Search results
Results from the WOW.Com Content Network
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate; Help; Learn to edit; Community portal; Recent changes; Upload file
Gastropod – any member of the class Gastropoda, which includes slugs and snails. What type of things are gastropods? Gastropods can be considered to be, or viewed ...
Good evidence exists for the appearance of gastropods, cephalopods and bivalves in the Cambrian period .However, the evolutionary history both of the emergence of molluscs from the ancestral group Lophotrochozoa, and of their diversification into the well-known living and fossil forms, is still vigorously debated.
Gastropods have the greatest numbers of named mollusk species. However, estimates of the total number of gastropod species vary widely, depending on cited sources. The number of gastropod species can be ascertained from estimates of the number of described species of Mollusca with accepted names: about 85,000 (minimum 50,000, maximum 120,000). [9]
The molluscan shell has been internalized in a number of lineages, including the coleoid cephalopods and many gastropod lineages. Detorsion of gastropods results in an internal shell, and can be triggered by relatively minor developmental modifications such as those induced by exposure to high platinum concentrations. [41]
In the most primitive gastropods, however, the stomach is a more complex structure. In these species, the hind part of the stomach, where the oesophagus enters, is chitinous, and includes a sorting region lined with cilia. [1] In all gastropods, the portion of the stomach furthest from the oesophagus, called the "style sac", is lined with cilia.
The scaly-foot gastropod is an obligate symbiotroph throughout post-settlement life. [24] Throughout its post-larval life, the scaly-foot gastropod obtains all of its nutrition from the chemoautotrophy of its endosymbiotic bacteria. [26] [24] The scaly-foot gastropod is neither a filter-feeder [5] [24] nor uses other mechanisms for feeding. [5]
Request to editors: please do not create any more categories of gastropods by country. Instead create list articles, article with a list of the marine or non-marine gastropods of whichever country or area you are interested in. We would also like to empty and delete the two remaining country categories we have, adding that information to list ...