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Zonitoides nitidus (Müller, 1774)
Black Gloss
Family: Gastrodontidae
Species account author: Robert Forsyth.
Introduction to the Land Snails of BC

Photograph

© Robert Forsyth     (Photo ID #322)

Map

E-Fauna BC Static Map

Distribution of Zonitoides nitidus in British Columbia in British Columbia

Species Information

Shell disc-shaped; spire moderately raised; brown, with growth lines but no spiral lines; animal blackish with a dull orange spot visible through the shell.

Animal Black throughout; when the animal is fully retracted, a dull orange spot on the mantle shows through the shell. It is best be seen through the shell behind the apertural lip, between the suture and the periphery.

Anatomy

The development of the genitalia is variable with both euphallic individuals (with fully developed genital organs) and hemiphallic ones (with small, degenerate male genitalia) present (Watson 1934, Pilsbry 1946, Jordaens et al. 1998).

Similar Species

Two species of Zonitoides, Zonitoides nitidus (Müller, 1774) and Z. arboreus (Say, 1817), occur in Canada (and BC). Sometimes, material in collections are confused because shells are often difficult to identify with certainty. Zonitoides nitidus grows to a slightly larger size, has a somewhat higher spire, and lacks the exceedingly fine and very weak spiral striae of Zonitoides arboreus. However, a better way to distinguish species is by the body pigmentation. Zonitoides nitidus (as its name suggests) has an entirely blackish body; that of Z. arboreus is lighter along the sides of the foot. There is also a spot, not present in the other species, that is sometimes described as “dull orange” and can be seen through the shell a little ways back from the aperture, especially in retracted animals. Take a look a the snail in the upper left of photo # 37371 in the photo gallery and you might make out this orangish spot.

Biology


Reproduction is thought to be mostly by self-fertilization (Jordaens et al. 1998).

Habitat


A calciphile. In some places (and in BC), restricted to very wet ground such as marshes and along the edges of waterbodies (Forsyth 2004). However elsewhere, in Ontario, the species occurs in mesic forest habitats and is often particularly abundant at anthropogenic sites. Snails live under dead wood, logs, rocks, leaf litter, and vegetation.

Distribution


Global range

Europe, North Africa, northern Asia, Iceland and most of North America; introduced to Australia and Madeira (Pilsbry 1946).

BC range

Known from suitable habitats in the Lower Fraser Valley, on Vancouver Island, and in the Okanagan. Apparently it is absent in central or northern areas of the province (Forsyth 2004). Pilsbry (1946) speculated that this species could be introduced along the west coast, and he could be correct.

Ecozones

Pacific Maritime, Montane Cordillera.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)		COSEWIC
NativeS5?YellowNot Listed



BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Notes

This is a small species of air-breathing land snail (Wikipedia 2009) that occupies wet calcareous habitats (it is a calciphile), including "marshes and wet areas along the edges of rivers, sloughs, lakes and ponds, where it lives under wood, rocks and vegetation (Forsyth 2004). It is an omnivorous species that eats vegetation and gastropod eggs (Forsyth 2004). It is considered carnivorous (Rondelaud 1975).

Additional Range and Status Information Links

NatureServe Explorer

Species References

Forsyth, Robert G. 2004. Land Snails of British Columbia. Handbook. Royal BC Museum, Victoria.

Rondelaud, D. 1975. Predation of Lymnaea (Galba) truncatula Müller by Zonitoides nitidus Müller (Mollusca Gastropoda Pulmonata Ann Parasitol Hum Comp 50(3):275-86.

Wikipedia. 2009. Zonitoides nitidus Information Page. Available: http://en.wikipedia.org/wiki/Zonitoides_nitidus.

General References

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