Spitting behaviour and fang morphology of spitting cobras [Elektronische Ressource] / Ruben Andres Berthé. Mathematisch-Naturwissenschaftliche Fakultät
238 Pages
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Spitting behaviour and fang morphology of spitting cobras [Elektronische Ressource] / Ruben Andres Berthé. Mathematisch-Naturwissenschaftliche Fakultät

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Spitting behaviour and fangmorphology of spitting cobrasDissertationzurErlangung des Doktorgrades (Dr. rer. nat.)derMathematisch-Naturwissenschaftlichen FakultätderRheinischen Friedrich-Wilhelms-Universitätvorgelegt vonRuben AndresBerthéausDüsseldorfBonn, April 2011Angefertigt mit Genehmigung der Mathematisch-NaturwissenschaftlichenFakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn1. Gutachter: Professor Dr. Horst Bleckmann2. Gutachter: Dr. Wolfgang BöhmeTag der Promotion: 20. September 2011Erscheinungsjahr: 2011Contents 3ContentsList of Figures 5List of Tables 81 Introduction 92 Materials and Methods 152.1 Distribution and habitat . . . . . . . . . . . . . . . . . . . . . . . . . 152.2 Behavioural experiments . . . . . . . . . . . . . . . . . . . . . . . . . 152.2.1 Comparison of eyes . . . . . . . . . . . . . . . . . . . . . . . . 162.2.2 of shapes . . . . . . . . . . . . . . . . . . . . . . . 172.2.3 Comparison of sizes . . . . . . . . . . . . . . . . . . . . . . . . 182.2.4 Venom distribution and target distance . . . . . . . . . . . . 192.2.5 Additional experiments . . . . . . . . . . . . . . . . . . . . . . 202.3 Analysis of venom fangs . . . . . . . . . . . . . . . . . . . . . . . . . . 222.3.1 Morphology data . . . . . . . . . . . . . . . . . . . . . . . . . 222.3.2 Spraying analysis . . . . . . . . . . . . . . . . . . . . . . . . . 243 Results 273.1 Behavioural experiments . . . . . . . . . . . . . . . . . . . . . . .

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Published 01 January 2011
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Spitting behaviour and fang
morphology of spitting cobras
Dissertation
zur
Erlangung des Doktorgrades (Dr. rer. nat.)
der
Mathematisch-Naturwissenschaftlichen Fakultät
der
Rheinischen Friedrich-Wilhelms-Universität
vorgelegt von
Ruben AndresBerthé
aus
Düsseldorf
Bonn, April 2011Angefertigt mit Genehmigung der Mathematisch-Naturwissenschaftlichen
Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn
1. Gutachter: Professor Dr. Horst Bleckmann
2. Gutachter: Dr. Wolfgang Böhme
Tag der Promotion: 20. September 2011
Erscheinungsjahr: 2011Contents 3
Contents
List of Figures 5
List of Tables 8
1 Introduction 9
2 Materials and Methods 15
2.1 Distribution and habitat . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2 Behavioural experiments . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.1 Comparison of eyes . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.2 of shapes . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.3 Comparison of sizes . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.4 Venom distribution and target distance . . . . . . . . . . . . 19
2.2.5 Additional experiments . . . . . . . . . . . . . . . . . . . . . . 20
2.3 Analysis of venom fangs . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.1 Morphology data . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3.2 Spraying analysis . . . . . . . . . . . . . . . . . . . . . . . . . 24
3 Results 27
3.1 Behavioural experiments . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.1.1 Comparison of eyes . . . . . . . . . . . . . . . . . . . . . . . . 27
3.1.2 of shapes . . . . . . . . . . . . . . . . . . . . . . . 27
3.1.3 Comparison of sizes . . . . . . . . . . . . . . . . . . . . . . . . 30
3.1.4 Venom distribution and target distance . . . . . . . . . . . . 39
3.1.5 General observations . . . . . . . . . . . . . . . . . . . . . . . 43
3.1.6 Additional experiments . . . . . . . . . . . . . . . . . . . . . . 44
3.2 Analysis of venom fangs . . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.2.1 Morphology data . . . . . . . . . . . . . . . . . . . . . . . . . 44
