Plants and Animals
Ventridens suppressus Flat dome
Key Characteristics
The shell of the flat dome is a glossy cream to pale yellow color with 5-7 whorls, and of a general dome shape. Typical width is about .3 inches. The body is approximately twice the length of the shell, with long slender eye peduncles and small tentacles.
Status and Rank
US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G5 - Secure
State Rank: SNR - Not ranked
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Genesee | 2 | 1947 |
| Hillsdale | 1 | 1938 |
| Ionia | 1 | 1947 |
| Jackson | 6 | 1939 |
| Livingston | 2 | 1937 |
| Oakland | 2 | Historical |
| Washtenaw | 4 | 1962 |
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Habitat
This species occurs among the leaf litter of mesic, rocky woodlands (Nekola 2009, Hubricht 1985).
Natural Community Types
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Management Recommendations
More thorough research of the distribution and specific habitat needs of the flat dome is required for management purposes. Land snails that depend on moist woodland litter may be negatively impacted by lost or trampled ground vegetation, decreased canopy cover and increased fragmentation, all of which potentially result in additional sun and wind exposure altering the microclimate of forest floors (Applegarth 1999, Walden 1995). Conservation of sizeable mesic forest tracts is therefore beneficial. Snag retention may provide important shelter to terrestrial mollusks and other invertebrates during periods of fire or drought (Applegarth 1999). Many herbicides and insecticides contain heavy metals which are rapidly bioaccumulated by snails and can alter feeding habits and prevent reproduction (Notten et al. 2006).
Active Period
Breeding from first week of May to fourth week of June
Survey Methods
As visual detection of this species is difficult, specimens are collected by litter sampling in suitable habitat. Samples are thoroughly heat-dried, soaked in water for a number of hours to separate the various components, and finally passed through a series of sieves. The shells are then able to be hand-picked from the remaining sample material (Nekola 2003).
Litter sampling
Survey Period: From first week of April to fourth week of October
Time of Day: Daytime
References
Survey References
- Nekola, J.C. 2003. Large-scale terrestrial gastropod community composition patterns in the Great Lakes region of North America. Diversity and Distributions 9:55-71.
Technical References
- Applegarth, J.S. 1999. Management recommendations for terrestrial mollusk species, Megophix hemphilli, the Oregon Megomphix. Version 2.0. 39pp.
- Baker, F.C. 1939. Fieldbook of Illinois Land Snails. Illinois Natural History Survey Manual 2, Urbana, Illinois. 166pp.
- Burch, J.B. 1962. How to Know the Eastern Land Snails. William C. Brown Company Publishers, Dubuque. 214 pp.
- Hubricht, L. 1985. The Distributions of Native Land Mollusks of the Eastern US. Field Museum of Natural History. Fieldiana: Zoology, No. 24.
- Nekola, J.C. 2009. Conservation Prioritization of the Ontario and Quebec Land Snail Faunas. Final Report Submitted to: Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 120 pp.
- Notten, M.J.M., A.J.P. Oosthoek, J. Rozema, and R. Aerts. 2006. Heavy metal pollution affects consumption and reproduction of the landsnail Cepaea nemoralis fed on naturally polluted Urtica dioica leaves. Ecotoxicology 15(3):295-304.
- Walden, H.W. 1995. Endangered species of land molluscs in Sweden and Madeira. In: The IUCN Species Survivial Commission, The Conservation Biology of Molluscs:19-24 (E. Alison Kay, Ed.) International Union for Conservation of Nature and Natural Resources, Gland, Switzerland.