ON THE OCCURRENCE OF FIVE LEECHES BARBRONIA WEBERI , GLOSSIPHONIA ANNANDALEI , GLOSSIPHONIA HETEROCLITA , GLOSSIPHONIA RETICULATA AND PLACOBDELLA UNDULATA IN WEST BENGAL , INDIA

During field survey leeches are collected from different districts of West Bengal [21 °25'26°50' (N) Longitude, 86°-89°58' (E) Latitude]. The lower Ganga plain extending from foot hills of DarjeeIing, Himalaya in the north to the Bay of Bengal in south (580 km.) and Chotanagpur high lands in the west to the border of Bangladesh and Assam in the east (200 km.). Out of these leeches, five leeches are unreported in West Bengal. Harding and Moore (1927) provided a comprehensive account of the Indian leeches. Other workers like Blanchard (1923), Bhatia (1930), Baugh (1960), Soos (1965), Mahajan and Chandra (1976), Soota and Ghosh (1977), Nandi and Raut (1987) and MandaI (2004a, 2004b, 2004c) have contributed a lot on the taxonomy of this group. The paper deals with the description of five species of the leech for the first time from West Bengal, India.


INTRODUCTION
During field survey leeches are collected from different districts of West Bengal [21 °25'-26°50' (N) Longitude, 86°-89°58' (E) Latitude].The lower Ganga plain extending from foot hills of DarjeeIing, Himalaya in the north to the Bay of Bengal in south (580 km.) and Chotanagpur high lands in the west to the border of Bangladesh and Assam in the east (200 km.).Out of these leeches, five leeches are unreported in West Bengal.Harding and Moore (1927) provided a comprehensive account of the Indian leeches.Other workers like Blanchard (1923), Bhatia (1930), Baugh (1960), Soos (1965), Mahajan and Chandra (1976), Soota and Ghosh (1977), Nandi and Raut (1987) and MandaI (2004aMandaI ( , 2004bMandaI ( , 2004c) ) have contributed a lot on the taxonomy of this group.The paper deals with the description of five species of the leech for the first time from West Bengal, India.

MATERI~L AND METHOD
In course of survey almost all niches are taken into consideration to find out the leech individuals occurring in the habitat/ecosystem.In case of free living species 5 sites from a selected ecosystem (water body) are taken into consideration to note the number of leeches occurring in the system.From each site/station and area of 1 sq.ft. has been selected at random and the number of leeches occurring there are counted.The mean of such five readings is considered for actual population density per sq.ft..In case of parasitic and malacophagous leeches attempt are made to note the number of leeches attached w~~h the host body.In such case five or more host individuals are taken into account at random and mean would be considered for population density of this external parasite per host.The malacophagous leeches are counted on the basis of samplings of pelagic molluscs from an area of 1 sq.ft.from the concerned water body.In this case also five such sampling sites are taken and the leeches attached/infested with snails are counted and mean of the five readings have been considered for the final data.
The breeding season of the leeches are determined on the basis of observation of the egg, young and mating activities.The leeches are narcotized and preserved (Kapur, 1968).

DESCRIPTION OF THE MATERIAL COLLECTED FROM WEST BENGAL
Barbronia weberi (Blanchard, 1897) (Plate 1; Figure 1) Slender body, tapering anteriorly.Head very small.Circular 'posterior sucker, mouth small, lip narrow.Colour pinkish white in living.Anterior part whitish but posterior part pinkish.Colour fate up in preservative.Eyes three pairs, one large pair 'on dorsum of IT, two smaller pairs on sides of anterior annulus of IV.Gonopores separated by five annuli.Male pore situated at XII bllB2.Glossiphonia heteroclita Linneaeus, 1971 (Plate 1; Figures 3 & 4) Ovate acuminate, flattened body.Body colour amber yellow in living and greyish in preserved state.Three pairs of eyes.The first pair lies in ring 5, Second and third pairs situated respectively in rings 7 and 8.Both male and female genital ducts open by a common pore between the first and second rings of Somite XII.Total rings of the body 70.Length 8-12 mm at rest, width 2.5-3 mm.Remarks: This species is recorded from West Bengal (Hooghly and MaIda districts) for the first time.The population density, feeding behaviour, number of egg of the specimen were also observed successfully for the first time.Due to the pesticides, the number of the specimens decreased.Kaburaki, 1921 (Plate 2; Figures 5 & 6)

Glossiphonia reticulata
Slender body, attenuated anteriorly.Rough dorsal surface due to the presence of numerous papillae.Colour olive in living, grey in preservative.Anterior sucker less in diameter than the half the width of the posterior sucker.The circular posterior sucker centrally attached and less than half the greatest width of the body.Total somites 27, Ring number 72, of which three are preocular.Somites I-IV are represented by the first six rings; V-XXIV are complete with three rings; Eyes two pairs; the first pair lie in ring 4 and the second and larger pair in ring 5. Male genital pore situated between the ring 26 and 27 in Somite XI.Female pore situated between the ring 28 and 29 just two ring behind this male pore.Mouth opens within anterior sucker.The anus lies between the ring 70 and 71 just two rings behind the posterior sucker.The crop or stomach has 7 pairs of branching diverticula.Some specimen found attached with Lymnaea (Molluscs) and some with the lower part of lotus leaf at Kandi, Murshidabad.
Remarks: It is also first recorded from West Bengal.During breeding season, some leeches of this species gave birth in the month of March-April and some in June-JUly of the year.
Placobdella undulata Harding, 1924 (Plate 2; Figures 7 & 8) Elliptic lanceolate body.A constriction is seen at this 30 ring just behind the female pore.Dorsal surface rough due to the presence of papillae on e~ch ring.Distinct head region.Posterior sucker circular and slightly oval, equal in width to half on the greatest width of the body.Colour greyish white in preserved state alcohol.Ring number 71.Somites V-XXIV complete with three annuli, XXV and XXVI biannulate.XXVIII uniannulate.Presence of one preocular ring single Two examples of the species were collected by C. K. MandaI on July 18 and.20, 1995 from Galshi, Burdwan and Krishnagar, Nadia, one attached with mollusca (Length 5 mm, width 1.5 mm).
Remarks: Placobdella undulata or leech of undulated head is found first time from-West Bengal (Nadia and Burdwan).
Fig. 1. : Barbronia weberi (Dorsal view) Fig. 2. : Glossiphonia annandalei (Ventral view) 15 mm. in full extension.One example of the species was collected by C. K. MandaI on August 10, 1995 from Bhadreswar, Hooghly and twelve examples on March 23, 1995 from Piasbari Nursery Pond Ramkeli, MaIda, West Bengal.Some examples are taken from the molluscs and some from beneath the leaves of water hyacinth.

Table 4 .
: Difference between the past and present collected Leech Glossiphonia reticulata.

Table 5 .
: Difference between past and present collected Placobdella un dulata.