Green Toad Bufo Research Articles

Влияние КВЧ-излучения на частоту микроядер и ядерных аномалий в эритроцитах личинок амфибий

The level of technogenic non-ionizing electromagnetic radiations of various frequencies constantly grows in the biosphere. Therefore, studies of these radiations influence on biological organisms are very actual. The purpose of the work was to study the consequences of prolonged exposure to EHF radiation on the stability of the genome of anurans. Larvae of the green toad (Bufo viridis) were subjected to EMR at four different EHF frequencies (34.52, 34.67, 34.79, and 35.04 GHz with an energy flux density of 4.88, 5.33, 4.94, and 3.76 mW/cm2, respectively) for 120 hours. After irradiation the frequencies of micronuclei (MN) and nuclear anomalies (NA) in peripheral blood erythrocytes of tadpoles were studied. EHF radiation with a frequency of 34.52 GHz induced a small and statistically insignificant increase in the frequency of MN and NA. Exposure to EHF radiation at frequencies of 34.67, 34.79, and 35.04 GHz caused a statistically significant increase in the frequency of MN and NA in tadpole erythrocytes. A statistically significant increase of the frequency of MN and NA in anuran larvae erythrocytes after exposure to EHF radiation proves a certain danger of an increasing level of EMR in the biosphere, as well as the need for further studies of the effect of non-ionizing radiation on the genomes of lower vertebrates.

Morphological Deformities of Green Toad (Bufo viridis) Tadpoles Caused by Petroleum Products

Morphological Deformities of Green Toad (Bufo viridis) Tadpoles Caused by Petroleum Products

The effects of water and bottom sediments from Lake Balkash (Central Asia) on early development of fish and amphibians

The effects of water and bottom sediments from Lake Balkash (Central Asia) on early development of fish and amphibians

Growth and development of the green toad (Bufo viridis) from the water bodies of the oil producing regions of Kazakhstan

Growth and development of the green toad (Bufo viridis) from the water bodies of the oil producing regions of Kazakhstan

Особенности научения жаб Bufo viridis в поведении, требующем учета границ собственного тела

The goal of this work was to study the ability of the green toad Bufo viridis to form skills based on tactile sensations arising in the process of interaction between animal’s body and external objects. During the experiment we varied the proportions of the holes in the experimental setup, through which the animal penetrated, and the limits of the animal bodies by attaching blankets to their body with an extraneous object. It was found that toads can to take into account the natural limits of their own body when interacting with external objects, and also transfer this experience in a situation where the proportions of the holes in the experiment setup was varied. When the limits of the toad body were urgently changed so that these changes prevent the animals from penetration into certain types of holes, these animals did not learn to take into account the fact that the holes previously permeable to the natural limits of their bodies became impenetrable after increasing these limits. We state that these data indicate that the toads even before the experiment began had experience of taking into account the natural boundaries of their bodies. But toads are not able to modify their body schema, when the limits of their bodies are urgently increased.

Impacts of temperature on growth, development and survival of larvalBufo (Pseudepidalea) viridis(Amphibia: Anura): implications of climate change

The changing global climate poses a new threat to amphibian populations since amphibian growth and development are strongly influenced by temperature. In general, low temperature reduces their physiological processes, decreasing development and growth rates. However, metamorphs of some amphibian species may be larger than their conspecifics grown at high temperatures. The increased temperature can reduce the metamorphic size in some species, whereas in other species, high temperatures accelerate growth with no changes in body size at metamorphosis. In order to test the influence of water temperature on larval growth, development and survival of the green toad Bufo viridis, 200 eggs were raised separately at two different water temperatures (18 and 21 °C) for the period of 16 weeks. The results show that the larvae reared at high temperature reached metamorphosis significantly faster (86.58 ± 13.47 days) than those reared at low temperature (105.4 ± 7.83 days). However, the larvae reared at high temperature showed a significant increase in survival rate (64% ± 34.22) compared to the larvae reared at low temperature (23.57% ± 4.18). The growth rate of the larvae reared at higher temperature was higher than that of the larvae reared at low temperature but this difference was not significant. In contrast, the average size at metamorphosis (SVL) at low temperature was significantly larger (19.05 ± 1.12 mm) compared with that of the individuals that metamorphosed at the relatively higher temperature (16.11 ± 1.54 mm).

