Using the TMT key

Introduction to the TMT key

This key was created to assist inspectors at U.S. ports of entry to determine the identity of terrestrial mollusk species intercepted in imported cargo and shipments in-transit. Some terrestrial mollusks are important agricultural and ecological pests, others may be contaminant species that may materially affect the quality of cargo, while others may be non-pest “hitchhiker” species. It is often difficult for non-experts to accurately determine the identity of terrestrial mollusks in a timely manner. This interactive key is designed to be a user-friendly tool to aid non-malacalogists to identify some important mollusk species that may affect commerce. It is however acknowledged that the scope of this key may be larger, and as such may also be used as an educational resource in a variety of fields. The taxonomy of terrestrial mollusks is very dynamic; hence, a large number of the entitiesEntities:
See also entity
(species, family, groups) included in this key may have been, and continue to be, revised. For each entityEntity:
In Lucid, entities are the items the key aims to identify. Lucid uses the term entity to encompass items of all types.
, 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 Identification and the Biology sections of this tool in order to use the key more effectively. Only adult specimens have all the characters required by the key to achieve correct identification. Juveniles of many gastropodGastropod:
A single-shelled mollusc.
species often lack adult characters or they may possess additional characters that are not maintained through to adulthood. 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 that will assist the user in successfully dissecting a snail and/or a slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.

It is important to remember that this key is not inclusive of all pestiferous mollusk species. This key is intended to serve as an aid in the identification of terrestrial molluscMollusc:
Common name for animals in the phylum Mollusca. These are invertebrate animals, which have soft unsegmented bodies and may or may not possess a shell. This group includes gastropods (slugs and snails), cephalopods (octopus) and bivalves (clams, oysters).
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.

Equipment required for the optimal use of this key:
  • hand lens (10-20X)
  • ruler or caliper
  • adult specimens
  • anatomy drawings (located in Biology and the Identification section)