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5. Morphometry of the turtles and tortoises of Manipur
5.1 Introduction
Turtles have been the subject of numerous morphometric and growth studies.
Morphometrics are commonly used to aid in identification of sex as well as age, growth,
and other characteristics of turtles such as colour variation (Berry and Shine, 1980;
Claude et al., 2003; Lovich et al., 1990). The relative growth of a part in relation to the
entire organism, has been studied in various turtles. These studies have compared either
changes in the mass or weight of the turtle with growth of the shell, or the growth of the
shell scutes or other body parts in relation to increases in shell length (Ernst and Lovich,
1986). Cryptodiran turtles in the families Chelydridae (Lagler and Applegate, 1943;
Mosimann and Bider, 1960), Kinosternidae (Mosimann, 1956, 1958; Hulse, 1976),
Emydidae (Mosimann, 1958; Jolicoeur and Mosimann, 1960; Graham, 1971; Rouault and
Blanc, 1978; Meek, 1982) have been previously studied.
The objective of this study was to record standard morphometrics alongwith
additional information gathered on the non-target species. Morphometry also forms an
important parameter for sub-species identification. Currently, four subspecies are
currently recognized for the turtle Cuora amboinensis viz., C.a.amboinensis,
C.a.kamaroma, C.a.couro and C.a.lineata. Rummler and Fritz (1991) provided
morphometric values such as body ratios for carapace length to body height and carapace
width to body height that distinguish the first three subspecies. Accordingly,
C.a.amboinensis is characterized by a flat, broad carapace with distinct margin;
C.a.kamaroma is highly domed and has a narrower carapace without a well-developed
margin; whereas the shell of C.a.couro shows intermediate characters (Rummler and
Fritz, 1991). C.a.lineata on the other hand can be distinguished from the former three
subspecies by the total lack of carapacial keels, diminished inguinal scutes, a more flared
posterior plastral lobe allowing a more completely closed posterior shell opening, and a
yellowish white middorsal stripe (McCord and Philippen, 1998). Applying unique marks
to individuals in ecological analysis allows for estimation of population size and
demographic profiles (birth, death and survivality) as well as movement, home range and
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individual growth rates (Krebs, 1989; Donnelly and Guyer, 1994). Krebs (1989)
suggested that either marks are not lost or misread which have no effect on recapture
rates. A wide range of techniques are being used to mark herpetofauna (Donnelly and
Guyer 1994; Ferner 2007) resulting in many of the traditional marking techniques like
shell notching in turtles (Cagle, 1939; Ernst et al., 1974) that have standardized coding
systems which facilitate quick, easy, and reliable data recording. Relatively new marking
techniques such as visible implant elastomers (VIEs; Northwest Marine Technology, Inc.,
Shaw Island, Washington, USA) however, often lack standardized coding systems despite
of their extensive use in the field (MacNeil et al., 2011).
Manipur state has altogether 7 in-situ conservation sites and 3 ex-situ conservation
sites. The Manipur Zoological Gardens (MZG), Iroishemba got established in the year
1976. It lies between ƒƍƎ(DQGƒƍƎ( and is located about 7 kilometres from
the Imphal city and holds the highest ex-situ repository of freshwater turtles and tortoises
in the state. Alltogether, 50 individuals are housed in the zoo premises which include 6
species belonging to 3 families namely Geoemydidae (3), Testudinidae (2) and
Trionychidae (1) (as shown in Table 5a). A total of 179 turtles and tortoises (inclusive of
50 individuals from MZG) of 10 species belonging to the 3 families namely Geoemydidae
(6), Testudinidae (2) and Trionychidae (2) were utilized during the present investigation.
5.2 Material and Methods
For the present study, turtles from the Manipur Zoological Gardens, Iroishemba,
Loktak lake and adjoining wetlands, wet markets, trade, pets and wild caught turtles and
tortoises from the different eco-zones and various localities of the 9 districts of the state
were utilized. Alltogether, 179 species of turtles and tortoises were utilized during the
morphometric analysis, of which 127 individuals having all the four morphological
parameters measured namely, straight carapace length (SCL), straight carapace width
(SCW), carapace depth or shell height (SH) and body weight (BW) were used for further
analysis. The preserved specimens in the Manipur Museum, Imphal could not be
measured and therefore left out in the present investigation due to lack of permission for
handling the same.
