International Journal of Soil Science

Year: 2011 | Volume: 6 | Issue: 2 | Page No.: 124-133
DOI: 10.3923/ijss.2011.124.133

Earthworm Resources of Western Himalayan Region, India

Deepshikha Verma and Shweta

Abstract: The aim of the study was to update the existing information on earthworm biodiversity in the study area with particular reference to vermicomposting species. A field survey of earthworms in Doon valley of Western Himalayan region conducted in September 2009, enlists 12 species belonging to 7 genera and 4 families. Information on earthworms’ scientific name, family, origin, locality and voucher specimen number, date of collection, general habitat are given for each species discussed in the text. Drawida nepalensis, Eutyphoeus orientalis, Lampito mauritii and Perionyx sansibaricus have been identified as potential species for vermicomposting with a preference for dung heap. Eutyphoeus pharpingianus Michaelsen, Octochaetona betarix Beddard, Lampito mauritii Kinberg, Metaphire anomala Michaelsen, Metaphire posthuma Vaillant are reported for the first-time from the study area. Need for exploration of such unstudied areas for earthworm biodiversity has been re-stressed.

Keywords: Doon valley, biodiverstiy, vermicomposting, Western Himalaya and Earthworm

INTRODUCTION

Indian earthworm fauna is predominantly represented by native species, which constitutes about 89% of total earthworm diversity in the country (Verma et al., 2010a; Julka and Paliwal, 2005a). Earthworm explorations in Western Himal dates back to 1889 (Verma et al., 2010b). Paliwal and Julka (2005) described the earthworm species of Typhoeus masoni (Syn. Eutyphoeus orientalis) for the first-time from Dehradun (Uttarakhand). Large-scale developmental activities like rapid industrialization and urbanization has eventually caused degradation of forests (Pal et al., 2009). Therefore, the native species are threatened because of extensive destruction of their natural habitats (Sinha et al., 2003). And, conservation of earthworm biodiversity can only be achieved through protection of biological habitats (Choudhuri et al., 2008) that require a detailed periodical survey and inventory of the existing bioresources.

Stephenson (1923) listed 28 species of earthworms from this region in the publication Fauna of British India (Volume on Oligochaeta). Information on diversity of earthworms of this region was further enriched by Cernosvitov (1931), Soota (1970), Halder (1980), Julka and Paliwal (2000, 2005c). Thereafter, the taxonomical studies in this region have been more or less neglected. The present investigation is based on this rationale and updates existing knowledge about the earthworm diversity in the study area.

MATERIALS AND METHODS

Field work was carried out in September 2009. The methodology adopted for earthworm collection was based on Gates (1972). Collected worms were washed in fresh water and stored in test tubes in the field. Ethyl alcohol was gradually added to the test tube and then transferred to the dish containing a solution of 5% formalin for fixation and kept for a period 6-8 h, followed by their preservation in 70% ethyl alcohol or 5% formalin. All specimens were serially numbered. Earthworms were identified with the help of monographs and other available literature on the subject (Stephenson, 1923; Gates, 1972; Julka, 1988) at the Vermiculture Research Station (VRS), D.S. College, Aligarh and confirmed at Zoological Survey of India (ZSI), Kolkata. Voucher specimens collected and examined in the present work are deposited in the Museum of VRS, for future reference and study.

Study site: Uttarakhand, a newly created State in India, is surrounded by Nepal in the East, China in the North, Himachal Pradesh in West and UP in South. The area from which data were derived is situated at 235 km North-East of Delhi, between 30° 19’ N latitude and 78° 04’ E longitude (Fig. 1). The areas and their surroundings visited include Dehradun, Mussoori and Rishikesh rural and forest pockets.

Doon valley is surrounded by the Mussoori in the North and the Shiwalik hills in the South West, the rivers Ganga and Yamuna in the East and West, respectively. The entire valley is drained by the river Song. Climate of the area is temperate and humid. Temperature ranges between 36 and 16.7°C during summer (March-June) and 23.4 to 5.2°C (November-February); mean annual rainfall is 15.23 cm (July-October). Forest types are diverse ranging from temperate to dry deciduous (Table 1).

Earthworm and soil sampling: Earthworms and soil samples for taxonomic studies were collected by digging and hand sorting method. Samples were collected from diverse ecological niches viz. Dense forest; Grass land (Ungrazed); Grass land (Grazed); Cultivated land (Maize Crop); Dung heap; Stream bank; Under stones and Bank of river.

Analysis of soil samples: Soil samples were analyzed for soil texture by international pipette method (Piper, 1966); pH by digital meter (Misra, 1968) (Table 2).

RESULTS

The earthworm species collected and identified from the study area are arranged family-wise in alphabetical order. Each entry gives the information in sequence: Earthworms’ scientific name, voucher specimen no., date of collection and general habitat. A brief introductory note on each family is also preceded before the text. Species marked asterisked (*) are reported for the first time from the study area.

Moniligastridae: A family of primitive earthworms in East and South Asia. A few species are hydrophilous and some are common in arable soils but most are confined to primary forests. Of the Indian genera Desmogaster, Drawida and Moniligaster, Drawida are the largest genera in terms of number of species. Its natural distribution extends from the Indian peninsula to the Eastern Himalaya. Occurrence of Drawida nepalensis in the Western Himalaya is suspected to be due to recent introduction (Julka, 1995).

