Rana Ridibunda Research Articles

Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity.

Green rods (GRs) represent a unique type of photoreceptor to be found in the retinas of anuran amphibians. These cells harbor a cone-specific blue-sensitive visual pigment but exhibit morphology of the outer segment typical for classic red rods (RRs), which makes them a perspective model object for studying cone–rod transmutation. In the present study, we performed detailed electrophysiological examination of the light sensitivity, response kinetics and parameters of discrete and continuous dark noise in GRs of the two anuran species: cane toad and marsh frog. Our results confirm that anuran GRs are highly specialized nocturnal vision receptors. Moreover, their rate of phototransduction quenching appeared to be about two-times slower than in RRs, which makes them even more efficient single photon detectors. The operating intensity ranges for two rod types widely overlap supposedly allowing amphibians to discriminate colors in the scotopic region. Unexpectedly for typical cone pigments but in line with some previous reports, the spontaneous isomerization rate of the GR visual pigment was found to be the same as for rhodopsin of RRs. Thus, our results expand the knowledge on anuran GRs and show that these are even more specialized single photon catchers than RRs, which allows us to assign them a status of “super-rods”.

Body Size, Age, Phenetic, Morphophysiological, and Cytogenetic Characteristics of Pelophylax ridibundus (Amphibia, Ranidae) Populations Inhabiting Polluted Thermal Reservoirs of Kamchatka

Body Size, Age, Phenetic, Morphophysiological, and Cytogenetic Characteristics of Pelophylax ridibundus (Amphibia, Ranidae) Populations Inhabiting Polluted Thermal Reservoirs of Kamchatka

Predation Pressure of Invasive Marsh Frogs: A Threat to Native Amphibians?

Anurans have been introduced in many parts of the world and have often become invasive over large geographic areas. Although predation is involved in the declines of invaded amphibian populations, there is a lack of quantitative assessments evaluating the potential risk posed to native species. This is particularly true for Pelophylax water frogs, which have invaded large parts of western Europe, but no studies to date have examined their predation on other amphibians in their invaded range. Predation of native amphibians by marsh frogs (Pelophylax ridibundus) was assessed by stomach flushing once a month over four months in 21 ponds in southern France. Nine percent of stomachs contained amphibians. Seasonality was a major determinant of amphibian consumption. This effect was mediated by body size, with the largest invaders ingesting bigger natives, such as tree frogs. These results show that invasive marsh frogs represent a threat through their ability to forage on natives, particularly at the adult stage. The results also indicate that large numbers of native amphibians are predated. More broadly, the fact that predation was site- and time-specific highlights the need for repeated samplings across habitats and key periods for a clear understanding of the impact of invaders.

Bioaccumulation of Trace Elements and Health Risk Predictions in Edible Tissues of the Marsh Frog.

Certain amphibian species have long served as a valuable protein source for humans, in addition to being good bioindicators for environmental pollutants. Hence, to investigate the consumption outcomes leading to potential health risks, we determined the trace element (TE) levels in the hind leg and liver tissues of marsh frogs (Pelophylax ridibundus), one of the delicacies of several cuisines today. The sediment, water, and frog tissue samples were collected from 15 different locations of NE Turkey and analyzed to determine the arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), and zinc (Zn) concentrations. The TE concentrations in the sediment, water, and individuals were detected to show significant variations among sampling stations (p < 0.05). Yet, Cd and Pb concentrations of the hind legs cooked and enjoyed in the diets were determined below the European Commission's permitted levels. Furthermore, based on the TEs in edible tissues, consumption of the marsh frog did not appear to pose a risk to humans in terms of provisional tolerable weekly intake (PTWI), target hazard coefficient (THQ), and hazard index (HI).