Each of the animals were weighed, measured and marked on the spot or bought to
convenient nearby location for further investigation on diet studies if and whenever
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applicable. Eventually, all the captured animals were released back to their original
habitats. Sex was visually determined, if possible, and recorded for each of the turtles.
External measurements were taken of all live turtles located. The parameters taken
as measurements are straight carapace length (SCL), straight carapace width (SCW) and
carapace depth or shell height (SH) were made to the nearest mm using dial vernier
FDOLSHUV ƎPP 1000mm (530 Series, Mitutoyo, Japan) and Digital vernier caliper
ƎPP(636HULHV%RG\ZHLJKW%:ZDVUHFRUGHGWRWKHQHDUHVWJVFDOHXVLQJ
Magnum 500 digital scale (1kg/0.1g), Wens AR (300g/0.01g) and JR-PES Series spring
balance (40kg/20g). Whenever nests or eggs were located they are weighed and
measured. Sony cybershot DSC-H×1(20X optical zoom) was used for photo
documentation. The turtles were identified using guide books (Das, 1995; Lim and Das,
1999; Iskandar, 2000).
Plate 5.a: A Cuora amboinensis WXUWOHPDUNHGZLWK,'³´RQWKHOHIW side of
the 2nd and 3rd marginal scutes, following the 1-2-4-7 technique by Cagle (1939)
with slight modification.
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$PDUNLQJV\VWHPXVLQJQXPEHUVIRUWXUWOHVWKH³-2-4-´V\VWHPDOORZVIRUDQ\
number between 1 and 9 marked by using a hexablade creating a 2mm vertical notch in
the periphery of the outer marginal scute (Cagle, 1939). Only Cuora amboinensis were
marked on the outer carapaceal scute during the present investigation. However, the other
turtle species were noted for any natural or unnatural markings on the carapace or
plastron. A marking system using numbers for tuUWOHV WKH ³-2-4-´ V\VWHP DOORZV IRU
any number between 1 and 9 marked by using a hexablade in the carapaceal scute. The
identification for the turtOHDVVKRZQLQ3ODWHDLV,'³´
5.2.1 Statistical Analysis
Mann-Whitney U-test was utilized on 5 species of turtles to investigate size
differences between the sexes. Only those turtles and tortoises having both the male and
female in one species were employed. Alltogether, 31 females and 51 males of Cuora
amboinensis, 5 females and 1 male of Amyda cartilaginea, 9 females and 15 males of
Cyclemys gemeli, 1 female and 3 males of Indotestudo elongata and 2 females and 4
males of Manouria emys were employed during the investigation. Cumulative assessment
for size difference (p= or <0.05) between the sexes were considered based on the analysis
of SCL, SCW, SH and BW. The turtles not having any one of the parameters were left out
and quoted individually. Single sex individuals (either male or female) were left out from
the sex-wise comparative analysis.
Linear regression analysis (ANOVA), is utilized for the study of allometric growth
to investigate if the width of the turtle changes with respect to length and if the shell
height became greater with respect to the lengthening of the carapace. The first analysis
compared the relationship of the ratio of SCW/SCL, SH/SCL and BW/SCL to SCL. The
ratio of SCW/SCL, SH/SCL and BW/SCL was calculated to minimize the skewing of the
distribution points. In the second calculation, SCL was log transformed to satisfy
assumptions of normality and analyzed to determine a relationship or determination with
SCW/SCL, SH/SCL and BW/SCL. However, only those turtle species having atleast 5
individuals each stands major chance of statistical validity in comparison to those that
GRQ¶W 7KH SURJUDP SPSS ver.20 and Microsoft Excel ver.2007 was utilized for the
analysis.
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Results was reported as mean and standard deviation (Mean±SD) alongwith
median of each parameter viz., SCL, SCW, SH and BW. As the data is far from normality
a non-parametric test like Mann-Whitney U was applied to test the sex-wise difference
between the median for each parameter as well as for each type of specimen separately.
In order to assess the impact of each parameter considered, first log transformation
was made to bring skew data into normal data and then used for linear regression analysis.
Regression coefficients, adjusted R2, Durbin-:DWVRQ³G´DQG)-value were estimated.
All comparisons were two sided and the p-values of <0.05 and <0.01 are treated as
the cut off values for significance and highly significance respectively.
