Most of the people misunderstand nematodes as earthworm, reason being both of them have two heads. It is difficult to distinguish nematodes from other phylum existing in the environment. Nematodes which are also known as round worms have derived its name from Greek work nematos which means thread which is found in most of the ecological space. Scientists have discovered 15,000 species of nematodes, whereas it is estimated that 500,000 exist on earth. While majority of nematodes are free living species, some of them are also known to be parasitic.
Nematodes can be found anywhere, in marine water, fresh water, in any soils from the polar region to the tropical place. They are also found in rocks, mountains and in deserts. It is estimated that some of the good top soils contain billions of nematodes per hectare. However, these worms work as pests. A free living nematode can reach 5cm, whereas, they are typically just 2.5mm long. The smallest nematode can be seen under a microscope. While the head of nematodes is radially symmetrical, rest of the body is bilaterally symmetrical. They have sensory bristles with solid head-shields and mouth of three or six lips. The body of the nematodes is covered with secreted, flexible, non-living cuticle which is similar to the material found in our fingernails.
Nematode worms are extensively used in biological research. They are also used in controlling insects. The presence of nematodes in garden soil ensures that the plants are free from pests. They can easily be applied and are harmless to children and pets. This is the reason, in many countries nematodes are used by the gardeners. Though they combat the pests, unlike other chemicals they are harmless to human beings. Nematodes solution to breed the species is easily available in the market.
Nematode Worms – Pictures