Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2007
Volume 10
Issue 1
Topic:
Veterinary Medicine
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Marycz K. , Rogowska K. 2007. THE LIVER MORPHOLOGY AND TOPOGRAPHY OF HORSFIELD’S (TESTUDO HORSFIELDI) AND HERMANN’S (T. HERMANNI) TERRESTRIAL TORTOISES, EJPAU 10(1), #25.
Available Online: http://www.ejpau.media.pl/volume10/issue1/art-25.html

THE LIVER MORPHOLOGY AND TOPOGRAPHY OF HORSFIELD’S (TESTUDO HORSFIELDI) AND HERMANN’S (T. HERMANNI) TERRESTRIAL TORTOISES

Krzysztof Marycz1, Katarzyna Rogowska2
1 Electron Microscope Laboratory, Departament of Animal Hygiene and Ichthyology, Wrocław University of Environmental and Life Sciences, Poland
2 Department of Genetics and Animal Breeding, Wrocław University of Environmental and Life Sciences, Poland

 

ABSTRACT

In Poland most often meet tortoises are Horsfield’s (Testudo horsfieldi) and Hermann’s tortoises (T. hermanni). Each of this species during winter and summer hibernate. On areas with very long winter, Horsfield’s tortoise is active only about three months a year. The most interesting is tortoise alimentary canal, because they are herbivorous. The one from more interesting organs of alimentary canal is the liver, which is the energy centre of the organism. The type of food influences on the shape and size of the tortoise liver. The aim of the study was examined the structure, shape, position and vascularity of the discussed organ.

In the investigation were used 19 Horsfield’s tortoises (11 females, 8 males) and 19 Hermann’s tortoises (5 females and 14 males). For the morphometrical study were used 15 individuals from every species, remaining (4 individuals of Horsfield’s tortoise and 4 individuals of Hermann’s tortoise) were used to made injection – corrosive preparations.

Livers both of species had very precise defined position with relation to the plastron and carapax. The liver mass of Horsfield’s tortoise was greater than liver mass of Hermann’s tortoise, what caused by difficult conditions in which it lived.

Key words: tortoise, liver, mass, asymmetry coefficient, morphometry, anatomy, topography.

INTRODUCTION

Turtles more often are patients of veterinary clinics, because people now little about its behavior, nourishment and principal conditions of maintenance. Very often owners treatment this animals like “live toys”. This leads to numerous diseases, especially from alimentary canal [12].

In Poland most often meet tortoises are the Horsfield’s tortoise (Testudo horsfieldi) and the Hermann’s tortoise (T. hermanni) in breeding. Both of they usually eat juicy stems, leaves and fruits. Besides they feed on insects and even excrements of birds and bones of small animals. This species during winter and summer hibernate. On some areas, where is very long winter, Horsfield’s tortoise is active only about three months a year.

Turtles are very interesting not only as domestic animals. Their origin, adaptative abilities, anatomy and physiological properties are frequent themes of many publications. The most interesting fact is their alimentary canal (apparatus digestorius), because they are herbivorous. Sometimes extreme herbivorous species accept the animal food.

Turtles during the winter and summer hibernation don’t take food (almost all the year sometimes). The anatomical structure of turtles alimentary canal wasn’t fully knowledge, especially morphometry, morphology and asymmetry of particular organs. The one from more interesting organs of alimentary canal is the liver, which is the energy centre of the organism. The type of food influences strongly on the shape and size of the tortoise liver [5]. The macroscopic description of this organ introduces following scientific publications and manuals [2,8,9,11,18]. Information about the microscopic structure of tortoise liver we could find in publications [7,8].

Aim of study
The aim of the work under a title “The liver morphology and topography of Horsfield’s and Hermann’s terrestrial tortoises” was examining the structure, shape, position and vascularity of the discussed organ. This work will be useful in clinical sciences and could underlie to further considerations, because we have constantly growing interest with study species in unprofessional breeding and lack of wider information in literature concerning above – mentioned problems.

MATERIAL AND METHODS

In the investigation were used 19 Horsfield’s tortoises (11 females, 8 males) and 19 Hermann’s tortoises (5 females and 14 males). The all material came from ZOOs. Dead individuals didn’t have any pathological changes in investigated organs.

The membership of study species was established on the ground of manual – key “Turtles of the World” [6]. For the morphometrical study were used 15 individuals from every species, remaining (4 individuals of Horsfield’s tortoise and 4 individuals of Hermann’s tortoise) were used to made injection – corrosive preparations. The sex of investigated individuals was marked by observations of gonads after the previous opening of the pectoral – ventral cavity.

