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An illustration of the human footprint on biodiversity are the faunal movements that have accompanied commercial and cultural exchanges between civilizations throughout history. In this article, we provide an integrative review of biogeographical and archaeological knowledge to understand these processes for the Mediterranean tree frog (Hyla meridionalis), an African species that has reached several regions of south-western Europe and associated islands. By re-analysing molecular (multilocus mitochondrial and genome-wide markers) and bioclimatic (ecological niche modelling) data, we give a comprehensive picture of the genetic diversity, structure and environmental suitability of H. meridionalis across its natural and exotic ranges, which in turn offer specific clues to the putative routes of colonization and associated events. Long-term monitoring efforts suggest northwards shifts of local range margins, potentially due to global warming, and we further demonstrate that this species is the most frequent amphibian to travel via the food supply chain in Western Europe. High dispersal ability, ecological tolerance and proximity to human settlements have made H. meridionalis a recurrent witness to the complexity and diversity of the civilizations that ruled the Western Mediterranean.

International audience; Whereas the effects of climate change on the potential range shifts of amphibians have been modeled at various scales, exploring the future impacts of land-use changes has rarely been considered. We modeled the potential distribution of Bombina variegata, Hyla arborea, Hyla meridionalis, and Triturus cristatus using ecological niche modeling, in the French administrative region Nouvelle-Aquitaine. The species are all at range margin in the study area which makes them interesting model species to study range shifts because of their potential local adaptations to their marginal habitat. We used Dyna-CLUE modeling framework to produce land-use change scenarios and combined them with RCP 2.6 and RCP 8.5 climate change scenarios to predict their impact on local amphibian distributions. B. variegata, H. arborea, and T. cristatus were predicted to shift eastward and northward. H. meridionalis was predicted to increase its probability of presence in the study area. The effect of climate determined the general pattern of distribution and was modulated depending on the scenarios of land-use change.

Alloparapatric species meeting in secondary contact zones are evolutionary witnesses to how reproductive isolation progresses over time and space. Western Palearctic tree frogs (Hyla) are phenotypically similar and all the species pairs tested can hybridize and eventually admix at range margins. All except one. The early-diverged Hyla meridionalis exhibits sharp phenotypic differences: a “long” breeding call and the absence of a lateral stripe. In southwestern Europe, this species co-occurs with the “short-call” striped tree frogs H. arborea and H. molleri, two expanding lineages that admix at their parapatric margins. We estimated local gene flow between these three taxa at several syntopic breeding sites in western France. We congruently matched genotypes to phenotypes: the “short-call” striped individuals were a nuclear mixture of H. arborea and H. molleri; the “long-call” stripeless individuals all featured pure H. meridionalis nuclear ancestry and mtDNA, confirming complete genetic isolation from H. arborea/molleri. Yet, we documented an F1 hybrid between a female H. arborea/molleri and a male H. meridionalis: an incompletely-striped male with an intermediate breeding call. These findings suggest H. meridionalis is still able to reproduce with parapatric congeneric species despite 20My of divergence and strong phenotypic differentiation, but that intrinsic incompatibilities (sterility) prevent genetic introgression.

Comparative molecular studies emphasized a new biogeographic paradigm for the terrestrial fauna of North Africa, one of the last uncharted ecoregions of the Western Palearctic: two independent east-west divisions across the Maghreb. Through a comprehensive phylogeography, we assessed how this model suits the genetic diversification documented for the tree frog Hyla meridionalis sensu lato. Analyses of mtDNA variation and thousands of nuclear loci confirmed the old split (low-Pliocene) between Tunisian and Algerian populations. These lineages meet but barely admix in the eastern Maghreb (Algerian-Tunisian border), a sign of putatively advanced reproductive isolation. In the western Maghreb, we report a Pleistocene divergence between Moroccan and Algerian populations. Tree frogs thus follow both predictions: a double east-west break that gave rise to two suture zones characteristic of North-African phylogeography. Moreover, some intraspecific mtDNA variation is not mirrored by the nuclear data, emphasizing that evolutionary units should always be designated by multilocus approaches. Last but not least, we describe the Tunisian lineage as a new species endemic to Africa.