5.3 Results and discussion
5.3.1 Size classes of the turtles and tortoises
In the turtle Cuora amboinensis, there is size dimorphism between the male and
female species. The females are found to be comparatively larger than the males [Plate 5b
and 5c]. The mean female SCL was 166mm in comparison to the mean male SCL of
156mm. Lim and Das (1999) had recorded a carapace length (CL) of 250mm for the
Malayan subspecies, C.a.kamaroma. The highest SCL during the present investigation
was recorded for two wild caught females with 212mm and the highest recorded male
SCL was 211mm. The maximum weight of 1022g was recorded for a female of SCL 176
mm and the maximum weight of 820g with a SCL of 167mm for the male Malayan Box
Turtle. Shoppe (2009) have recorded a maximum weight of 1650g at a SCL of 199mm for
a female and 1950g for a male Malayan Box Turtle at a SCL of 172mm which constitute
the known weight record for the species. In the turtle Cyclemys gemeli the females are
found to be comparatively larger than the males with a mean female SCL of 192mm in
comparison to 152mm in males (Figure 5b). The softshell turtle Amyda cartilaginea has a
mean female SCL of 324mm in comparison to a single male SCL of 257mm (Figure 5c).
In Manouria emys tortoise the mean female SCL at 404mm is comparatively smaller than
the mean male SCL at 548mm (Figure 5d). The tortoise Indotestudo elongata has a
smaller female SCL of a single sample with 173mm and a male mean SCL of 204mm
(Figure 5e). Size distribution for female Cuora amboinensis showed with (~20cm) with
three size classes (Figure 5a). The size class of male and female Chelonia mydas were
noted for female with a range of 83-114cm in the nesting beach of Florida. The minimum
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SCL for juvenile was 5cm and 10cm for the male and female individuals have been
considered arbitrarily and the basis of this study could be supported from various workers
(Witherington et al., 2006; Bresette et al., 2010). Cuora amboinensis recorded during this
investigation was the highest for the juvenile (Figure 5a), however with the emergence of
the breeding period the frequency of females were larger. Almost identical observation
were made on Chelonia mydas and could be supported by many workers (Bresette et al.,
2000; Eharhart et al., 2007). Then it could be inferred that adult individuals were deeper
water habitat dwellers than the juveniles and the same could be supported from the work
of Bresette et al. (2010), where it has been hypothesized that the size class partitioning
maybe due to differing habitat requirements and predation risk.
Figure 5.a: Size distribution graph of Cuora amboinensis male, female and juvenile SCL
(Straight Carapace Length).
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Importance of fecundity as a factor that influence body size in female turtles and
the larger body size for females favor them to produce more offspring (Berry and Shine,
1980; Gibbons and Lovich, 1990). Larger female size generally results in more or larger
eggs (Gibbons et al., 1982). Thus, Brophy (2006) was able to explain the many relatively
wider, higher and larger shell characteristics demonstrated by female M.macrocephala.
Therefore, the inference could be drawn that the size difference of male and female
C.amboinensis might be evolved to exploit different resources in the environment to
reduce the competition between them (Brophy, 2006) and there has been differences in
the food habit of the species. And in all probability, it might be that ecological differences
between the sexes are simply consequences of sexually selected dimorphism (Shine,
1986).
Figure 5.b: Size distribution graph of Cyclemys gemeli male, female and juvenile SCL.
(Straight Carapace Length).
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Figure 5.c: Size distribution graph of Amyda cartilaginea male, female and juvenile
(Straight Carapace Length).
Size distribution graph against the counts observed in various turtle groups of
Manipur has provided certain interesting findings. The highest size range of female
C.amboinensis was observed at 175 to 199mm range against a count of 25. The
observation led us to speculate that there is little or no overlap in size structure of
C.amboinensis with that of the other species in their habitat. In this context Bresette et al.
(2010) very aptly hypothesized that there was a strong effect of size on which the green
turtle has to forage. And size specific effects may include limited access to shallow waters
by large turtle. They also observed clumped spatial distribution in green turtles which
demonstrated an evidence on herding. However, such observations on herding of
C.amboinensis could not be made during this investigation and it is very much suggestive
of such type of work.
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Figure 5.d: Size distribution graph of Manouria emys male, female and juvenile SCL
(Straight Carapace Length).