A Single Transcriptome of a Green Toad (Bufo viridis) Yields Candidate Genes for Sex Determination and -Differentiation and Non-Anonymous Population Genetic Markers.

Large genome size, including immense repetitive and non-coding fractions, still present challenges for capacity, bioinformatics and thus affordability of whole genome sequencing in most amphibians. Here, we test the performance of a single transcriptome to understand whether it can provide a cost-efficient resource for species with large unknown genomes. Using RNA from six different tissues from a single Palearctic green toad (Bufo viridis) specimen and Hiseq2000, we obtained 22,5 Mio reads and publish >100,000 unigene sequences. To evaluate efficacy and quality, we first use this data to identify green toad specific candidate genes, known from other vertebrates for their role in sex determination and differentiation. Of a list of 37 genes, the transcriptome yielded 32 (87%), many of which providing the first such data for this non-model anuran species. However, for many of these genes, only fragments could be retrieved. In order to allow also applications to population genetics, we further used the transcriptome for the targeted development of 21 non-anonymous microsatellites and tested them in genetic families and backcrosses. Eleven markers were specifically developed to be located on the B. viridis sex chromosomes; for eight markers we can indeed demonstrate sex-specific transmission in genetic families. Depending on phylogenetic distance, several markers, which are sex-linked in green toads, show high cross-amplification success across the anuran phylogeny, involving nine systematic anuran families. Our data support the view that single transcriptome sequencing (based on multiple tissues) provides a reliable genomic resource and cost-efficient method for non-model amphibian species with large genome size and, despite limitations, should be considered as long as genome sequencing remains unaffordable for most species.

Effects of salinity stress on Bufo balearicus and Bufo bufo tadpoles: Tolerance, morphological gill alterations and Na+/K+-ATPase localization

Freshwater habitats are globally threatened by human-induced secondary salinization. Amphibians are generally poorly adapted to survive in saline environments. We experimentally investigated the effects of chronic exposure to various salinities (5%, 10%, 15%, 20%, 25%, 30% and 35% seawater, SW) on survival, larval growth and metamorphosis of tadpoles from two amphibian populations belonging to two species: the green toad Bufo balearicus and the common toad Bufo bufo. In addition, gill morphology of tadpoles of both species after acute exposure to hypertonic conditions (20%, 25%, and 30% SW) was examined by light and electron microscopy. Tadpoles experienced 100% mortality above 20% SW in B. balearicus while above 15% SW in B. bufo. We detected also sublethal effects of salinity stress on growth and metamorphosis. B. bufo cannot withstand chronic exposure to salinity above 5% SW, tadpoles grew slower and were significantly smaller than those in control at metamorphosis. B. balearicus tolerated salinity up to 20% SW without apparent effects during larval development, but starting from 15% SW tadpoles metamorphosed later and at a smaller size compared with control. We also revealed a negative relation between increasing salt concentration and gill integrity. The main modifications were increased mucous secretion, detachment of external layer, alteration of epithelial surface, degeneration phenomena, appearance of residual bodies, and macrophage immigration. These morphological alterations of gill epithelium can interfere with respiratory function and both osmotic and acid-base regulation. Significant variations in branchial Na+/K+-ATPase activity were also observed between two species; moreover an increase in enzyme activity was evident in response to SW exposure. Epithelial responses to increasing salt concentration were different in the populations belonging to two species: the intensity of histological and ultrastructural pathology in B. bufo was greater and we noticed the appearance in exposed samples of the tubular vesicle cells (TVCs). Taken together, our results demonstrated that increased salinity of freshwater may give cause for concern and must be considered a stressor for amphibians as well as other pollutants.

