Gastropods

       The Class Gastropoda belongs to the Phylum Mollusca.  Gastrpopds, or snails, may be marine (salt water), fresh water, or terrestrial (land dwelling) mollusks that have a well developed head with tentacles, eyes and a mouth equipped with a file-like tongue or radula.  At its base the animal is provided with a muscular foot which can be expanded and contracted to allow for mobility.  Generally, the internal organs are protected by an external calcarious shell which is secreted by the mantel.  The shell may be conical or saucer-shaped and is usually coiled into a spiral.  The shell may be a right-handed or left-handed coil (uncommon) which enlarges as the animal grows.

       The shells grow as accretions of shell matter are secreted by the mantle and added to the edge of the opening.  As the shell grows, features are added to the whorls (coils of the shell), like: folds, ribs, rows of nodes or spines, that may be closely or widely spaced.  Whorls may be broad or narrow.  There may be a notch in the whorl.  Some whorls may be robust, others flat.  The whorls and shell features are used to indicate the Family, Genus, and Species of the animal.

       This section has been set up to showcase individual gastropods.  They will be sorted first by location.  And finally, where enough detail is warrented, by species..

  
 

 

South Dakota