Journal of Threatened Taxa | www.threatenedtaxa.org | 26 August 2018 | 10(9): 12194–12202

 

Diversity and distribution of freshwater turtles (Reptilia: Testudines) in Goa, India

 

Trupti D. Jadhav 1, Nitin S. Sawant 2 & Soorambail K. Shyama 3    

1,2,3 Department of Zoology, Goa University, Taleigao Plateau, Goa 403206, India

1 truptijadhav2@gmail.com (corresponding author), 2 nitinnature@yahoo.co.in, 3 skshyama@gmail.com

 

 

 

Abstract: Freshwater turtles symbolize a key component of biodiversity in aquatic ecosystems.  Of the 356 living species of turtles and tortoises in the world, 34 species are recorded from India.  The number of freshwater turtle and tortoise species found in the state of Goa, however, is debatable.  No study specific to the Goa region has been carried out on freshwater turtles.  Therefore, baseline data on diversity and distribution of freshwater turtles is scanty.  The present study was conducted to address this lacuna in knowledge, which will further aid in identifying threats to the population of freshwater turtles and in devising appropriate methods for their conservation.  The diversity and distribution of freshwater turtles was investigated in 186 sites in Goa from June 2012 to May 2015.  A total of 337 specimens of two native and one introduced species of freshwater turtles belonging to three families—Trionychidae (Indian Flap-shell Turtle Lissemys puncata), Geomydidae (Indian Black Turtle Melanochelys trijuga) and Emydidae (Red-eared Slider Trachemys scripta elegans)— were identified.  Melanochelys trijuga (52.23%) was the most widely and abundantly distributed species, and was recorded from 132 sites.  L. punctata (46.88%) was recorded from 113 sites, while T. scripta elegans (0.89%) was rare and was recorded from only two sites. While Melanochelys trijuga is generalized in habitat selection, making it the widely distributed species in the State of Goa, L. punctata is more specific in habitat selection thus restricting its range to coastal, middle-level plateau and the foothills of Western Ghats.

 

Keywords: Distribution, diversity, freshwater, Goa, invasive, turtle.

 

 

 

doi: http://doi.org/10.11609/jott.2835.10.9.12194-12202  |  ZooBank: urn:lsid:zoobank.org:pub:EDD2A1E7-21C0-4106-B513-08D65ADEE7CB

 

Editor: Nikhil Whitaker, Madras Crocodile Bank Trust, Mahabalipuram, India.           Date of publication: 26 August 2018 (online & print)

 

Manuscript details: Ms # 2835 | Received 11 February 2018 | Final received 29 June 2018 | Finally accepted 20 August 2018

 

Citation: Jadhav, T.D., N.S. Sawant & S.K. Shyama (2018). Diversity and distribution of freshwater turtles (Reptilia: Testudines) in Goa, India. Journal of Threatened Taxa 10(9): 12194–12202; http://doi.org/10.11609/jott.2835.10.9.12194-12202

 

Copyright: © Jadhav et al. 2018. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

 

Funding: Inspire Fellowship-DST, Delhi.

 

Competing interests: The authors declare no competing interests.

 

Author Details: Ms. Trupti Jadhav, MSc  Zoology, research student, working in the field of ecology, wildlife biology and biodiversity.  Dr. Nitin S. Sawant, Assistant Professor, Department of Zoology, working in the field of ecology, wildlife biology, herpetology, biodiversity assessment and environmental conservation. Dr. S.K. Shyama, Professor, Department of Zoology, working in the field of genetic toxicology, environmental mutagenicity, human genetics, ecotoxicology, nanotoxicology.

 

Author Contribuion: TJ has contributed in the field work and writing of the manuscript; NS has contributed in the field work; SKS has contributed in the final editing of the manuscript.

 

Acknowledgements: Goa Forest Department, Government of Goa, and Goa University.

 

 

 

Introduction

 

Freshwater turtles are a key component of biodiversity in aquatic ecosystems, aiding other animals and plants by scavenging on dead animals and plants in the aquatic ecosystem.  They not only form the major component of freshwater biomass but also participate in the aquatic food web and assists the co-dependent species thus helping in the energentic operation of the ecosystem.  Without turtles, aquatic ecosystems would progressively degrade in ways yet to be understood, and would undergo loss of biodiversity (Iverson 1982; Congdon & Gibbons 1989).