Fatal chytridiomycosis and infection loss observed in captive toads infected in the wild

A parasitic fungus,Batrachochytrium dendrobatidisis now recognised as an important factor in the amphibian biodiversity crisis. Toad species of the genusBufoare among those susceptible to infection by the pathogen in Europe. The aim of this study was to observe the presence and impact of infection in adults of two toad species collected for captive breeding. The total number of animals included in the study was 162, but only subsets were used for sampling at different occasions (35 specimens in the initial sampling in summer 2011, 48 post hibernation during winter 2011, and 31 in summer 2012, after all toads in captivity were treated with itraconazole). We performed TaqMan real-time quantification PCR to detect and quantify the pathogen. We found that a large infection load was linked to mortality in a single adult green toad (Bufo viridis). However, low infection loads observed in fiveB. viridisand five natterjack toads (B. calamita)were lost over time, with no apparent adverse effect. Intraconazole treated animals were all clear of infection. As infection in these two toad species either led to mortality or recovery, it seems unlikely they could act as permanent carriers ofB. dendrobatidisand therefore persistence of the pathogen is likely maintained by different host species. This is the first study to date that has detected infection and observed its impact and persistence in wild-infected toads in Europe.

Population divergence of life history traits in the endangered green toad: implications for a support release programme

There is an increasing awareness that adaptive differences among local populations may affect the success of translocation programmes. A mismatch in habitat quality of the target localities and in the local adaptations of the translocated individuals may reduce the success rate of the translocation programme. The green toad Bufo viridis is the most threatened amphibian in Sweden and has been the focus of an extensive translocation programme of eggs, tadpoles and juvenile toads to several localities with apparently favourable conditions for green toads. However, the success of these measures has been poor. In this study, we investigated the extent of local adaptation in the green toad by examining population divergence and the effect of thermal and saline conditions on larval performance in four Scandinavian populations. In a common garden experiment, we measured larval survival and development as well as the occurrence of spinal deformations. In addition, we quantified pond temperature and water salinity, two important environmental variables for larval performance in anurans in the breeding ponds as well as in seven additional localities included in the conservation programme. We found significant variation among the localities in water temperature and salinity, and significant among-population divergence in larval life history traits and spinal deformations, including both trait means and plastic responses to salinity and temperature. The available evidence suggests that at least part of this divergence is adaptive. We did not find direct support for local adaptation affecting the success of the translocations, however, we argue that the population origin and the impact of rearing conditions on the fitness-related larval traits should be taken into account in the introduction measures of the Swedish green toad conservation programme as well as in translocation programmes in general.

Nordens Ark - a university conservation field station

Nordens Ark is a non-profit foundation aiming to provide self-sustainable viable populations of threatened species through conservation breeding and reintroduction programmes. In 2001, an important decision was made to be part of a scientific society with close contacts to universities, and to appoint a professor in conservation biology as the scientific leader. Together with the universities, new programmes were developed where traditional academic knowledge could be combined with the experience and practical hands-on knowledge of the zoo world. Components of these programmes are held at Nordens Ark on a contracted basis. Nordens Ark has developed international research schools together with Gothenburg University, and conservation aspects of threatened wild animal species and domestic breeds provide the overarching theme. Nordens Ark has successfully taken part in breeding and reintroduction programmes for, among others, the White-backed woodpecker Dendrocopos leucotos, the Peregrine falcon Falco peregrinus, the Lesser white-fronted goose Anser erythropus, the Green toad Bufo viridis and the Fire-bellied toad Bombina bombina. Nordens Ark has also been contracted by national and international conservation authorities or organizations to ensure that the best possible conservation measures are taken when conflicts arise between infrastructure projects and the conservation of threatened species.

First report of a green toad ( Bufo viridis sensu lato) in the Early Pleistocene of Spain: Palaeobiogeographical and palaeoecological implications

For the first time unequivocal fossil remains of a green toad ( Bufo viridis s.l.) are described in the Iberian Peninsula. The fossils come from the Cueva Victoria site, a late Early Pleistocene (ca. 1.1–1.2 Ma) karstic filling in semi-arid southeastern Spain (Murcia region). By extension, other remains from two other Early Pleistocene Spanish localities, Barranco León D (ca. 1.3 Ma) and Almenara-Casablanca 3 (ca. 1.1 Ma), are cautiously attributed to the group B. viridis. The B. viridis group was previously reported with some uncertainty to the west of its current distribution area in Western Europe (Spain and France) in the Pliocene ( Bufo cf. viridis) and less probably in the Early Miocene ( Bufo aff. viridis). Since no osteological differences have been established between the recently described extant species of B. viridis s.l. (e.g. Bufo balearicus, Bufo siculus, Bufo boulengeri, B. viridis sensu stricto and Bufo variabilis) no precise palaeobiogeographical relationships can be drawn for the Spanish fossils. However, the occurrence of a third species of bufonid toad during the Pleistocene in the South of the Iberian Peninsula raises some interesting ecological questions in relation to the local disappearance of the green toad, which can be hypothetically linked to the intensification of the Pleistocene glacial/interglacial climate dynamic or to probable competition with another toad, Bufo calamita.