Drawida nepalensis Michaelsen:

Lumbricidae: Lumbricids occurring in the Western Himalaya, are well known peregrines which have possibly been transported to this region in soil around roots of exotic plants. They have successfully colonized in certain areas of hills.

Octolasion tyrateum Savigny:

Octochaetidae: Endemic Octochaetids in this region belong to the genus Eutyphoeus are represented by fairly large sized geophagous worms of 5 species which are inhabitants balui domat soil. They form casts on soil surface in the form of coiled towers. Octochaetona betarix, a native worm occurs in agriculture land (paddy crop) and soil rich in organic matter.

Eutyphoeus incommodus Beddard:

Eutyphoeus orientalis Stephenson:

Eutyphoeus pharpingianus Michaelsen*:

Eutyphoeus nicholsoni Beddard:

Octochaetona betarix Beddard*:

Eutyphoeus waltoni Michaelsen:

Megascolecidae: Its distributional range extends between warm-temperate Asia and Australia. Native species of Lampito mauritii have been recorded from almost all Western Himalayan districts in Uttarakhand. Metaphire anomala is well known inhabitant of litter and Metaphire posthuma inhabits in gravelly soils near water line. Endemic Megascolecids in this region belong to the genus Perionyx. Species explosion seems to have occurred in the Eastern Himalaya, a region with considerable and regular rainfall and high organic matter in the soil.

Lampito mauritii Kinberg*:

Metaphire anomala Michaelsen*:

Metaphire posthuma Vaillant*:

erionyx sansibaricus Michaelsen

DISCUSSION

The present study records 12 species of earthworms from Doon valley of Uttarakhand State in India, representing 7 genera and 4 families. Of these, megascolecidae represents the most active earthworms Lampito mauritii and Metaphire posthuma are predominant species with wide distribution in the study area at all sites (Table 3).

The moderately active earthworms of the family octochaetidae and moniligastridae are short moving. A review of pertinent literature indicates that species marked astersked (*) have not been recorded earlier from the study area (Julka, 1995; Paliwal and Julka, 2005).

High diversity at moderate altitudes may be due to soils rich in organic matter and subtropical and mild temperate climate. Low number of species at higher elevations is possibly due to extreme cold and unfavorable soil conditions. The present observations agree with the species-altitudes relationship studies in other parts of the world. An inverse relationship between number of species of megascolecidae and altitude on mountains in North Iceland of New-Zealand. Sergienko (1969) have also opined that the number of Lumbricid species decrease with rise in altitude in Russia and France, respectively.

The study indicates that of the species recorded from the study area, 09 are native to Indian subcontinent and the remaining 03 are well known peregrine of extra Indian origin. Drawida nepalensis, Eutyphous orientalis Lampito mauritii and Perionyx sansibaricus have been identified as potential species for vermicomposting, with a preference for dung heap comprising very high organic matter (Table 4).

Since, these species thrive well in cattle dung and soils rich in organic matter, they could be best suited and used in vermicomposting because of their affinities for high organic matter.

The majority of native species of earthworms have been recorded from 1000 to 2000 m altitudes whereas exotic species are found between 300 and 4000 m. Species from other biogeographical regions occur primarily at elevations between 300 and 2000 m. Further, the peregrine exotic species in Western Himalaya are suspected to have been introduced to Doon hills, possibly as a result of their transportation in soil around roots of exotic plants and through other agencies (Julka and Paliwal, 2005b). Introduction of peregrines in soil around roots of plants or otherwise has also been recognized by Gates (1972) during his studies on the oligochaetes intercepted by US Bureau of Plant Quarantine. Out of 50 exotic species so recorded by Gates, incidentally, 20 species were reported in Western Himalaya.

Table 4 indicates the species habitat preference for each of the twelve species collected from the study area. This shows that three species viz., Drawida nepalensis, Octochaetona betarix and Lampito mauritii show preference for a wide range of ecosites as observed by earlier workers (Gates, 1972). Drawida nepalensis is the most eurytopic species, recorded in cultivated land, grassland (ungrazed and grazed), mixed forest, stream bank and dung heap but with higher frequencies in ungrazed grassland. Among lesser eurytopics E. nicholsoni recorded in cultivated land, ungrazed grassland and mixed forest, while E. waltoni thrives best in cultivated and ungrazed grassland, stream bank and Metaphire posthuma in cultivated land, ungrazed grassland, mixed forest, stream bank, D. nepalensis, E. orientalis, L. mauritii and P. sansibaricus are indeed coprophilous; they are encountered in other habitats as well, but with very low frequency except D. nepaleansis which has been recorded from wide range of habitats. Species with restricted habitat preference are Octolasion tyrateum, E.incommodus, E. orientalis, E. pharpingianus and Metaphire anomala agreeing with field reports of Paliwal and Julka (2005).

The study represents a contribution to our present knowledge on the contemporary biodiversity of earthworm resources in the study area and contribute material for the preparation of earthworm inventory for the region. It is likely that through such investigations in unexplored areas, new species which are very specific in vermicomposting may be discovered.

ACKNOWLEDGMENT

The authors are thankful to the Department of Biotechnology, Ministry of Science and Technology, Government of India, New Delhi, for financial assistance and Dr. V.K. Singh, Adviser-cum-Consultant, for editorial support.

REFERENCES