Trematodes (on going)

• Trematodes is also known as Flukes
• Characteristics of trematodes:

  • Unsegment and leaf-like, EXCEPT for Schistosoma (cylindrical)
  • ALL are hermaphroditic EXCEPT Schistosoma (dioecious)
  • ALL will have an oral and ventral sucker
  • ALL require TWO intermediate hosts EXCEPT Schistosoma
  • Infective stage is metacercariae EXCEPT Schistosoma (Cercariae)
  • ALL eggs are operculated EXCEPT Schistosoma
  • The first intermediate host is ALWAYS a snail
  • The second intermediate host may be a fish, another snail, freshwater plants, or crustacean
• LIVER FLUKES

  Fasciola hepatica

  Fasciola gigantica

  Clonorchis sinensis

  Opisthorchis felineus

  Opisthorchis viverrini

  Dicrocoelium dendriticum
• INTESTINAL FLUKES

  Fasciolopsis buski

  Echinostoma ilocanum

  Heterophyes heterophyes
• BLOOD FLUKES

  Schistosoma japonicum

  Schistosoma mansoni

  Schistosoma haematobium

  Schistosoma intercalatum

  Schistosoma mekongi
• All Schistosoma adult worms exist as separate sexes (dioecious)
• Transmission of Schistosoma via skin penetration
• Infective stage of Schistosoma is Cercariae
• Blood flukes has only one intermediate host