The total length of carapax was marked as the section among the neck scutum and epicaudal scutum. The width was marked as the section among the most pull out points of the bone – bridge. The measurements of the armour were took by slide gauge with precision to 1 millimeter. The mass of tortoises was marked by the electronic balance with precision to 1 gram. The morphometrical measurements of the liver were done after removal of plastron, ventral integuments and pectorales muscles. The position of the organ was marked according to methods used in the topographical anatomy, as: skeletotopy, syntopy and holotopy. The length of the liver was marked as the section among the most pull out points on the liver in medial plane along the long axis of the body.

The width of the liver was measured among the most pull out points lay on the right and left border of liver. Measurements was took by the electronic slide gauge with the precision to 0.01 millimetre.

The mass of the organ was marked by the analytical balance with precision to 0.001 gram after the first extraction from the body, rinsed out and drayed by the filter paper. The relative mass of turtles liver was marked as the percentage of liver mass to the animal body mass [15]. On the ground of obtained masses was marked the asymmetry coefficient A, which was introduced as the quotient of the liver right lobe mass to the left lobe mass [19].

The injection – corrosive preparations was made for defined the course of arteries providing the investigated organ, duracryl was used as the filling material [1,13]. In further considerations concerning females and males weren’t used above – mentioned criterions, because there weren’t differences in liver morphometry, position and vascularity.

Under the study encountered many divergences of Latin time – limits, which concerned bone and horn elements of the armour, blood – vessels and components of the investigated organ. Because of that, Latin names presented on the study came from different publications [2,8,9,10]. For the better description of the liver some its parts had compatible names with the NAV (1994).

RESULTS

Horsfield’s tortoise
The liver lay transverse to the long axis of the body and was composite by two lobes, right and left. Both of lobes in the half of the organ width were joint by a narrow strand of connective tissue. From the dorsal side liver was hung on the dorsal mesentery, from the ventral side connected with the ventral mesentery. The all organ was darkly – red. The liver with its shape resembled the cone with truncated top and base turned toward to caudal direction.

On the liver were marked the surfaces: parietal, dorsal and celiac and borders – right and left. The parietal surface stuck to the plastron and in its central part among lobes the ventricle of heart was found. From the dorsal side the right lobe was in contact with the right lung, left covered the suitable lung and some part of stomach. On visceral surface, on the right lobe was found the impression for the strongly extended duodenum, pancreas and spleen. The left lobe from the visceral side was in contact with the remaining part of the stomach. In the notch of the right lobe lay the bile sacculus. Its canal with the liver canal escaped to the duodenum in its first section. The right lobe occupied the surface from second to the fourth ribs scutum, it was defined by horn scutums of carapax. The left lobe embraced with its range the second and third ribs scutum. In relation to the plastron both of the lobes in their range embraced caudal part of pectoral plate and the important part of ventral plate.

The average length of the liver was the 25.87% length of carapax, the proportional ratio of the liver width to the carapax width was on average 71.74%. All measurements of investigated organ was showed in Tab.1, 2 and 3. The liver right piece dominated in balance over left, the right lobe was 2.04 gram and left 1.195 gram (Tab.3). The asymmetry coefficients of the both pieces showed the large variability and were from A=0.92 to A=3.85, on average 2.04 (Tab. 3).

Hermann’s tortoise
In liver morphology and color of Hermann’s tortoises was many similarities to liver of Horsfield’s tortoise. Topographical locality of liver in relation to another organs and skeleton was similar to species which was described first.

Measurements of liver length and width were introduced in Tab. 1 and 2. The mass of the liver within the investigated group was from 1.572 gram to 3.545 gram, on average 2.253 gram (Tab.3). The participation of liver mass with relation to all tortoises mass was on average 1.79% (Tab. 3). The liver right lobe dominated in balance over left, similar to Horsfield’s tortoise. The average mass of right lobe was 0.914 gram and the left 0.428 gram (Tab.3). The value of asymmetry coefficient A both of this elements was very varied and it was from A=0.36 to A=3.01, in average 1.5 (Tab.3).

The liver vascularity both of species was similar and was defined on the ground of injection – corrosive preparations. In the half of cases hepatic artery separated from left arch of aorta on high of second and third vertebra scutum. In remaining individuals noticed that the hepatic artery separated from the left aortic arch with the celiac artery at the stomach cardiac part.

