THE LAND SNAILS OF BRITISH COLUMBIA

Oregon Forestsnail, photo by Ryan Durand

INTRODUCTION

By Robert G. Forsyth
Research Associate
Royal British Columbia Museum

There are about 94 species of  terrestrial snails and slugs in British Columbia, but it seems likely that this number will increase as additional species are recognized from the province. Snails and slugs are gastropods (class Gastropoda) belonging to a large and successful group of invertebrate animals known as molluscs (phylum Mollusca).  Strictly speaking, in British Columbia all of our terrestrial gastropods  possess a ‘lung’ for respiration rather than gills, which are typical of most aquatic forms, and belong to the order (or subclass) Pulmonata.  However, there frequently live several other somewhat amphibious snails — often in close proximity to ‘typical’ land snails — that are traditionally treated as components of either the freshwater (Bakerilymnaea bulimoides and Fossaria spp.) or semi-marine fauna (Littorina subrotundata, Cecina manchurica, Assiminea translucens and Myosotella myosotis). In other parts of the world, and especially in the tropics, gill-bearing, ‘prosobranch’ gastropods have fully adapted to life on land.

Pacific Sideband, photo by Ryan Durand

Land snails and slugs live in a wide variety of terrestrial habits throughout British Columbia— including forests of all types, rock slides, alpine tundra and meadows and marshes. Many of these are not native, live in city gardens and in other modified habitats.

At least 26 species of terrestrial snails and slugs in British Columbia are introduced. Most of these exotic species are ultimately of European origin, but their date of arrival and means of introduction are not known. It can be inferred, however, that most arrived through passive dispersal on imported plants, and snails, slugs and their eggs continue to be dispersed between neighbourhoods and around British Columbia this way, or with garden refuse, soil, wood, rocks, and other materials.

TERRESTRIAL SNAILS AND SLUGS OF BRITISH COLUMBIA

Species	Common Name	BC List Status
Aegopinella nitidula	Waxy Glass Snail	Exotic
Allogona ptychophora	Idaho Forestsnail	Yellow
Allogona townsendiana	Oregon Forestsnail	Red
Ancotrema hybridum	Oregon Lancetooth	Yellow
Ancotrema sportella	Beaded Lancetooth	Yellow
Anguispira kochi	Banded Tigersnail	Blue
Ariolimax columbianus	Pacific Bananaslug	Yellow
Arion circumscriptus	Brown-banded Arion	Exotic
Arion distinctus	Darkface Arion	Exotic
Arion hortensis	Garden Arion	Exotic
Arion intermedius	Hedgehog Arion	Exotic
Arion rufus	Chocolate Arion	Exotic
Arion silvaticus	Forest Arion	Exotic
Arion subfuscus	Dusky Arion	Exotic
Bithynia tentaculata	Mud Bithynia	Exotic
Boettgerilla pallens	Wormslug	Exotic
Carychium minimum	Herald Thorn	Exotic
Carychium occidentale	Western Thorn	Blue
Catinella vermeta	Suboval Ambersnail	No Status
Cepaea nemoralis	Grovesnail	Exotic
Cochlicopa lubrica	Glossy Pillar	Yellow
Columella columella	Mellow Column	Yellow
Columella edentula	Toothless Column	Yellow
Cornu aspersum	Brown Gardensnail	Exotic
Cryptomastix devia	Puget Oregonian	Red
Cryptomastix germana	Pygmy Oregonian	Yellow
Cryptomastix mullani	Coeur d'Alene Oregonian	Blue
Deroceras hesperium	Evening Fieldslug	Red
Deroceras laeve	Meadow Slug	Yellow
Deroceras panormitanum	Longneck Fieldslug	Exotic
Deroceras reticulatum	Gray Fieldslug	Exotic
Discus rotundatus	Rotund Disc	Exotic
Discus shimekii	Striate Disc	Yellow
Discus whitneyi	Forest Disc	Yellow
Gastrocopta holzingeri	Lambda Snaggletooth	Blue
Haplotrema vancouverense	Robust Lancetooth	Yellow
Hemphillia camelus	Pale Jumping-slug	Blue
Hemphillia dromedarius	Dromedary Jumping-slug	Red
Hemphillia glandulosa	Warty Jumping Slug	Blue
Lauria cylindracea	Chrysalis Snail	Exotic
Lehmannia valentiana	Threeband Gardenslug	Exotic
Limacus flavus	Yellow Gardenslug	Exotic
Limax maximus	Giant Gardenslug	Exotic
Magnipelta mycophaga	Magnum Mantleslug	Blue
Microphysula cookei	Vancouver Snail	Yellow
Microphysula ingersolli	Spruce Snail	Yellow
Monadenia fidelis	Pacific Sideband	Blue
Nearctula sp.	Threaded Vertigo	Red
Nesovitrea binneyana	Blue Glass	Yellow
Nesovitrea electrina	Amber Glass	Yellow
Oreohelix strigosa	Rocky Mountainsnail	Blue
Oreohelix subrudis	Subalpine Mountainsnail	Blue
Oxychilus alliarius	Garlic Glass-snail	Exotic
Oxychilus cellarius	Cellar Glass-snail	Exotic
Oxychilus draparnaudi	Dark-bodied Glass-snail	Exotic
Oxyloma groenlandicum	Ruddy Ambersnail	No Status
Oxyloma hawkinsi	Boundary Ambersnail	No Status
Oxyloma nuttallianum	Oblique Ambersnail	No Status
Planogyra clappi	Western Flat-whorl	Yellow
Pristiloma arcticum	Northern Tightcoil	Blue
Pristiloma chersinella	Black-foot Tightcoil	Blue
Pristiloma johnsoni	Broad-whorl Tightcoil	Blue
Pristiloma lansingi	Denticulate Tightcoil	Yellow
Pristiloma stearnsi	Striate Tightcoil	Yellow
Prophysaon andersoni	Reticulate Taildropper	Yellow
Prophysaon coeruleum	Blue-grey Taildropper	Red
Prophysaon foliolatum	Yellow-bordered Taildropper	Yellow
Prophysaon vanattae	Scarletback Taildropper	Blue
Punctum randolphi	Conical Spot	Yellow
Pupilla hebes	Crestless Column	Blue
Striatura pugetensis	Northwest Striate	Yellow
Succinea oregonensis	Oregon Ambersnail	Yellow
Succinea rusticana	Rustic Ambersnail	Yellow
Succinea strigata	Striate Ambersnail	Yellow
Testacella haliotidea	Earshell Slug	Exotic
Vallonia cyclophorella	Silky Vallonia	Blue
Vallonia excentrica	Iroquois Vallonia	Exotic
Vallonia gracilicosta	Multirib Vallonia	Yellow
Vallonia pulchella	Lovely Vallonia	Exotic
Vertigo andrusiana	Pacific Vertigo	Red
Vertigo arthuri	Callused Vertigo	Blue
Vertigo binneyana	Cylindrical Vertigo	No Status
Vertigo columbiana	Columbia Vertigo	Yellow
Vertigo cristata	Crested Vertigo	Yellow
Vertigo elatior	Tapered Vertigo	Red
Vertigo gouldi	Variable Vertigo	Yellow
Vertigo modesta	Cross Vertigo	Yellow
Vertigo ovata	Ovate Vertigo	Yellow
Vespericola columbianus	Northwest Hesperian	Yellow
Vitrea contracta	Contracted Glass-snail	Exotic
Vitrina pellucida	Western Glass-snail	Yellow
Zonitoides arboreus	Quick Gloss	Yellow
Zonitoides nitidus	Black Gloss	Blue
Zoogenetes harpa	Boreal Top	Yellow