The non-indigenous red swamp crayfish (Procambarus clarkii) has been shown to be a threat for amphibian conservation. Many amphibian species breed in temporary ponds to diminish predation risk as such ecosystems are free of large predators. However P. clarkii, occurring as an invasive species in the Camargue delta, can readily disperse on the ground and thus colonize isolated ponds. We studied the current impact of the exotic crayfish on the reproductive success of the Mediterranean tree frog (Hyla meridionalis). In a mesocosm experiment, we tested the effect of two crayfish densities (1 and 3 crayfish/m2) on tadpole abundance. We also tested in a field experiment, within a temporary pond, the crayfish’s predation on the tree frog’s eggs. Finally, we developed site occupancy models using data from 20 ponds to assess the effect of crayfish abundance on tadpole abundance. Neither the experiments, nor the site occupancy models showed a negative impact of the current crayfish abundance on the tree frog populations breeding in ponds. We found that recorded crayfish densities were lower than in other areas where crayfish has impacted amphibian populations, but we hypothesize that current crayfish abundance in the area may increase in the future, thus impacting tree frog populations.

Environmental and social factors are critical to determine the timing and duration of lekking behavior since they provide species with signs to maximize benefits over costs in sexual displays. However, these factors have rarely been studied under different environmental conditions, and thus, it remains unclear whether exogenous factors affecting group displays show a general species-specific pattern or whether they are population-specific. Using audio-trapping techniques, we compared factors influencing the daily occurrence and duration of lekking behavior in two populations of Hyla molleri and two populations of Hyla meridionalis located at the thermal extremes (coldest vs. hottest) of their Iberian distribution range. From 12,240 hourly recordings over one season, multimodel inference revealed that the major determinants of chorus occurrence were similar between populations and species (i.e., chorus size the previous day, daytime air temperature, relative humidity, and barometric pressure), and accounted for 51–79 % of its deviance. In contrast, the major determinants of chorus duration differed between populations and species (i.e., chorus size, number of day, and air temperature and relative humidity at the onset of the chorus), and accounted for 38–69 % of its variance. Our findings suggest that the decision making related to lek attendance is environment-dependent, takes place at time between lekking events, and is associated with exogenous factors that may be both stable across species ranges and population-specific when populations are under different climatic conditions. This intraspecific variation might be underlain by plasticity mechanisms providing tree frogs with means to cope with changing environments. Moreover, social facilitation related to male-male acoustic competition seems to play a relevant role on the daily time invested by males in lek attendance.

SUMMARY 1. Although the influence of water availability and precipitation regimes on amphibians has been studied at large scales, whether and how interannual rainfall and hydrological variations affect amphibians dynamics at a local scale have rarely been addressed. In this respect, accounting for variations in species detectability in space and time has also been overlooked. 2. We assessed the effects of rainfall and hydrological variations on the breeding dynamics of three amphibian taxa: Pelodytes punctatus, Hyla meridionalis and Pelophylax spp. in 20 ponds of the Camargue region (southern France) over a 7-year study period. 3. We used multiple season occupancy models to test the effect of winter‐spring rainfall and interannual variations in hydroperiod, mean water depth and drought events on tadpole presence in spring (March‐June), a proxy for breeding dynamics. 4. We used an independent survey with spatial replicates (dipnet sweeps) to disentangle the relative contributions of phenology and detectability to the absence of records in a given month. For the three taxa considered, the probability of missing a species when that species was actually present in a pond was most often negligible. Hence, we could consider that multiseason models properly tracked changes in species phenology. 5. Pelodytes punctatus was first detected in March, while the two other taxa appeared later in April. Hyla meridionalis appeared as a mid-season species with much more synchronous pond occupancy than Pelodytes punctatus. The detection peak of Pelophylax spp. was short and unexpectedly early for this taxon. 6. Seasonal winter‐spring rainfall was associated with a decrease in extinction rates and even more strongly with an increase in colonisation rates at individual ponds. 7. Colonisation rate increased following an annual drought and was best modelled as a negative quadratic effect of the variance of pond hydroperiod. Extinction probability was best modelled by a negative quadratic effect of mean water level. Hence, breeding was more stochastic (i) in unpredictable and shallow ponds because of yearly drying up and (ii) in highly predictable and deep ponds, possibly due to the presence of predators such as fish and crayfish. 8. Overall, we show that ponds with intermediate rather than extreme variations in environmental conditions currently correspond to optimal breeding sites. Our study demonstrates that amphibian monitoring coupled with fine-scale analysis of environmental conditions is necessary to understand species dynamics in the long run and to inform conservation efforts for these species.

