Salient Characters of Phylum Nemathelminthes Dr AJIT KUMAR

Salient Characters of Phylum: Nemathelminthes Dr. AJIT KUMAR Department of Veterinary Parasitology Bihar Veterinary College Bihar Animal Sciences University Patna-800014 Image source: Google image

Salient Characters of Phylum: Nemathelminthes o Parasites are eukaryotic organisms. Parasites Helminths Arthropods (Metazoa. Multicellular) Phylum: Platyhelminthe s Phylum: Nemathelminthes Phylum: Acanthocephala Protozoa (Unicellular)

Salient Characters of Phylum: Nemathelminthes ü Helminth word has been derived from a Greek word helmins or helminthos which means a worm. ü Helminths (worms) are mainly endoparasites. Helminths Platyhelminthes Nemathelminthes Acanthocephala

Salient Characters of Phylum: Nemathelminthes Class: Nematoda General Characters: o Commonly called nematodes ( Roundworms). o Body is generally cylindrical with pointed ends. o o Body is round in cross section and hence they are called as roundworms. Cuticle of Nematodes is rich in collagen and a carbohydrate-protein polymer called chitin. Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o Body cavity present (Pseudocoelomate). o Body segmentation absent. o Sucker absent. o Complete alimentary canal is present. Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o Unisexual (dioecious) o Females are longer than male. o Excretory organs are lateral canals Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o Life-cycle includes eggs and five larval stages and mature adult worm. o Larval stages are designated as 1 st, 2 nd 3 rd, 4 th and 5 th stage larva i. e. L 1, L 2, L 3 , L 4 and L 5 ( Immature adult). o Molting or ecdysis i. e. shedding of cuticular sheath takes places between two larval stages. o Four molting occur in the life-cycle of nematodes. Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o Infective stage: Generally 3 rd stage larva ( L 3) Exception: o o In Ascarid worms: Egg containing 2 nd stage larva is infective stage. In Trichuris spp. (Whip worm): Embryonated eggs Life-cycle of Dictyocaulus viviparous ( Lung worm) Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o In Ascarid worms: Egg containing 2 nd stage larva is infective stage Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: o In Trichuris spp. (Whip worm): Infective stage is embryonated eggs Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: Life-cycle : Direct. Image source: Google image

Salient Characters of Phylum: Nemathelminthes General Characters: Life-cycle : Indirect. Image source: Google image

Phylum- Nemathelminthes Class: - Nematoda ( Roundworms) Toxocara vitulorum Haemonchus contortus ( Stomach worm) Ascaridia galli Trichuris sp. ( Whip worm) Ancylostoma caninum ( Hook worm of dog) Dioctophyma renale ( Kidney worm of dog Image source: Google image

Salient Characters of Phylum: Nemathelminthes Nematodes ( Roundworms) Nematodes Common Name Haemonchus contortus Stomach worm Dictyocaulus viviparous Lung worm of cattle Oesophagostomum spp. Nodular worms Stephanurus dentatus Kidney worm of pig Ostertagia spp. Brown stomach worms Syngamus trachea Gape worm Dirofilaria immitis Heart worm of dog Thelazia callipaeda Eye worm of dog Strongylus spp. Pallisade worm or red worms Spirocerca lupi Oesophageal tumour worm of dog Oxyuris equi Pin worm of equines

THANK U