Amphibian diversity of the Dnipro river within the limits of the Dnipro city agglomeration

Amphibians play an important role in the formation of biodiversity and functioning in most terrestrial and freshwater ecosystems. Urbanization threatens to survive many species due to the destruction of natural ecosystems whose remains become fragmented, isolated, and modified by urbanization processes. The floodplain and coastal ecosystems along both banks of the Dnipro River within the limits of the Dnipro city agglomeration are investigated. The current diversity of amphibians in this territory is represented by six species, which is 55% of the total amount of amphibian fauna of the Dnipropetrovsk region. They are Lissotriton vulgaris, Pelophylаx ridibundus, Pelobates vespertinus, Bombina bombina, Hyla orientalis, and Bufotes viridis. The largest diversity of amphibians was found on the site near the Samara Gulf, where small urbanization and anthropogenic influence are observed. The smallest diversity of amphibians was found for the site of residential community "Pobeda", where only two species of amphibians were revealed. The assessment of the similarity of amphibian communities shows that their diversity is the most similar for ecosystems of the right bank of the Dnipro River near the residential communities "Chervony Kamin", "Pokrovsky", and "Parus" and the ecosystems on the left bank near the Samara Gulf. The most numerous and widespread species is the marsh frog P. ridibundus, which lives along the coastline of the Dnieper River. Its populations are relatively stable according to their high number and distribution. The populations of L. vulgaris, B. bombina, and H. orientalis are under the threat of declining, as evidenced by their low number and dependence on small water bodies. Therefore, the reconstruction of the coastline and any earthwork and building activity should be accompanied by the measures on the preservation of small reservoirs along the Dnieper River. The obtained results develop our knowledge about the actual state of biodiversity and species wealth abundance of the Dnieper River within the northern steppe subzone of Ukraine and may be used for planning of the environmental protection measures.

The reaction of spermaturia in male marsh frogs in the diagnosis of miscarriage

Currently, there are still no perfect clinical methods for early diagnosis of miscarriage, as a result of which the final diagnosis is usually made only after long-term observation of patients. The disappearance of reliable signs of pregnancy does not always solve the problem. The difficulty of diagnosis lies in differentiating a miscarriage from a normal pregnancy, from a threatening and incipient miscarriage.

Growth Layers and Its Complex Structure in a Common Species Under Uncommon Conditions: &lt;i&gt;Pelophylax ridibundus&lt;/i&gt; in the Talysh Mountains

In the Talysh Mountains, the marsh frog, Pelophylax ridibundus (Pallas, 1771), increases its distribution due to human activity. In the mountain forest belt, frogs inhabit flowing ponds with cold spring water. These reservoirs are characterized by a stable temperature regime: the water in them is kept at the level of 10 – 12°C in winter and does not fall below 6°C, and in summer does not rise above 18°C. Probably, the cold flow water of ponds in the mountain-forest belt of Talysh can cause some features of growth and maturation for P. ridibundus. The aim of our work was to study the features of the structure of growth layers including the variation in degree of expression of lines of arrested growth (LAGs) of the marsh frogs in ponds with cold flow water. Frogs were collected in the upper part of the Tangeru River gorge in Sym village of Astara District of Azerbaijan (480 m a.s.l.) in August 2018. In total, we studied skeletochronologically 8 females and 9 males. In contrast to the results of the tubular bones studies in the marsh frog presented in earlier works, the studied individuals are characterized by a more complex and diverse structure in the cross section of shin bones. All the revealed diversity of this structure can be divided into three groups. To the first group are relatively rare cases in which there are growth layers with wintering LAGs and additional growth layers but without additional LAGs. The second group includes more frequent cases in which there are growth layers not only with wintering LAGs but with additional LAGs differing discretely from wintering LAGs. The third group includes the rarest cases where there are growth layers with wintering LAGs and with additional LAGs without discrete difference from wintering LAGs. The revealed high variable structure of growth layers and distinctiveness of LAGs in P. ridibundus can be explained by unusual temperature regime in habitat of studied population and the existence of several activity period during a year. The most continuous period of low temperatures (February and March) corresponds to formation hibernation LAGs and dark rings in growth layers. Besides, period from early December to late January may be so cold that frog growth retard sufficiently or stop completely. The formation of more dark parts of growth layers or even several additional LAGs can correspond to this period.