Table 1. The measurements of carapax and liver morphometry

Horsfield’s tortoise

Hermann’s tortoise

Length of carapax
(mm)

The liver length
(mm)

Liver length to body length ratio (%)

Length of carapax
(mm)

The liver length
(mm)

Liver length to body length ratio (%)

1A

92.34

20.25

21.92

1B

90.24

21.73

24.08

2A

94.26

23.33

24.75

2B

87.56

17.65

20.15

3A

93.56

21.20

22.65

3B

92.72

26.74

28.83

4A

91.26

20.02

21.93

4B

88.29

21.04

23.19

5A

92.57

19.38

20.93

5B

95.86

20.48

21.36

6A

91.01

27.43

30.13

6B

79.76

24.04

30.14

7A

91.94

22.02

23.95

7B

91.45

13.87

15.16

8A

79.67

22.36

28.06

8B

90.90

13.93

15.32

9A

88.51

15.51

17.42

9B

68.17

19.39

28.44

10A

89.99

22.02

42.48

10B

98.40

19.58

21.9

11A

89.92

26.25

29.19

11B

94.58

30.21

31.94

12A

92.46

20.39

22.05

12B

95.39

23.76

24.9

13A

97.87

24.78

25.31

13B

90.70

22.76

25.09

14A

87.85

28.25

32.15

14B

82.17

21.00

25.55

15A

92.68

23.39

25.23

15B

102.85

22.19

21.57

Min

79.67

15.51

17.42

Min

68.17

13.87

15.16

Max

97.87

28.25

32.15

Max

102.85

26.74

30.14

Mean

78.73

24.43

25.87

Mean

83.88

21.22

23.84

Table 2. The measurements of carapax and liver morphometry

Horsfield’s tortoise

Hermann’s tortoise

Width of carapax
(mm)

The liver width
(mm)

Liver width to body width ratio (%)

Width of carapax
(mm)

The liver width
(mm)

Liver width to body width ratio (%)

1A

78.83

75.63

95.94

1B

73.95

61.02

82.51

2A

98.34

47.12

47.91

2B

69.85

64.40

66.49

3A

75.94

58.60

77.16

3B

75.83

73.04

96.32

4A

74.27

57.50

77.42

4B

81.96

65.23

79.58

5A

77.27

50.80

65.74

5B

87.90

58.14

66.14

6A

74.78

61.41

82.12

6B

75.15

63.79

84.88

7A

74.20

61.80

83.28

7B

84.47

57.63

68.22

8A

56.98

15.51

27.22

8B

82.00

54.32

66.24

9A

74.93

52.36

69.87

9B

67.21

51.09

76.01

10A

75.18

55.00

73.15

10B

86.45

52.99

61.29

11A

70.34

55.88

79.44

11B

85.34

58.79

68.88

12A

79.46

56.72

71.38

12B

84.66

61.69

73.18

13A

78.97

49.27

62.39

13B

87.80

57.11

65.04

14A

72.69

56.33

77.49

14B

85.16

67.01

78.68

15A

74.82

64.05

85.60

15B

87.52

68.22

77.94

Min

56.98

15.51

27.22

Min

67.21

51.09

61.29

Max

98.34

75.63

95.94

Max

87.52

73.04

96.32

Mean

75.80

54.53

71.74

Mean

81.01

60.96

74.09

Table 3. Body and liver mass, proportional ratio both of masses and asymmetry coefficient value

Horsfield’s tortoise

Hermann’s tortoise

Tortoise mass
(g)

The liver mass
(g)

The body mass to liver mass ratio (%)

The liver left lobe mass
(g)

The liver right lobe mass
(g)

The asymmetry coefficient A

Tortoise mass
(g)

The liver mass
(g)

The body mass to liver mass ratio (%)

The liver left lobe mass
(g)

The liver right lobe mass
(g)

