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The trophic niche is one of the most important ecological traits for any species, providing information about trophic position in the food web, habitat preferences, and interspecific interactions. In this study, we describe the autumn diet of two sympatric species of salamander from central Italy—Italian Cave Salamanders (Speleomantes italicus) and Fire Salamanders (Salamandra salamandra), assessing whether competition for the same prey occurs. Furthermore, we combine our data with those obtained for the same population during a different season (spring) and assess potential seasonal variation in the diet of these two salamander species. The overlap of the trophic niche between the two species was limited, with S. italicus consuming smaller and fast-moving prey (e.g., Diptera, Collembola), and S. salamandra consuming slow and often elongated prey (e.g., Gastropoda, Haplotaxida, Diplopoda). Seasonal differences in diet composition were observed in both species between spring and autumn; in autumn, both species narrowed their trophic niche breadth. This seasonal divergence is likely due to the variation of prey phenology and availability. The consumption of prey of different size was likely the main factor allowing the coexistence of these two salamander species. In both species we observed a general increase in the proportion of generalist individuals in autumn, most likely because of a reduction in prey availability. In addition to providing information on the trophic niche of these species, our study represented a further step that helps unravel the dynamics promoting the coexistence of potentially competing species. [ABSTRACT FROM AUTHOR]

Amphibians are small ectothermic vertebrates with high permeable skins that are highly constrained by environmental conditions, such as humidity and temperature. Therefore, terrestrial salamanders regulate their surface activity, including foraging, to minimize evaporative water loss. The influence of local micro-climatic factors on the foraging success of European forest dwelling salamanders has rarely been analysed in detail. We examined the role of local climatic conditions on the foraging success, measured by the total number of prey items, of two syntopic forest-dwelling salamanders: Strinati's cave salamander, Speleomantes strinatii (family Plethodontidae), and Northern spectacled salamander, Salamandrina perspicillata (family Salamandridae). We evaluated the effects of rainfall, temperature and body size on the foraging success of these two species, in eight sampling sites in the Northern Apennines of Italy, for a total of 11 salamander populations. Our findings show that different climatic variables affected the two species differently. Salamandrina perspicillata foraged more intensively during periods of prolonged rainfall with higher temperatures. On the contrary, S. strinatii foraging success was negatively influenced by rising temperature, while rainfall seemed to have no significant effect. Interestingly, body size increased success in S. perspicillata but not in S. strinatii. Overall, our findings show that, when foraging in the same environment, these two species are conditioned by different climatic factors possibly due to their differences in overall body size and their ability to resist dehydration. [ABSTRACT FROM AUTHOR]

Simple Summary: Studies on species' trophic niches are essential to understand the characteristics of species' ecology and life traits, as well as to improve conservation strategies. In the absence of competitors, species realize their trophic niche including in their diet the most profitable food resources. In the presence of competitors, species modify their preferences to reduce competition and maintain the highest benefits at the same time. In this study, we assessed the trophic niche of two species of salamanders coexisting in a forested area of Italy and evaluated which might be the mechanisms that these two species adopted to reduce competition. We found that the Italian cave salamander (Speleomantes italicus) mostly consumed flying prey with a hard cuticle, while the fire salamander (Salamandra salamandra) preferred worm-like and soft-bodied prey. In conclusion, we hypothesize that in our case, the two species of salamanders did not have to change their prey preference in order to avoid competition, but divergences in metabolism and behavioral traits likely worked as natural deterrent. The trophic niche of a species is one of the fundamental traits of species biology. The ideal trophic niche of a species is realized in the absence of interspecific competition, targeting the most profitable and easy-to-handle food resources. However, when a competitor is present, species adopt different strategies to reduce competition and promote coexistence. In this study, we assessed the potential mechanisms that allow the coexistence of two generalist salamanders: the Italian cave salamander (Speleomantes italicus) and the fire salamander (Salamandra salamandra). We surveyed, in April 2021, a forested area of Emilia-Romagna (Italy) during rainy nights. Analyzing the stomach contents of the captured individuals, we obtained information on the trophic niche of these two sympatric populations. Comparing our results with those of previous studies, we found that the two species did not modify their trophic niche, but that alternative mechanisms allowed their coexistence. Specifically, different prey preferences and predator metabolisms were likely the major factors allowing reduced competition between these two generalist predators. [ABSTRACT FROM AUTHOR]

Highlights: [•] We present an integrative approach of phylogeny and populations genetics. [•] We analyzed 900 individuals of 37 populations for nuclear and mitochondrial markers. [•] We use a multilocus coalescent species tree approach to estimate species divergence. [•] We estimated a much more recent divergence time compared with previous studies. [•] We found differences in population history in the sister species of Salamandrina. [Copyright &y& Elsevier]

