TAXONOMIC AND ECOLOGICAL STUDIES ON THE AMPHIBIANS OF CALCUTTA AND ITS ENVIRONS By

While working out a large collection of amphibians accumulated in the Zoological Survey of India for the last 22 years it became apparent that quite a big lacuna existed regarding the knowledge of amphibian fauna of Calcutta and its surroundings. The work comprises the consolidated account on the amphibians of the said area. So far only a few stray records by Anderson (1871), Annandale (1909), Bhaduri (1945 & 1947), Boulenger (1890 & 1920), Mukerji (1933) and Parker (1934) are available on the amphibians of the area.


INTRODUCTION
While working out a large collection of amphibians accumulated in the Zoological Survey of India for the last 22 years it became apparent that quite a big lacuna existed regarding the knowledge of amphibian fauna of Calcutta and its surroundings.The work comprises the consolidated account on the amphibians of the said area.So far only a few stray records by Anderson (1871), Annandale (1909), Bhaduri (1945Bhaduri ( & 1947)), Boulenger (1890Boulenger ( & 1920)), Mukerji (1933) and Parker (1934) are available on the amphibians of the area.
By keeping this in view a long-term amphibian survey project of Calcutta and environs was undertaken between July 1961 to March 1963 by Miss M. B. Kripalani (Mr. M. R. Mansukhani) and staff of the Amphibia Section.Weekly surveys within a radius of 60 km. of Calcutta were undertaken covering the vast area of four major districts namely, 24-Parganas, Nadia, Hooghly and Howrah of West Bengal (between latidudes 22°7'-23°N and longitudes 87°45'-88°40'E).The work also includes the observations on the large collection from Salt Lake of Calcutta made by Dr. B. Biswas and party during May 1963to February 1967.About 1713 examples of amphibians were collected from different ecological habitats like muddy drains, tanks, lakes, canals, bushes, trees, under fallen leaves, from moist ground and village huts, while undertaking the above surveys.Amphibians are distributed among three orders namely, Apoda (or Gymnophiona), Caudata (or Urodela) and Anura.Amphibians of Calcutta and its environs are lacking former two orders and are only represented by the order Anura.
Distribution; Calcutta and environs, -As mentioned above.~18e where, -Common throughout the plains of India, Sri Lanka and Burma.Its range extends to Southern China, Malaya Peninsula and Archipelago.
Measurements: Snout to Vent length 11-114 mm.Remarks: It is the most common toad available in Calcutta and environs.It is nocturnal in habit and generally found in gardens and on roadsides while preying on various a~thropode and other invertlbrates.Juveniles are' found during the day also.Baring the bre~di~g 2Omm.

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Text-fig. 1. Bufo meZanostiotuB Sohneider season adults are found inside the burrows and in dark corners of the village huts during the day.This toad is mainly terrestrial and found in and near the water only during breeding season.On provocation its parotid glands secrete a milky fluid which causes irritation on the human skin.Material: 24-Pargans district: 47 ex.(4 adults, 37 juveniles and 6 tadpoles), Cemented tank of Eden Garden, Calcutta, S.vii.1961.ColI., M. B. Kripalani.Nadia dist.: 7 ex., Phulia, 4.xi.1964.ColI.D. ,K.Ghosal.

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Records of the Zoo~gical Sur~ey of India Distribution: Calcutta and environs, -As mentioned above.Annandale (1909)  Remarks: I~ is quite.rare, nocturnal, terrestria:l toad and found in or near water during the breeding season (April to September).Adult and juvenile toads were collected during July while inhabiting the muddy substratum beneath the large stones scattered in the Eden Gardens, Juveniles and tadpoles were also collected from a near by cemented tank.Annandale (1909) has reported that Bulo stomaticus is common in Calcutta, but it is rarely seen owing to its strictly nocturnal habits.He has also mentioned that during rains large numbers of them are found to huddle together in the many crevices afforded by the ~ee ..

