The Herpetological Journal

pp.119-123

Authors: Dan Cogalniceanu

Abstract: Studies carried out in England on the reproduction of smooth newts have revealed that under relatively constant, favourable conditions, they spend a period of up to six months in the water, with oviposition lasting about 4-6 weeks. The reproductive strategies of two Romanian smooth newt populations inhabiting unpredictable, highly variable and hostile environments were analysed for comparison. Females in both populations had an average body weight at the beginning of the reproductive period of 1 .09 and 0.96 g respectively, one third of the average body weight of adult females in England. The average snout-vent lengths were 34.9 and 33.8 mm, about 25% shorter than those from English populations. The average numbers of eggs deposited by female newts from the two populations were 74 and 51 respectively, compared to an average of 300 eggs in England. The average age of females from one of the populations studied was 4.2 years and age at first reproduction was estimated at three years, similar to another English population studied. At the end of the oviposition period females still contained yolked oocytes, suggesting that clutch size cannot be correctly estimated by counting the initial numbers of yolked ovarian oocytes. Their reproductive effort was reduced since, due to environmental hostility, body size was significantly diminished and this leads to a smaller clutch size.

Keywords: Triturus, newts, reproductive strategies, variable environments