Plants and Animals

Mediappendix protracta A land snail (no common name)

Key Characteristics

The fragile, translucent yellow shell of Catinella protracta (also called Catinella avara) grows up to .6 inches in length, commonly with 3 whorls, and features a large oval aperature and sharp lip. The snail's body is light brown to gray, broad at the front, tapering behind with short and thick eye peduncles and tentacles. The mantle is pale grey spotted with black and white.

Status and Rank

US Status: No Status/Not Listed
State Status: E - Endangered (legally protected)
Global Rank: G2 - Imperiled
State Rank: SNR - Not ranked


CountyNumber of OccurrencesYear Last Observed
Calhoun 2 1947
Cass 1 1975
Oakland 1 1946
Washtenaw 1 1947
Wexford 1 1958

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.


This species is found in a variety of habitats, such as carbonate cliffs, alvars, grasslands (Nekola 2003b), beneath leaf litter, logs and stones on the forest floor, lakeshores, dunes, ditches, and pastures (Burch and Jung 1988).

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

Snails bioaccumulate chemical pollutants and heavy metals (Berger and Dallinger 1993, Regoli et al. 2006). High exposure to heavy metals has been found to alter feeding patterns and prevent reproduction (Notten et al. 2006). Where vulnerable gastropods may be present, herbicide and insecticide application, as well as other common sources of chemical and heavy metal pollution, should be limited and affected populations monitored. Habitat loss, fragmentation and degradation are considered the greatest threats to land snail species (Kay 1995). Depedence on specific microhabitat conditions renders many species vulnerable to changes brought about by increased edge area, forest canopy reductions, and the loss of vegetative ground cover (Applegarth 1999, Gotmark et al. 2008, Walden 1995). Fire can negatively affect land snail populations and microhabitats. Large downed logs may provide important refuges during periods of fire and drought, and should be retained (Applegarth 1999). Heavy recreational traffic may negatively impact snail habitat (McMillan et al. 2003). Identifying and protecting areas of suitable habitat will aid Catinella protracta.

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 first week of October

Time of Day: Daytime


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

  • 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.
  • Burch, J.B. and Y. Jung. 1988. Land Snails of the University of Michigan Biological Station area. Walkerana 3(9)
  • Hubricht, L. 1985. The Distributions of Native Land Mollusks of the Eastern US. Field Museum of Natural History. Fieldiana: Zoology, No. 24.
  • Kay, E.A. 1995. Hug a slug, save a snail: A status report on molluscan diversity and a framework for conservation action. Pp. 53-79. In: E.A. Kay (ed). 1995. The Conservation Biology of Molluscs. IUCN, Gland, Switzerland.
  • McMillan, M.A., J.C. Nekola, and D.W. Larson. 2003. Effects of Rock Climbing on the Land Snail Community of the Niagara Escarpment in Southern Ontario, Canada. Conservation Biology 17(2):616-21.
  • Nekola, J.C. 2003b. Terrestrial gastropod fauna of Northeastern Wisconsin and the Southern Upper Peninsula of Michigan. American Malacological Bulletin 18(1/2).