How to Distinguish from Similar Species:_Acanthina spirata also has dark spiral ridges but is less elongated and has a distinct tooth on the outer lip of the aperture; Nucella canaliculata has similar spiral ridges but is less elongated and the whorls are separated by a deep groove. Geographical Range: Chirikof Island, Alaska, to Monterey, CA. Abundant in British Columbia, Washington and Oregon; spoty in California. Said to be the commonest littoral snail in rocky shores of N. British Columbia. Depth Range: Mostly intertidal (but also on Cobb Seamount at 35 m depth) Habitat: Rocky shores; lower edges of rocks in gravel or mud in bays Biology/Natural History: Predatory or mainly scavenging. Prey include Littorina, limpets, barnacles, chitons, worms, and other animals; specializing in finding and eating injured animals which it often eats without drilling into the shell of (it does not seem to be able to drill into shells). Readily eats carrion such as dead crabs or fishes. Proboscis can extend the length of the shell. May extend proboscis to digest worms in their tubes, or to feed on prey that are being eaten by the everted stomach of Pisaster ochraceous. Predators include the seastars Orthasterias keohleri and Leptasterias hexactis, and Barrow's Goldeneyes (Bucephala islandica). Hatchling snails are eaten by hermit crabs Pagurus hirsutiusculus and by purple shore crabs Hemigrapsus nudus. The slipper snail Crepidula adunca may be found living on the shell. In muddy bays, this shell is a favorite of the hermit crab Pagurus granosimanus (but not of P. hirsutiusculus). Females deposit low, convex egg capsules in clusters on rock walls of crevices from September to May. Most of the eggs in a cluster ("nurse eggs") do not develop fully and are used as food by the veliger larvae that do develop. Do not migrate with the tides. Larger individuals are more common in the lower intertidal. May live 15 years.
References:Dichotomous Keys:Flora and Fairbanks, 1966 Kozloff 1987, 1996 Smith and Carlton, 1975 General References:
Scientific
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General Notes and Observations: Locations, abundances, unusual behaviors: ![]() This view shows the operculum, the open siphonal canal, and the shiny, sinuous columella. Photo by Dave Cowles, July 2005 ![]() The dark spiral lines can very easily be seen on the inside of the outer lip of the aperture. Photo by Dave Cowles, July 2005
Authors and Editors of Page: Dave Cowles (2005): Created original page |