'2Z0
Records oj the ZooliJu.icatSurvey oj India •Remarks: This is a very rare microhylid frog which leads a secre-' tive subterraneous life and found on the surface only during breedin.gseason.Two examples from Barrackpore have been collected Oat a depth of ca. 3 feet while the ~oundation of a building was being dug.
Distribution: Calcutta and environs,-As mentioned above.This species is being recorded for the first time from Calcutta and environs.Acharji and Kripalani (1951) have recorded it from Sukhna in Darjeeling district, West Bengal.Elsewhere.-It is a widely distributed species in India and found all over the plains of the country up to an altitude of 1524 metres.Also Sri Lanka, Burma, South China, South-east Asia and Taiwan.
Measurements: Snout to Vent length 9-20 ronl.Remarks: This quite common toad-like tiny frog is mostly found in the grasses and under the dry leaves covering the moist soil.It has been noticed that ideal habitat of these frogs in the suburbs of Cal~utta is under the falleQ bamboo leaves on the banks of ponds and tanks.In comparison to its tiny size it can cover considerably a good distance by jumping.In monsoon days they are sometimes attracted by night-lamps and found inside the rooms.Remarks: This toad-like painted frog is also quite rare and mostly found underground.In the evening of monsoon days it is sometimes found to climb moist boundary-walls of the houses in the suburbs of Calcutta.It inhales air,• swells like a small baloon keeping its head a little down and secretes a milky sticky fluid through epidermal pores of skin, when disturbed.In captivity these frogs prefer white ants (Termites).Tadpoles of this s'pecies have been brought" to the light of Science for the first time and being described separately.Three tadpoles have been collected from the stagnant rain water accumulated in an earthern pot at Hijalpukuria, Habra, 24-Parganas.Dorsum of tadpoles deep brownish with pinkish spots and ventrum light brownish with pinkish spots below the margin of lower lip.Abdulali (1962) found them in copula in temporary rain water pool in May in Western India.

Family III. RANIDAE
This family is represented in Calcutta and environs by seven species of the genus Rana Linnaeus, which can be distinguished by the following key.

Rana ttgerina
Distribution: Calcutta and its environs, -As mentioned above.

Remarks:
In Calcutta and environs this frog is generally found floating in the ponds with floating green aquatic vegetation in which it can hide properly to protect itself from the predators.Bhaduri (1947) records this frog from the environs of Calcutta and mentions that it can be obtained from old.ponds with rich green aquatic vegetation.Dr. B. Biswas has collecte.dspecimen sitting on the bank of a pond in the evening and observed that it is very common in the ponds and fishing bherie8 with floating green vegetation in the suburbs of Calcutta.Author has come across with these frogs on lanq.during the night, when they probably came insearch of food.Monda! (1970) has discussed on the culture possibilities and food of these frogs.The population of this species has declined in the area on account of exporting their legs abroad.Material: 124 frogs and 63 tadpoles.Collected from 24-Parganas district (Budge Budge, Dhakuria, Diamond Harbour, Baruipur, Halishahar, Barasat, Habra, Salt Lake); Howrah district (Botanical Garden, Jogatballavpur, Amta, Bagnan, Uluberia, Bally); Hooghly district (Sheakhala, Kristrampur, Tarakeshwar, Kamarkundu).
Distribution: Calcutta and its environs, -As mentioned above.
EZ8ewhere.-It is common throughout India from the base of the Hima-Text-fig.9. Balta tigerina Daudin lava to South India.Also Nepal, Sri Lanka, Burma, Thailand, South China and Taiwan.

