Bionomics, Distribution and Relationships of Earthworms

Abstract

Earthworms are commonly found in all Tropical and Subtropical regions of the world. These animals are active in rainy session and are detritus feedus. They are considered as friends of farmers, several species of earthworm like Pheretima, Eutyphoeus, Dravida, Megascolax Tonoscolox etc. are found in Indian subcontinent. Usually earthworms are found in soil but some forms like Perionyx is found in water, Dichogaster on top of palm tree, Pheretima musica is found in humas under the epiphytic ferns growing on trees, whereas Dendrobaena is found in burrows in green ice of glaciers. Before independence and several years after independence description of Lumbricus, which is a European and American form of Earthworm was given and described in our books. In 1926, Prof. Karm Narayan Bahal who was professor in Dept. of Zoology, of University of Lucknow, for first time wrote a Memoir on Indian earthworm Pheretima base on his own studies on it between 1919-1926. Like all organisms earthworm is especially adapted to its ecological conditions. Their life style, structure, and biochemistry given them a special position in animal kingdom. Earthworms are member of phylum Annelida and are placed between class Polychaeta and Hirrudinida as it show some resemblance with both. This review article deals with description of Biodiversity, Ecological relationships, Distribution, its Relationship with other two classes and its placement position in Oligochaeta.