Food web collapse and regime shift following goldfish introduction in permanent ponds.

In a global context of invasive alien species (IAS), native predators are often eradicated by functionally different IAS, which may induce complex cascading consequences on ecosystem functioning because of the key role predators play in structuring communities and stabilizing food webs. In permanent ponds, the most abundant freshwater systems on Earth, global human-mediated introductions of alien omnivores such as the pet trade goldfish are driving broad-scale patterns of native predators' exclusion, but cascading consequences on food web structure and functioning are critically understudied. We compared food webs of naturally fishless ponds versus ponds where dominant native predators (newts) had been extirpated by invasive goldfish within the last decade.

Invading new climates at what cost? Ontogenetic differences in the thermal dependence of metabolic rate in an invasive amphibian.

Global warming can either promote or constrain the invasive potential of alien species. In ectotherm invaders that exhibit a complex life cycle, success is inherently dependent on the capacity of each developmental stage to cope with environmental change. This is particularly relevant for invasive anurans, which disperse on land while requiring water for reproduction.

Piecing the barcoding puzzle of Palearctic water frogs (Pelophylax) sheds light on amphibian biogeography and global invasions.

Palearctic water frogs (genus Pelophylax) are an outstanding model in ecology and evolution, being widespread, speciose, either threatened or threatening to other species through biological invasions, and capable of siring hybrid offspring that escape the rules of sexual reproduction. Despite half a century of genetic research and hundreds of publications, the diversity, systematics and biogeography of Pelophylax still remain highly confusing, in no small part due to a lack of correspondence between studies. To provide a comprehensive overview, we gathered >13,000 sequences of barcoding genes from >1700 native and introduced localities and built multigene mitochondrial (~17 kb) and nuclear (~10 kb) phylogenies.

What makes a great invader? Anatomical traits as predictors of locomotor performance and metabolic rate in an invasive frog.

Invasive species are characterized by their ability to establish and spread in a new environment. In alien populations of anurans, dispersal and fitness-related traits such as endurance, burst performance and metabolism are key to their success. However, few studies have investigated inter-individual variation in these traits and more specifically have attempted to understand the drivers of variation in these traits.

Strong restructuration of skin microbiota during captivity challenges conservation of amphibians.

In response to the current worldwide amphibian extinction crisis, conservation instances have encouraged the establishment of collections for endangered species. The resulting assurance populations are managed under strict biosecure protocols, often involving artificial cycles of temperature and humidity to induce active and overwintering phases, which likely affect the bacterial symbionts living on the amphibian skin. However, the skin microbiota is an important first line of defense against pathogens that can cause amphibian declines, such as the chytrid .

Encouraging news for in situ conservation: Translocation of salamander larvae has limited impacts on their skin microbiota.

The key role of symbiotic skin bacteria communities in amphibian resistance to emerging pathogens is well recognized, but factors leading to their dysbiosis are not fully understood. In particular, the potential effects of population translocations on the composition and diversity of hosts' skin microbiota have received little attention, although such transfers are widely carried out as a strategy for amphibian conservation. To characterize the potential reorganization of the microbiota over such a sudden environmental change, we conducted a common-garden experiment simulating reciprocal translocations of yellow-spotted salamander larvae across three lakes.

Repeated ecological and life cycle transitions make salamanders an ideal model for evolution and development.

Observations on the ontogeny and diversity of salamanders provided some of the earliest evidence that shifts in developmental trajectories have made a substantial contribution to the evolution of animal forms. Since the dawn of evo-devo there have been major advances in understanding developmental mechanisms, phylogenetic relationships, evolutionary models, and an appreciation for the impact of ecology on patterns of development (eco-evo-devo). Molecular phylogenetic analyses have converged on strong support for the majority of branches in the Salamander Tree of Life, which includes 764 described species.

Adult-Juvenile interactions and temporal niche partitioning between life-stages in a tropical amphibian.

Divergence in ecological niche offers organisms the opportunity of exploiting different food and habitat resources, scaling down competition and predation both among species, and within different age or size-classes of the same species. In harsh environments, where abiotic factors determine a clustering of resources during short timespans, competition and predation between organisms is likely to be enhanced. This is the case in tropical dry forests, where amphibians have limited opportunities to feed, their activity being restricted to the short rainy season.

Behavior and gene expression in the brain of adult self-fertilizing mangrove rivulus fish (Kryptolebias marmoratus) after early life exposure to the neurotoxin β-N-methylamino-l-alanine (BMAA).

β-N-Methylamino-l-alanine (BMAA), a neurotoxin naturally produced by cyanobacteria, diatoms and dinoflagellates, constitutes a serious environmental and health threat especially during acute blooms, which are becoming more frequent. This neurotoxin is implicated in several neurodegenerative diseases (ND) in humans through contaminated water or food consumption. Even low doses of neurotoxic compounds (NCs) can have lasting effects later in life.

How to recover from a bad start: size at metamorphosis affects growth and survival in a tropical amphibian.

Background: In species with complex life cycles, size at metamorphosis is a key life-history trait which reflects the complex interactions between costs and benefits of life in the aquatic and terrestrial environments. Whereas the effects of a deteriorating larval habitat (e.g.

Fifteen shades of green: The evolution of Bufotes toads revisited.

