Question

Contrast the life cycle of a liver fluke vs a blood fluke in humans. Your essay should be no more than one paragraph.

Include in your essay the following:

1. Miracidium
2. Sporocyst
3. Cercariae
4. Rediae
5. Monoecous
6. Dioecious

Answer 1

Liver fluke is monoecious( hermaphrodite) whereas blood fluke is dioecious. Immature eggs of liver flukes are passed in the bile duct of rumminents and the released outside with faeces where they become  embroyated in fresh water and release miracidium ( which is a free swimming ciliated larvael stage) which invade its intermediate host i.e. snail and here it undergoes several stages of asexual development ( from sporocyst to rediae then to cercariae) and produce large no. of cercariae ( which are tailed and free swimming)leaves the body of snail and then they encyst as metacercariae on leaves of fresh water plants which are the ingested by definitive host which is human and in humans larvae excyst and penetrate the gut wall ad moves to peritoneal cavity from where they enter liver capsule ad migrate i hepatic tissue and after 7 weeks these half grown fluke larvae enter bile duct and after becoming mature begin producing eggs which are again released through faeces unfertilised whereas in case of blood flukes adult male and females worms produces large no. of eggs in human mesetric or vesical venules and through blood vessels reaches gut or urinary bladder and released into environment and after releasing as cercariae from snail they directly penetrate human skin from water and migrate to lungs and then to heptoportal system where they mature and mate and passed down to mesentric or vesical venules in human.