Earthworms are seen all over the world. Earthworms belong to the phylum Annelida. Followings are the impacts and importance of “Earthworm”
Normal earthworm is classified under order Haplotaxida. They are normally seen under the earth up to 2 meters, moist soil is the main home of earthworms, it has a capacity to reproduce and duplicate the lost segments.
Shape and size.
A mature worm measures nearly 8-21 cm in length and 3-5 mm in thickness. Earthworm is extended, long, narrow, cylindrical and bilaterally symmetrical. The forward end is tapering and the latter end is blunt. It has dorsal and ventral area.
It has reddish-gray dyed body and very thin, soft, flexible and highly vascular with multicellular but single covered body. Moist body wall helps in breathing process. Body cavity named the coelom is seen among the alimentary canal and it is filled with coelomic fluid, which retains body surface in moist condition needed for respiration.
Nonstop process of contraction and relaxation of body wall supports the earthworm for the locomotion from one place to other. This process affects the forward movement of the body.
They feed on decomposing organic matter and expel it, which are rich in nutrients and so it helps to manure the soil. It takes the soil into alimentary canal and the organic matters are processed and engaged. The undesirable soil particles are come out as excretory product named as worm cast.
In earthworm, 14th to 17th parts are bounded by thick girdle-like glandular matter called clitellum. Cocoon development takes place in clitellum. It is seen only in the mature worm so it helps to distinguish the mature from immature worms
Earthworm is inter sexual in nature. But they cannot self-fertilize, so it is necessary to find a mate for interchanging the sperm cells, it takes 4 weeks to attain sexual maturity, while matting, two worms are facing opposite direction and then the sperms are replaced by both and after matting they became separate, finally the coon is formed, it is 2 mm in size, fertilization takes place inside the cocoon.
• In earthworms eyes are absent.
• Absence of heart
• Its life duration is about 5-8 years
• It helps to decrease the acidity and alkalinity of the soil
• While fishing it is used as a bait for fishes
• It is also used as a nutrition for some mammals, frogs, toads, moles, hedgehogs and birds
• Many people produce money by catching these worms and providing it to scientific laboratories
• Earthworm is named Farmer’s friend for the reason that more over it can consume all decompose materials and convert the soil into highly nutritive. Agriculturalists use earthworms for making manure this process is called vermicomposing.
• Earthworms are recommended for dropping body weight, removing bladder stone, curing jaundice and piles.
But now the population of the earthworm gets reduced due to the human activity like throwing plastic bags in the agriculture field, spraying fertilizer in the land and organic sewage.