Wednesday, May 14, 2008

Gastropoda - Neritimorpha

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I am sure a few of you can no longer stand seeing or reading about snails but there will be more today. Don't dispear! Today's contribution will be rather short.

Neritimorpha

The Neritimorpha include the Neritoidea, Neritopsoidea, Platyceratoidea and Hydrocenoidea. Common characteristics are good preservation of highly variable color paterns, a protoconch consisting of aragonite and a teleconch consisting of calcite. In many species the larva is marine but the adults live in freshwater. Few species are completely adapted to living in freshwater conditions.

Neritopsoidea

Theodoxus
  • representative of the Paratethys
  • habitat: rivers, brackish water
  • salinity: 2 - 15 ‰ but lives mainly in freshwater
  • no larval stadium because they would be swept away by currents in rivers
  • no connection to the ocean necessary
  • protoconch spheroidal
Nerita
  • marine
  • whorls partially dissolved thus no columella visible
  • few terrestrial species

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