The arthropoda are also known as the animals with jointed feet. Aristotle described it and Lamarck divided it into three classes such as crustacean, hexapoda and arachnida. Von Seibold proposed the arthropoda. They are found everywhere on land, soil, sea and fresh water and also ...

The hirudinaria is also known as cattle leech. It may occur as a free living or parasite. It is a free living in ponds, streams and rivers. It acts as a parasite on cattle. It feeds on blood and has an anticoagulant known as hirudin. ...

The pheretima posthuma is known as earth worm. It is found in the wet soil which is rich in organic matter. They belong to class oligochaeta. They are found in lawns, fields and gardens. They are nocturnal and omnivorous. The undigested food moves through the ...

The nereis is also known as clam worm or rag worm. They occur in the sea. They are unisexual and has a reproductive phase called as heteronereis. They fertilize in sea water and form a larva. Their head is made up of prostomium and peristomium. ...

The phylum annelida is divided into polychaeta, oligochaeta and hirudinea. The polychaeta are also known as the multiple hair animals. They are marine with the fully formed parapodia and setae. They have a definite head and have separate sexes. They have eyes, tentacles etc. Their ...

Annelida are also known as the segmented animals. They resemble a ring. Lamarck has established this phylum. They are aquatic and occur on moist soil. A few of them are free living; some are burrowing and are parasitic too. The annelids show metameric segmentation ...

The trichuris is also known as whip worm. It is whip shaped and resides in the caecum, appendix and colon. It occurs in the warm moist climates. The eggs are released in the faeces of host. The source of infection is contaminated food and water. ...

The dracunculus is known as guinea worm. It occurs in the subcutaneous tissue of man. It produces a secretion which causes a blister on the skin. The female worm releases larvae in the water. They have an intermediate host known as Cyclops. The larvae goes ...