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We present nine observations of abnormal amplexus in anurans, reported for the first time from Latvia. In total, nine types of abnormal amplexi are documented for four anuran species: Bombina bombina (Bombinatoridae), Bufo bufo (Bufonidae), Pelophylax lessonae and Rana temporaria (Ranidae). According to the one of our observations, abnormal amplexus resulted in the extirpation of a competing anuran species from a breeding pond for two seasons. [ABSTRACT FROM AUTHOR]

Hyaloklossia Labbé, 1896 (Apicomplexa: Sarcocystidae) is a renal coccidium that infects anuran species. The genus consists of two species: H. lieberkuehni , recorded from Pelophylax kl. esculentus, Pelophylax ridibundus, and Rana temporaria in Europe; and H. kasumiensis , recorded from Pelophylax porosus porosus in Japan. However, there have been no reports of Hyaloklossia in the other anurans in Japan. On June 2021, we examined a total of 58 adult frogs comprising 2 P. p. porosus, 23 Pelophylax nigromaculatus , 8 Rana japonica , 3 Glandirana rugosa (Ranidae), 13 Fejervarya kawamurai (Dicroglossidae), and 9 Buergeria buergeri (Rhacophoridae) for infection by Hyaloklossia. Microscopic examination of kidney tissues revealed a high infection incidence of 47.8% (11/23) in P. nigromaculatus, but the other frog species were negative for Hyaloklossia. Morphological and molecular analyses using nuclear ribosomal and mitochondrial genes confirmed the infective species as H. kasumiensis. This is a new host record for H. kasumiensis. [Display omitted] • Hyaloklossia genus contains two parasitic coccidian species that infect anurans. • A total of 58 frogs of 3 families, 5 genera, and 6 species were examined for renal coccidian parasites in Japan. • We found that 47.8% of Pelophylax nigromaculatus hosted Hyaloklossia kasumiensis. • All other frog species examined did not harbour Hyaloklossia infections. • This is the first description of H. kasumiensis in Pelophylax nigromaculatus. [ABSTRACT FROM AUTHOR]

Urbanization has caused a significant decline in amphibians worldwide due to habitat loss, fragmentation, and degradation of habitat quality. Accordingly, parks have become “islands,” or habitat fragments, for amphibians in highly urbanized areas. Understanding the habitat use pattern of amphibians in fragmented urban environments is essential for biodiversity conservation in urban ecosystems. Several environmental features may affect anuran communities in urban parks, including the characteristics of fragmentation, landscape heterogeneity, breeding habitat, and human disturbance. In particular, it is unclear whether a larger habitat area could lead to higher anuran species richness (species-area relationship) in urban parks. The aim of this study was to examine whether the species-area relationship is relevant for anurans in urban parks, and to determine the environmental characteristics that likely influence anuran communities. We used a visual encounter method to survey anuran communities (species richness and abundance) in 16 parks located in highly urbanized areas of Shanghai, China. Fragmentation characteristics included fragment size and shape index. Landscape heterogeneity was measured as compositional heterogeneity (using the Shannon diversity index of wetland types) and configurational heterogeneity (using edge density of different land use types). We found that compositional and configurational heterogeneity had significant positive effects on anuran species richness and relative abundance, respectively, in the urban parks. We also found that high edge density along streams benefited anuran abundance. However, there was no significant relationship between fragment size and anuran communities, and the abundances of Pelophylax plancyi and P. nigromaculata were negatively associated with the edge density of large ponds and roads. Our results suggest the importance of landscape structure in urban parks for sustaining anuran persistence. In addition, diverse breeding habitats and landscape heterogeneity should be considered positive indicators of anuran biodiversity conservation in fragmented urban habitats. [ABSTRACT FROM AUTHOR]