5.3.2 Ex situ repository, Manipur Zoological Gardens (MZG)
Except for the Asian Brown tortoise all the other turtles and tortoises are enclosed
together in a very restricted enclosure which limits healthy colony proliferation. An
annotated list of the turtles and tortoises occurring in different zoos can be made into an
online database for future reference and proper documentation. There is an urgent need
for the assessment of ex-situ repositories in the state since there is a possible rapid
extirpation of wild populations due to the threats posed by hunting for meat, pets and
rampant habitat loss. A captive population of assurance colonies can be eventually built
up for more re-introduction in the wild to replenish the possibly declining wild colonies.
The results of the initial documentation and record standard morphometrics are tabulated
in Table 5a, Table 5b and Table 5c.
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Figure 5.e: Size distribution graph of Indotestudo elongata male and female SCL (Straight
Carapace Length).
A single female Manouria emys laid a clutch of 25 spherical eggs in end of June
month, 2011 out of which six hatchlings emerged on September, 2011 and only two
juveniles survived. The two juveniles of the endangered Asian Brown tortoise having a
mean SCL 120mm and SCW of 117mm as on November, 2011 that hatched successfully
in the zoo premises is a clear indication that the ex-situ conservation measures can be
recommended in the near future. MZG houses presently four males and two females
having a mean SCL of 405mm and SCW of 365mm and is the biggest amongst the turtles
housed at the zoo (Table 5b). A male having SCW of 584mm and SCW of 558mm and
having a BW of 20kg is the biggest.
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Table 5.a: Turtles and Tortoises in the Manipur Zoological Gardens (MZG),
Iroishemba
+HUH³0´VWDQGVIRUPDOHLQGLYLGXDOV³)´IRUIHPDOHLQGLYLGXDOVDQG³´DUHWKHXQVH[HG
juveniles
The Malayan Box Turtle, Cuora amboinensis having a mean SCL of 138mm and
a mean SCW of 108mm with a total number of 29 species is found to be the most
abundant in captivity, followed by Cyclemys gemeli having a mean SCL of 152mm and a
mean SCW of 116mm with 8 individuals (Table 5b).
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Table 5.b: Size measurements for the turtle species having more than 5 individuals
sample size. Range of measurements is followed by standard deviation (mean±SD) in
parenthesis, followed by the mean and number of individuals measured (n).
A single softshell turtle Amyda cartilaginea, a female of SCL 381mm and SCW
302mm was deposited by Manipur Forest Department officials at MZG on July 2009.
This happens to be the third record in the state from the Nambul river in Imphal West
district. The lone softshell turtle eventually expired on August 2011. Recently, 3
individuals of the endangered Yellow tortoise (Indotestudo elongata) having a mean SCL
of 203mm and SCW of 134mm have been deposited during August and October, 2012.
The smaller female with SCL of 173mm amongst them had a multitude of scratch marks
from a possible carnivorous predator. A single Melanochelys trijuga male deposited on
October, 2010 from Tamenglong district having a SCL of 166mm is the first
documentation from this region (Table 5c). The posterior part of the carapace bear burn
scars which stands probable chances of accidental burning during shifting cultivation. The
morphometric documentation of captive colony is of prime importance for future long
term comparative analysis with the wild populations for assessment of biological
parameters like growth, breeding biology studies and study of food habits which can be
implemented in future conservation planning efforts.
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Table 5.c: Size measurements for the turtle species having less than 5 individuals
sample size. Range of measurements is followed by standard deviation (mean±SD) in
parenthesis, followed by the mean and number of individuals measured (n).
During the investigation, it was noted that the clutch size of the tortoise Manouria
emys ranged between 23-25 and the size of the eggs were spherical. They nests several
times in a year. Incubation time has been reported to be of 90 days against the reported
days of 76 (Barbour and Ernst, 1982) and the sexual maturity is said to be attained by the
age of 4-5years having life span between 25-30 years (Barbour and Ernst, 1982), which
could not be performed in this investigation.
5.3.3 Sexual size dimorphism using Mann-Whitney U test
Sexual size dimorphism is common in both plants and animals, which in fact
reflects the adaptation of male and female to their different reproductive activities. The
regression of log value of male and female indicates that sexual size dimorphism (SSD)
LQFUHDVHVZLWKVL]HZKHUHIHPDOHVDUHORQJHUNQRZQDV³5HQVFK¶VUXOH´)DLUEairn, 1997).