Rem,arks;
In Calcutta and its environs' this giant edible frog generally found while resting inside the bushes grown on the banks of water bodies, where it retreats itlJ.mediately even on a slightest disturbance.Frogs hide inside the burrows and under heaps of dry leaves to protect their moist skin fronl the scorching sun and dry weather.
It was happened to be very common in Calcutta and its environs, but at present the population has reduced considerably on account of exporting theit legs abroad to earn foreign exchange.It has been observed in 1982 that in a ditch at Bally (Howrah district) only two to five males have been found to croak with the start of pre-monsoon shower, whereas more than fifty frogs were found to do so in the pre-monsoon of 1972.Croaking is one of the signals of arrival of monsoon for the villagers of the plains of West Bengal, and this colourful harmless 'Bull Frog' locally known 'Kola Bang' has got a suitable place in village rhyme since old days.
It has been mentioned by earlier authors that Bull Frog feeds on squi.rrels,mice, shrews, small birds of consumable size, small snake upto a metre in leng~h, spiny-tailed lizards (Uromastyx), land crabs, fishes etc., though its main diet consists of insects.Bhatta~harya (1936) reported its tadpoles feeding on mosquito larvae.Due to merciless removal of this common frog from nature villagers in many areas in the suburbs of Calcutta are gradually feeling a sort of distu~.bance in the balance in nature and they are chasing the frog-collectors when met with.This frog is more active at night, though it is usually found in day-time.It can remember its hide-out well.Sometimes this frog has been found to spend day-time in some moist dark corner of human dwellings from where with little singh of disturbance it could easily escape and reach its proper hide-out, preferably a marshy ditch, even after traversing a zig zag path. 10.Rana crassa Jerdon (J erdon' s Bull Frog) (T ex-fig.10) 1853.Ban.a crassa J erdon, J. Asiat. Soc. Bengal,22 : 531.Material: 24-Parganas dist.: 1 ex., Halishahar, 4.x.1962;1 ex., Duttapukur, 8.xi.1962. Nadia dist.: 2 ex., H9ringhata, 25.x.1962. All ColI.M. B. Kripalani.
Distribution: Calcutta and environs,-As mentioned above.Elsewhere It is a broadly disributed species in India and found in almost all the biotopes of the country.Also Eastern Asia from Pakistan.Nepol, Sri Lanka and China to Japan.Re1narks: This is a common terrestrial frog generally found in Paddy-field and inside bushes near water.It jumps into water, when disturbed, but returns to the banks soon owing to inability of swimming for a long time for short webbing of toes.In monsoon days these frogs are occurred in almost grassy-patches found on the road-sides of suburbs of Calcutta.Five examples collected from Uluberia, Howrah dist., on 2.7.1962and two examples from Magra and Champadanga of Hooghly dist. on 20.9.1962and 6.4.1962Distribution; Calcutta and environs, -As mentioned above.This is the first record of the species from the area.Elsewhere.-AndhraPradesh (Kuddappah), Gujarat (Surat Dangs), Himachal Pradesh (Simla), Kerala (Malabar and Travancore), Madhya Pradesh (Chanda), Maharastra (Bombay, Khandala, Nagpur and Ratnagiri), Karnataka Bangalore), Rajasthan (Jodhpur, Nagpur and Udaipur), Tamil Nadu (Anaimalai Hills and Madras) and Uttar Pradeshm (Allahabad and Agra) in India.Also Sri Lanka, Nepal and Upper Burma.
Remarks: This is more or less common and only species of treefrog found in the area.It is nocturnal in habit and sometimes found inside the room in monsoon,nights.It has been noticed in the suburbs of Calcutta that this frog prefers moist and dark atmosphere of bathroom and also found to rest inside thick leaves of plants like pines, and roofs of thatched village huts.This frog is locally known as 'Shepo-Bang' or Geccho-Bang' and avoided by human beings, because it secretes a large quantity of urin, when caught.Two examples collected from Sonarpur by Shri P. K. Mallick show a little difference by possessing more darker body .. colour, more broader web of toes and rugose head.These examples have been reported to make their foamnest among the leaves of trees grown on the banks of ponds, whereas the foam-nests of this species are usually found to be made inside the bushes and grasses grown at the edge of water.

SUMMARY
This paper deals with the An1phibian fall:na of Calcutta and its environs based on the collections mainly made during "Calcutta and environs Survey (M.B. Kripalani and Staff) from July 1961 to March 1963" and "Salt Lake Survey (B.Biswas and Staff) from May 1963 to February 1967", organised by the Zoological Survey of India.It consists of 1713 examples of Anurans (Frogs and Toads) belonging to four families, six genera and thirteen species, out of which Microhyla ornata, Rana erythraea, Rana limnocharis and Rana brevicep8 are recorded fol" the first time from the area.Tadpoles of Kaloula pulchra taprobanica have been brought to the light of Science for the first time since the description of the species by Parker in 1934.ACKNOWLEDGEMENT The author is highly indebted to Dr. B. K. Tikader, Qirector, Zoological Survey of India for the inspiration to carry out this work on the local fauna and' for providing all the facilities ; to Mrs. M.R. Mansukhani, Ex-Deputy Director of Z.S.I" for guidance; to Dr. B. Biswas, Ex-Joint Director of Z.S.I.) for making such an excellent collection from Salt had recorded it from Calcutta.Elsewhere, -Assam, Uttar 'P~adesh (Agra) and Maharastra (Bombay) in India.Also Nepal~ Burma, Sri Lanka, P~kistan and Arabia.