About 3000 species of earthworms are found worldwide.
Out of which, approximately 384 species are reported
to be found in India and their detail taxonomic
studies have been done already [16]. Majority of earthworm
species live in the soil, except some species like
Pontodrilus burmudensis, which lives in estuarine water.
Earthworms vary greatly in length [viz., Microscotex
phosphoreus (Duges) is around 20 mm long while
Drawida grandus (Bourus) may be one meter in length].
Earthworms are known to inhabit in diverse ecological
niches. Besides, they are also found in organic materials
like manures litter, compost, and hydrophilic environments
near fresh and brackish water and also in snowy
patches. Most of the earthworms are omnivorous; however,
Agastrodrilus a carnivorous genus of earthworms
from the Ivory Coast of Africa has been reported to feed
upon other earthworms of the family Eudrilidae [17].
The most effective use of earthworms in organic waste
management could be achieved when a detailed understanding
of biology of all potentially useful species and
their population dynamics, productivity and the life cycles
of earthworms are known. Detail studies on Indian
species [18] and tropical species [19] and knowledge
about the reproductive strategies of earthworms have
been done. Earthworms belong to the family Lumbricidae.
Earthworms are hermaphrodites but self-fertilization
is rarity. Cocoons or eggs are small varying according to
earthworm species. Cocoon color changes with aging. At
the age of 6 weeks, earthworm starts laying cocoons. In
favorable food and weather conditions one pair of earthworms
could produce approximately 100 cocoons in 6
weeks to 6 months [20]. Cocoons incubate roughly for
about 3 - 5 weeks. Earthworms possess the ability to regenerate
body segments, which are lost by accident or