Publications

analysis of the avoidance of nitrogen fertilizers in the water column by juvenile iberian water frog, pelophylax perezi (seoane, 1885), in laboratory conditions.	in an experiment carried out in the laboratory in beakers, the avoidance of ammonium chloride, isolated or combined with sodium nitrite and sodium nitrate, in aquatic habitat by froglets of pelophylax perezi was studied. the results obtained suggest that nitrogen polluted treatments were not avoided by froglets of the studied species. however, despite the non-avoidance of the aquatic environment as a consequence of the presence of nitrogen compounds, significant inter-individual variation in tre ...	2008	18193144
conserved pattern of otp-positive cells in the paraventricular nucleus and other hypothalamic sites of tetrapods.	the paraventricular nucleus complex (pa) is a component of central neural circuitry that regulates several homeostatic variables. the paraventricular nucleus is composed of magnocellular neurons that project to the posterior pituitary and parvicellular neurons that project to numerous sites in the central nervous system. according to the revised prosomeric model, the paraventricular nucleus is located caudal to the eye stalk along the rostrocaudal dimension of the dorsal hypothalamic alar plate. ...	2008	18331876
calbindin-d28k and calretinin as markers of retinal neurons in the anuran amphibian rana perezi.	in the present study we have analyzed the distribution of the calcium binding proteins calbindin-d28k (cb) and calretinin (cr) immunoreactive cells in the retina of the anuran rana perezi using poly- and mono-clonal antibodies that were proven to be specific in the amphibian brain, without cross-reactivity. double immunohistofluorescence techniques were used to demonstrate colocalization of both proteins in the same retinal cells. in addition, retrograde tracing experiments from the optic nerve ...	2008	18331902
patterns of dnase sensitivity in the chromosomes of rana perezi (amphibia: anura).	we have analyzed the patterns of dnase i/nick translation in the chromosomes of rana perezi. the results show a nonuniform dnase sensitivity in different chromosome domains; the hypersensitivity appears to be concentrated at both the nor and the distal regions. the resemblance to the situation in mammals, where active genes are dnase i hypersensitive, is discussed.	1995	18470173
effects of a uranium mine effluent in the early-life stages of rana perezi seoane.	amphibians have been reported as sensitive organisms whose survival has been impaired by several environmental factors. nevertheless, sometimes amphibians are found inhabiting extreme environments. thus, in order to perceive how iberian green frogs (rana perezi seoane) are able to survive in the ponds of a uranium mine (central portugal) this study aimed to assess the ecotoxicological effects promoted by the mine effluent in the early-life stages of this species. to attain this objective, eggs ( ...	2008	18538823
histopathological changes and erythrocytic nuclear abnormalities in iberian green frogs (rana perezi seoane) from a uranium mine pond.	in spite of their sensitivity to anthropogenic stressors, adults of rana perezi seoane were found inhabiting effluent ponds from a uranium mine. due to the presence of such organisms in this environment, it becomes of paramount importance to assess the damages induced by local contamination on these aquatic vertebrates, in order to integrate this information on a site-specific risk assessment that is being carried out in the area. to attain this purpose an ethically and statistically acceptable ...	2009	18541315
learning, memorizing and apparent forgetting of chemical cues from new predators by iberian green frog tadpoles.	many antipredator adaptations are induced by the prey's ability to recognize chemical cues from predators. however, predator recognition often requires learning by prey individuals. iberian green frog tadpoles (pelophylax perezi) have the ability to learn new potential predators. here, we tested the memory capabilities of iberian green frog tadpoles. we conditioned tadpoles with chemicals cues from a non-predatory fish in conjunction with conspecific alarm cues, and examined whether tadpoles ret ...	2009	19449191
populational divergence in the impact of three nitrogenous compounds and their combination on larvae of the frog pelophylax perezi (seoane, 1885).	pollution by nitrogenous compounds is a putative stressful factor that may be causally linked to the decline of amphibians. one way to understand the potentially detrimental consequences of eutrophication on amphibian populations is to investigate variation among populations differing in exposure to nitrogen, this variation potentially indicating evolutionary potential to cope with this stressor. we have examined the effect of nitrogenous compounds (nh(4)(+); no(2)(-); no(3)(-), both alone and i ...	2009	19540549
