FWGNA > Species Accounts > Planorbidae > Gyraulus crista
Gyraulus (Armiger) crista (Linneaus 1758)

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> Habitat & Distribution

The range of G. crista is holarctic, across northern latitudes worldwide.  Here in North America populations inhabit the range of rich, lentic habitats, from eutrophic lakes to temporary ponds, extending from Ontario to the Northwest Territories and Alaska, and from Maine to Minnesota (Clarke 1981).  In Norway, Økland (1990) categorized G. crista as a “pond species.”  The population inhabiting Poland’s Mikolajskie Lake appeared positively associated with macrophytes (Soszka 1975).

Although not uncommon in Canada (Prescott & Curteanu, 2004), populations of G. crista are rare in the U.S. Great Plains.  We are aware of previous records from a single site in South Dakota (Over 1915), a single site in north-central Nebraska (Taylor 1960), two sites in Wyoming (Beetle 1989) and from four temporary habitats in North Dakota (Cvancara, 1983).  We ourselves have documented five populations of G. crista in our four-state Great Plains study area, inhabiting the backwaters of rivers and creeks in glaciated regions of North Dakota.

> Ecology & Life History

Dillon (2000: 138 – 140) conducted a survey of the relationship between adult size and newborn size in freshwater gastropods across approximately 55 reference works, 74 populations,  ultimately discovering that G. crista has both the smallest adult size and the smallest hatchling size among the Pulmonata.  

One or two eggs are deposited per capsule, twice to thrice a year (Richardot-Coulet and Alfaro-Tijera, 1985; Jokinen, 1992).  Adults overwinter and disappear after oviposition in the spring (Richardot-Coulet and Alfaro-Tijera, 1985).  This is life cycle type D(iis) of Dillon (2000:156 – 162).

> Taxonomy & Systematics

The species we identify here as Gyraulus crista was initially described in the genus Nautilus by Linneaus in 1758.  It was subsequently placed in Planorbis by O. F. Müller (1773), and then split out to Armiger by Hartmann (1843).  Both Baker (1945) and Hubendick (1955) preserved Armiger at the genus level, but the taxon was ultimately subsumed under Gyraulus by Meier-Brook (1983).

Populations of G. crista can demonstrate substantial variation in the prominence of shell ridges (Clarke 1973, Cvancara 1983).  Reduction of ridges has been correlated with substrate type, especially decaying Typha cattails (Spyra and Strzelec, 2013).

> Supplementary Resources

> Essays

  • See my post to the FWGNA blog of 11Apr08 for a review of the Classification of the Planorbidae.
  • Or view the (Hubendick 1955) classification of North American planorbids in a tabular format [here].

> References

Baker, F. (1928) Freshwater Mollusca of Wisconsin, Part I, Gastropoda. Bull. Wisc. Geol. Natur. Hist. Survey, no. 70.  University of Wisconsin Press, Madison.
Baker, F. (1945) The Molluscan Family Planorbidae. Urbana: University of Illinois Press.  
Baker, H. B. (1946) Index to F.C. Baker's "The Molluscan Family Planorbidae." Nautilus, 59, 127-41. 
Burch, J.B. (1989) North American Freshwater Snails. Malacological Publications, Hamburg, Michigan.   
Clarke, A.H. (1979)
Gastropods as indicators of trophic lake stages. Nautilus 93:138-142.  
Clarke, A.H.  (1981)  The Freshwater Molluscs of Canada. National Museum of Natural Sciences, National Museums of Canada, Ottawa, Canada.  
Dillon, R.T., Jr. (2000) The Ecology of Freshwater Molluscs. Cambridge University Press, Cambridge, United Kingdom.  
Hubendick, B.  (1955)  Phylogeny in the Planorbidae.  Trans. Zool. Soc. London 28: 453-542. 
Jokinen, E.H. (1992) The freshwater snails of New York State. New York State Museum Biological Survey, New York State Museum Bulletin 482. 
Meier-Brook, C. 1983. Taxonomic studies on Gyraulus (Gastropoda: Planorbidae). Malacologia 24: 1 - 113.
Økland, J. (1990)  Lakes and Snails.  Oegstgeest, Netherlands.  W. Backhuys.
Prescott, D.R.C., and Curteanu, M.M. 2004. Survey of Aquatic Gastropods in the Central Parkland Subregion of Alberta. Edmonton, AB: Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No.92.
Richardot-Coulet, M.L. and Alfaro-Tijera, L. 1985. The life cycle and ecology of the freshwater Planorbidae Armiger crista L. Journal of Molluscan Studies 51: 31–51.
Soszka, G. (1975) The invertebrates on submerged macrophytes in three Masurian lakes.  Ekol. Pol. 23: 371 – 391.