Calliostoma annulatum, common name

Common name

A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

s the purple-ring topsnail, blue-ring topsnail, jeweled topsnail etc, is a medium-sized sea snail

Snail

Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

 with gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s and an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

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This is a sublittoral

Littoral

The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...

 marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusk in the family Calliostomatidae

Calliostomatidae

Calliostomatidae is a family of sea snails within the superfamily Trochoidea and the clade Vetigastropoda.- Description :The Calliostomatidae are unusually diverse. They are characterized by a stepped spire and a pointy aperture. They may possess or lack an umbilicus. The columella is sometimes...

. This snail lives off of the Pacific coast of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

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Range of distribution

This top shell can be found from Isla San Geronimo, Baja California

Baja California

Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

, north to Forrester Island

Forrester Island

Forrester Island is an ice-capped island 3.5 nautical miles long that lies 13 nautical miles north-northeast of Shepard Island, off the Getz Ice Shelf of Marie Byrd Land. The island was discovered and charted from the USS Glacier on February 5, 1962. Named by Advisory Committee on Antarctic...

, Alaska

Alaska

Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

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Shell description

This species is distinguished by its brilliantly colored shell, which is lustrous with a gold field and a purple stripe. The brilliance of the colors fades somewhat once the animal dies.

The shell height is up to approximately 30 mm.

Life habits

This species is fairly omnivorous

Omnivore

Omnivores are species that eat both plants and animals as their primary food source...

, feeding seasonally on kelp

Kelp

Kelps are large seaweeds belonging to the brown algae in the order Laminariales. There are about 30 different genera....

, sessile fauna such as bryozoans, and detritus.