Ascaris lumbricoides: example of nematelmint

What they are - biological definition

The Nematelminths or Nematodes, also popularly known as cylindrical worms, are animals belonging to the phylum Nematoda, kingdom Animalia and Domain Eukaryota.

Summary of the main characteristics of Nematelminths

- The body of the Nematelminths is cylindrical, non-segmented and elongated.

- They are triblastics (have three types of tissues): ectoderm, mesoderm and endoderm.

- Have partially centralized nervous system.

- Have complete digestive system.

- They have excretory system formed by two longitudinal channels.

- They have body with bilateral symmetry and three germ layers.

- They have no circulatory and respiratory system (gas exchange occurs by diffusion through the body surface).

- Some species are terrestrial while others inhabit water (mainly freshwater).

- Some species are microscopic, while others can reach up to 10 meters in length.

- Most species have internal fertilization.

Examples of Nematelminths:

- Ascaris lumbricoides (popularly known as roundworm)

- Ancylostoma duodenale

- Wuchereria bancrofti

- Oxyurus vermicularis

- Strongyloides stercoralis

Main diseases caused by Nematelminths:

Many nematelmints are parasites and when they penetrate the human body can cause disease.

Name of nematelminite parasite and disease caused

- Ascaris lumbricoides - ascariasis

- Ancylostoma duodenale - hookworm (popularly known as yellowing).

- Wuchereria bancrofti - lymphatic filariasis (popularly known as elephantiasis).

- Oxyurus vermicularis - oxyuriasis (enterobiosis).

Biological curiosity:

- More than ten thousand species of nematelminth worms have been cataloged.

Wuchereria bancrofti: causative nematelminth of lymphatic filariasis.