Size determination is a necessary component to sort out the difference at which the
respective sex reaches at a particular size during maturity and development. Recently,
Benitez et al. (2013) suggested that morphological studies of sexual size dimorphism
(SSD) will be benefitted from the comparative approach to assess the effect of
SK\ORJHQHWLF KLVWRU\ DQG LW¶V XQFHUWDLQW\ DQG LQ WXUQ WKLV ZRXOG DOORZ WR TXDQWLI\ WKH
uncertainty of specific evolutionary processes. In the Malayan Box Turtle, sexual
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dimorphism is evident at around 15 months (Schoppe 2008a, 2009). Males are generally
slightly smaller and lighter than females (Rummler and Fritz, 1991; Schoppe 2008a,
2009) ( Plate 5b and Plate 5c). The males also possess a relatively longer tail and a slightly
concave plastron and known to mature at a SCL of 130mm, females at 152 mm (Paull et
al., 1982).
Plate 5.b: A female and male Cuora amboinensis showing morphological size
difference (Carapaceal view).
In fact, it has been clearly stated that sexual dimorphism between males and
females is not prominent and very difficult to mark the distinction between them upto the
age of 4-5years (Barbour and Ernst, 1982). Generally, the males possess a more slightly
concave plastron, longer thicker tails and longer claws when mature. Females have stubby
tails and shorter claws which confirms the observations of earlier workers (Barbour and
Ernst, 1982; Hall, 1995). Sexual dimorphism could be determined easily for all, but one,
of the Geoemydidae species, Cuora amboinensis, Morenia petersi, Pangshura tentoria,
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Cuora mouhotii and Melanochelys trijuga. The males have concave plastron with longer
and thicker tails (Plate 5d).
Plate 5.c: A male and female Cuora amboinensis showing morphological size
difference (Plastral view).
However, for the other Geoemydid species, Cyclemys gemeli, there is no visible
sexual dimorphism aside from females outgrowing the male turtles. However, shorter tail
length and location of the vent near the tip is used for identification of the male
individual. For the Testudinidae species, Manouria emys and Indotestudo elongata the
males possess longer and thicker tails with a concavity in the plastron. The males of
Indotestudo elongata have longer claws and narrower shells. As for the softshell
Trionychid turtles, Amyda cartilaginea and Nilssonia hurum the males have a relatively
longer tail that extends to the edge of the carapace with the vent situated near the tip
(CFH/MCBT, 2005). Juveniles of all species were not separated by sex since these
species are not known to be sexually dimorphic prior to their sexual maturity. It has been
established that the tail morphology has been considered as the primary character of
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sexual identification of Malayemys macrocephala (Brophy, 2006). Sexual dimorphism in
terms of tail morphology is well pronounced in both subadults and and adults with males
having much longer and thicker tails (Ernst and Barbour, 1989; Srinarumol, 1995).
Plate 5.d: A concave plastron of male Cuora amboinensis turtle.
The Mann-Whitney U test is a non-parametric test that is employed to test
significant size differences between the sexes in terms of SCL, SCW, SH and BW sexwise comparisons. The values of SCL, SCW, SH and BW are log-transformed to follow
the normal distribution pattern for analysis. Here, 5 turtle species having both male and
female are employed during the present investigation (Table 5e). Cumulative sex-wise
comparison of male and female individuals regardless of the type specimen was given in
Table 5d. The median values provide visible mean size differences. In the turtle species
Cuora amboinensis, the SCL and BW are found to significantly vary between the male
and female species with probability (p) values of 0.05 and 0.00 respectively. However,
there is no significant size dimorphism in the SCW and SH in comparison. In the softshell
turtle Amyda cartilaginea there was no significant size differentiation between male and
female individuals at the SCL, SCW, SH and BW parameters with all the p-values being
insignificant. The turtle Cyclemys gemeli have highly significant size differences between
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males and females with p-values of 0.00 to 0.01 of the SCL, SCW and BW morphometric
parameters, but insignificant SH parameter. The tortoise Indotestudo elongata GRQ¶WKDYH
any significant differences between male and females with all p-values being
insignificant. The same goes for the tortoise Manouria emys with no significant male and
female size dimorphism. Maturity in the turtle Trachemys scripta could be correlated with
the plastron length (Gibbons and Greene, 1990) against the male and female maturity of
the species Sternotherus odoratus with a plastron length of 54mm and 58mm respectively
(Mitchell, 1988). The identification of sexual dimorphism had been recorded based on the
method developed by Gibbons and Lovich (1990) and as such the number of females
were 31 against 51 male counterpart. The calculation of SDI (Sexual dimorphism Index =
mean plastron length of adult female/ mean plastron length of adult male) was introduced
for S.odoratus and T.scripta (Cloninger, 2007).