adaptation to osmotic stress provides protection against ammonium nitrate in pelophylax perezi embryos.	the negative effects of pollution on amphibians are especially high when animals are additionally stressed by other environmental factors such as water salinity. however, the stress provoked by salinity may vary among populations because of adaptation processes. we tested the combined effect of a common fertilizer, ammonium nitrate (0-90.3 mg n-no3nh4/l), and water salinity (0-2 per thousand) on embryos of two pelophylax perezi populations from ponds with different salinity concentrations. embry ...	2010	19800720
intraspecific and interspecific tolerance to copper sulphate in five iberian amphibian species at two developmental stages.	intraspecific and interspecific variations have been observed across many taxa with respect to resistance to natural environmental stressors. it has already been well documented that amphibians are sensitive to habitat degradation and are regarded as bioindicators of aquatic and agricultural ecosystems. in southern spain, different toxic substances, including copper sulphate, which is used to control cycloconium oleaginum (fungi, ascomycota, venturiaceae) during spring and autumn, are used in in ...	2010	20162266
testing procedures for the determination of several biomarkers in different species, for environmental assessment of pollution.	antioxidant defences are the primary mechanisms by which organisms compensate oxidative damage caused by contact with several types of substances prone to establish oxidative cycles. biomarkers are one of the most useful tools to assess effects consequent to environmental exposure to a large number of xenobiotics. however, the use of biomarkers requires previous standardization of enzymatic protocols in order to guarantee accuracy and relevance of obtained results. this article describes standar ...	2010	20589292
immunohistochemical localization of darpp-32 in the brain and spinal cord of anuran amphibians and its relation with the catecholaminergic system.	the relationship between dopaminergic neuronal structures and dopaminoceptive structures in the amphibian brain and spinal cord are assessed by means of single and double immunohistochemical techniques with antibodies directed against darpp-32 (a phosphoprotein related to the dopamine d(1)-receptor) and tyrosine hydroxylase (th) applied to the brain of the anurans rana perezi and xenopus laevis. the darpp-32 antibody yielded a well-differentiated pattern of staining in the brain of these anurans ...	2010	20887782
light-dependent magnetic compass in iberian green frog tadpoles.	here, we provide evidence for a wavelength-dependent effect of light on magnetic compass orientation in pelophylax perezi (order anura), similar to that observed in rana catesbeiana (order anura) and notophthalmus viridescens (order urodela), and confirm for the first time in an anuran amphibian that a 90° shift in the direction of magnetic compass orientation under long-wavelength light (≥ 500 nm) is due to a direct effect of light on the underlying magnetoreception mechanism. although magnetic ...	2010	20978882
invasive predatory crayfish do not trigger inducible defences in tadpoles.	invasive species cause deep impacts on ecosystems worldwide, contributing to the decline and extinction of indigenous species. effective defences against native biological threats in indigenous species, whether structural or inducible, often seem inoperative against invasive species. here, we show that tadpoles of the iberian green frog detect chemical cues from indigenous predators (dragonfly nymphs) and respond by reducing their activity and developing an efficient defensive morphology against ...	2011	21450734
behavioral responses of the iberian waterfrog, pelophylax perezi (seoane, 1885), to three nitrogenous compounds in laboratory conditions.	several studies have assessed the effects of nitrogenous compounds on amphibian behavior. however, few have focused on the effects of their combination with other stressors or on the variation of the response to pollutants among populations. we analyzed the effect of nitrogenous compounds (nh(4)(+); no(2)(-); no(3)(-), both alone and in combination) on larval behavior (activity level and location in the water column) in four populations of pelophylax perezi naturally exposed to different levels ...	2011	21512748
antioxidant response and metal accumulation in tissues of iberian green frogs (pelophylax perezi) inhabiting a deactivated uranium mine.	human mining activities tend often to generate greatly impacted areas which remain contaminated for long periods of time, giving rise to extreme habitats. mining sites are usually characterized for the production of metal rich effluents with very low ph. in this work we analyzed physical and chemical parameters of water from a deactivated uranium mine pond (m) and a reference site (ref) as well as their metal content. furthermore, we determined and compared metal accumulation in liver, kidney, b ...	2011	21516444