Turtles belong to the order Chelonia/Testudines, sub-order Cryptodira of class Reptilia, and comprise of 14 identified families.  These include freshwater turtles (Family: Geomydidae and Trionychidae), marine turtles (Family: Cheloniidae and Dermochelyidae), and land tortoises (Family: Testudinidae) (Fritz & Havas 2007).  Rhodin et al. (2017) and Stanford et al. (2018) reported 356 living species of turtles and tortoises found in different habitats of the world.  India hosts the richest diversity of turtles in the world (Iverson 1992) with 34 species of Chelonians—25 freshwater, five marine, and four land tortoises (Fritz & Havas 2007).

Three species of Testudines, namely, Nilssonia leithii, Vijayachelys silvatica, and Indotestudo travancorica (tortoise) are endemic to India.  Vijayachelys silvatica and Indotestudo travancorica are endemic to the Western Ghats, whereas Nilssonia leithii is endemic to peninsular India (Deepak & Vasudevan 2009).  The number of freshwater turtle and tortoise species found in Goa, however, is debatable as some authors (Tikader & Sharma 1985) reported the presence of two species, Lissemys punctata punctata and Melanochelys trijuga trijuga, in Goa and have stated Nilssonia leithii and Geochelon elegans  to be distributed in peninsular india.  Pradhan (2008) reports the presence of four species in Goa: three freshwater species, namely, Nilssonia leithii, Lissemys punctata punctata, and Melanochelys trijuga, and one tortoise Geochelone elegans.  Murthy & Das (2009) reported the presence of specimens of two species in the collection of Zoological Survey of India, namely, Lissemys punctata punctata and Melanochelys trijuga trijuga from few localities in Goa while others (Srivastava & Nigam 2009) reported the presence of only one species in Goa, namely, Lissemys punctata punctata.

Studies on freshwater turtle specific to the Goa region are scanty; therefore, baseline data on the existence and distribution of freshwater turtles is deficient.  For managing and conserving natural habitats, information on the distribution of a species is imperative (Rubin et al. 1998).  The present study was conducted to address this lacuna in knowledge, which will further aid in identifying threats to turtle populations and in devising appropriate methods for their conservation.

 

 

Materials and Methods

 

Study Area

Goa is the smallest state in India and is located along its central-west coast (Fig. 1).  It is situated at the latitude 15.299320N and longitude 74.1239960-E.  The mountainous region of the Sahyadris in the east, the middle-level plateaus in the centre, and the low-lying river basins along with the coastal plains form are the three main physical divisions (Rao 1985–86) of this region.  The average rainfall is 2500–3000 mm.  The mean daily temperature is around 300C and the maximum temperature is 360C.  The climate is humid throughout the year, with humidity level ranging from 75%–95% in the monsoon.  The main feature of the climate is the southwest monsoon that occurs between June and September.  Champion & Seth (1968) classified the major forest types of Goa into west coast tropical evergreen, west coast semi-evergreen, and southern moist deciduous forest.

 

Methods

Potential sites (rivers, wetlands, streams, ponds, agricultural lands, and forest areas) were visited and transect walks were carried out to observe turtles in the wild throughout the geographical region of Goa; 186 sites (Table 1) were surveyed across Goa as shown in Fig. 1.  The sites were randomly selected and were readily accessible.  The study was conducted from June 2012 to May 2015 across seasons (summer: March–May, monsoon: June–August, post-monsoon: September–November, and winter: December–February) following the methodology of Akbar et al. (2006).  Active searches in the undergrowth were carried out using visual encounter method (Litzgus & Mousseau 2004).  Basking turtles were observed and directly counted.  Dip net was used for the capture of turtles (Spinks et al. 2003).  Netted animals were counted, their species identified, and then released back into the same water.  All freshwater turtles encountered during the study were identified up to species level following Smith (1933), Tikader & Sharma (1985), and Das (1985, 2008).  The exact location and altitude of the area were recorded using GPS (geographical positioning system) to depict the pattern of distribution of freshwater turtles.  Potentially suitable habitats were also identified.  In sites where no turtles were captured or encountered, it was assumed that the site had no turtles or that they occurred at very low densities (Lin et al. 2010).  Turtles captured opportunistically by local volunteers were also considered.

