Comment of Planaria
Distribution:
planaria is found in India, Myanmar, UK, USA and U.S.S.R.
Habit and Habitat:
Planaria (Dugesia is a Freshwater triclads. It is found in the Freshwater streams, springs, ponds and lakes under the stones throughout the temperature zone.
General characters:
1) Body of Planaria or Dugesia is elongated, bilaterally symmetrical and dorsoventrally flattened.
2) They are 2-15 mm in length and brown to black in color.
3) Head is triangular with conspicuous auricles and two eyes.
4) Digestive system consists of the mouth, proboscis, pharynx and a branched intestine.
5) Reproduction is sexual, asexual and by regeneration.
6) Pharynx plicate directed backwards.
7) General pore is situated a little posterior to the mouth.
Economic Importance:
They were reported as being capable of eradicating the entire earthworm population on farms.
Diagram of Planaria
Comment of Fasciola hepatica
Distribution:
Fasciola hepatica is cosmopolitan in distribution through sheep raising areas. In the USA and India it is endemic.
Habit and Habitat:
Fasciola hepatica is found as an endoparasite in the bile ducts of the liver of sheep.
General characters:
1) Fasciola hepatica is commonly known as liver Fluke.
2) Body is leaf-like, dorso-ventrally Flattened measures 25-30mm in length and 4-5m in breath.
3) Mouth is situated at the anterior end and its surrounded by the oral sucker. .
4) Excretory pore lies at the extreme posterior end of the body.
5) Life cycle is complicated and includes an intermediate host, lymnaea, a mollusc.
6) Liver-Fluke causes a disease known as liver rot.
7) Hermaphroditic. Male system consists of testes, vasa deferentia,seminal vesicle, ejaculatory duct and penis, while Female system comprises ovary, uterus and vitelline glands.
Economic Importances:
Fasciola Hepatica causes liver rot in sheep.