Question

q- give an account of life history of fasciola hepatica .

Answer 1

Fasciola Hepatica is digenetic parasite. It completes its life history in sheep and fresh water snail.sheep is the primary host and snail acts as an intermidiate host.Johan de Brie" in 18th century  identified Fasciola in the sheep liver. Leuckart-Thomos reported the life cycle of liver fluke in snail.
 
Systematic position of  Fasciola:

 

PHYLUM: PLATYHELMINTHES

CLASS: TREMATODA

ORDER: DIGENEA

 

It is distributed throughout the world. It attacks sheep and causes liver rot disease in them.

 

The life cycle of Fasciola hepatica is completed within two hosts. The primary hosts, is the sheep, while the intermediate host, is a snail. This type of life cycle, involving two hosts, is termed as digenetic parasite.

 

The liver fluke undergoes copulation in the bile duct of sheep. During copulation the penis of one liver fluke is inserted into laurer's canal of another fluke and sperms are transferred. In the oviduct fertilization takes place. In liver fluke cross fertilization takes place by copulation. Self-fertilization also takes place.

 

The fertilized egg is surrounded by yolk cells and is developed into shelled egg or capsule. The shelled egg is light brown in colour. It shows a lid. It is 130 to 150 microns in length. These eggs will reach intestine through bile duct. They will be sent out of the body of sheep through fecal matter. Thousands of eggs are liberated by sheep every day. These eggs will undergo early development when the environmental conditions are favorable. At 25 degrees centigrade the egg gives rise to Miracidium larva in 9 to 15 days.

 

MIRACIDIUM LARVA:

 

In the life history of liver fluke the first larval stage is miracidium when the egg is placed in water the lid opens and miracidium comes out. This larva swims in the water.

J

Answer 2

Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic trematode (fluke or flatworm, a type of helminth) of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, including humans. The disease caused by the fluke is called fasciolosis or fascioliasis, which is a type of helminthiasis and has been classified as a neglected tropical disease.[2] Fasciolosis is currently classified as a plant/food-borne trematode infection, often acquired through eating the parasite's metacercariae encysted on plants.[3] F. hepatica, which is distributed worldwide, has been known as an important parasite of sheep and cattle for decades and causes significant economic losses in these livestock species, up to £23 million in the UK alone.[4] Because of its relatively large size and economic importance, it has been the subject of many scientific investigations and may be the best-known of any trematode species. F. hepatica's closest relative is Fasciola gigantica. These two flukes are sister species; they share many morphological features and can mate with each other.
Hope this will help you...Plz mark it as brainliest...