A REPORT ON EARTHWORM SPECIES OF TARAKESWAR AND ADJOINING AREA OF HOOGHL Y DISTRICT, WEST BENGAL WITH SOME ECOLOGICAL NOTES

Earthworms are elongated soft bodied segmented small invertebrates. In 1881 Darwin realised that the earthworms play an important role on the fertility of the soil. They burrow under the soil, leave the castings outside and help in mixing and churning of the soil. The burrows increase drainage and aeration. Moreoever, the castings are rich in macro and micro nutrients, which are essential for plants growth.


INTRODUCTION
Earthworms are elongated soft bodied segmented small invertebrates.In 1881 Darwin realised that the earthworms play an important role on the fertility of the soil.They burrow under the soil, leave the castings outside and help in mixing and churning of the soil.The burrows increase drainage and aeration.Moreoever, the castings are rich in macro and micro nutrients, which are essential for plants growth.
Recently (due to so called green revolution), farmers are suffering from the loss of soil fertility, water content deficiency and many other problems due to indiscriminate use of chemical fertilisers and pesticides.Now all people are searching for a sustainable lifestyle and agronomists are also recommending sustainable agriculture, which may succeed by the use of bio-pesticide and bio-fertiliser, which are very costly till now.If farmers make their own compost by simple methods then it may succeed.
For commercial Vermicomposting we need some special epigeic species (Edwards Lofty 1977, Dash, 1994).In our country mainly two exotic species, namely, Eisenia foetida and Eudrilus eugeniae are being used for this purpose.But these species are costly and their extensive use may be harmful in ecological aspect, as some conservationist are shouting about this matter.Most of the earthworms feed on decaying organic matter in the soil and after its assimilation in the alimentary canal, excrete the soil as cast (vermicast) which is rich in nutrients.This vermicast contains various amino acids, minerals and micro-organisms which humify the organic matter in the surrounding soil and act as soil conditioners and biofertilisers.However, the capability of decomposing organic matter varies from species to species.It is very essential to select suitable species of earthworms for the purpose of waste conversion by Vermicomposting.Therefore, we need detailed information about the availability of earthworm species, their habitat, conditions of living, and nature of a particular area (Annonymous, 1993).
So it is very urgent to inventorise the local species of earthworms before going to commercial Vermicomposting in a certain locality.
Keeping these words in our mind, we are going for a random survey for earthworm species available in and around Tarakeswar locality, for the compatible species of earthworm for Vermicomposting.
Out of about 3900 global species and some 390 species reported from India, and 63 species are known to occur in West Bengal (Halder, 1994).The present report is based on the study made during July-September, 2004.Out of 46 specimens collected so far, 9 species were identified belonging to 6 genera and 2 families.Seven species are reported for first time from Hooghly district, where as one species namely Drawida willsi is recorded here for the first time from this state.
The diagnostic characters and proper habitat of each species are provided in this short communication with short ecological notes (Gates, 1972;Julka, 1988).Diagnosis: Length 40-150 mm, diameter 2.5 mm, segments 75-102.Clitelum in XIV-XVI; spermathecal pores two pair, small transverse slits, just median to C; genital markings one small, circular, translucent area lateral or anterior to each male porophore, another similar one on VII, just anterior to each spermathecal pore; male pores paired at or median to B C in 10/11, and just in front of female pore (11112).Gizzards 2-4, in XII-XX; prostates glandular, prostatic capsules 2-4 mm long, slenderly club-shaped; spermathecal ampula irregularly pear-shaped; diverticulum sac-like, 3-5 mm long in VII with regular annulations.

Phylum
Ecological notes: Occurs in soil of gardens, lawns, open area and jungles; living in soil under bamboos and banyan trees.We observed its high population at the shed of a large Bamboo bush.Polulation counted as -30\ sq.ft.Status of this species here considered as plenty.

Remarks:
The original home of this species is China.In West Bengal, it was reported to occur from Darjeeling and Kolkata.Now it's reported for the first time from Hooghly district.(Baird, 1809) Materials: 2 exs., ploughed field at Bhanjipur village, dated 4.vii.2004,ColI.S. Mitra.