The distribution of all three species in seven different habitats was tested using two-way ANOVA.  The seasonal encounter of the three species across seasons (summer, monsoon, post-monsoon, and winter) was tested using two-way ANOVA.  A difference of p<0.05 was regarded as statistically significant.  All the calculations were carried out using Microsoft Excel 2010.

 

 

 

Results

 

During the survey conducted from June 2012 to May 2015, a total of 337 individuals (334 individuals of native species and three individuals of introduced species) of three species of freshwater turtles belonging to three families, viz., Trionychidae (Indian Flap-shell Turtle Lissemys puncata), Geomydidae (Indian Black Turtle Melanochelys trijuga) and Emydidae (the invasive Red-eared Slider Trachemys scripta elegans) were recorded.  Melanochelys trijuga (Image 1) was the most abundant species and comprised of 52.23% (n=176) of the total individuals encountered, followed by L. punctata (Image 2) comprising of 46.88% (n=158), and T. scripta elegans (Image 3) comprising of 0.89% (n=3).

Of the 186 sites surveyed, freshwater turtles were encountered at 181 sites.  Melanochelys trijuga was the most widely distributed species and was recorded from 132 sites, followed by L. punctata, which was reported from 113 sites, and T. scripta elegans, which was rare and was reported from only three sites.  At 67 sites both M. trijuga and L. punctata were recorded (Fig. 1).

It was observed that freshwater turtles exhibit nocturnal habits and are active mostly during night, dusk, and dawn.  A few individuals were also found while crossing the road.   During the day hours, they mostly remain submerged in water, bury themselves in soil, or stay hidden in crevices and moist leaf litter.  It was observed that M. trijuga was distributed throughout the state of Goa.  L. punctata was recorded in all terrains except rocky habitats and mountainous regions (Western Ghats).  Melanochelys trijuga was recorded in slow- and fast-moving rivers and ditches at low and high elevations, in wetlands, agricultural lands, ponds and streams on plains, plateaus, and mountainous areas, and in artificial drainages in urban areas.  L. punctata was encountered in slow-moving waters, wetlands, agriculture lands, ponds, and streams on plains.  Trachemys scripta elegans was encountered in a pond (Taleigao, Tiswadi Taluka), a residential area (Upasnagar, Marmugoa Taluka), and in a river (Khandepar, Ponda Taluka).  The number of turtles of all the three species found in different habitat types is given in Fig. 2.  ANOVA showed that the distribution of freshwater turtles in different habitats was highly significant (df=12, F=4.23, p=0.00024).

Distribution of turtles varied with seasons.  During monsoon they were encountered at all 180 sites, whereas in summer and winter they were observed at only 50 and 72 sites, respectively.  The highest number of individuals was encountered during monsoon season (Fig. 3).  ANOVA showed that the encounter of freshwater turtles varied significantly with seasons (df=6, F=1.44, p=0.24).

 

 

 

 

 

 

 

 

 

Table 1. List of Site and habitat surveyed; Road*- Indicates road passing through paddy fields; Road# - Indicates road passing through forests; Road@ - Indicates road passing through wetland; ‘□’ Indicates sites where no turtles were encountered

 

 

Taluka / Site No.

Name of Locality

Habitat

Latitude

Longitude

Pernem

 

 

 

 

1

Korgao

Pond

15042’28.94”N

73045’11.83”E

2

Chandel

Wetland

15043’39.30”N

73053’49.57”E

3

Kondalwada

Pond

15042’41.26”N

7304814.66”E

4

Tuvem

Agriculture land

15040’9.92”N

73047’35.01”E

5

Mandrem

Wetland

15040’2.13”N

73043’32.34”E

6

Morjim

Agriculture land

15037’53.80”N

73044’5.15”E

7

Parse

Pond

15037’52.55”N

73044’3.75”E

8

Dadachiwadi

Stream

15041’45.93”N

73050’59.66”E

9

Hasapur

Pond

15044’21.3”N

73053’54.71”E

10

Harmal

Wetland

15041’2.32”N

73042’32.95”E

11

Vadnem

Drainage

15043’7.39”N

73053’13.54”E

12

Varkhand

Stream

15043’31.90”N

730 50’7.00”E

13

Ugvem

Agriculture land

15044’57.55”N

73056’0.40”E

14

Keri

Pond

15042’57.55”N

73049’57.78”E

16

Vajri

River

15042’3.14”N

73053’9.26”E

16

Mopa

Agriculture land

15045’30.75”N

73051’13.38”E

17

Tamboxem

Road*

15045’30.51”N

730 56’38.02”E

18

Shemecheadvan

Agriculture land

15043’37.24”N

73056’59.07”E

19

Dhargal

Pond

15040’19.08”N

73050’46.90”E

Bardez

 