International audience; A key issue in Evolutionary Developmental Biology is to assess the roles of homeotic genes in order to uncover the origins of animal diversity. Within parasitic platyhelminths which show a large diversity of developmental strategies, only one study related to the expression of Hox genes has so far been conducted involving a digenean species with a complex life cycle. In the present study, we considered the expression levels of the Pg-Lox4 gene within Polystoma gallieni of the Monogenea which displays alternative phenotypes throughout its direct life cycle, depending on the physiological stage of its amphibian host Hyla meridionalis upon which free swimming larvae attach. Dissimilar expression patterns were found along the two morphogenetic routes revealing a putative role of Pg-Lox4 in the process of developmental plasticity. Pg-Lox4 was also shown to be upregulated in both reproducing parasite phenotypes indicating its apparent involvement in tissue differentiation of the reproductive organs.

New records of the frog Hyla meridionalis have been reported on the Iberian Central mountain range, although it is not clear if those records correspond to an expansion process or to a lack of sampling. The species' global distribution was modelled to identify possible areas of expansion in the current environment and in a near future environment. To verify the effects of modelling a dynamic situation, the hypothetical expansion process from south to north was simulated in the current scenario. The species records were partitioned in four different datasets and modelled iteratively over a study area enclosing all records: records only from North Africa, from North Africa and South Iberian Peninsula, from North Africa and all the Iberian Peninsula, and from the entire distribution. The complete dataset was also used to extrapolate the model to a current and future global environmental scenarios. The models were compared by subtraction per pairs and by Cohen's Kappa. No spatio-temporal trends were detected in species records; therefore, the hypothesis of a recent expansion is nor supported. The species spread only to the Mediterranean part of the Iberian Peninsula when modelling only with African records, and to Europe when modelling also with Iberian records. The extrapolation models were moderately similar: large suitable areas were predicted in all the continents. Temperature variables contributed more to models. The species can expand to new suitable areas, although it is not possible to know if it would expand outside the biogeographical regions where the species is present.

Genetic differentiation of Hyla arborea molleri and H. meridionalis was studied through allozyme electrophoresis and through essays of artificial hybridization. Samples were taken at several localities in Portugal, where these species occur either in sympatry or allopatry, and at one locality in France. Of the 21 presumptive loci analyzed, 6 were monoallelic, while 9 loci were discriminative between both species. A relatively high level of genetic differentiation was found between the two species (NEI's D = 0.725), contrasting with their morphological similarity. Remarkably low levels of genetic variability were found within species, with greater differentiation found among samples of H. meridionalis than of H. a. molleri. Although the capacity for interspecific hybridization was low, hybrid embryos resulted from both reciprocal crosses, but with much greater success in the cross ♂H. a. molleri x δH. meridionalis. Hybrids showed greater similarity with the male parent, and showed heterozygote allozymic phenotypes for discriminative loci. Results are compared with those of similar studies on the same and different species of Hyla, and differentiation of H. a. molleri and H. meridionalis is discussed in relation to their taxonomic status and origin.