Amynthas diffringens
Diagnosis: Length 45-170 mm, diameter 3-6 mm, segments 79-121; clitelum XIV-XVI; first dorsal pore usually at 11112; genital marking small circular or shortly elliptical disk, paired pre-setal, just median to the line of spermathecal pores in some or all or VI-IX; spermathecal pores 4 pairs, minute, superficial, each in a small circular to transversely elliptical disk in 5/6-8/9; female pores mid ventral.Gizzard large, somewhat conical, narrow in front; intestinal origin usually in XVI; last pair of hearts in XIII.
Ecological notes : It prefers soils in forest floor with high organic matter, under stones and rocks and rotten woods near pond water.We collect it from the surrounding area of a cultivated field.Status of this species is moderately common.
Ecological notes: This species was collected from the soil beneath the rotten cow dung beside a cultivated land.It is also collected from the hard soil of Jute field.Generally it occurs in soils of gardens, lawns, open fields, bamboo groves and deciduous jungles, rain forests, under logs.Status of the species here is not so common.
Remarks: This species originated from South East Asia and is endemic to Oriental Region.So far it was reported from Calcutta, Darjeeling and Jalpaiguri district from West Bengal.It is the first report from Hooghly district.
Ecological notes: Greyish-yellow in living condition; living in top 10 cm of semi-moist sandyloam soil, sometimes blackish soil; castings abundantly available in lawns and grass beds on the border line of grassy area and open area, deposited on the surface of the soil in the form of small heaps of spheroidal or nearly globular pellets.It is a commonly occurring species of this area.
Remarks: These worms are reported to be utilised as waste conditioners.But survival rate of this species is very poor in artificial culture beds.Here it is collected from a semi decomposed sandy soil beside a big pond.
6. Metaphire posthuma (Vaillant, 1868) Materials : 3 exs., from beside a pond at Bhanjipur, Tarakeswar, 5.vii.2005,ColI.K. Ghosh.Ecological notes: Light to dark grey in living condition, curled into ball when touched; living in top 15 to 20 cm. of moist and semi-moist clayey loam soil, available in flower beds, grass beds and soil covered with dry heaps of leaf litter; comes out of the burrow after overnight shower; castings deposited on the surface of the soil in the form of small heaps of loose ovoidal pellets.This species is not so common in this area.

Diagnosis:
Remarks: This is a very common species in India.In West Bengal it was known to occur from Burdwan, Calcutta and 24-Parganas (N) districts only.So this the first record of this species from Hooghly district.It is commonly used as laboratory materials in India.
Ecological notes: Living in top 10 cm of semi-moist sandy-loam soil, manure and compost heaps, under logs, bricks, rocks at edge of a water bodies, under barks of standing and fallen trees.
Leaves of aquatic plants.Soil near water cources, soil saturated with water from bathroom and kitchen.Sometimes blackish soil; castings abundantly deposited on the surface of the soil in the form of short thread or rods.
Remarks: These worms are reported being utilized as waste conditioners.Probably this is the most common Indian species which has potentialities for Vermicomposting.This species has a bad habit of escaping the vermibed just after some rain.This is the most commonly occurring species in this area.(Perrier, 1872) Material: 1 ex., Padmapukur, 5.vii.2005, ColI. S. Mitra.Diagnosis: Length 40-360 mm, diameter 1.5-10 mm, segments 136-297.Prostomium rudimentary or lacking.Genital markings transversely elliptical, paired, presetal on XIX and successive segments in line with or slightly median to male pores, occasionally on VI, VII and XVII.First dorsal pore at 12/13.Female pore single, mid ventral, on XIV.Male pores paired, Septa 8/9-0/10 absent.Intestinal origin in XVI.Last pair of hearts in XII.

Polypheretima elongata
Ecological notes : Under compost and manure heaps, rubbish, soils-red, black cotton or black taro; castings are found on soil surface in the form of cords of about 2 mm thickness and 20-24 mm in length or in irregular piles of 10-20 mm high and 20-35 mm wide.

Drawida willsi
Ecological notes : This species was collected from the moderately hard soil beside a jute cultivated field.The soil is somewhat brownish in colour and clayey in nature.Population of this species is very scanty.