 

 

 

20

Kanka

Agriculture land

15035’26.98”N

73048’09.97”E

21

Kuchelim

Stream

15036’40.91”N

73049’09.46”E

22

Quitla

Agriculture land

15032’09.33”N

73050’26.80”E

23

Pilern

Road@

15032’00.22”N

73048’49.26”E

24

Revora

Wetland

15039’24.44”N

73050’38.67”E

25

Porvorim

Drainage

15031’31.90”N

73050’05.01”E

26

Haliwada

Stream

15031’18.01”N

73050’32.14”E

27

Virlosa

Agriculture land

15030’37.38”N

73050’31.62”E

28

Badem

Pond

15031’39.09”N

73050’47.85”E

29

Shivolim

Road*

15037’16.12”N

73047’27.65”E

30

Anjuna

Pond

15035’06.84”N

73044’57.84”E

31

Caisua

Pond

15036’14.34”N

73044’40.85”E

32

Nerul

Stream

15035’06.84”N

73044’57.84”E

33

Assagao

Stream

15030’26.82”N

73049’55.67”E

Tiswadi

 

 

 

 

34

Shirdona

Wetland

15026’49.61”N

73052’03..91”E

35

Carambolim

Wetland

15029’12.75”N

73055’47.82”E

36

Malar,Divar

Agriculture land

15031’40.28”N

73054’45.87”E

37

Campal

Garden

15029’50.95”N

73049’08.24”E

38

Bhatlem

Stream

15029’02.49”N

73049’48.56”E

39

Aggasaim

Agriculture land

15026’08.89”N

73053’34.08”E

40

St.Cruz

Agriculture land

15028’09.72”N

73050’43.29”E

41

Kalapur

Agriculture land

15028’04.23”N

73050’48.03”E

42

Carambolim Lake

Wetland

15029’49.01”N

73055’07.89”E

43

Amaral Band

Agriculture land

15028’12.20”N

73049’43.56”E

44

Taleigao

Agriculture land

15028’40.20”N

73048’45.81”E

45

Dongrim

Stream

15027’02.77”N

73055’16.96”E

46

Neura

Road*

15026’26.82”N

73054’15.13”E

47

Chorao

Agriculture land

15032’36.11”N

73053’32.03”E

48

Divar

Pond

15031’52.79”N

73055’34.02”E

49

Bambolim

Agriculture land

15027’33.28”N

73051’36.93”E

50

Goa Velha

Agriculture land

15025’36.93”N

73053’12.37”E

51

Merces

Agriculture land

15029’10.88”N

73051’22.53”E

52

Chimbel

Pond

15029’06.36”N

73052’08.58”E

53

Curca

Wetland

15027’32.11”N

73052’22.42”E

54

Goa University Campus

Road*

15027’39.18”N

73050’04.56”E

Bicholim

 

 

 

 

55

Mayem

Stream

15034’29.88”N

73055’53.02”E

56

Pilgao

Pond

15033’24.60”N

73057’30.28”E

57

Kumbharwada, Mayem

Wetland

15034’38.96”N

73055’13.78”E

58

Mayem lake

Pond

15034’30.42”N

73056’21.11”E

59

Poira

Wetland

15035’46.46”N

73053’47.05”E

60

Menkurem

Pond

15041’51.66”N

73053’49.47”E

61

Sarvan

Pond

15034’33.74”N

73057’58.38”E

62

Navelim

Agriculture land

15031’41.16 N

74000’6.80”E

63

Kudnem

Pond

15032’51.34”N

74000’51.45”E

64

Sal

Agriculture land

15041’12.21”N

73055’34.95”E

65

Latambarcem

Agriculture land

15039’56.55”N

73057’06.95”E

66

Pirna

Agriculture land

15040’33.33”N

73052’59.62”E

67

Advalpal

Agriculture land

15038’47.18”N

73053’16.97”E

68

Mulgao

Agriculture land

15036’39.10”N

73055’38.58”E

69

Asnora

River

15037’37.07”N

73054’25.85”E

70

Bordem

Wetland

15035’42.14”N

73056’06.69”E

71

Karapur

Pond

15033’47.68”N

73059’25.13”E

72

Shirgao

Agriculture land

15036’18.98”N

73054’01.94”E

Sattari

 