adaptive forgetting in iberian green frog tadpoles (pelophylax perezi): learned irrelevance and latent inhibition may avoid predator misidentification.	predator recognition often requires learning by prey individuals. iberian green frog tadpoles (pelophylax perezi) have the ability to learn to recognize new potential predators when their chemical cues are found paired with conspecific alarm cues. however, a random pairing of alarm cues and chemical stimuli of a nonpredator might later induce costly antipredator responses to nondangerous species. here, we studied the potential existence in this frog species of two phenomena (learned irrelevance ...	2013	22866772
plastic changes in tadpole trophic ecology revealed by stable isotope analysis.	amphibian larvae constitute a large fraction of the biomass of wetlands and play important roles in their energy flux and nutrient cycling. interactions with predators and competitors affect their abundance but also their foraging behaviour, potentially leading to non-consumptive cascading effects on the whole trophic web. we experimentally tested for plastic changes in larval trophic ecology of two anuran species in response to competitors and the non-lethal presence of native and non-native pr ...	2013	22915331
differential gene expression in iberian green frogs (pelophylax perezi) inhabiting a deactivated uranium mine.	iberian green frogs (pelophylax perezi) were found inhabiting a deactivated uranium mine, especially an effluent pond, seriously contaminated with metals and radionuclides. these animals were previously assessed for oxidative stress parameters and did not revealed significant alterations. in order to better understand which mechanisms may be involved in the ability to withstand permanent contamination gene expression analysis was performed in the liver, through suppression subtractive hybridizat ...	2013	23146668
biochemical and metabolic effects of a short-term exposure to nanoparticles of titanium silicate in tadpoles of pelophylax perezi (seoane).	this study aimed to evaluate sublethal effects of a short-term exposure (96 h) to titanium silicate nanoparticles (tisio(4)-np) on pelophylax perezi tadpoles. tadpoles were exposed to five concentrations of tisio(4)-np (8.2, 10.2, 12.8, 16 and 20 mg/l) plus a control. effect criteria were: mortality, cholinesterases, glutathione s-transferases, lactate dehydrogenase, and catalase activities, and alanine and lactate contents. light scattering was used for physical characterization of tisio(4)-np ...	2013	23314277
evaluation of growth, biochemical and bioaccumulation parameters in pelophylax perezi tadpoles, following an in-situ acute exposure to three different effluent ponds from a uranium mine.	mining activities invariably produce metal contaminated effluents. depending on factors such as ph and metal concentration the toxicity of the effluent may vary. to assess the effects of three characteristically different effluent ponds from a deactivated uranium mine, with toxicologically relevant data, an in situ exposure with pelophylax perezi tadpoles, was conducted. tadpoles were exposed to the three effluent ponds, ranked by increasing order of metals concentrations (ref, m1, m2). survival ...	2013	23348721
influence of low levels of water salinity on toxicity of nitrite to anuran larvae.	reactive nitrogen compounds such as nitrite (no2(-)) are highly toxic to aquatic animals and are partly responsible for the global decline of amphibians. on some fish and caudata amphibian species low levels of sodium chloride significantly reduce the toxicity of nitrite. however, the nitrite-salinity interaction has not been properly studied in anuran amphibians. to verify if chloride (cl(-)) attenuates no2(-) toxicity, eggs and larvae of three anuran species were subjected to a series of no2(- ...	2013	23466091
salinity and copper interactive effects on perez's frog pelophylax perezi.	the present study was intended to assess the influence of salinity on the effects of copper on 2 life stages of pelophylax perezi. single and combined effects of salinity (nacl) and cu on survival, malformations, body length, and biochemical markers (catalase [cat], cholinesterases, lactate dehidrogenase [ldh], and glutathione s-transferase) of individuals were evaluated in a multifactorial design. two experiments were performed, 1 with embryos and the other with tadpoles. each of these life sta ...	2013	23625701
call transmission efficiency in native and invasive anurans: competing hypotheses of divergence in acoustic signals.	invasive species are a leading cause of the current biodiversity decline, and hence examining the major traits favouring invasion is a key and long-standing goal of invasion biology. despite the prominent role of the advertisement calls in sexual selection and reproduction, very little attention has been paid to the features of acoustic communication of invasive species in nonindigenous habitats and their potential impacts on native species. here we compare for the first time the transmission ef ...	2013	24155940
