title: Bithynia siamensis
text: # Bithynia siamensis
  
  Bithynia siamensis is a species of a freshwater snail with a gill and an operculum, an aquatic prosobranch gastropod mollusk in the family Bithyniidae.
  
  ## Subspecies
  
  WHO (1995) recognized the following subspecies:
  
  * Bithynia siamensis siamensis - synonym: Bithynia siamensis goniomphalus
  * Bithynia siamensis funiculata
  * Bithynia siamensis laevis
  
  Bithynia siamensis and Bithynia funiculata (synonym: Bithynia goniomphala) were recognized as separate species in the 2012 IUCN Red List.
  
  ## Distribution
  
  This species occurs in:
  
  * Cambodia
  * Laos
  * Malaysia
  * Myanmar
  * Thailand
  * Vietnam
  
  The population of Bithynia siamensis fluctuates during the year.
  
  ## Parasites
  
  Bithynia siamensis serves as a first intermediate host for Southeast Asian liver fluke Opisthorchis viverrini. The number of excretory cells of the digestive system is increased in infected Bithynia siamensis.
  
  Parasites of Bithynia siamensis include trematode Multicotyle purvisi.
  
  