13 páginas, 3 figuras, 2 tables et al.., Aim To study the patterns of genetic variation and the historical events and processes that influenced the distribution and intraspecific diversity in Hyla meridionalis Boettger, 1874. Location Hyla meridionalis is restricted to the western part of the Mediterranean region. In northern Africa it is present in Tunisia, Algeria and Morocco. In southwestern Europe it is found in the south of France, north-western Italy and northeastern and south-western Iberian Peninsula. There are also insular populations, as in the Canaries and Menorca. Methods Sampling included 112 individuals from 36 populations covering the range of the species. We used sequences of mitochondrial DNA Cytochrome Oxidase I (COI) for the phylogeographical analysis (841 bp) and COI plus a fragment including part of tRNA lysine, ATP synthase subunits 6 and 8 and part of Cytochrome Oxidase III for phylogenetic analyses (2441 bp). Phylogenetic analyses were performed with paup*4.0b10 (maximum likelihood, maximum parsimony) and MrBayes 3.0 (Bayesian analysis). Nested clade analysis was performed using tcs 1.18 and GeoDis 2.2. A dispersal-vicariant analysis was performed with diva 1.0 to generate hypotheses about the geographical distribution of ancestors. Results We found little genetic diversity within samples from Morocco, southwestern Europe and the Canary Islands, with three well-differentiated clades. One is distributed in south-western Iberia and the High Atlas, Anti-Atlas and Massa River in Morocco. The second is restricted to the Medium Atlas Mountains. The third one is present in northern Morocco, north-eastern Iberia, southern France and the Canaries. These three groups are also represented in the nested clade analysis. Sequences from Tunisian specimens are highly divergent from sequences of all other populations, suggesting that the split between the two lineages is ancient. diva analysis suggests that the ancestral distribution of the different lineages was restricted to Africa, and that an explanation of current distribution of the species requires three different dispersal events. Main conclusions Our results support the idea of a very recent colonization of south-western Europe and the Canary Islands from Morocco. South-western Europe has been colonized at least twice: once from northern Morocco probably to the Mediterranean coast of France and once from the western coast of Morocco to southern Iberia. Human transport is a likely explanation for at least one of these events. Within Morocco, the pattern of diversity is consistent with a model of mountain refugia during hyperarid periods within the Pleistocene. Evaluation of the phylogenetic relationships of Tunisian haplotypes will require an approach involving the other related hylid taxa in the area., Support during part of the development of this project for A.I. was provided by an Aranzadi fellowship and for E.R. by an I3P grant of the CSIC.

The effect of predation by large non-gape-limited vertebrates on the survivorship and size distribution of larvae of four anuran species was assessed using two syntopic freshwater turtle species, Emys orbicularis and Mauremys leprosa. Predator species and predator sex within species were used as treatments in replicated, factorial experiments for predation trials on tadpoles of Bufo calamita, Hyla meridionalis, Rana perezi, and Pelobates cultripes. Tadpole consumption rates were significantly higher for the carnivorous E. orbicularis than for M. leprosa. Rana perezi tadpoles were the least consumed, whereas P. cultripes and H. meridionalis had the lowest survivorship rates, being relatively easier to catch than R. perezi. Significant size selection occured for larger tadpoles of P. cultripes, whereas predation upon R. perezi tended to concentrate on the smaller size classes. The results point to an overall tendency of turtles to predate upon large tadpoles, yet the outcome of size selection by large vertebrates may depend on phenotypic traits that enhance the escape potential of tadoles. Mauremys leprosa had a high rejection rate of tadpoles, suggesting a higher sensitivity to unpalatability as compared to E. orbicularis, especially with relation to R. perezi. The results indicate that the effect of unpalatability as a predation deterrent may vary even among taxonomically close predator species.

