Worms

Worms are a name given to a diverse group of animals that have long, soft bodies and no legs or backbone. Some of them can be seen through naked eyes while some can only be seen under a microscope. There are thousands of species of worms. Out of which 2,700 are earthworms. Helminthes are a medical name for parasitic worms and their study is called Helminthology.

Habitats:

Worms usually live in soil, but few species can be found in freshwater, marine seawater and on the seashores. Many worms thrive as parasites of plants, animals and humans, while most of them are non-parasitic. Some worms like the earthworms enrich and aerate the soil thus help in conditioning it.

Groups of worms:

There are three main groups:

• Platyhelminthes: These include flatworms. They have flat, ribbon shaped bodies with a pair of eyes in the front. Some of them are parasites.
• Nematoda: These include threadworm, roundworms and hookworms. The threadworms are found in damp earth, moss, and decaying matter or freshwater. Some may be microscopic while some could be more than 3 feet long. Some may be parasitic like few species of roundworms.
• Annelida: They are segmented worms such as the earthworms. Their bodies are divided into several segments or rings.

Some insects in their immature larva stage may also be known worms, such as silkworms, bloodworms, glowworms or inchworms.

However, ringworms are not a type of worm, they are skin fungi.

Characteristics:

• Worms are invertebrates. They have different shapes and sizes. They are either a cylindrical, flat or leaf-shaped body and their size may vary from less than 1 mm to more than 30 meters. Many of them are microscopic.
• Some worms are hermaphroditic, which means they have both male and female sex organs and they reproduce sexually, while some reproduce asexually wherein a new body is developed from the body cells.
• Most of them do not have developed body muscles hence they cannot move about on their own. They take the help of other animals or forces in the surrounding. Many species have bodies with major muscles and can move on their own without any external forces.

Worms form an integral part of our ecosystem as many species have the ability to decompose organic matters such as dead plants and animals and convert them into soil nutrients. Hence they are very important to nature in ecological terms.