought to be a different species.

Global Range Code

Global Range Description

>2,500,000 square km (greater than 1,000,000 square miles)

ELEMENT_GLOBAL.2.109396