The distribution of neurotensin (NT) was studied in the brain of three species belonging to the three major classes of cold-blooded vertebrates: teleost fishes (Carassius auratus), anuran amphibians (Hyla meridionalis), and reptiles (Gallotia galloti; Lacertidae). By using antibodies directed against synthetic bovine NT in the three species, immunoreactive cell bodies were discovered mostly in the telencephalon and diencephalon, in particular at the level of the preoptic region the mediobasal hypothalamus, and the thalamus. In the frog and the lizard, additional immunoreactive (ir) structures were observed in the optic tectum and the tegmentum of the mesencephalon. In the goldfish pituitary, an extensive innervation was consistently observed at the level of the rostral pars distalis, whereas in both frog and lizard, positive fibers were only detected in the external layer of the median eminence. In the three species there is a striking overlap between the distribution of the NT-ir cell bodies and that of the target cells for sexual steroids. The results are discussed in relation with those reported in birds and mammals, and with the possible interactions among NT, sexual steroids, and the neuroendocrine control of pituitary hormone release, in particular prolactin and gonadotrophin.

International audience; Among parasitic platyhelminths with complex life cycles, it has been well documented that transmission opportunities are the main forces shaping the diversity of life-history traits and parasite developmental strategies. While deviations in the development pathway usually involve shortening of life cycles, their extension may also occur following perception of remaining time by parasites. Polystoma gallieni, the monogenean parasite of Hyla meridionalis, is able to trigger two alternative developmental strategies depending on the physiological stage of the tadpoles upon which larvae attach. The distribution and reproductive outputs of both resulting phenotypes were surveyed to address questions about the dynamics of transmission in natural environments. Because modifications in the completion of life cycles can have drawbacks which may perturb the dynamic equilibrium of the resulting host-parasite systems, experimental infestations were also performed to assess parasite-parasite interactions. Our results suggest that the bladder adult phenotype, which involves transmission between frogs and tadpoles, is supplied secondarily by the branchial phenotype which involves transmission between tadpoles and metamorphs. They also support the occurrence of finely tuned trade-offs between hosts and parasites and highlight positive trends behind the extension of direct life cycles, in which host-derived signals account for the remaining time to achieve parasitic transmission.

Timing of larval periods of 9 species of amphibians (Hyla meridionalis, Pelobates cultripes, Discoglossus galganot, Bufo calamita, Bufo bufo, Rana perezi, Triturus marmoratus, Triturus boscat, Pleurodeles waltl) was followed in 7 different years Total larval season may last from autumn to summer, whereas in low rainy years it may last from late winter to summer In rainy years, two species are early breeders, starting to breed m autumn, six species commonly start in mid-winter and one species always breeds later, in spring The widest interannual variability m the onset and duration of larval season occurs in the earliest breeders In general, the more rainy the autumn and the higher temperatures were reached, the earlier the season started In contrast, duration of the season was not correlated with rainfall and temperature Interannual variability is interpreted as the possibility of adjusting the reproduction of the species to the availability of breeding habitats, constrained by physiological features of the species and interspecific relationships

International audience; Among monogeneans that display direct life cycles, plastic developmental strategies may have been selected to counter the lack of transmission opportunities. Within amphibian polystomatids, some species of the genus Polystoma develop into two different phenotypes depending on the host physiological stage to which free swimming larvae attach. When oncomiracidia infest old tadpoles, they develop slowly and migrate during host metamorphosis towards the bladder where they reach maturity. On the other hand when larvae infest young tadpoles, they develop rapidly into neotenic phenotypes that reproduce in the branchial chamber. These alternative developments are explored through experimental infestations with Polystoma gallieni, the specific polystome of the stripeless tree frog Hyla meridionalis. When oncomiracidia were left for 6 h in water in which young tadpoles had been previously maintained for one day, they mainly developed into the neotenic phenotype regardless of the tadpole stage they encountered later. This indicates that P. gallieni could collect released host-derived signals before physical contact with its host.

Abstract A tree-frog with unusual mating calls was found in an area of sympatry between H. arborea and H. meridionalis. This individual was studied by analysis of mating call structure and allozyme variation. The structure of the testes was also examined. The intermediate characteristics of the mating calls, the heterozygosity of all discriminative loci examined, and the apparent sterility, as shown by testis histology, all corroborate the identification of this hybrid.

