Добірка наукової літератури з теми "P. ridibundus"

AbstractCentral European water frog Pelophylax esculentus (formerly known as Rana esculenta) is a natural hybrid between P. lessonae and P. ridibundus. The hybrids reproduce by hybridogenesis and usually share populations with one of the parental species. Natural ridibundus-esculentus (R-E) mixed populations are rare. The population described herein is composed of 80% P. ridibundus and 20% P. esculentus represented by both sexes. We analyzed 159 adults and 228 juveniles. Age of adults collected from breeding sites ranged from 2 to 6 years in males and from 3 to 7 years in females of both taxa. The percentage of individuals older than 5 years was low. Average age of P. ridibundus was higher than that of P. esculentus. In P. ridibundus the average age of females was higher than that of males. In P. esculentus the difference between ages of females and males was not significant. Measurements of yearly radial growth of long bones revealed that the frogs grew intensively before reaching sexual maturity (3 years for females and 2 years for males). In the group of juveniles before I hibernation, P. esculentus were significantly bigger than P. ridibundus, however, there was no difference in body size between both taxa after I hibernation i.e., before the start of a new growth season. Mean LAG-1 diameters were significantly greater in adults P. ridibundus than in juveniles after I hibernation, but not in P. esculentus.

Abstract In Central Europe, water frog species coexist in assemblages consisting of Pelophylax lessonae, P. ridibundus and their hybridogenetic hybrid, P. esculentus. Population compositions are poorly understood, partly because of difficulties in distinguishing hybrids from parentals by means of morphology alone. Environmental change and human-mediated, cryptic introductions of non-native water frog species have modified local assemblages. In this contribution we examined the structure of nine water frog populations inhabiting mostly large fish ponds in the Upper Vistula river valley of southern Poland using morphology and PCR-based genotyping of single loci in the nuclear and mitochondrial genomes. We found four different water frog population compositions: two with only P. ridibundus, one composed of P. lessonae and P. esculentus, three with P. ridibundus and P. esculentus, and three containing all three water frog taxa. Historical data show that the area was previously inhabited by lessonae-esculentus populations. We propose that both ecological and genetic replacement by expanding P. ridibundus may have contributed to the decline of the former. Overall, 18% of P. ridibundus frogs contained introgressed P. lessonae mtDNA, however, the frequency of introgressants was most pronounced in populations with a high proportion of P. esculentus. Exotic water frogs were not detected in the study area. Our results bear significance for water frog population dynamics and conservation in Central Europe and highlight the importance of long-term monitoring for the detection of changes in population composition in these amphibians.

AbstractGreen frogs of Central Europe consist of three taxa: Pelophylax ridibundus, P. lessonae and their natural hybridogenetic hybrid, P. esculentus, which forms as a rule mixed populations with its parental species. We examined 659 095 eggs from P. ridibundus (48 females), P. lessonae (133 females) and P. esculentus (170 females) originating from 39 populations in Austria, Denmark, Germany and Poland. Some females of each taxon laid eggs that fell into discrete size classes (small, medium and large). Large eggs were mostly diploid gametes from which triploids developed. They were found in P. esculentus (25 233 large eggs in 152 spawns), P. lessonae (81 in 10 spawns) and P. ridibundus (7 in 3 spawns). The main purpose of the paper was to demonstrate that the numbers of large eggs were clearly associated with triploid P. esculentus frogs. In pure hybrid (esculentus) populations large eggs comprised between 2.44-40.96% of all ova, while triploid adult frogs constituted between 13.9-73.2% of all individuals, in mixed ridibundus-esculentus populations the large eggs and triploid frogs ranged between 0.85-36.6% and 9.2-56.2%, respectively. However, in mixed lessonae-esculentus populations large eggs comprised only 1.74% of the spawns, whereas triploid frogs represented 2.1% of the adults in the population.

The aim of this study was to investigate the integral indicator for developmental stability, the fluctuating asymmetry (FA), in the marsh frog Pelophylax ridibundus populations that inhabit biotopes of different types (running rivers and still, dam lakes), when exposed to different types of anthropogenic pollution (domestic sewage pollution and heavy metal pollution) in south Bulgaria. A total of 920 P. ridibundus individuals were used for FA analyses over three years (2009-2011). Fluctuating asymmetry was defined by 10 morphological traits, using the index frequency of asymmetric manifestation of an individual (FAMI). In closed water basins, regardless of the nature of toxicants, the FA values in P. ridibundus populations were statistically lower than those in river populations. The FA values were constantly the highest under conditions of sustained anthropogenic pollution, with high concentrations of toxicants in rivers with domestic sewage pollution and heavy-metal pollution. The results provide better opportunities to use FA in P. ridibundus populations for bioindication and biomonitoring, and for parallel and independent analyses of the physicochemical assessment of the environmental condition.

