Mossy Valvata

Valvata sincera Say, 1824

Mossy valvata

Gastropoda (Gastropods)
State Protection
Special Concern
Listed as Special Concern by New York State: at risk of becoming Threatened; not listed as Endangered or Threatened, but concern exists for its continued welfare in New York; NYS DEC may promulgate regulations as to the taking, importation, transportation, or possession as it deems necessary.
Federal Protection
Not Listed
State Conservation Status Rank
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
Secure globally - Common in the world; widespread and abundant (but may be rare in some parts of its range).


Did you know?

Snails in this family possess a unique gill that protrudes outside the mantle facilitating the tolerance of low dissolved oxygen concentrations.

State Ranking Justification

It seems clear that the southern range margin of this boreal snail is retreating northward through New York, and that it has apparently gone missing from many of the smaller lakes where it was historically found around the state (Jokinen 1992). However, because it can live in the bottom sediments of larger lakes such as Oneida and Ontario, it will be difficult to assess its overall status. At this time, it does not appear to be one of the most imperiled freshwater Gastropods in New York and the S1 rank could be altered pending further survey work.

Short-term Trends

Recently (2012), a large population was discovered in Oneida Lake, and a smaller one in Cayuga Lake was re-confirmed as extant. The Oneida Lake population has apparently been known at least since the mid 1800s.

Long-term Trends

The species seems to have had a much wider historical (1800s-1900s) distribution, ranging nearly statewide (Jokinen 1992).

Conservation and Management


This species has a wide distribution, presumed large population, lack of substantial immediate threats, and because it is not in decline or is unlikely to be declining fast enough to qualify for listing in a more threatened category. However, a recent assessment of freshwater Gastropods in North America revealed that 74% of the species are imperiled or already extinct and they have the highest modern extinction rate yet recorded--almost 10,000 times background rates (Johnson et al., 2013). The top threats to the group as a whole are; highly restricted ranges (narrow endemics), habitat destruction (hydrological alteration), and water pollution.

Conservation Strategies and Management Practices

Presumably this species would benefit from efforts to clean up Onondaga Lake where only dead shells were found in the late 1960s (Harman and Berg 1971).

Research Needs

As for all freshwater snails, this species would benefit immensely from a statewide inventory in order to determine basic distributional information.



This is a coldwater species that can live at considerable depths in high calcium large lakes in association with submerged aquatic vegetation and mud. For example, it has been dredged up in good numbers from the benthos of Lake Ontario (Hiltunen 1969). Although primarily a large lake species, it can sometimes turn up in other habiats such as rivers, creeks, and eutrophic waters.

Associated Ecological Communities

  • Mesotrophic dimictic lake (guide)
    The aquatic community of a lake that is intermediate between an oligotrophic lake and a eutrophic lake. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall); they are thermally stratified in the summer, and they freeze over and become inversely stratified in the winter.
  • Oligotrophic dimictic lake (guide)
    The aquatic community of a nutrient-poor lake that typically occurs in a deep, steeply-banked basin. These lakes are dimictic: they have two periods of mixing or turnover (spring and fall), they are thermally stratified in the summer, and they freeze over and become inversely stratified in the winter.


New York State Distribution

Apparently confined to the St. Lawrence/Champlain watershed in northern New York as well as the larger lakes in central New York and the depths of Lake Ontario.

Global Distribution

This is a northern species found from the Arctic Circle southward to Connecticut and Minnesota. It seems seems to have been extirpated from states further to the south (e.g., Indiana, Pennsylvania).

Best Places to See

  • Oneida Lake (Onondaga County)

Identification Comments

General Description

The shell is yellowish-brown, sub-globose to conic, about 5 mm wide, exhibiting four rounded whorls; the spire is moderately elevated.

Identifying Characteristics

The shell is dextral, small, turreted, and moderately thin, with deeply impressed sutures. The spire is weakly elevated. There are approximately 2.5 inflated whorls, circular in cross section, gradually increasing in size. The surface appears dull due to fine growth lines. The color is a very light and translucent. The aperture is circular and entire; outer lip is straight; operculum multi-spiral, circular, fragile and translucent.

Characters Most Useful for Identification

The small size, but with a high spire, is distinctive.

Best Life Stage for Proper Identification



The snails attach their egg capsules to aquatic plants.


As is common among small freshwater snails, we presume this species scrapes biofilms from submerged surfaces. In turn, it forms an important part of the diet for Whitefish and Perch.

Best Time to See

This species has an annual life cycle.

  • Present
  • Larvae present and active

The time of year you would expect to find Mossy Valvata present and larvae present and active in New York.

Similar Species

  • Threeridge Valvata (Valvata tricarinata)
    The radula of these two species is similar.

Mossy Valvata Images


Mossy Valvata
Valvata sincera Say, 1824

  • Kingdom Animalia
    • Phylum Mollusca (Mollusks)
      • Class Gastropoda (Gastropods)
        • Order Heterostropha
          • Family Valvatidae

Additional Resources


Clarke, A.H. 1981a. The freshwater mollusks of Canada. National Museum of Natural Sciences, National Museums of Canada, D. W. Friesen and Sons, Ltd.: Ottawa, Canada. 446 pp.

Harman, W. N., and C. O. Berg. 1971. The freshwater snails of central New York with illustrated keys to the genera and species. Cornell University Agricultural Experiment Station in Entomology. Ithaca, NY.

Hiltunen, J. 1969. The benthic macrofauna of Lake Ontario. Great Lakes Fishery Commission Technical Report 14:39-50.

Johnson, P.D. et al., 2013. Conservation status of freshwater Gastropods of Canada and the United States. Fisheries 38:247-282.

Jokinen, E.H. 1992. The Freshwater Snails (Mollusca: Gastropoda) of New York State. New York State Museum, Bulletin, 482: 1-112.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.


About This Guide

This guide was authored by: Jeffrey D. Corser

Information for this guide was last updated on: March 29, 2016

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Valvata sincera. Available from: Accessed June 23, 2024.