Several authors have suggested that nitrogen-based fertilizers may be contributing to the global amphibian decline. We have studied the impact of sodium nitrite on early aquatic stages of Epidalea calamita, Pelophylax perezi and Hyla meridionalis larvae from Doñana National Park (coastal wetland) and P. perezi from Gredos Mountain (high mountain ponds), exposed during 10 to 16 days. After 8 days of exposure all P. perezi larvae from Doñana presented 100% mortality at 5 mg l−1View the MathML source while E. calamita larvae mortality rates were significantly lower at that concentration after 15 days. However, for H. meridionalis at day 15 no deaths were registered at 5 mg l−1View the MathML source and at 20 mg l−1View the MathML source presented intermediate mortality rates. In Doñana the 10 d LC50 of older H. meridionalis larvae was between 20 and 30 mg l−1View the MathML source whilst for P. perezi it was below 5 mg l−1View the MathML source. These results indicate inter-specific variation of the sensitivity of larval amphibians to nitrite. Gredos Mountain P. perezi larvae exposed since the egg stage were highly sensitive to nitrite, with a 16 d LC50 below 0.5 mg l−1View the MathML source. The same species in Doñana had a 15 d LC50 between 5 and mg l−1View the MathML source. These results suggest that there is also intra-specific variation in sensitivity of amphibian larvae to nitrite: mountain amphibian populations appear to be more sensitive to polluted environments than coastal populations. Geographic and genetic variation and evolutionary adaptation of tolerance may also be the keys to variation amongst populations of the same species.

[EN] We present the revised catalogue of the amphibians deposited in the “Colección de Anfibios y Reptiles” of the Museo Nacional de Ciencias Naturales that have been collected in the Comunidad Autónoma of Madrid. It consists of 2272 records of 18 species, including all species present in Madrid except Hyla meridionalis. We evaluate the collection on the basis of the representation of the specimens collected in relation with: 1) the present distribution of each amphibian species in Madrid, considering the number of UTM 10x10 km grid cells represented in the collection in relation with the total number of grids occupied by each species in Madrid; 2) the number of intraspecific subunits that are relevant from a conservation perspective (subspecies or groups of populations that are differentiated on ecological or genetic grounds) that are represented in the collection. Representation values range from 0% (Hyla meridionalis) to 50% (Triturus alpestris). We also include information on the conservation status of some populations from historical collection sites and conclude that at least 10 breeding sites have disappeared as a consequence of human activities, with the subsequent local extinction of their associated amphibian populations. We have also documented the disappearance of some species from unaltered areas. Finally, we discuss the utility of scientific collections in facing practical aspects of the management and conservation of endangered groups like amphibians., [ES] Se presenta el catálogo revisado de los anfibios de la Colección de Anfibios y Reptiles del Museo Nacional de Ciencias Naturales colectados en la Comunidad de Madrid. En total, consta de 2272 entradas correspondientes a 18 especies, que incluyen todas las presentes en la Comunidad excepto Hyla meridionalis. Se valora la colección en función del grado de representatividad de los ejemplares de la colección en relación con: 1) la distribución actual de las especies de anfibios en Madrid, considerando el % de cuadrículas UTM de 10x10 km del total del área de distribución de cada especie que se encuentran representadas en la colección; 2) el número de unidades infraespecíficas relevantes desde el punto de vista de la conservación (subespecies o grupos de poblaciones diferenciados ecológica o genéticamente) representados en la colección para cada especie. Los valores de representatividad obtenidos oscilan entre el 0% (Hyla meridionalis) y el 50% (Triturus alpestris). Además, se aporta información acerca de algunas de las poblaciones asentadas en los lugares de colecta históricos, lo que permite concluir que al menos 10 puntos de reproducción han desaparecido durante los últimos años como resultado de la actividad humana, con la consiguiente extinción local de esas poblaciones de anfibios. Por otro lado, en ciertos casos también se ha documentado la desaparición de especies en áreas aparentemente inalteradas. Finalmente, se discute la utilidad de las colecciones museológicas para afrontar aspectos prácticos relacionados con la gestión y conservación de grupos amenazados como los anfibios., El trabajo de IMS estáfinanciado por una beca predoctoral MNCN-CSIC-CAM.