3.2.2 Spraying analysis . . . . . . . . . . . . . . . . . . . . . . . . . 80
4 Discussion 83
4.1 Behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
4.2 Fang morphology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Summary 88
References 894 Contents
A Test results 95
B Source code 97
C Computers 202
D 3D reconstruction of fangs 203
E Circumferences and areas of venom canals 229
F Exemplary eccentricities 235
Acknowledgements 236List of Figures 5
List of Figures
1 Phylogenetic tree – Serpentes and Elapidae . . . . . . . . . . . . . . 10
2 Ph tree – Naja and Hemachatus . . . . . . . . . . . . . . . 11
3 Comparison of fangs from a spitting and a non-spitting cobra (sa-
gittal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4 Comparison of fangs from spitting and non-spitting cobras (trans-
versal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5 Photos of glass eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6 Compared shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7 Example two disk target . . . . . . . . . . . . . . . . . . . . . . . . . 19
8 Illustration of spitting angle . . . . . . . . . . . . . . . . . . . . . . . 20
9 Sample spitting pattern with rectangle . . . . . . . . . . . . . . . . . 21
10 Example for venom canal and fitted ellipse . . . . . . . . . . . . . . 23
11 Illustration of fang measures . . . . . . . . . . . . . . . . . . . . . . . 24
12 Connection between fang and tube . . . . . . . . . . . . . . . . . . . 25
13 Comparison of eyes characteristics . . . . . . . . . . . . . . . . . . . 29
14 Co of differently shaped targets . . . . . . . . . . . . . . . . 31
15 Distribution of reaction times . . . . . . . . . . . . . . . . . . . . . . 33
16 Venom distribution on two disks without eyes . . . . . . . . . . . . 35
17 Venom on two disks with eyes on the larger disk . . . 36
18 Venom distribution on two disks with eyes on the smaller disk . . 37
19 Height and width of spitting patterns . . . . . . . . . . . . . . . . . 40
20 Vertical and horizontal spitting angles . . . . . . . . . . . . . . . . . 41
21 3D reconstruction of fang hae1 . . . . . . . . . . . . . . . . . . . . . . 47
22 3D of fang naj3 . . . . . . . . . . . . . . . . . . . . . . 48
23 3D of fang nig1 . . . . . . . . . . . . . . . . . . . . . . 49
24 3D reconstruction of fang pal1 . . . . . . . . . . . . . . . . . . . . . . 50
25 3D of fang sia1 . . . . . . . . . . . . . . . . . . . . . . 51
26 Relative length of discharge orifices and fang tips . . . . . . . . . . 54
27 Width of discharge orifice (spitting cobras) . . . . . . . . . . . . . . 56
28 Width of discharge orifice (non-spitting snakes) . . . . . . . . . . . 57
29 Comparison with fitted ellipses (hae1) . . . . . . . . . . . . . . . . . 58
30 Co with fitted ellipses (hae2) . . . . . . . . . . . . . . . . . 59
31 Comparison with fitted ellipses (nig1) . . . . . . . . . . . . . . . . . 60
32 Co with fitted ellipses (nig2) . . . . . . . . . . . . . . . . . 61
33 Comparison with fitted ellipses (nig3) . . . . . . . . . . . . . . . . . 626 List of Figures
34 Comparison with fitted ellipses (nig4) . . . . . . . . . . . . . . . . . 63
35 Comparison with fitted ellipses (nig5) . . . . . . . . . . . . . . . . . 64
36 Comparison with fitted ellipses (pal1) . . . . . . . . . . . . . . . . . 65
37 Comparison with fitted ellipses (pal2) . . . . . . . . . . . . . . . . . 66
38 Comparison with fitted ellipses (pal3) . . . . . . . . . . . . . . . . . 67
39 Comparison with fitted ellipses (pal4e) . . . . . . . . . . . . . . . . . 68
40 Comparison with fitted ellipses (sia1e) . . . . . . . . . . . . . . . . . 69
41 Comparison with fitted ellipses (sia2e) . . . . . . . . . . . . . . . . . 70
42 Comparison with fitted ellipses (sia3) . . . . . . . . . . . . . . . . . . 71
43 Comparison with fitted ellipses (sia4) . . . . . . . . . . . . . . . . . . 72
44 Comparison with fitted ellipses (D.angusticeps & N.haje) . . . . . 73
45 Comparison with fitted ellipses (N.kaouthia) . . . . . . . . . . . . . 74
46 Comparison with fitted ellipses (N.melanoleuca) . . . . . . . . . . . 75
47 Comparison with fitted ellipses (N.naja) . . . . . . . . . . . . . . . 76