USEFUL LITERATURE FOR IDENTIFYING
TERRESTRIAL SNAILS AND SLUGS OF BC

Forsyth, R. G. 2004. Land Snails of British Columbia. Royal B.C. Museum Handbook. Victoria: Royal British Columbia Museum. iv, 188 pp., 8 col. pp.

Pilsbry, H. A. 1939. Land Mollusca of North America (north of Mexico), 1(1). The Academy of Natural Sciences of Philadelphia, Monographs 3: i-xvii + 1-573 + i-ix.

Pilsbry, H. A. 1940. Land Mollusca of North America (north of Mexico), 1(2). The Academy of Natural Sciences of Philadelphia, Monographs 3: viii + 994 + ix pp.

Pilsbry, H. A. 1946. Land Mollusca of North America (north of Mexico), 2(1). The Academy of Natural Sciences of Philadelphia, Monographs 3: frontis., i-vi, 1-520.

Pilsbry, H. A. 1948. Land Mollusca of North America (north of Mexico), 2(2). The Academy of Natural Sciences of Philadelphia, Monographs 3: i-xlvii + 521-1113 pp.

USEFUL LITERATURE FOR IDENTIFYING EUROPEAN SPECIES INTRODUCED TO BC

Cameron, R. 2003. Land snails in the British Isles. Field Studies Council, Occasional Publication 79: iv + 82 pp

Cameron, R. A. D., B. Eversham, & N. Jackson. 1983. A field key to the slugs of the British Isles. Field Studies 5: 807-824.

Kerney, M. P., & R. A. D. Cameron. 1979. A field guide to the land snails of Britain and north-west Europe. London: Collins. 288pp, 24 pls.

LINKS

COSEWIC assessment and status report on the Dromedary Jumping-slug, Hemphillia dromedarius, in Canada.

COSEWIC Assessment and Status Report on the Oregon Forestsnail, Allogona townsendiana, in Canada:.

COSEWIC assessment and status report on the Puget Oregonian snail, Cryptomastix devia, in Canada.

COSEWIC assessment and status report on the Warty Jumping-slug, Hemphillia glandulosa, in Canada.

Gastroclass: Gastropod classification. http://www.nhm.ac.uk/research-curation/projects/gastroclass/

Land Snails of British Columbia: http://www3.telus.net/rforsyth/

North American Land Snail Links: http://www.unc.edu/%7Ekeperez/land%20snail%20webpage.html

Terrestrial Gastropods of the Columbia Basin, British Columbia: http://www.livinglandscapes.bc.ca/cbasin/molluscs/contents.html

Terrestrial Gastropods of the Peace River – Northern Rockies of British Columbia: http://www.livinglandscapes.bc.ca/prnr/prnr_snails/index.html

Terrestrial Gastropods of the Upper Fraser Basin of British Columbia: http://www.livinglandscapes.bc.ca/upperfraserbasin/ufb_snails/index.html