Comparison of the cold hardiness capacities of the oviparous and viviparous forms of Lacerta vivipara - Université Claude Bernard Lyon 1 Accéder directement au contenu
Article Dans Une Revue Journal of experimental zoology. Part A, Comparative experimental biology. Année : 2004

Comparison of the cold hardiness capacities of the oviparous and viviparous forms of Lacerta vivipara

Résumé

The lizard Lacerta vivipara has allopatric oviparous and viviparous populations. The cold hardiness strategy of L. vivipara has previously been studied in viviparous populations, but never in oviparous ones. The present study reveals that both the oviparous and viviparous individuals of this species are able to survive in a supercooled state at -3 degrees C for at least one week when kept on dry substrates. The mean crystallisation temperatures of the body, around -4 degrees C on dry substrata and -2 degrees C on wet substrata, do not differ between oviparous and viviparous individuals. All the individuals are able to tolerate up to 48-50% of their body fluid converted into ice, but only viviparous individuals were able to stabilize their body ice content at 48%, and hence were able to survive even when frozen at -3 degrees C for times of up 24 hours. Ice contents higher than 51% have been constantly found lethal for oviparous individuals. This suggests that, in L. vivipara, the evolution towards a higher degree of freezing tolerance could parallel the evolution of the viviparous reproductive mode, a feature believed to be strongly selected under cold climatic conditions. This is the first report, among reptiles, of an intraspecific variation regarding the freeze tolerance capacities.

Domaines

Autre [q-bio.OT]

Dates et versions

hal-00069605 , version 1 (18-05-2006)

Identifiants

Citer

Y. Voituron, Benoit Heulin, Yann Surget-Groba. Comparison of the cold hardiness capacities of the oviparous and viviparous forms of Lacerta vivipara. Journal of experimental zoology. Part A, Comparative experimental biology., 2004, 301, pp.367-73. ⟨10.1002/jez.a.20042⟩. ⟨hal-00069605⟩
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