48 Angles and eccentricities of N.haje . . . . . . . . . . . . . . . . . . . 77
49 Angles and eccen of N.naja . . . . . . . . . . . . . . . . . . . 78
50 Angles and eccentricities of N.siamensis . . . . . . . . . . . . . . . . 79
51 Droplets: 75% glycerol . . . . . . . . . . . . . . . . . . . . . . . . . . 81
52 85% . . . . . . . . . . . . . . . . . . . . . . . . . . 82
53 3D reconstruction of fang ang1 . . . . . . . . . . . . . . . . . . . . . 203
54 3D of fang ang2 . . . . . . . . . . . . . . . . . . . . . 204
55 3D of fang hae1 . . . . . . . . . . . . . . . . . . . . . . 205
56 3D reconstruction of fang hae2 . . . . . . . . . . . . . . . . . . . . . . 206
57 3D of fang haj1 . . . . . . . . . . . . . . . . . . . . . . 207
58 3D of fang kao1 . . . . . . . . . . . . . . . . . . . . . . 208
59 3D reconstruction of fang kao2 . . . . . . . . . . . . . . . . . . . . . . 209
60 3D of fang kao3 . . . . . . . . . . . . . . . . . . . . . . 210
61 3D of fang mel1 . . . . . . . . . . . . . . . . . . . . . 211
62 3D reconstruction of fang mel2 . . . . . . . . . . . . . . . . . . . . . 212
63 3D of fang naj1 . . . . . . . . . . . . . . . . . . . . . . 213
64 3D of fang naj2 . . . . . . . . . . . . . . . . . . . . . . 214
65 3D reconstruction of fang naj3 . . . . . . . . . . . . . . . . . . . . . . 215
66 3D of fang nig1 . . . . . . . . . . . . . . . . . . . . . . 216
67 3D of fang nig2 . . . . . . . . . . . . . . . . . . . . . . 217
68 3D reconstruction of fang nig3 . . . . . . . . . . . . . . . . . . . . . . 218
69 3D of fang nig4 . . . . . . . . . . . . . . . . . . . . . . 219List of Figures 7
70 3D reconstruction of fang nig5 . . . . . . . . . . . . . . . . . . . . . . 220
71 3D of fang pal1 . . . . . . . . . . . . . . . . . . . . . . 221
72 3D of fang pal2 . . . . . . . . . . . . . . . . . . . . . . 222
73 3D reconstruction of fang pal3 . . . . . . . . . . . . . . . . . . . . . . 223
74 3D of fang pal4 . . . . . . . . . . . . . . . . . . . . . . 224
75 3D of fang sia1 . . . . . . . . . . . . . . . . . . . . . . 225
76 3D reconstruction of fang sia2 . . . . . . . . . . . . . . . . . . . . . . 226
77 3D of fang sia3 . . . . . . . . . . . . . . . . . . . . . . 227
78 3D of fang sia4 . . . . . . . . . . . . . . . . . . . . . . 228
79 Circumferences and areas of venom canals of D.angusticeps . . . . 229
80 Circumferences and areas of venom canals of H.haemachatus . . . 229
81 Circumferences and areas of venom canals of N.kaouthia . . . . . . 230
82 Circumferences and areas of venom canals of N.melanoleuca and
N.haje . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
83 Circumferences and areas of venom canals of N.naja . . . . . . . . 231
84nces and areas of venom canals of N.nigricollis . . . . . 232
85 Circumferences and areas of venom canals of N.pallida . . . . . . . 233
86nces and areas of venom canals of N.siamensis . . . . . 234
87 Exemplary eccentricities . . . . . . . . . . . . . . . . . . . . . . . . . 2358 List of Tables
List of Tables
1 Mean values of the results of the comparison of eye characteristics 28
2 Results of the tests of the comparison of eye characteristics . . . . 28
3 Comparison of N.nigricollis and N.pallida regarding glass eyes . . 30
4 of differently shaped targets concerning spitting fre-
quency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5 Comparison of N.nigricollis and N.pallida regarding target shapes 34
6 Proportion of venom found on large or small disk . . . . . . . . . . 38
7 Correlation between distance and spitting patterns . . . . . . . . . 42
8 Nonlinear regression for the spitting angles . . . . . . . . . . . . . . 43
9 External measurement of the fangs (l , l , l , l , l , A ) . . . . 52F O Ct Cc T O
10 Test results for differences between fangs of spitting and non-
spitting cobras. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
11 Length of ridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
12 Fang suture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
13 Measures of the droplet patterns . . . . . . . . . . . . . . . . . . . . 80
14 Spitting at eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95