Fight for your life: antipredator mechanisms in amphibians

Egon Heiss

University ofVienna

„arms“ against enemys

Eisner and Aneshansley, 1999

Arnold, 1982

© Steinmann

Ambystoma gracile

Ambystoma cingulatum

Bolitoglossa franklini

Taricha rivularis

Euricea lucifuga

Ambystoma laterale

Echinotriton andersoni Tylototriton shanjing

Brodie, 1977

• response to predator-like stimulations

„tail elevated posturing“

„body-arched posturing“

secretion

• Histological studies revealed 3 types of skin glands

GG I

GG II

MG

Glands

Glands

MG

GGI

GGII

PAS AB CB

Glands

MG GG I GG II

5 µm 5 µm5 µm

active secretion

Myoepithelium

G Ct G MyE Ct

100µm

active secretion

Gland density

• Parotoid Glands: Densely packed GGI

RT: 0.00 - 50.00 SM: 15G

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50Time (min)

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Rel

ativ

e Ab

unda

nce

33.06642.30548

6.51128.08188

32.78470.27585

6.75266.99698

44.02387.17944

13.21133.07532

31.71420.27423

12.82146.06001

44.83335.22156

22.53501.3259312.48

136.03973 30.45511.24652

22.96259.15524

34.50852.70459

4.45178.07231

37.40432.27444

2.29118.08635 18.83

70.0807027.68

532.26672 49.70494.25357

35.07395.07458

11.09371.10123

8.89371.10123

40.28402.26367

14.50245.18593 23.46

427.1768546.29

371.0997921.35

371.10123

NL:1.12E8Base Peak MS Pleuro1zu10_HSST3

nano-LC-ESI/MS basepeak chromatogram

Hurt yourself to hurt your enemy!

Heiss et al., 2010

„relaxed“ „threatened“

Mobility of the ribs

„relaxed“ „threatened“

Mobility of the ribs

„threatened“„relaxed“

Mobility of the ribs

di

pa tu

ca

skin penetration

Echinotriton sp.Tylototriton sp.

Pleurodeles

Echinotriton

Tylototriton

© Salamanderland

Brodie, 1983

Tylototriton verrucosus

Rib movements as useful strategy to appear larger

© utaherps

Blackburn et al., 2008

Blackburn et al., 2008

Arnold, 1982

Von Byern et al., in press

Conclusions

> Skin gland distribution correlates with behaviour

> Specialized behaviour potentiates effect of skin gland secretions

> Skin glands in amphibians are highly specialized and actively used in defence

Thank you for your kind attention!

Brodie et al., 1993