About the Key

This key was created to assist inspectors at U.S. ports of entry who are inspecting cargo to determine the identity of potentially important, invading organisms, specifically terrestrial molluscs.It is acknowledged that the scope of this key may be larger and as such may be used as an educational tool for a variety of fields.

The taxonomy of terrestrial molluscs is very dynamic, hence a large number of the entities (species, families, groups) included in this key may have been and continue to be revised. For each entity, a list of synonyms has been included in the supporting fact sheets to assist in clarifying the nomenclature.

It is recommended that the user read the “About this tool” and the “Biology” sections of this tool before attempting to use the pictorial key. The key can reliably identify only adult specimens, as juveniles may not possess the characteristic features of the species. This is true for both snails and slugs. Slugs are generally more difficult to key to the species level and often require dissection. If dissection is necessary, there is a dissection tutorial available in this tool to assist the user to successfully dissect a snail and/or a slug.

Equipment required for the optimal use of this key:

  • Hand lens (10-20 X)
  • Ruler or Caliper
  • Adult specimens
  • Anatomy drawing (located in Biology section)

It is important to remember that this key is not inclusive of all pestiferous mollusc species. This key is intended to serve as an aid in the identification of terrestrial mollusc species documented as major agricultural and ecological pests as well as contaminant and non-pest species that are commonly intercepted at U.S. ports of entry.