copper-driven avoidance and mortality in temperate and tropical tadpoles.	amphibians have experienced an accentuated population decline in the whole world due to many factors, one of them being anthropogenic contamination. the present study aimed to assess the potential effect of copper, as a worldwide and reference contaminant, on the immediate decline of exposed population due to avoidance and mortality responses in tadpoles of three species of amphibians across climatic zones: a south american species, leptodactylus latrans, a north american species, lithobates cat ...	2014	24291082
contrasting effects of nitrogenous pollution on fitness and swimming performance of iberian waterfrog, pelophylax perezi (seoane, 1885), larvae in mesocosms and field enclosures.	amphibians are declining worldwide and pollutants have been implicated as a major contributor to these declines. to understand these declines, many studies have assessed the impact of pollutants on amphibian behaviour. however, information regarding their effect on locomotor abilities, as well as the intra-specific variation of the tolerance to pollutants, is extremely rare. further, the majority of studies examining the impact of pollutants on amphibians have been conducted in simplified labora ...	2014	24296112
molecular survey of parasites in introduced pelophylax perezi (ranidae) water frogs in the azores.	water frogs, pelophylax perezi, that are introduced in the azores, were screened for parasites using pcr primers known to amplify apicomplexa parasites, and using nematode-specific primers. with the former, three different organisms were detected: hepatozoon, a trichodinid protozoan ciliate and a possible stramenopile. using the latter set of primers, a single unknown spirurid nematode was also detected. phylogenetic analyses indicate that hepatozoon detected within amphibian hosts appear to for ...	2013	24338327
rapid evolution of constitutive and inducible defenses against an invasive predator.	invasive alien predators can impose strong selection on native prey populations and induce rapid evolutionary change in the invaded communities. however, studies on evolutionary responses to invasive predators are often complicated by the lack of replicate populations differing in coexistence time with the predator, which would allow the determination of how prey traits change during the invasion. the red swamp crayfish procambarus clarkii has invaded many freshwater areas worldwide, with negati ...	2014	25039217
impact of the insecticide alphacypermetrine and herbicide oxadiazon, used singly or in combination, on the most abundant frog in french rice fields, pelophylax perezi.	the potential impact of agricultural pesticides is a major concern with regard to biodiversity conservation. pesticides are considered as one of the main causes of the worldwide decline of amphibians. they are rarely used singly, but their cumulative impact and interaction are often neglected, as is the importance of the age or stage of the animal on which the impact of the molecules is assessed. we therefore tested the potential cumulative impact of the only authorized insecticide (alphacyperme ...	2016	27107241
diversity of cutaneous microbiome of pelophylax perezi populations inhabiting different environments.	potential synergetic interaction between chemicals, climate change and the emergence of opportunistic diseases is of utmost concern within the amphibian decline scenario. understand the structure and dynamic of this microbiome and how environmental stressors act on this community is a priority. the present study aimed to: i) characterize the skin microbiome of pelophylax perezi frog by looking for variations between populations in reference and under stress conditions (one metal contaminated and ...	2016	27522290
effects of 4-mbc and triclosan in embryos of the frog pelophylax perezi.	the widespread and increasing use of personal care products (pcps) have led to environmental contamination by substances included in these products. these substances have been detected in aquatic compartments and shown to cause adverse effects on non-target aquatic organisms. in this work toxicity of the antimicrobial triclosan (tcs) and of the uv-filter 3-(4-methylbenzylidene) camphor (4-mbc) was assessed in the embryos of perez' frog pelophylax perezi. lethal and sub-lethal parameters were eva ...	2017	28334672
effects of sample size and full sibs on genetic diversity characterization: a case study of three syntopic iberian pond-breeding amphibians.	accurate characterization of genetic diversity is essential for understanding population demography, predicting future trends and implementing efficient conservation policies. for that purpose, molecular markers are routinely developed for nonmodel species, but key questions regarding sampling design, such as calculation of minimum sample sizes or the effect of relatives in the sample, are often neglected. we used accumulation curves and sibship analyses to explore how these 2 factors affect mar ...	2017	28444211