Frog Reproduction and Community Structure in relation to Water Attributes: Setting the stage to understand effects of Climatic Variables and Climate Change

ABSTRACT As amphibians have declined more than other vertebrates and are important environmental bio-indicators for aquatic ecosystems, we must understand how attributes of such ecosystems affect individual frogs, populations, and multi-species communities. For aquatic-breeding frogs, pond physical/chemical properties influence all life-stages and therefore populations, species, and communities. However, studies have focussed on tadpoles, considered few water variables, and not considered relationships between water attributes and frog populations or communities. Inter-specific differences in how water attributes affect tadpole populations, and hence possibly adult choice of breeding site, should reflect habitats where different species occur, but has been little investigated. We studied the only frog species on Broughton Island, off the east coast of Australia: the threatened Green and Golden Bell Frog Litoria aurea (GGBF); and the widespread and abundant Striped Marsh Frog Limnodynastes peronii (SMF). Suitability of pond breeding habitat, measured by encounter rates during 57 visits over 17 years with different life stages, depended on depth, salinity, pH and temperature, with responses by the two species in essentially opposite directions. For both species, encounter rates increased with increasing depth and with decreasing salinity. Encounter rates peaked at neutral to alkaline pH for GGBF (i.e., 6.8 to 8.0 or higher) and acidic pH for SMF (i.e., 5.5 to 6.0). As water temperature increased, encounter rates increased for GGBF and decreased for SMF. Frog community structure depended on average pond temperature and how it changed over time. If recorded temperature, averaged over the year, was less than 22°C or declined to below this level, the GGBF population, as indexed by numbers of adults observed and occurrences of earlier life stages, was low or declined, while the SMF population was high or increased. This threshold yearly average temperature translates into a required temperature at onset of spring breeding for the GGBF of about 20°C. The GGBF population on the island has declined since 1998, when our study began, due to increased aquatic vegetation and consequent decline in water temperature in major breeding ponds. As ponds are small, manual vegetation removal should reverse the trend. A comprehensive understanding of the biological effects of climate change, past and future, can now be pursued.

SURGICAL MANAGEMENT OF A DIGESTIVE TRACT HERNIA IN A FREE RANGING WILD MARSH FROG (PELOPHYLAX RIDIBUNDUS)

A wild-caught mature female marsh frog (Pelophylax ridibundus) was presented for a left-sided dorsal swelling. No other abnormalities were detected during the examination. Fine needle aspiration was non-diagnostic. Baseline hematological and biochemical analyses were within normal range and medical imaging did not provide further useful information. Surgical exploration under general anaesthesia was performed. The swelling was confirmed to be a digestive tract hernia protruding through a breach of the dorsal muscles and coelomic membrane. Reduction was made difficult by the presence of multiple adhesions between the herniated tissue and the coelomic membrane, suggesting a relatively chronic lesion. A traumatic cause was hypothesised. One month later, the animal was healthy and was released back in the wild. Hernias in amphibians are poorly reported in literature, and are only ventral. To the best of authors’ knowledge, a dorsal hernia has never been described in a captive or a free ranging amphibian before.

Changes in morphological and physiological parameters of adult marsh frogs at different phases of their feeding and breeding technology

The article discusses the possibility of keeping a marsh frog in a farm on the territory of central Russia to obtain delicious meat. For this, at different stages of keeping and after spawning, body weight and length, as well as hematological parameters, were studied. During the study, marsh frogs were kept in different conditions, depending on the season of the year, and fed on different foods. During the summer and early autumn, when kept in a summer enclosure in the air temperature range from 15 to 23 °C, when fed with natural food (live invertebrates) and fed with cultivated cockroaches and flour beetle, a positive increase and an increase in weight was observed. Hematological indices were slightly below the conditional norm, but the number of segmented neutrophils and eosinophils in frogs in the aviary turned out to be quite high, since the natural food they consumed could activate antiparasitic immunity. When the frogs were kept in an aquarium at an air temperature of 22 °C and fed only with cultivated food, the distribution of weight gain and plumb weight was approximately equal. After hibernation at 4 °C, the frogs lost a lot of weight and were placed in a special spawning pool. After hormonal stimulation of frogs with a mixture of drugs “chorionic gonadotropin” and “surfagon”, successful spawning was observed with 100% fertilization of eggs, while the plumb line was small and more uniform. A low number of red blood cells and a low hemoglobin were found in the blood. The total number of neutrophils in frogs kept in the pool decreased, and the number of monocytes increased by 3 times, exceeding the conditional norm by half, which may indicate a monocytic-macrophage reaction necessary for the resorption of remnants of reproductive products. There was also a rapid development of a conditioned reflex in frogs to feeding on a floating feeder, which is an important link in the mechanization of frog farms.