AbstractIn this research, a total of 298 Eurasian marsh frogs, Pelophylax ridibundus (Pallas, 1771) were collected from different localities in Denizli province (Inner-west Anatolia Region, the eastern part of Aegean Region) Turkey between 2006 and 2009 and examined for helminths. Of 262 (87.91 %) Pelophylax ridibundus samples were infected with one or more helminths. Pelophylax ridibundus harbored eight species of digeneans (Diplodiscus subclavatus, Gorgoderina vitelliloba, Gorgodera cygnoides, Pleurogenoides medians, Prosotocus confusus, Skrjabinoeces breviansa, Encyclometra colubrimurorum and Ophistoglyhe ranae), one species of cestode (Nematotaenia dispar), two species of acanthocephalans (Acanthocephalus ranae and Pomphorhynchus laevis), and six species of nematodes (Rhabdias bufonis, Oswaldocruzia filiformis, Cosmocerca ornata, Oxysomatium brevicaudatum, Eustrongylides sp. and Abbreviata sp.). P. ridibundus represents a host record for Nematotaenia dispar in Turkey.

Ecological and evolutionary consequences of population-genetic processes that occur because of natural cross-species hybridization can show mechanisms of overcoming the reproductive barrier and obtaining the species status by a hybrid taxon. This is clearly seen in the population systems of Eurasian water frogs – Pelophylax esculentus complex. The P. esculentus (E) hybrid usually discards one of the parental genomes of P. lessonae (L) or P. ridibundus (R) and reproduces semi-clonally. The genetic structure and direction of gene flows precisely depend on the type and distribution of mixed or pure population systems of water frogs. Three population systems in the south of Ukraine were identified and confirmed as RR, RE and REL. The populations of P. ridibundus are most common (76.2%). A mixed population systems of P. ridibundus and P. esculentus (20.0%) are concentrated in the floodplains of large rivers where triploids were found and the unisexual hybrids (1.0♂ : 0.1♀) were proved. Parent species populations having different ploidy of P. esculentus such as 3n and for the first time 4n were found. A mixed system of three taxa (REL) is rare (3.8%) and locally concentrated in the lower Danube and Dnieper with the smallest proportion of P. lessonae. We did not find populations of P. lessonae (LL), P. esculentus (EE, very rare system of hybrids only), and two mixed populations of parental species RL and semi-clonal LE in the south of Ukraine, but they are known for northern areas. The high number of P. ridibundus tends to decrease; the scarce P. esculentus and the extremely rare P. lessonae require special conservation measures. P. ridibundus (RR) occupies a wide range of diverse natural, permanent, temporary, coastal, continental, and artificial freshwater bodies, including synanthropic ecosystems. Mixed population systems inhabit willow and poplar forests in the floodplains of large rivers. In the south of Ukraine rare and isolated populations of the water frogs occurring outside the main range can be relict. Biotopic preferences, ratio and number of constituent taxa are crucial for an adequate assessment of biological (taxonomic) diversity and development of an appropriate strategy for the population systems’ conservation. Such characteristics as unisexuality of hybrids, their spreading patterns, specific sex structure and ploidy in different population systems of the P. esculentus complex contribute to the understanding of the hybridogenetic dynamics; produce new tendencies of becoming independent hybridogenous taxa and emergence of new evolutionary relationships.

AbstractWater frog mating calls from two localities were studied and analyzed. Recordings were made in the summer of 2010 at the Arkutino swamp near the town of Primorsko and at the Vurbitza River near the town of Momchilgrad. A total of 154 calls were analyzed and the results suggested the presence of both the Marsh frog (Pelophylax ridibundus) and the Levant frog (Pelophylax bedriagae) in both sites, with the former being more frequent in Vurbitza River, and the latter – in Arkutino. At Vurbitza, we also captured and measured 2 specimens, which morphological characteristics differed from P. ridibundus and matched those of P. bedriagae. These are the first localities for P. bedriagae in Bulgaria.

The introduction of alien water frogs is perhaps one of the most underestimated herpetological conservation issues in Europe. The identification of distinct species is highly challenging at the phenotypic level, and artificial syntopy between various taxa and lineages may lead to diverse outcomes, including hybridisation and local extinction. In central Italy the native synklepton of Pelophylax bergeri (the parental taxon) and P. kl. (klepton) hispanicus (the hybridogenetic hybrid, which clonally transmits the genome of an extinct ridibundus-like taxon) is present. Until recently, data regarding the presence of alien water frogs in central Italy was scarce, and no alien taxa have been reported for Tuscany. In this study, four distinct non-native Pelophylax lineages have been identified via molecular analysis in the Cecina and Arno river basins and ascribed to the Marsh frog group (P. ridibundus sensu lato). Alien Pelophylax ridibundus, P. kurtmuelleri, and P. cf. bedriagae sensu stricto currently appear to be widespread in the Cecina basin. Furthermore, evidence of hybridisation with autochthonous taxa has been suggested by genetic analyses in four out of eight sampling localities. With a view to evaluate urgent conservation strategies, a greater sampling effort is required to assess the actual distribution and ecology of the alien lineages, and further research is necessary to measure their impact on the native hybridogenetic system of the central-southern Italian pool frogs.

Abstract The results of herpetological investigations in the Buila-Vânturariţa massif (Southern Carpathians, Romania) and its surrounding areas are reported here. 19 amphibian and reptile species were identified (Salamandra salamandra, Triturus cristatus, Ichthyosaura alpestris, Lissotriton vulgaris, Bombina variegata, Bufo bufo, B. viridis, Hyla arborea, Rana temporaria, R. dalmatina, Pelophylax ridibundus, P. lessonae, Emys orbicularis, Lacerta agilis, L. viridis, Podarcis muralis, Zootoca vivipara, Zamenis longissimus, Natrix natrix) and are presented together with distribution and ecological data.