E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Batillaria attramentaria G. B. Sowerby II, 1855
Asian Hornsnail; Mudflat Snail
Family: Batillariidae
Photo of species

© Brian Klinkenberg  Email the photographer   (Photo ID #10979)

E-Fauna BC Static Map
Distribution of Batillaria attramentaria in British Columbia
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Species Information

This is a distinctive introduced marine snail species that tends to be found in BC in large aggregations. It has a tall, turretlike spire with 8 or more whorls, acute apex, rounded aperature with teeth inside, a well-defined siphonal canal, horny and multispiraled operculum; the shell has both axial ribs (12) and spiral ridges (5 or more), which tend to form "beads" where they intersect (Cowles 2009). Color grayish, with brown on the beads (Cowles 2009), however, shell colour is significantly correlated with temperature of the locality of occurrence (Miura et al. 2007). This species ranges in size from about 3 mm in its first year to 2-3.5 cm at maturity (Global Invasive Species Database 2009).



This species can live for up to ten years based on studies carried out on Galiano Island in BC (Yamada 1982).


Diatoms make up 70 to 80% of this species' diet (Global Invasive Species Database 2009).


Eggs are attached to the mud surface where the snail lives (Global Invasive Species Database 2009). “They broadcast spawn from April to June. Larval dispersal is limited. Lifespan is about 15 years” (Wikipedia 2009).


This species is found in mid to high intertidal areas, salt marshes, mud flats and pannes in estuarine habitats, marine habitats, riparian zones, and wetlands (Cowles 2009, Global Invasive Species Database 2009).


Global Distribution

This species is native to Japan and Hong Kong, and was brought to North America sometime in the 1920's when it was brought in with the Pacific oyster (Crassostrea gigas) (Byers, 1999). Introduced from California to British Columbia, although it is also present in Washington (Global Invasive Species Database 2009).
Distribution in British Columbia

This species is found along the south coast of BC, including the coast of Vancouver Island (Gillespie et al. 2007).


Cowles (2009) says: “This species was introduced from Asia, probably along with oysters. Since they seem to remain in areas near where oysters were planted, their larvae probably have a very short or no pelagic stage. This species is slowly replacing the native snail Cerithidea californica in California bays where they coexist. Both this species and C. californica frequently are infested with abundant cercariae larvae from flukes (Trematodes), and serve as alternate hosts to the flukes which infect seabirds.”

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Synonyms and Alternate Names

Batillaria cumingi (Crosse, 1862)

Additional Range and Status Information Links

Additional Photo Sources

Species References

Byers, J.E. 1999. The distribution of an introduced mollusc and its role in long-term demise of a native confamilial species. Biological Invasions. 1: 339-352. Cowles, Dave. 2009. Batillaria attramentaria (G.B. Sowerby I). Wallawalla University. Available online.

Gillespie, Graham E. Antan C. Phillips, Debbie L. Paltzat and Tom W. Therriault. 2007. Distribution of Non-indigenous IntertidalSpecies on the Pacific Coast of Canada. Fisheries and Oceans Canada.

Global Invasive Species Database. 2009. Batillaria attramentaria (mollusc). Available online.

Miura, Osamu, Syuhei Nishi and Satoshi Chiba. 2007. Temperature-related diversity of shell colour in the intertidal gastropod Battilaria. Journal of Molluscan Studies 2007 73 (3): 235-240.

Wikipedia. 2005. Batillaria attramentaria page. Available online.

Yamada, Behrens S. 1982. Growth and longevity of the mud snail Batillaria attramentaria. Marine Biology 67 ( 2 ): 187-192.

Additional Useful References:

Harbo, Rick M. 2001. Shells & Shellfish of the Pacific Northwest. A Field Guide. Harbour Publishing, Madeira Park, BC. harbo

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-05-25 4:12:10 PM]
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