Roundworms

Nematodes

The phylum Nematodes also known as roundworms are one of the most common phyla of animals. There are over 20,000 different species of roundworms. Roundworms can be found in water, and on land. Roundworms have a complete digestive system with two separate openings one for food and one for getting rid of waste. This type of digestive system is very common in complex animal. Nematodes use external and internal pressure and body movement to move food through their digestive tracts. As the round worm grows it molts and forms new cuticles. Most Nematodes are microscopic though a few parasitic forms can grow to be several inches in length. Round worms eat bacteria, algae and fungi. Reproduction in roundworms is mostly sexual. the male round worm has a bent tail that is used to hold the female roundworm during copulation.

Parasitic species in roundworms often have very complicated lives, they spend the majority of their life cycle traveling from one host to another. Acquiring a parasitic roundworm can happen by eating uncooked meat with larvae in it, by entrance into unprotected cuts or directly through the skin, by transfer via mosquitoes or other blood sucking insects. The parasitic nematodes that plague humans most often are whipworms, hookworms, pinworms, ascarids and filarids. The species that is responsible for trichinosis a deadly disease to both humans and life stocks, is also apart of the Nematodes phylum.

Nematodes can be devastating economically. Nematodes can infect livestock and often make them unfit for human consumption for fear of spreading the parasitic worms to the human population. Nematodes can also have damaging effects on many crops. The most prolific species of nematodes that attack plants are folaiar nematodes, root knot nematodes, cyst nematodes. Many of these nematodes transmit virus to the plant while feeding on their root systems.

Nematodes while having a negative connotation also provide many ecological necessary functions. Nematodes are considered to be decomposers and predators. Nematodes help break down plants and other items in the soil. Often where there is productive growing soil there will be a large amount of Nematodes in the soil causing the decomposition of plants and minerals.

An interesting fact about nematodes is that they have the ability to suspend life if the environment they