geologically dated sea barriers calibrate a protein clock for aegean water frogs.	reliable estimates of phylogenetic relationships and divergence times are a crucial requirement for many evolutionary studies, but are usually difficult because fossils are scarce and their interpretation is often uncertain. frogs are fresh water animals that generally are unable to cross salt water barriers (their skin is readily permeable to both salt and water). the geologically determined ages of salt water barriers that isolate related frog populations thus provide an independent measure of ...	1996	28565728
reliable effective number of breeders/adult census size ratios in seasonal-breeding species: opportunity for integrative demographic inferences based on capture-mark-recapture data and multilocus genotypes.	the ratio of the effective number of breeders (nb) to the adult census size (na), nb/na, approximates the departure from the standard capacity of a population to maintain genetic diversity in one reproductive season. this information is relevant for assessing population status, understanding evolutionary processes operating at local scales, and unraveling how life-history traits affect these processes. however, our knowledge on nb/na ratios in nature is limited because estimation of both paramet ...	2017	29238556
effects of the herbicides linuron and s-metolachlor on perez's frog embryos.	presence of pesticides in the environment and their possible effects on aquatic organisms are of great concern worldwide. the extensive use of herbicides in agricultural areas are one of the factors contributing to the known decline of amphibian populations. thus, as non-target species, amphibians can be exposed in early life stages to herbicides in aquatic systems. in this context, this study aims to evaluate effects of increasing concentrations of two maize herbicides, linuron and s-metolachlo ...	0	29241134
sensitivity to salinization and acclimation potential of amphibian (pelophylax perezi) and fish (lepomis gibbosus) models.	predictions of the international panel for climate changes on sea level rise foresee that the number of coastal regions impacted with salinization will increase in a near future. the present work intended to evaluate the sensitivity to salinization of two freshwater vertebrate species (the frog pelophylax perezi and the fish lepomis gibbosus) and their ability to acclimate to this stressor. for this, three specific objectives were targeted: (i) to assess if nacl may be used as a safe surrogate f ...	2019	30731265
genetically inherited tolerance may unveil trait dominance patterns in an amphibian model.	chemical contamination may cause genetic erosion in natural populations by wiping out the most sensitive genotypes. this is of upmost concern if the loss of genetic variability is irreversible due to contaminant-driven elimination of alleles, which may happen if tolerance is a recessive or incompletely dominant trait - the recessive tolerance inheritance (working-) hypothesis. accordingly, this work investigated the tolerance inheritance to lethal levels of a metal-rich acid mine drainage (amd) ...	2019	31844122
contrasting demographic trends and asymmetric migration rates in a spatially structured amphibian population.	natural populations often persist at the landscape scale as metapopulations, with breeding units (subpopulations) experiencing temporal extinction and recolonization events. important parameters to forecast population viability in these systems include the ratio of the effective number of breeders (nb ) to the total number of adults (na ) and migration rates among subpopulations. here, we present the results of a 10-year integrative monitoring program of a metapopulation of the iberian green fro ...	2020	32329558
morphological determinants of jumping performance in the iberian green frog.	predation is one of the main selective forces in nature, frequently selecting potential prey for developing escape strategies. escape ability is typically influenced by several morphological parameters, such as morphology of the locomotor appendices, muscular capacity, body mass, or fluctuating asymmetry, and may differ between sexes and age classes. in this study, we tested the relationship among these variables and jumping performance in 712 iberian green frogs pelophylax perezi from an urban ...	2020	32617090
high pathogen prevalence in an amphibian and reptile assemblage at a site with risk factors for dispersal in galicia, spain.	ranaviruses are agents of disease, mortality and population declines in ectothermic vertebrates and emergences have been repeatedly linked to human activities. ranaviruses in the common midwife toad ranavirus lineage are emerging in europe. they are known to be severe multi-host pathogens of amphibians and can also cause disease in reptiles. recurrent outbreaks of ranavirus disease and mortality affecting three species have occurred at a small reservoir in north-west spain but no data were avail ...	2020	32730306