The Balkan Water frog (Pelophylax kurtmuelleri) is the most widespread frog in Greece, occurring also in Albania, Montenegro and Serbia and recently introduced in Italy and Denmark. However, its biology remains surprisingly understudied. Here we assess for the first time the feeding ecology of the species. We focused on two populations from Attica (central Greece), one from a natural habitat (Erasinos River) and another from an artificial landscape (Diomidous Botanical Garden). We aimed to clarify the impact of the habitat on the feeding preferences of the species, and also to examine how food availability affects food composition and selectivity. For the purposes of the study a total of 75 individuals (41 from the Botanical Garden and 34 from Erasinos River) were captured and stomach content was removed following the flushing method. We measured body weight, snout-vent length and mouth width for all captured individuals and also width and length for each prey item. Prey availability was evaluated with the quadrat counts method. The diet of P. kurtmuelleri followed the same general feeding pattern of other ranid species in the broader area, with insects, spiders, isopods and gastropods dominating in stomach content. The habitat had a strong impact on the feeding preferences of the species: food composition, prey frequency, size and volume differed considerably between the two populations. Niche breadth was higher in the Botanical Garden, probably as a result of the lower invertebrate diversity and abundance. [ABSTRACT FROM AUTHOR]

Urbanization affects amphibian communities through habitat loss, fragmentation, and degradation of habitat quality. The effects of these changes in habitat at different scales vary depending on the sensitivity of individual species. We assessed the breeding distribution of anurans along an urban–rural gradient in Shanghai, China, a region experiencing intensive urbanization. Our results showed that urban density had a significantly negative influence on the overall anuran abundance and diversity and that the responses of individual species to urbanization varied. Pond age was an overall predictor in models describing the responses of Pelophylax nigromaculatus , Fejervarya multistriata , and M. fissipes and total anuran abundance. The quality of habitat at a pond was also important, and the high abundance of Bufo gargarizans and Pelophylax plancyi was associated with ponds with aquatic vegetation coverage. Urban density showed strong negative effects on B . gargarizans , total anuran abundance, and species richness. The broad-scale landscape variables associated with forests, agricultural fields, and wetlands surrounding breeding ponds have been shown to affect anuran abundance and species richness. The response of individual species, total abundance, and species richness to urbanization reflected differences in their ecological requirements. We quantified the effects of urbanization on frogs in a rapidly urbanizing region, and our results demonstrated that both multi-spatial and temporal variables affect anurans in Shanghai. Our results emphasized the importance of anuran conservation planning in urbanized areas to preserve and/or restore terrestrial habitat and to improve connectivity between ponds and other wetlands. [ABSTRACT FROM AUTHOR]

In a previous study, the authors had predicted that the local green frog population had developed adaptations to live and breed in mixoligohaline waters, however the registered in 2010 mass migration of the adults into the sea near the Shablenska Tuzla lagoon was an isolated event, conditioned by the correlated impact of defined climatic factors. To support that hypothesis, the site was an object of five-year monitoring. Additionally, other three regions with similar topographic characteristics - the Black sea shores near Durankulak lake, Ezeretz lake and the Bolata bay - were investigated. During the period of the field surveys and according to data from fishers and biologists working in the region, no further mass migration of frogs in the sea waters was detected. An isolated observation of a specimen, swimming in the sea at Bolata bay (water with conductivity of 19.55 mS/cm), leads to the conclusion that the adult green frogs from the local population are able to inhabit the sea waters, but other factors like the sea surf prevent them to colonise the sea shores. [ABSTRACT FROM AUTHOR]

