Biogeographic history moulds population differentiation in ageing of oxidative status in an amphibian

Regulation of oxidative status plays a substantial role in physiological ageing. However, we know little about age-related changes of oxidative status in wild animals, and even less about the role of population history in moulding ageing rates. We addressed these questions by means of a common garden experiment, using the Tyrrhenian tree frog Hyla sarda as study species. This species underwent a range expansion from northern Sardinia (source) up to Corsica (newly founded) during the Late Pleistocene, and then the two populations became geographically isolated. We found that, at the beginning of the experiment, Sardinia and Corsica frogs had similar concentrations of all oxidative status markers analysed. One year later, Corsica frogs had higher oxidative stress and suffered higher mortality than Sardinia frogs. Our results suggest the intriguing scenario that population differentiation in rates of physiological ageing owing to oxidative stress might be an overlooked legacy of past biogeographic processes

Biogeography of telomere dynamics in a vertebrate

International audience; Telomere length variation has been implicated in processes of ecological and evolutionary importance in a wide range of organisms. However, while the temporal component of this variation has been the subject of much research, we do not know yet whether a spatial component exists within species in telomere dynamics. Here, we investigated for the first time whether the biogeographic history of populations, a key driver of eco-evolutionary processes, can influence telomere dynamics. Based on a one-year longitudinal common-garden experiment in a tree frog species we found that co-specific populations can show striking differences in telomere dynamics, not explained by distinct environmental conditions experienced by individuals through time. Indeed, the populations did not differ in telomere length at the beginning of the study, yet they did after one year under standard conditions. We observed stability of telomere length over time within historically stable populations, but remarkable elongation (31.2% on average) within populations arisen during a recent range expansion. Our results suggest the intriguing scenario that non-equilibrium processes, such as range expansions, might promote plasticity in the molecular machinery regulating telomere dynamics

First records of the crayfish Procambarus clarkii (Girard, 1852) (Decapoda, Cambaridae) in Lake Varano and in the Salento Peninsula (Puglia region, SE Italy), with review of the current status in southern Italy

The occurrence of the red swamp crayfish Procambarus clarkii is documented in the surroundings of Lake Varano (Puglia region, SE Italy), testifying to the ongoing diffusion of this invasive crayfish in north-eastern Puglia, an area characterised by an extensive network of natural and artificial watercourses. In addition, the species is recorded for the first time in the Salento Peninsula, in the south-western part of the region. The hydrology of the area is dominated by karstic phenomena, and the ecological consequences of the colonization of hypogean environments by P. clarkii are discussed. These records, in conjunction with a number of recent observations made in Puglia and in other regions of southern Italy including Sicily and Sardinia, indicate that the species is far more widespread in the area than previous studies have suggested