Earthworms

Earthworms are segmented worms, with a shiny outer body. They have segmented cylinders which taper on both ends. They have approximately 3000 known species. The sizes of the earthworms are from few millimeters to two or three meters in length.

The buildup of earthworms simplified!

• The earthworms have a body with no prominent body parts which makes it easier for them to crawl through narrow burrows without any obstruction.
• The earthworm brain is not very complex. It just has the function of directing the body in response to light.
• A typical earthworm has five hearts. There are calciferous glands situated between the hearts to manage excess calcium in its diet.
• The earthworms breathe through its skin. It does not have lungs.
• Earthworms are hermaphroditic; it has both male and female reproductive organs.

Reproduction:

Earthworms’ male reproductive organ has two pairs of testes which are present in the 10th and the 11th segment, counted ventro-laterally. The sperm passes through the sperm ducts to two male genital openings on the 11th and the 12th segment that collects the fluid. The sperms are received from the other partner while mating.

The eggs are formed in a pair of ovaries that releases from the oviducts into one of the two tiny pores (female genital opening).

The male and female sexual openings are situated near the clitellum, which is a rubbery, band-like swelling that secretes a cocoon to receive the eggs.

The mating usually occurs in moist environment. The egg cocoons are deposited in the soil. The eggs are hatched into young ones. They grow continuously until they reach adult size.

Benefits of earthworms:

• Earthworms are said to be very helpful to nature in ecological terms. They have the ability to convert organic matters (dead leaves) into rich humus with improves soil fertility.
• They also ingest other soil particles and digest them into fine paste in its stomach. The casting from these particles is minerals and plant nutrients that are either deposited on the surface or deeper in the soil.
• They plow the soil by their burrowing action which provides air and water circulation to the soil. This helps plant roots and other soil micro-organism to breathe and grow.
  
  Earthworms are very beneficial to the biosystem and acts as a vital component for healthy soil. They make excellent worms for vermiculture. However weird it may sound, but earthworms are served as a delicacy in Maori in New Zealand.