Table 5.d: Cumulative sex-wise comparison of parameters irrespective of type
specimen.
Here, the test could not be applied between sexes of those individuals either with
only one sex. Morenia petersi female (n=1), Melanochelys trijuga male (n=1), Nilssonia
hurum female (n=1), Panghura tentoria male (n=1) were however taken into account in
the cumulative analysis of all the individuals.
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Table 5.e: Sex-wise comparison of parameters of turtles and tortoises having both
the male and female in each species utilizing the Mann-U Whitney test.
5.3.4 Study of Allometry using Linear Regression analysis
Linear regression analysis were performed on five turtle and tortoises species
(Table 5f). The softshell turtle Amyda cartilaginea showed negative allometry with
respect to SCW/SCL to SCL, SH/SCL to SCL, BW/SCL to SCL growth comparisons in
the linear regression analysis showing insignificant allometric growth with p>0.05, which
infers that there is no significant proportionate growth of the carapace length in relation to
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the carapace width as well as the increase in the carapace length related to the decrease of
the deepening of the shell. Brophy (2006), using CL as independent variable for
regression analysis showed that intercepts were significantly different at zero, using
student t-test which suggested differential growth. Sexual dimorphism of the shell was
also evident and observed that the regression slope differed significantly. The body
weight is not found to increase significantly either with the increase in the SCL. These
results obtainded were not significant which possibly may be attributed to the smaller
sample size of the species. However, the results stand to be significant with p<0.05 with
20 numbers of Amyda cartilaginea individuals after regression analysis and support the
findings of Jensen, 2006. Sexual dimorphism and allometry of the turtle shell has been
extensively reviewed by several workers (Berry and Shine, 1980; Ernst and Lovich, 1986;
Gibbons and Lovich, 1990). Brophy (2006) was able to highlight the frequency of CL
which indicated that the females were longer than the males and this difference was
statistically significant (p<0.001). Thus, the allometry attributes that the adult males with
relatively narrower and flatter shells compared to relatively wider and higher shells of
C.amboinensis females observed in this study conform the view of various workers
(Brophy, 2006; Platt et al., 2008). The turtle Cuora amboinensis showed positive
allometric growth with only two parameters viz., SH/SCL to SCL and BW/SCL to SCL
showing that for every one unit increase in SH parameter and BW parameter there is
uniform increase or decrease in the SCL parameter value. The turtles are known to have
highly domed structures of the carapace (SH) and the results are significant (p<0.05)
which implies that as the carapace lengthens the shell height increases in due time
showing proportionate growth. This results agree with the findings of Jensen (2006). The
body weight parameter is also found to increase significantly with the increase in the
carapace length. However, the results for SCW with relation to SCL is not found to be
significant with p > 0.05 indicating that there is no proportionate increase in the carapace
width with respect to increase in the carapace length.
Similarly, for the turtle Cyclemys gemeli there is positive allometry with the two
parameters viz., SH/SCL to SCL and BW/SCL to SCL. Here, the deepening of the
carapace (SH) is found to be significant at p<0.05 with respect to the lengthening of the
carapace (SCL) indicating that the carapace length increases with the shell height does not
attain at a greater depth as it does in length (Jensen, 2006). However, the relation of the
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widening of the carapace with respect to the lengthening is not found to be significant as
opposed to the findings of Jensen (2006), which possibly may be attributed to great
variation in size parameters with some animals having narrower shell width, flattened
shell height or otherwise highly domed in others (Jensen, 2006). The tortoises Indotestudo
elongata and Manouria emys showed negative allometry and the results showed to be
insignificant with p>0.05 with respect to SCW/SCL to SCL and BW/SCL to SCL growth
comparisons in the linear regression analysis. However, it showed positive allometry for
both the tortoises with the SH/SCL to SCL parameter with significant p-value. This can
be attributed to smaller sampling during analysis. Allometric curve with biological
intercepts could be used to estimate carapace length and growth rates throughout all size
classes of loggerhead turtle Caretta caretta (Snova et al., 2007).
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Table 5.f: Results for the test of Allometry using ANOVA (Linear Regression
Analysis).
Here, for the turtle species Melanochelys trijuga, Pangshura tentoria, Nilssonia hurum and
Morenia petersi the Regression analysis could not be performed due to less frequencies.
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