 

 

 

73

Kumthal

Stream

15030’58.20”N

74012’12.31”E

74

Velge

Road+

15030’52.62”N

74008’54.71”E

75

Gulelim

Stream

15027’17.73”N

74008’17.41”E

76

Paikul

Pond

15026’55.16”N

74007’48.72”E

77

Shel

Pond

15027’33.53”N

74008’11.93”E

78

Melaulim

Agriculture land

15027’24.88”N

74008’28.23”E

79

Nanus

Road*

15030’32.55”N

74044’57.84”E

80

Sheldobar

Pond

15035’06.84”N

74007’53.39”E

81

Shel-Dhadyar

Pond

15027’21.30”N

74008’22.66”E

82

Paikul (Ragada)

River

15028’02.37”N

74007’12.03”E

83

Shel-Melaulim

Pond

15027’23.33”N

74008’25.10”E

84

Khotodem

Agriculture land

15028’49.31”N

74008’53.62”E

85

Khadki

River

15030’11.88”N

7408’13.49”E

86

Bramhakarmali

Wetland

15034’13.22”N

74009’46.79”E

87

Sathre

Stream

15036’54.55”N

74012’49.42”E

88

Ivrem

Stream

15038’02.72”N

74008’52.22”E

89

Surla

Stream

15039’54.15”N

74010’18.37”E

90

Derode

Pond

15035’47.42”N

74012’59.92”E

91

Caranzole

Pond

15030’15.65”N

74013’09.00”E

92

Dhave

Agriculture land

15033’10.57”N

73010’28.50”E

93

Ushte

Agriculture land

15033’16.41”N

74011’54.68”E

94

Gotelim

Wetland

15036’55.25”N

74003’39.90”E

Ponda

 

 

 

 

95

Bondla

Pond

15026’24.70”N

74006’02.95”E

96

Ganjem

River

15028’02.22”N

74005’15.25”E

97

Keri

Agriculture land

15027’24.62”N

74000’10.24”E

98

Khandepar

River

15026’06.19”N

74002’44.61”E

99

Kundai

Agriculture land

15027’30.94”N

73057’19.74”E

100

Usgao

River

15024’35.98”N

74004’33.07”E

101

Talaulim

Road*

15022’39.16”N

73059’02.06”E

102

Kavale

Stream

15023’37.65”N

73059’17.33”E

103

Dabal

Stream

15020’47.49”N

74006’35.17”E

104

Palem

Agriculture land

15021’03.89”N

74001’13.26”E

105

Madkai

Agriculture land

15025’25.63”N

73056’39.30”E

106

Priol

Stream

15026’11.07”N

74000’02.64”E

107

Khandola

Agriculture land

15031’31.57”N

73057’56.04”E

108

Borim

Pond

15021’03.99”N

74001’12.67”E

109

Kurti

Agriculture land

15024’49.50”N

73001’49.25”E

Marmugoa

 

 

 

 

110

Upasnagar

Pond

15022’25.67”N

73053’33.12”E

111

Vasco

Road@

15023’52.08”N

73049’15.57”E

112

Casaulim

Wetland

15020’19.25”N

73053’45.35”E

113

Arrosim

Wetland

15020’00.63”N

73054’07.05”E

114

Issorcim

Wetland

15022’14.80”N

73051’31.74”E

115

Cortalim

Agriculture land

15023’25.95 N

73054’53.96”E

116

Sancoale

Pond

15023’42.92”N

73054’14.95”E

Dharban-dora

 

 

 

 