The radiation of Palearctic green toads (Bufotes) holds great potential to evaluate the role of hybridization in phylogeography at multiple stages along the speciation continuum. With fifteen species representing three ploidy levels, this model system is particularly attractive to examine the causes and consequences of allopolyploidization, a prevalent yet enigmatic pathway towards hybrid speciation. Despite substantial efforts, the evolutionary history of this species complex remains largely blurred by the lack of consistency among the corresponding literature.

Call a spade a spade: taxonomy and distribution of , with description of a new Balkan endemic.

The genomic era contributes to update the taxonomy of many debated terrestrial vertebrates. In an accompanying work, we provided a comprehensive molecular assessment of spadefoot toads () using genomic data. Our results call for taxonomic updates in this group.

Phylogeography of a cryptic speciation continuum in Eurasian spadefoot toads (Pelobates).

Cryptic phylogeographic diversifications provide unique models to examine the role of phylogenetic divergence on the evolution of reproductive isolation, without extrinsic factors such as ecological and behavioural differentiation. Yet, to date very few comparative studies have been attempted within such radiations. Here, we characterize a new speciation continuum in a group of widespread Eurasian amphibians, the Pelobates spadefoot toads, by conducting multilocus (restriction site associated DNA sequencing and mitochondrial DNA) phylogenetic, phylogeographic and hybrid zone analyses.

Reproductive fitness consequences of progenesis: Sex-specific pay-offs in safe and risky environments.

Progenesis is considered to have an important role in evolution because it allows the retention of both a larval body size and shape in an adult morphology. However, the cost caused by the adoption of a progenetic process in both males and females remains to be explored to explain the success of progenesis and particularly its biased prevalence across the sexes and environments. Here, through an experimental approach, we used a facultative progenetic species, the palmate newt (Lissotriton helveticus) that can either mature at a small size and retain gills or mature after metamorphosis, to test three hypotheses for sex-specific pay-offs of progenesis in safe versus risky habitats.

The role of predation risk in metamorphosis versus behavioural avoidance: a sex-specific study in a facultative paedomorphic amphibian.

Evolutionary theory predicts the evolution of metamorphosis over paedomorphosis (the retention of larval traits at the adult stage) in response to life in unfavourable habitats and to the benefits of dispersal. Although many organisms are canalised into obligatory complex or simple life cycles, some species of newts and salamanders can express both processes (facultative paedomorphosis). Previous research highlighted the detrimental effect of fish on both metamorphic and paedomorphic phenotypes, but it remains unknown whether predation risk could induce shifts from paedomorphosis to metamorphosis, whether behavioural avoidance could be an alternative strategy to metamorphosis and whether these responses could be sex-biased.

Jailed in the mountains: Genetic diversity and structure of an endemic newt species across the Pyrenees.

The Pyrenees represent a natural laboratory for biogeographic, evolutionary and ecological research of mountain fauna as a result of the high variety of habitats and the profound effect of the glacial and interglacial periods. There is a paucity of studies providing a detailed insight into genetic processes and better knowledge on the patterns of genetic diversity and how they are maintained under high altitude conditions. This is of particular interest when considering the course of past climate conditions and glaciations in a species which is considered site tenacious, with long generation times.

On the identification of paedomorphic and overwintering larval newts based on cloacal shape: review and guidelines.

Paedomorphosis is an alternative process to metamorphosis in which adults retain larval traits at the adult stage. It is frequent in newts and salamanders, where larvae reach sexual maturity without losing their gills. However, in some populations, larvae overwinter in water, while remaining immature.

Do sex reversal procedures differentially affect agonistic behaviors and sex steroid levels depending on the sexual genotype in Nile tilapia?

In Nile tilapia Oreochromis niloticus, phenotypic males and females with different sexual genotypes (XX, XY, YY) have particular behavioral and physiological traits. Compared to natural XX females and XY males, XY and YY females and XX males expressed higher level of aggressiveness that could be related to higher levels of 17β-estradiol and 11-ketotestosterone, respectively. Our results suggest that the presence of a Y chromosome increases aggressiveness in females.

Multiple uprising invasions of Pelophylax water frogs, potentially inducing a new hybridogenetic complex.

The genetic era has revolutionized our perception of biological invasions. Yet, it is usually too late to understand their genesis for efficient management. Here, we take the rare opportunity to reconstruct the scenario of an uprising invasion of the famous water frogs (Pelophylax) in southern France, through a fine-scale genetic survey.

Morphological Integration and Alternative Life History Strategies: A Case Study in a Facultatively Paedomorphic Newt.

Tetrapod limbs are serially homologous structures that represent a particularly interesting model for studies on morphological integration, i.e. the tendency of developmental systems to produce correlated variation.

The 'male escape hypothesis': sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian.

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats.

Out of the ground: two coexisting fossorial toad species differ in their emergence and movement patterns.

Understanding the way species with similar niches can coexist is a challenge in ecology. The niche partitioning hypothesis has received much support, positing that species can exploit available resources in different ways. In the case of secretive species, behavioural mechanisms of partitioning are still poorly understood.

High gene flow between alternative morphs and the evolutionary persistence of facultative paedomorphosis.

Paedomorphosis and metamorphosis are two major developmental processes that characterize the evolution of complex life cycles in many lineages. Whereas these processes were fixed in some taxa, they remained facultative in others, with alternative phenotypes expressed in the same populations. From a genetic perspective, it is still unknown whether such phenotypes form a single population or whether they show some patterns of isolation in syntopy.