Amino Acid Spectrum in the Blood of the Endemic and Invasive Amphibian Species in the Fauna of the Ural.

For the first time, the results of a comparative analysis of free amino acids in the blood plasma of amphibians of the Ural fauna are presented: an endemic species (Siberian salamander (Salamandrella keyserlingii Dybovsky, 1870)) and an invasive species (marsh frog (Pelophylax ridibundus Pallas, 1771)). The species diversity of adaptive strategies of thermoresistant amphibionts both to negative and positive temperatures is shown.

Synchrotron-Based Imaging Reveals the Fate of Selenium in Striped Marsh Frog Tadpoles.

Synchrotron-based X-ray fluorescence microscopy (XFM) coupled with X-ray absorption near-edge structure (XANES) imaging was used to study selenium (Se) biodistribution and speciation in Limnodynastes peronii tadpoles. Tadpoles were exposed to dissolved Se (30 μg/L) as selenite (SeIV) or selenate (SeVI) for 7 days followed by 3 days of depuration. High-resolution elemental maps revealed that Se partitioned primarily in the eyes (specifically the eye lens, iris, and retinal pigmented epithelium), digestive and excretory organs of SeIV-exposed tadpoles. Speciation analysis confirmed that the majority of accumulated Se was converted to organo-Se. Multielement analyses provided new information on Se colocalization and its impact on trace element homeostasis. New insights into the fate of Se on a whole organism scale contribute to our understanding of the mechanisms and risks associated with Se pollution.

Sensitivity of Quails (Coturnix coturnix), Siskins (Carduelis spinus), and Frogs (Rana ridibunda) to West Nile Virus.

The level of viremia and features of the course of experimental infection caused by West Nile virus were studied in two species of migratory birds, siskins Сarduelis spinus and quails Coturnix coturnix, and in one species of amphibians, frogs Rana ridibunda. In quails, the virus caused a fatal disease; histological analysis revealed pathological changes in the heart, kidneys, liver, and brain stem. In siskins and frogs, virus antigen was detected in cloacal smears despite the absence of clinical manifestations, the level of viremia was sufficient to infect insect vectors during bloodsucking. These findings suggest that siskins and frogs can be potential reservoirs of West Nile virus and play a role in its circulation.

Molecular determinants of protein reabsorption in the amphibian kidneys

Participation of molecular determinants of endocytosis in the processes of glomerular filtration and tubular reabsorption of albumin and lysozyme in the mesonephros of grass frogs (Rana temporaria L.), lake frogs (Rana ridibunda P.), and newts (Triturus vulgaris L.) is investigated. In all studied species, the constitutive expression of endocytic receptors in proximal tubule (PT) cells is established using immunofluorescence microscopy and immunoblotting. The certain stages of lysozyme and albumin endocytosis involving megalin/LRP2, cubilin, clathrin and protein Rab11 are detailed, and the central role of ligand-induced megalin/LRP2 activity in this process is shown. Increased ligand-induced expression for clathrin and Rab11was also found. In grass frogs, the different patterns of endocytic receptors and both absorbed proteins in the initial parts of proximal tubules suggest the proximo-distal specialization of absorptive processes along these tubule segments, similar to this in more complex mammalian nephrons. This data, as well as the revealed peculiarities of ligand-receptor interactions during intracellular trafficking of proteins prove that megalin is mainly involved in the absorption of lysozyme. At the same time, albumin absorption is mediated by both receptors, or cubilin contributes the most. The detection of endocytic receptor in glomerular structural elements in frogs and newts suggests the participation of filtration barrier components in endocytosis of filterable proteins. The results represent a new contribution to the study of the fundamental mechanisms of renal protein uptake in the amphibian mesonephros as a more primitive kidney compared to mammalian metanephros.

