The effects of temperature and pH on the embryonic development of two species of Triturus (Caudata: Salamandridae)

Amphibian populations are especially sensitive to aquatic parameters, in particular during embryonic and larval life. Our aim was to test for an effect of temperature (T = 13◦C, 20◦C and 25◦C at constant pH = 7) and pH (pH = 5.5, 7 and 8.5 at constant T = 20◦C) on embryos of two species of Triturus, T. carnifex carnifex and T. italicus (Amphibia, Salamandridae) using GLM procedure. Trend of embryogenesis processes, time to hatching and rate of development have a similar effect in both species in the used range of temperature and pH. Time to hatching decreased significantly with the increasing temperature. The pH experimental conditions had no effect on T. carnifex embryos survival, while the acidic pH condition raised the mortality rate in T. italicus, whose embryos should be more vulnerable than those of T. carnifex to acidification in nature.