We investigated the phylogeographical patterns of Lissotriton italcus, a newt endemic to the Italian peninsula, aiming to determine why hotspots of intraspecific diversity so 'hot'. We found two main mitochindrial DNA lineages (net sequence divergence of 6.8% at two fragments of total length of 1897 bp): one restricted to part of the Calabrian peninsula (i.e the southernmost portion of the species range) and the other widespread throughout the rest of the species range. Both lineages, which had a parapatric distribution, showed evidence of further subdivisions, with an overall number of eight terminal haplogroups, most of whose times to the most recent common ancestors were estimated at the Late Pleistocene. Analysis of molecular variance suggested that partitioning populations according to the geographical distribution of these haplogroups can explain 97% of the observed genetic variation. These results suggest that L. italicus underwent repeated cycles of allopatric fragmentation throughout the Pleistocene, and that it likely survived the Late Pleistocene paleoenvironmental changes within eight separate refugia. Thus, the current hotspot of intraspecific diversity of L. italicus (within the Calabrian peninsula) has not been moulded by long-term stability of large populations but rather by multiple events of allopatric fragmentation and divergence. When compared with the patterns recently identified in other species, these results suggest that the occurrence of phases of allopatric divergence (eventually followed by secondary admixture) could be a common, albeit probably underrated feature in the history of formation of hotspots of intraspecific diversity. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 42-55. [ABSTRACT FROM AUTHOR]

We carried out a mark-recapture survival analysis of female Salamandrina perspicillata in two central Italian populations. Overall survival was similar in both populations (about 85-90% per year) and the estimated lifespan was about twelve years. We detected transients in one population, possibly related to the high density of females in this site. The breeding probability of females was independent from that of the preceding year. [ABSTRACT FROM AUTHOR]

The Sardinian mountain newt Euproctus platycephalus, endemic to the island of Sardinia, (Italy), is considered a rare and threatened species and is classed as critically endangered by IUCN. It inhabits streams, small lakes and pools on the main mountain systems of the island. Threats from climatic and anthropogenic factors have raised concerns for the long-term survival of newt populations on the island. MtDNA sequencing was used to investigate the genetic population structure and phylogeography of this endemic species. Patterns of genetic variation were assessed by sequencing the complete Dloop region and part of the 12SrRNA, from 74 individuals representing four different populations. Analyses of molecular variance suggest that populations are significantly differentiated, and the distribution of haplotypes across the island shows strong geographical structuring. However, phylogenetic analyses also suggest that the Sardinian population consists of two distinct mtDNA groups, which may reflect ancient isolation and expansion events. Population structure, evolutionary history of the species and implications for the conservation of newt populations are discussed. [Copyright &y& Elsevier]

The Sardinian brook salamander, Euproctus platycephalus, is an endemic newt restricted to the internal and mountainous regions of Sardinia (Italy). We study the age structure and the morphometric sexual dimorphism in one of the known largest breeding populations of this species. It takes both sexes a minimum of four years to reach maturity, and the period of immaturity often extends to six years. At the breeding site, males are significantly older than females, but we do not know whether these differences are because of a sex-biased longevity or to sex- and age-dependent differential activity patterns. Independently of age, sexes differ in both body size and body shape. Males are longer and heavier than females and show proportionally longer and larger heads, shorter cloacas, and longer hind limbs. Most of these between-sex differences might be explained in the light of the brook salamander's mating behavior, in which males capture females and directly force their spermatophora into the female cloaca. [ABSTRACT FROM AUTHOR]

Nonylphenols ethoxylates (NPEs) are surface active agents (surfactants) commonly used in cleaning products, in industrial processes, agricultural formulations and paints. They are found in sewage, municipal wastewaters and industrial effluents, and as contaminants in water bodies. Accumulating data suggest that exposure to NPEs can adversely affects functional properties of the neurologic, reproductive, immune, and endocrine systems. In order to examine whether NPEs exert similar damaging effects on the cardiovascular system, we used an amphibian model to examine the ultrastructural alterations of the ventricular myocardium following exposure to NPEs. Adult Lissotriton italicus in the aquatic phase were exposed to NPE10 (100 μg/L, ppb) for 96 h. Heart specimens were collected from a total of 10 individuals and processed for scanning and transmission electron microscopy. Our ultrastructural examinations demonstrated that amphibian ventricle is susceptible to the effects of NPEs. The most pronounced alterations were observed in the membrane compartments of both myocardial and endothelial cells as demonstrated by the presence of swollen mitochondria with disrupted cristae and dilated rough endoplasmic reticulum. We suggest that destabilization of the lipid milieu within membranes might represent one of the potential mechanisms by which NPEs exert their toxic effects on amphibian heart., (Copyright © 2011 Elsevier Ltd. All rights reserved.)