Heavy metal pollution of the aquatic environment is of great concern worldwide. Heavy metals are capable of inducing oxidative stress by increasing the formation of reactive oxygen species (ROS), and directly affecting the antioxidant defense system (AOS) in living organisms. The frog Pelophylax kl. esculentus is a semiaquatic species with semipermeable skin and a complex lifecycle, and represents a potentially useful bioindicator organism. The aim of this study was to investigate the accumulation of several heavy metals (Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb and Zn), and their effects on selected parameters of the AOS, including the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), phase II biotransformation enzyme glutathione-S-transferase (GST), the total glutathione (GSH) contents and sulfhydryl (SH) group concentrations, as well as cholinesterases (ChEs) activities in the liver, skin and muscle of P. kl. esculentus . Frog samples were collected at two sites (the Danube–Tisza–Danube canal (DTDC) and the river Ponjavica) in Serbia, which are characterized by different levels of metal pollution. Differences between the metal contents in different tissues showed that the skin of frogs from the DTDC accumulated statistically higher concentrations of Cd, Cu, Pb and Zn, while only the Fe concentration was lower. No significant differences between metal concentrations in muscle tissues of frogs from the DTDC and Ponjavica were observed. Examination of the parameters of the AOS revealed that frogs from the DTDC had higher concentrations of GSH in the liver and of SH groups in the skin and muscle, whereas the activities of the antioxidative enzymes SOD, GHS-Px and GR in the liver and of GR in the skin were lower than in frogs from the Ponjavica. The relationship between metal concentrations and AOS parameters showed the highest number of correlations with GSH, GR and CAT, and with Ni, Zn, Hg, Cr and Cd. Based on the results in this study, we concluded that increased concentrations of heavy metals in frog tissues can alter the AOS, which leads to higher concentrations of GSH and SH groups and lower activities of antioxidative enzymes. The response of the AOS to metal pollutants allowed us to make a distinction between different frog tissues, and to conclude that the liver and skin are more suitable for assessing metal-induced oxidative stress in frogs than muscle. [ABSTRACT FROM AUTHOR]

There have been a few studies on the negative effects of pollutants on amphibian skin, the first structural barrier that interacts with the environment and its potential contaminants. In this study an ex vivo skin organ culture from the amphibian Pelophylax bergeri was used to evaluate cell stress responses induced by short-term exposure to cadmium (Cd), a toxic heavy metal known to be an environmental hazard to both humans and wildlife. Histopathological studies were carried out on skin explants using light microscopy and changes in the expression of stress proteins, such as Metallothionein (MT) and Heat shock proteins (HSPs), were investigated by Real-time RT-PCR. Results revealed that amphibian skin reacts to Cd-induced stress by activating biological responses such as morphological alterations and dose- and time-dependent induction of Mt and Hsp70 mRNA expression, suggesting their potential role as biomarkers of exposure to Cd. This work provides a basis for a better understanding of the tissue-specific responses of amphibian skin as a target organ to Cd exposure and its in vitro use for testing potentially harmful substances present in the environment. [ABSTRACT FROM AUTHOR]

The article discusses a study on the refinement of criteria for species-level identification among the European green frogs Pelophylax ridibundus and Pelophylax lessonae, and their associated klepton Pelophylax kl. P. esculentus. Topics covered include intra- and interspecific variations in continuous and discrete iliac characteristics, differences in sexual dimorphism and population structure, and a biometrical method for differentiating between central European water frogs' fossil ilia.

Abstract: 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 hybridization (SSH). The SSH outcome in the liver revealed the up-regulation of genes coding for the ribosomal protein L7a and for several proteins typical from blood plasma: fibrinogen, hemoglobin and albumin. Besides their normal function, some of these proteins can play an important role as protective agents against oxidative stress. This work provides new insights on possible basal protection mechanisms that may act in organisms exposed chronically to contamination. [Copyright &y& Elsevier]

The article presents the study which examined the phenotypic flexibility of tadpoles of various species under natural conditions of the different water-quality parameters of their habitats. The aim of the study is to increase understanding on larval development, growth and complete metamorphosis in various water bodies. The six species that were studied are the striped newt Triturus vittatus vittatus, the fire salamander Salamandra infraimmaculata, the tree frog Hyla savignyi, the green toad Bufo viridis, the water frog Rana bedriagae, and the spadefoot Pelobates syriacus.

The article presents a study which examined the prevalence of Chytridiomycosis caused by Batrachochytrium dendrobatidis in wild frog species on Prince Edward Island in Canada. Skin swabs were tested through single round end-point polymerase chain reaction (PCR) collected from 115 frogs including green frogs, wood frogs and leopard frogs from 18 separate site across the province. It reveals that juvenile green frogs were more frequently positive for Chytridiomycosis than adults while there is no significant difference between the prevalence among green frogs and adult leopard frogs.

The article discusses the unusual feeding behavior of water frogs in the Mediterranean Island. It states that the Pelophylax bedriagae of water frog have adopted different ways of feeding pattern especially on terrestrial and aquatic invertebrates. It also notes that the predation of animals are prohibited on terrestrial vertebrates.