117

Sonaulim

River

15018’44.10”N

74017’49.86”E

118

Sacordem

Agriculture land

15024’58.82”N

74011’17.93”E

119

Campsite, Mollem

River

15020’29.09”N

74015’08.66”E

120

Satpal

Agriculture land

15024’10.87”N

74012’21.78”E

121

Sunset point, Mollem

Stream

15024’13.47”N

74015’59.32”E

122

Tambdisurla

Stream

15026’23.20”N

74015’08.97”E

123

Collem

Pond

15020’27.26”N

74014’28.46”E

124

Shigao

Agriculture land

15020’17.10”N

74012’32.50”E

Salcete

 

 

 

 

125

Varca

Agriculture land

15013’28.04”N

73056’29.37”E

126

Betul

Stream

15008’32.65”N

73057’48.54”E

127

Velim

Agriculture land

15009’24.51”N

73058’03.25”E

128

Maina-Curtorim

Wetland

15016’05.46”N

74001’04.76”E

129

Raia

Pond

15018’51.85”N

73059’30.52”E

130

Rachol

Pond

15018’26.45”N

74006’00.96”E

131

Chandor

Agriculture land

15015’28. 48”N

74002’21.49”E

132

Caurim

Agriculture land

15014’59.31”N

74002’26.62”E

133

Guirdolim

Road*

15016’28.16”N

74002’12.04”E

134

Loutolim

Road*

15020’42.98”N

73058’44.96”E

135

Seraulim

Pond

15017’01.40”N

73055’57.34”E

136

Macazana

Agriculture land

15017’28.01”N

74003’18.00”E

137

Sao Jose De Areal

Stream

15014’38.23”N

74000’08.19”E

138

Colva

Wetland

15017’10.32”N

73054’58.20”E

139

Benaulim

Pond

15014’45.93”N

73056’03.82”E

140

Sarzora

Road*

15012’57.50”N

74000’07.20”E

Sanguem

 

 

 

 

141

Verle

Agriculture land

15002’48.24”N

74014’50.73”E

142

Kalem

Pond

15017’57.12”N

74011’09.72”E

143

Ugem

Pond

15014’04.96”N

74011’10.70”E

144

Bhati

Pond

15011’30.56”N

74014’11.98”E

145

Savordem

Road*

15011’09.33”N

74006’27.15”E

146

Valkini

Agriculture land

15013’18.81”N

74011’50.65”E

147

Savri

Stream

15004’20.38”N

74013’24.70”E

148

Tudov

Stream

15003’34.55”N

74015’15.76”E

149

Saljini

Stream

15000’30.99”N

74014’40.96”E

150

Nundem

Stream

15032’07.67”N

74012’06.41”E

151

Rivona

Stream

15009’52.89”N

74006’29.21”E

152

Curpe

Agriculture land

15007’53.07”N

74010’14.37”E

153

Colomb

Agriculture land

15008’35.76”N

74008’23.52”E

154

Sangod

Agriculture land

15021’36.38”N

74010’40.83”E

155

Shigone

Pond

15009’05.70”N

74014’03.47”E

156

Naiquini

Agriculture land

15011’32.61”N

74014’16.52”E

Quepem

 

 

 

 

157

Bali

Stream

15008’36.31”N

74001’28.68”E

158

Shirvoi

Agriculture land

15011’29.42”N

74005’52.90”E

159

Morpirla

Stream

15006’55.07”N

73059’56.07”E

160

Paroda

Pond

15014’01.78”N

74002’11.43”E

161

Fatorda

Wetland

15009’20.26”N

73059’30.85”E

162

Kunkolim

Agriculture land

15010’03.75”N

74000’35.62”E

163

Maina

Agriculture land

15007’18.35”N

74005’45.78”E

164

Tilamol

Agriculture land

15013’04.36”N

74005’07.62”E

165

Cacora

Road*

15014’39.30”N

74007’22.86”E

166

Curchorem

Road*

15013’56.64”N

74006’29.00”E

167

Cavrem

Stream

15009’52.99”N

74004’05.47”E

168

Padi

Agriculture land

15005’11.34”N

74001’44.48”E

169

Mangal

Agriculture land

15003’34.15”N

74011’03.71”E

170

Barcem

Stream

15004’11.83”N

74002’19.83”E

171

Molkornem

Stream

15011’42.07”N

74008’31.60”E

Canacona

 

