You've probably heard about roundworms, geography and yellowtail. These diseases are caused by animals belonging to the Phylum Nematoda. Let's get to know more about them?
These worms are beings with an elongated body and tapered ends, which resemble a thread. It is because of this characteristic that they were named nematodes (nematodes means thread and helminthes means worm).
These animals have a mouth on the front of the body and anus on the back (complete digestive system). Males have a cloaca, a structure common to the digestive and reproductive system through which they eliminate sperm and feces. Nematodes have separate sexes (male and female), with the female being larger than the male.
Breathing takes place through the surface of the body, as they do not have lungs. They also lack circulatory system.
The excretory system is formed by structures called renets. These rennets can be of several types, the most common being a cell in the shape of the letter H that runs through the entire body of the nematode. Excretions are eliminated to the external environment through the excretory pore.
They move by flexing their muscle fibers, this is the only way they can move, since their fibers are only arranged in a longitudinal direction. Muscle cells communicate with a dorsal and a ventral nerve cord. These cords connect to a nerve ring from which other nerve cords depart.
There are several species of nematodes and most live freely without causing diseases to humans or other animals. We say they have a free life. They can be found in aquatic and terrestrial environments.
Washing food well can prevent some diseases caused by nematodes
There are also species that are parasitic on animals and plants. In this case, we can mention the lumbricoid ascaris, which is known as roundworm. The disease caused by it is called ascariasis. In addition to ascariasis, other diseases caused by nematodes are: hookworm, geography animal, filariasis and oxyurosis.
by Vanessa dos Santos
Graduated in Biology