In static renewal experiments, we studied how developmental stage influences the effect of ammonium nitrate on embryonic and larval stages of anuran amphibians. The observed lethal effects caused by ammonium nitrate increased with both concentration and duration of exposure. Significant differences were observed in sensitivity to ammonium nitrate as a function of developmental stage in Discoglossus galganoi, Pelobates cultripes, and Bufo calamita. In D. galganoi and P. cultripes, younger individuals displayed greater acute effects from the chemical fertilizer compared with older individuals. For example, 100% of P. cultripes hatchlings died after 4 d of exposure to a nominal concentration of 225.8 mg N-NO3NH4/L, whereas less than 40% of individuals from older larval stages died when exposed to this concentration. A delay of 4 d in the beginning of the exposure to the chemical was enough to cause significant differences in sensitivity. Bufo calamita showed a higher sensitivity in later larval stages after 12 d of exposure. Hyla meridionalis and B. calamita were less sensitive than the other two species. Peak ammonium nitrate concentrations usually occur when amphibians are breeding and, thus, when the most sensitive aquatic stage is in the water. The developmental stage of the test animals should be considered when evaluating the risk of ammonium nitrate to amphibians.

The amphibian community of the Biological Reserve of Doñana (SW Spain) is composed of 10 species, their period of larval occurrence commonly taking place from autumn to early summer, although it may vary from year to year in relation to the flooding conditions of ponds. A segregation is observed according to temporal use of temporary ponds by larvae of different species. Pelobates cultripes and Discoglossus galganoi tadpoles occur in ponds during their whole persistence, from flooding to drying up. Hyla meridionalis, Triturus marmoratus and Triturus boscai larvae commonly exploit a shorter temporal range, appearing about two months later until early summer. Bufo bufo, Bufo calamita and normally also Rana perezi have the shortest larval periods, of about two months. Rana perezi is also characterized by its delay in temporal use of the ponds in comparison with the other species. The flexibility of the larval period season is considered an adaptation to the unpredictability of temporary ponds. Thus, under certain climatic conditions, the two first groups of species may occur in the same temporal range.

Four species of Anuran Amphibians (Hyla meridionalis, Bufo bufo, Bufo mauritanicus, Discoglossus pictus) were collected at an elevation of 2,650 m in and near a lake at Oukaïmeden (Upper Atlas Mountains, Morocco) in July 1980. The population of Hyla meridionalis was very important, which suggests that a «demographic explosion» followed the creation of the dam in 1976., Dubois Alain. Les Amphibiens de la station d'altitude d'Oukaïmeden (Haut-Atlas, Maroc). In: Bulletin mensuel de la Société linnéenne de Lyon, 51ᵉ année, n°10, décembre 1982. pp. 329-333.

The diets of the larvae of five anuran species are described (Discoglossus pictus, Bufo calamita, Hyla meridionalis, Pelobates cultripes and Rana perezi). They all are basically composed of three abundant categories of food: algae, detritus and phanerogams. Other rarely encountered food categories are pollen, fungi, animals, bacteria and protozoa. A classification can be deduced by relating the use of the space in the ponds, diets and several morphological characters of larvae of each species: a) bottom-dwellers —tadpoles with a depressed body form which feed mainly on detritus — b) water column users — tadpoles with larger dorsal tail crests and tail surfaces which feed mainly on algae and phanerogams.