 

 

 

172

Aave

Stream

15001’44.86”N

73009’47.95”E

173

Eda

Stream

15000’13.06”N

74010’27.06”E

174

Agonda

Agriculture land

15002’59.68”N

73059’46.54”E

175

Shirtvoti, Khola

Stream

15°04'43.03''N

73°58'33.06''E

176

Khola

Stream

15004’49.24”N

73058’16.55”E

177

Loliem

Agriculture land

14056’13.10”N

74005’20.46”E

178

Galgibag

Wetland

14058’16.49”N

74004’08.04”E

179

Talpan

Pond

14059’02.69”N

74002’42.52”E

180

Dhantali

Stream

14058’34.71”N

74010’51.90”E

181

Bamanbudo

Stream

15003’28.88”N

74009’29.47”E

182

Ambeghat

Road#

15003’40.53”N

74009’37.16”E

183

Mashem

Wetland

14057’47.02”N

74003’15.04”E

184

Bhatpal

River

14059’55.26”N

74005’09.26”E

185

Gaodongrim

Stream

15000’32.89”N

74007’31.68”E

186

Polem

Pond

14055’15.92”N

74004’25.47”E

 

 

 

Discussion

 

Reptile species inhabit distinct microhabitats and are not randomly distributed in space (Heatwole 1982). The findings with respect to the two native species augment to that of Murthy & Das (2009) and Tikader & Sharma (1985).  The presence of Nilssonia leithii, however, was not reported during the present study.  The presence of T. scripta elegans was recorded for the first time in the state of Goa.  Trachemys scripta elegans a native of Mississippi Valley area (Pendlebury 2006) was imported to other countries in pet trade (Pendlebury 2006), which eventually led to illegal trade (Pupins 2007).  Its impact on the native turtle species in Goa, however, needs to be investigated.

It was observed that M. trijuga and L. punctata were widely distributed and occupied all potential habitats (agricultural fields, ponds, wetlands, gardens, drainages, rivers, and streams) across the State of Goa.  Similar habitats were reported by Tikader & Sharma (1985) for both the species and by Hoassain et al. (2008) for L. punctata.  Lissemys punctata, however, was not reported from the hilly areas of the Western Ghats during the present study and M. trijuga occupied all the possible habitats, including drainages, in the urban setup.  M. trijuga was found to be the most abundant species (52.22%), followed by L. punctata (46.88%) and T. scripta elegans, which was the rarest (0.89%).  Lissemys punctata preferred agricultural fields (37.97%), ponds (28.48%), and wetlands (20.25%), and was rarely sighted in streams (5.69%), gardens (1.27%), and rivers (0.63%).  No individuals of L. punctata were found in drainages.  The highest encounters of L. punctata were in agricultural fields and the lowest were in rivers and gardens.  This suggests that L. punctata prefers marshy areas and stagnant waters that might assist in burrowing, which provides protection from predators.  This also elucidates their absence in hilly regions where the stream beds consist mostly of pebbles and rocks that possibly will not serve as good refuge grounds.  Hossain et al. (2008) reported that marshlands and agricultural fields were the most preferred habitats of L. punctata, followed by ponds, streams, and lakes.

On the contrary, M. trijuga preferred streams (30.11%), agricultural lands (26.7%), and ponds (22.16%) followed by wetlands (6.81%), rivers (5.68%), drainages (2.84%), and gardens (1.14%).  This suggests that M. trijuga can acclimatize to all habitat types.  The distribution of all the three species in different habitats was highly significant.

The encounter of freshwater turtles in different seasons was significant when tested statistically.  Highest numbers of individuals were encountered in monsoon and post-monsoon season, which may be attributed to favorable climatic conditions and rich prey base, as compared to summer and winter, when the resources required for survival are limited, thus restricting the distribution of species.  Similar observations were made in other groups of reptiles such as snakes by Sawant et al. (2010).  Thus, the present study reports the presence of three species of freshwater turtles in Goa, namely, M. trijuga, L. punctata, and T. scripta elegnas.  Melanochelys trijuga is generalized in habitat selection thus making it the most widely distributed species in the state of Goa and L. punctata is more specific in habitat selection thus restricting its range to coastal, middle-level plateau, and foothills of Western Ghats.

 

 

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