The asymmetry coefficient A

1A

112

4.020

3.58

1.143

2.877

2.51

1B

78

3.426

4.44

2.512

0.914

0.36

2A

154

4.129

2.76

2.016

2.113

1.04

2B

97

2.948

3.03

1.431

1.517

1.06

3A

123

6.804

5.52

2.872

3.932

1.36

3B

167

2.002

1.19

0.987

1.015

1.02

4A

154

4.277

2.77

1.578

2.699

1.71

4B

126

1.572

1.24

0.651

0.921

1.41

5A

111

3.15

2.83

1.003

2.147

2.14

5B

149

2.117

1.41

1.142

0.975

0.85

6A

106

3.412

3.21

1.452

1.96

1.34

6B

188

3.021

1.6

1.341

1.68

1.25

7A

154

2.731

1.77

0.562

2.169

3.85

7B

166

1.866

1.12

0.523

1.343

2.56

8A

97

2.014

2.07

0.751

1.263

1.86

8B

106

1.679

1.57

0.429

1.25

2.91

9A

98

1.876

1.9

0.461

1.415

3.06

9B

154

2.651

1.72

1.001

1.65

1.64

10A

154

2.149

1.38

1.119

1.03

0.92

10B

159

2.387

1.49

1.231

1.156

0.93

11A

92

1.332

1.44

0.379

0.953

2.51

11B

157

1.90

1.21

0.678

1.222

1.8

12A

132

1.970

1.49

0.431

1.539

3.57

12B

143

2.975

2.07

1.419

1.556

1.09

13A

153

3.313

2.16

1.187

2.126

1.79

13B

102

1.72

1.68

0.428

1.291

3.01

14A

143

2.829

1.97

1.021

1.808

1.77

14B

157

1.983

1.26

0.521

1.462

2.8

15A

112

4.123

3.67

1.88

2.243

1.19

15B

185

3.545

1.91

1.676

1.867

1.11

Min

92

1.332

1.38

0.379

0.953

0.92

Min

78

1.572

1.12

0.428

0.914

0.36

Max

154

6.804

5.52

2.872

2.877

3.85

Max

188

3.545

4.44

2.512

1.867

3.01

Mean

126,33

3.28

2.56

1.195

2.018

2.04

Mean

142.26

2.253

1.79

1.06

1.321

1.5

Photo 1. Topography of liver of T. hermanni 1 – pectoralis muscles 2 – left lobe of liver 3 – right lobe of liver 4 – heart

DISCUSSION

Tortoises could tolerated for the long time unfavourable conditions, because they had many adaptative abilities, specific anatomical structure, biochemistry and physiology [11]. This animals their own resistant to unfavourable conditions owe to a high degree the liver.

Generally on the structure of studied organ large influence firstly had its function, type of animal life and neighbourhood of other organs [14]. On the morphology of the alimentary canal the huge influence had also the type of food and evolutional origin [3,5]. The liver of present reptiles had very varied anatomical structure. This organ could appeared as long singlelobe and spindle – shaped organ at snakes, or the multilobe form at remaining representatives of the group [2,18]. Within Testudinata the liver had very similar shape and morphology. The differences most often concerned mass of this organ, which at carnivorous tortoises was relatively greater [4,9].

In investigated tortoises liver was located transverse to the long axis of body and was composed of two lobes – left and right. Morphology of that organ wasn’t very differ from descriptions placed in other publications [2,8,9,18]. However, for better anatomical description, on the organ were distinguished surfaces: parietal, dorsal, celiac and borders – right and left.

The standards of size and range of their variability were marked by morphometrical analysis. The length of the study organ both of species was about 25% of carapax length, the width 74% of armour width. Masses of investigated organ showed differences among species. The Hermann’s tortoise liver was on average 1.79% of the all body mass, in Horsfield’s tortoise it was 2.56%, so that was higher result by half. The liver stored a lot of alimentary components in view of very long intervals without raven, caused by winter and summer hibernation. Received results of liver masses were corresponded with observations Crile [4]. It seems also that the low mass of investigated organ of study species is natural and common for reptiles. The asymmetry coefficient A showed differences in structure, size and uneven growth of organ even parts. In presenting results such dependence was established for liver, which had greater right lobe. In the classification gave by Van Valen [17] the asymmetry of liver lobes belonged to directional, and in relation to the Szuba [16] classification it was independent asymmetry.

During the clinical operations important function had also the position of blood vessels. Defined, that on the half of cases hepatic artery separated from left arch of aorta at the high of second and third vertebra scutum. At remaining individuals this artery separated from left arch with celiac artery at the stomach cardiac part. Above results supplement observations published by Gurtowoj et al. in 1978.

CONCLUSIONS

  1. The large similarity in the range of morphology, topography and liver vascularity caused by kinship, closely type and environment of life.

  2. The length of Horsfield’s tortoise and Hermann’s tortoise liver was 25% of carapax length.

  3. The liver width of investigated species was 74% of carapax width.

  4. The liver mass of Horsfield’s tortoise was greater than Hermann’s tortoise, what caused by difficult conditions in which it lived.

  5. Livers both of species had very precise defined position with relation to the plastron and carapax.

  6. The hepatic artery leaved the left aortic arch from two localities.


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Accepted for print: 8.02.2007


Krzysztof Marycz
Electron Microscope Laboratory,
Departament of Animal Hygiene and Ichthyology,
Wrocław University of Environmental and Life Sciences, Poland
Kożuchowska 5b, 50-375 Wrocław, Poland
Phone: +48 71 320 58 88
email: krzysztofmarycz@interia.pl

Katarzyna Rogowska
Department of Genetics and Animal Breeding,
Wrocław University of Environmental and Life Sciences, Poland
Kożuchowska 7, 51-631 Wrocław, Poland
email: rogows_ka@op.pl

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