Nematode comes from the word can not see which means thread, and ear which means form. These worms are also often called worms. Among other phyla, this phylum has the most members, both types and individuals. In this article will discuss in more detail about nematodes.
General Characteristics of Nematodes
- can be found on land, fresh water, and sea water, from the polar regions to the tropics.
- Their lives are free, but some are parasitic on plants and animals.
- It does not have a circulatory system and a heart, but contains fluids such as blood that can seep into parts of the body due to body contractions.
- The body shape is long and has bilateral symmetry
- The body is ciliated and unsegmented, covered by a transparent cuticle.
Food Digestive System
His digestive system is complete and has seudoselum fluid that helps circulate food throughout the body. The digestive tract is a straight pipe that starts from the esophagus and continues into the intestines and ends at the anus.
- Excretion System
Consists of two lateral canals that open into a ventral opening
- Respiratory system
Respiration by gas exchange by diffusion across the body surface.
- Nervous System
The nervous system is better developed than the platyhelminthes, with the presence of a cerebral ganglion and 2-3 longitudinal nerve bundles.
- Reproduction system
Sexual reproduction. The male and female genitalia are separate. Generally, female worms are larger than male worms. Another difference is in the tail. In males, near the anal canal there are protrusions called penial setae which are used for copulation, whereas in females there are none.
- Members of the Phylum Nematoda
- Bracelet Worms ( Ascaris lumbricoides)
Generally live as parasites in the human intestine. These animals are cosmopolitan (found everywhere), especially in the tropics. Ascaris causes a disease known as ascariasis.
This worm is a parasite in the human intestine and is often found in mining areas, especially in hot climates. This worm sucks blood so it can cause death. When sucking blood, worms secrete anti-coagulant substances that prevent the victim’s blood from clotting
- pinworm ( Enterobius vermicularis)
Lives in the human colon. The female worm is between 9-15 mm long. when laying eggs, female worms point the anus to obtain oxygen, which the larvae need for growth. The movement of this worm causes itching in the anus.
- Filarial worms ( Wuchereria bancrofti)
Filarial worms have intermediate hosts such as mosquitoes and permanent hosts, namely humans in the lymphatic vessels. During the day the larvae are in the lungs or in large blood vessels. At night, the worms move into the upper arteries and peripheral veins near the skin.
- Muscle Worms (Trivinela spiralis)
This worm causes trichinosis in humans, pigs, or mice. This parasite enters the human body through undercooked pork.
These worms live parasitically on plant roots and cause swelling of the roots.
Thank you, I hope this article is useful.
Also read: Know More About Cestodes (tapeworms)