Terrestrial Gastropods of the Columbia Basin, British Columbia

Family VITRINIDAE Fitzinger, 1833
 

Genus Vitrina Draparnaud, 1801

For taxonimic changes since Pilsbry (1946), see the publications of Forcart (1955) and Bequaert & Miller (1973).
 

Vitrina pellucida (Müller, 1774): Western Glass-snail
Synonym. Vitrina alaskana Dall, 1905.

Vitrina pellucida

Vitrina pellucida

Vitrina pellucida

Description: Shell small (width to 6.2 mm, but usually smaller), heliciform; shiny, translucent greenish, yellowish green or nearly colourless; very thin-shelled and fragile; spire small, low and convex; whorls 2.5-3, convex, regularly and rapidly increasing in width; periphery rounded; suture shallow and bordered by a more opaque band; teleoconch with irregular, low axial wrinkles that are a little more evident near the suture; aperture very large and subovate, without denticles; outer lip unthickened and with a very narrow, membranous edge; umbilicus narrow, formed by a fold in the columellar lip next to the base.

When the animal is extended from its shell, a small lobe of the mantle on the right side encroaches slightly over the shell and covers the termination of the suture. The animal is brownish, especially near the tentacles and on the head.

Similar species: Vitrina is easily distinguished from all other species occuring in the Kootenays by the combination of relatively few whorls, glassy shell and capacious aperture. However, Vitrina angelicae Beck, 1837 (synonym: V. limpida Gould in Agassiz, 1850), of eastern North America, has been reported from Alberta (Taylor 1895; Platt 1980). The shell is indistinguishable from V. pellucida and dissection is required for distinguishing the two species. In V. angelicae, the vas deferens is mostly free from the penis, but in V. pellucida, the vas deferens is enclosed in a large sheath of connective tissue surrounding part of the penis; additionally, the spermathecal duct of V. pellucida has a large swelling at its base adjacent to the atrium (Forcart 1955).

Habitat: Under rocks, logs, and in grass and leaf litter. Vitrina is a cold-weather snail seen in the fall and early spring, often in seasonally dry situations from sea level to mountain tops above the tree-line, and dead shells are usually more often found. Carl & Hardy (1945) reported this species at 2,377 m [7,800 ft] at Paradise Mines near Windermere.

Biology: The life-span of this snail is probably one year (Boag & Wishart 1982). V. pellucida is usually seen alive in the spring and often there is still remnants of snow and ice on the ground. It is carnivorous and "feeds on almost anything but vascular plants" (Ellis 1969).

Range: Palearctic and western Nearctic. In North America: Alaska to Wyoming and South Dakota, south to California, Arizona and New Mexico (Bequaert & Miller 1973). Additionally, Russell (1951) reported "Vitrina alaskana", from the Cypress Hills of southwestern Saskatchewan.

Distribution: Throughout British Columbia, along the coast and inland, but more common in the north.

Notes: Forcart (1955) reviewed the northern species of the genus Vitrina, but did not treat V. alaskana because the reproductive anatomy was unknown to him. Later however, Bequaert & Miller (1973) placed V. alaskana in the synonymy of Vitrina pellucida stating that the reproductive anatomy of V. alaskana in examples they dissected agreed with that of Eurasian V. pellucida as illustrated and described by Forcart. Bequaert & Miller retained 'alaskana' as the North American subspecies of V. pellucida on the basis of its geographical separation.

Identifications of Vitrina in this report were based upon geography. None have been dissected.

Name: Both genus and species names are in reference to the glassy, translucent shell.

Records: Olsen Park, Rock Creek (49°03.37'N, 118°59.90'W) (Forsyth Coll. 97-093-4237); Lodgepole Road at Kisoo Pass, SE of Fernie (49°17.03'N, 114°42.72'W) (RBCM 998-00288-004); Elk River valley, along Hwy. 3, S of Fernie (circa 49°27.5'N, 115°4.2'W) (Forsyth Coll. 97-109-634); Coal Creek on E side of Cokato Road, Fernie (49°29.72'N, 115°03.75'W) (Forsyth Coll. 97-108-1047); Cummings Creek, N of Sparwood (49°46.32'N, 114°54.95'W) (RBCM 998-00293-001); Paradise Mine, at source of Springs Creek, W of Windermere (circa 50°28'N, 116°14'W) (Carl & Hardy 1945); Sale Creek Road, Revelstoke (51°09.1'N, 118°11.0'W) (RBCM 998-00260-002); W of snow sheds, Glacier National Park (circa 51°15.5'N, 117°28'W) (Staatliches Museum für Naturkunde Görlitz); Lake Revelstoke, Hwy. 37 to Mica Dam (51°39.56'N, 118°33.73'W) (RBCM 998-00258-004). View the map.

 

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