Morphological variability of Oswaldocruzia filiformis (Nematoda: Molineidae) in amphibians from European Russia

The morphological and morphometric variability of the nematode Oswaldocruzia filiformis from ten amphibian species (Pelophylax ridibundus, Pelophylax lessonae, Pelophylax esculentus, Rana arvalis, Rana temporaria, Bufo bufo, Bufotes viridis, Pelobates vespertinus, Bombina bombina and Lissotriton vulgaris) was studied. The sampling was performed during the period of 2018–2020 in fifteen localities of European Russia. We examined the following morphological features: the number of crests in mid-body level, the shape of lateral alae, the shape of cephalic vesicle, shape and structure of spicules in males, the shape and structure of male caudal bursa, the shape and structure of the dorsal ray of bursa; and the measurements of nine morphometric characteristics in nematode females and seven characters in males, subjected to variability. Significant differences in the variability of morphometric characteristics of O. filiformis of both sexes in different amphibian species and amphibians from various regions were revealed. Likewise, significant differences were revealed for most of morphometric features of O. filiformis from amphibians of the same species from different regions of Russia. The type of male caudal bursa and the structure and shape of spicules were identical in all O. filiformis males studied. Likewise, we have not found variability in the structure of the reproductive system in O. filiformis females. Variability was noted in the shape and size of the cephalic vesicle and lateral alae, in the number at the mid-body level, in the shape and structure of the dorsal rib of male caudal bursa. Differences in morphometric characteristics of O. filiformis from amphibians of the same species from different regions of Russia can be explained by the phenotypic plasticity of the species. While variations in the nematode morphology from different amphibian species are caused by the host-induced morphological variability of the parasite. Differences in the size of nematodes and their morphology in different regions of Russia studied may be caused by changes in ecological conditions in amphibian habitats. The broad morphological variability of the nematode O. filiformis increases the adaptive capabilities of the helminth and allows it to parasitize a wide range of hosts.

Impact Assessment of the Amur Sleeper Perccottus glenii Dybowski, 1877 on Amphibians in Samara Oblast

The author found that in the study area, an invasive alien species of fish, the Amur sleeper Perccottus glenii, lives in 35 amphibian habitats. Of these, 14 are large water bodies, coastal areas and bays of watercourses, 21 are small water bodies. Larval development is completed by 8 species of tailless amphibians when they have the same habitats with the Amur sleeper. In 4 out of 17 examined populations of the European fire-bellied toad Bombina bombina, the cessation of larval development is noted in syntopic habitats with the Amur sleeper. The author assumes that the distribution of this invasive species is one of the factors in the disappearance of the common newt Lissotriton vulgaris and the European fire-bellied toad Bombina bombina populations in the reservoirs of Samara and Samarskaya Luka National Park. In the natural biotopes the distribution of the Amur sleeper is slower due to the presence of predators-fish and fish-eating reptiles. The marsh frog and the pool frog co-exist with the Amur sleeper; the green toad successfully spawns and undergoes larval development. The absence of common species of helminths confirms the absence of trophic links between the populations of the Amur sleeper and Amphibians in natural habitats of the study area

Isolation and identification of the bacterium producing antitumor and antimicrobial compounds derived from Iranian swamp frog (Rana ridibunda) skin.