TSH-like producing cells have been studied using the peroxidase-antiperoxidase (PAP) immunohistochemical technique and rabbit anti-human thyrotropin (TSH) antiserum in the pars distalis of five species of amphibian anuran tadpoles at different stages of development as well as in 1-year-old postmetamorphic animals. This cell type has been identified and located in the pars distalis ventral zone of Bufo calamita showing no changes in its distribution pattern throughout development, and in Rana perezi where TSH-like cells were located in the central zone of the gland in premetamorphic stages, occupying the ventral zone at the end of metamorphosis. No immunoreaction has been observed in the other species studied (Hyla meridionalis, Alytes cisternasii, and Pelobates cultripes). Morphometry and stereology were used to evaluate the changes observed in pars distalis volume and TSH immunoreactive cells during development. Pars distalis volume increased during the larval growth period and decreased throughout the metamorphic climax. TSH volume density and cellular area showed different evolutions in the species studied. The correlation between these parameters suggests a greatly proliferative period followed by an increase in cellular size. The changes observed in TSH total volume as well as the physiological data found by other authors lead us to conclude that there are two phases in amphibian development: first a period of TSH storage (pre- and prometamorphosis) and second a period of TSH release at metamorphic climax.

Mating behavior of Hyla meridionalis was observed at an artificial reservoir in Punta del Hidalgo, Tenerife. Playback experiments were conducted in the field near the reservoir. The density of calling males was extremely high, and individuals sometimes called within 5 cm of each other. Males often changed calling positions and successfully attempted to clasp one another. Gravid females were common and most often found in amplexus. In three of four observations, the male initiated amplexus from a distance of 5 to 10 cm. Only 11 of 107 gravid females responded in two-choice playback experiments. Ten chose the calls of a conspecific male recorded at Punta del Hidalgo, and one female chose the calls of a male of H. a. arborea recorded in Germany. Our observations and experimental results are compared with those of similar studies of North American hylids.

The peroxidase-antiperoxidase (PAP) immunocytochemical technique and rabbit antihuman prolactin (PRL) antiserum were used to localize and identify PRL-producing cells in the pars distalis of Bufo calamita, Hyla meridionalis, Alytes cisternasii, Pelobates cultripes, and Rana perezi tadpoles at different stages of development as well as in 1-year-old post-metamorphic animals. This cell type was located throughout the gland in P. cultripes and R. perezi and in the caudal two-thirds in B. calamita, H. meridionalis, and A. cisternasii in premetamorphic animals. These distribution patterns do not show changes throughout development. Morphometry was used to evaluate the changes observed in pars distalis volume and stereological parameters of PRL immunoreactive cells during development. Pars distalis volume increased during the larval growth period and decreased throughout the metamorphic climax. PRL volume density and cellular area showed different patterns in the different species, although the correlation between these parameters suggests a period of great proliferative rate followed by changes in cellular size. The changes observed in PRL total volume suggest the existence of two phases in amphibian development: (i) a period of PRL storage during pre- and prometamorphosis and (ii) a period of release at the metamorphic climax.

Thirteen kinds of interspecific and intraspecific crosses were performed with Eurasian treefrogs of the genus Hyla. Progeny of eight kinds of interspecific crosses (between females of H. japonica and males of H. hallowellii, H. chinensis, H. suweonensis, H. savignyi, H. meridionalis, H. arborea arborea and H. arborea sarda and between a female of H. suweonensis and males of H. japonica and H. hallowellii) metamorphosed into froglets. The results are consistent with other lines of evidence that indicate close phylogenetic relationship among these Eurasian species. At metamorphosis, all of the hybrids had either nearly normal testes or abnormal ovaries. Sex ratio differed significantly from a 1:1 ratio among progeny in five kinds of interspecific crosses; most of the control froglets had normal ovaries or testes in nearly equal proportion. Gonadal structures in hybrids after one year were also abnormal, suggesting that fertility of adults would be very low, if not absent. The presumed low hybrid fertility supports the specific status of H. japonica, which has often been treated as a subspecies of H. arborea. It also supports the specific status of H. suweonensis, which was distinguished originally on the basis of its characteristic vocalization. This study also suggests specific status of H. savignyi and some genetic divergence between H. japonica of Japan and Korea.