Background and Objectives:Cancer incidence and recurrence, antibiotic resistance, and overuse of antibiotics have become a global concern. The purpose of this study was to identify and isolate bacteria from the skin of the Rana ridibunda, Iranian swamp frog, which has produced antimicrobial compounds, and investigate its cytotoxic activity on the breast (MCF7) and glioblastoma (U87) cancer cell line.Materials and Methods:An antibiotic-producing bacterium was isolated from the frog skin. The bacterium was identified based on 16S rDNA sequencing and biochemical and morphological characteristics. Antimicrobial activity of the culture supernatant was examined by disc diffusion and MIC methods. Cytoplasmic and cell wall extracts of bacteria were prepared by sonication. SDS-PAGE was then used to examine protein contents of them. The cancer cell lines were treated with cytoplasmic and cell wall extracts at different concentrations. The effects of cytotoxicity were assessed by MTT assay at 24 and 48 h intervals. Finally, the results were analyzed by SPSS.Results:The isolated bacterium was identified as a new strain of Bacillus atrophaeus. MIC and disc diffusion methods showed that the Bacillus atrophaeus antimicrobial activity was broad spectrum. MTT assay showed IC50 values 30 μg/ml and 20 μg/ml for U87 and MCF7 cells after 24–48 h exposure, respectively.Conclusion:The cytoplasmic extracts of Bacillus atrophaeus has anticancer potential and can be used as an alternative or complementary candidate in the treatment of cancer. Further in vivo and in vitro mechanistic studies are suggested to confirm the biological activities.

Effect of some heavy metals synergism on the longevity and bioaccumulation inside the muscles of frog ridibunda species under the laboratory conditions

Rana ridibunda frogs (Amphibians) are examined under laboratory conditions (10-18 C°) of the aquarium water (tap water), oxygen saturation, non-saturation and starvation. Body weight for two groups of frogs were (260-285 gr) and (58-115 gr). Two types of heavy metals effect were examined (single type and mixed types) of Cdcl2 and HgSo4 used. Longevity as LT50% and LT100% were determined by single heavy metals effect and synergism effect for both oxygen saturated and oxygen non-saturated waters experiments were conducted, then the bioaccumulation inside the legs muscles of the frog were examined for the heavy metals poisoning media (2PPT) concentration. Synergism effects were very clear and differences of O2 saturation were giving clear different results.

Anatomical histological structure of the cerebellum in the Iraqi frog Rana ridibunda ridibunda

The current study was designed to investigate the histological structure of the cerebellum in the Iraqi frog Rana ridibunda ridibunda. The cerebellum was removed surgically from 20 Iraqi frogs, Rana ridibunda ridibunda, and preserved in fixative of 10% formalin solution for a period of 72 hr, then the histological sections were prepared by the method of paraffin. The results of the study showed that the cerebellum of the adult Iraqi frog is one of the rhombencephalon regions, and consists of three layers, molecular layer, purkinje cells layer, and granular layer. The present histological findings suggest that the cerebellum of the Iraqi frog is very similar to that of other vertebrates, Therefore it represents the basic rule in understanding the histological formation of the cerebellum.

Comparison of sperm parameters and testis histological structure in lake frog (Pelophylax ridibundus) from areas with different level of anthropogenic pollution

The aim. The aim of the work was to study the indicators of spermatogenesis in the lake frog, Pelophylax ridibundus (Pallas, 1771), in the zone of the influence of emissions from the Burshtyn Thermal Power Plant (TPP).&#x0D; Materials and methods. Urinal sperm and testes samples were taken from male frogs under conditions of anthropogenic pollution (Burshtyn industrial area). Such parameters as sperm concentration in ejaculate, the number of live spermatozoa, total amount of actively mobile forms, and percentage of spermatozoa with progressive motion were determined by calculations in the hemocytometer. Testis samples were processed for routine histological method. The diameter of seminiferous tubules and histological abnormalities were studied.&#x0D; Results. Studies have revealed that near the Burshtyn TPP industrial site, the sperm concentration in the sperm sample and the total number of motile spermatozoa of the lake frogs significantly decreased. The number of dead spermatozoa increases. Amphibians from polluted sites had histological abnormalities in testes such as dilation of the seminiferous tubules with sparse sperm. At the same time, the diameter of the seminiferous tubules in the animals from polluted site significantly decreased.&#x0D; Conclusions. The impact of the emissions from the Burshtyn thermal power plant has an expressive reprotoxic effect that is manifested by depressive changes in testes tissue and gametes. The reproductive system of the lake frog is quite sensitive to environmental pollution. Sperm parameters and histological changes in testes are informative biomarkers and can be used for bioindication of technogenically transformed territories