Thirteen polymorphic microsatellite markers for the European green toad Bufo viridis viridis, a declining amphibian species

We report 13 new polymorphic microsatellite markers for the European green toad Bufo viridis viridis (B. viridis subgroup), a declining amphibian from Central, Southeastern and Eastern Europe. Diversity at these loci estimated for 19 individuals ranged from two to ten alleles. Most of these primers also cross-amplify in related West-Mediterranean green toad species (Bufo balearicus, B. siculus and B. boulengeri). These microsatellites will be useful for conservation genetics of threatened Bufo viridis viridis populations and evolutionary studies of green toad taxa in secondary contact to examine hybridization.

Foraging Response to Risks of Predation and Competition in Artificial Pools

Although ecologists have learned much about the influence of competitors and perceived risk of predation on foraging in terrestrial systems by measuring giving-up density (GUD, the amount of food left behind in a resource patch following exploitation), GUDs have rarely been used in aquatic environments. Here we use foraging activity (proportion foraging) and GUDs to assess the effects that two periphyton consumers and potential competitors, green toad (Bufo viridis) tadpoles and mosquito (Culiseta longiareolata) larvae, have on each other. We also examine the effects of perceived risk of predation imposed by a dragonfly nymph (Anax imperator). To do so, we conducted an artificial pool experiment and developed a food patch appropriate for measuring GUDs for periphyton grazers. MoreCulisetaindividuals foraged in rich food patches than in poor patches.Bufoshowed a similar tendency. FewerBufoforaged in both patch types in the presence of cagedAnax. Culisetashowed a similar tendency. However, in the rich patches, onlyBuforeduced foraging activity when the caged predator was present. BothBufoandCulisetadepleted food patches through exploitation, resulting in lower GUDs. Both competitors together resulted in lower GUDs than did food depletion of each species alone. However, the presence of cagedAnaxhad little or no effects on GUDs. Overall, bothBufoandCulisetarespond to food and safety. They are able to direct foraging effort to richer patches and devote more time to those patches, and they respond to predation risk by choosing whether or not to exploit resource patches.

Amphibians of Gniezno

From 2005 to 2007 the water bodies in the area of Gniezno have been controlled to establish amphibian species composition and their number. Thirty four of water bodies were under observation. In 23 among them (67.6%) the following species of amphibians were present: common frog Rana temporaria, moor frog Rana arvalis, “water frogs” Rana esculenta complex, common spadefoot, fire-bellied toad Bom- bina bombina, common toad Bufo bufo; green toad Bufo viridis; and smooth newt Tritunis vulgaris. “Water frogs” and common frog formed the largest populations. Great crested newt Tritunis cristatus, natterjack toad Bufo calamita, and tree frog Hyla arborea were not observed.

Amphibian communities in small water bodies in the city of Olsztyn

The aims of the study were determine the effects of anthropogenic pressure on the species composition and population size of amphibians of small water bodies in Olsztyn city (NE Poland). The presence of 11 amphibian species was noted in 83.5% of water bodies. The dominants were: the common frog Rana temporaria, the edible frog Rana esculenta, the pool frog Rana lessonae, the common toad Bufo bufo and the moor frog Rana arvalis. The fire-bellied toad Bombina bombina was an influent, while the common newt Triturns vulgaris, the common spadefoot Pelobates fnsciis, the tree frog Hyla arborea, the green toad Bufo viridis and the crested newt Tritimis cristatus were the recedents. The most frequent were “green frogs”, which occur in 71.9% of water bodies inhabited by amphibians (60.0% of all water bodies). The species characterized by the lowest occurrence frequency were the tree frog (6.0% and 5.0%, respectively), the green toad (5.4% and 4.5%) and the crested newt (3.6% and 3.0%). In the paper the urban pressure on amphibian communities is widely discussed.

In vitro cardiotoxicity and mechanism of action of the Egyptian green toad Bufo viridis skin secretions

Amphibian skin secretions are considered a rich source of biologically active compounds and are known to be rich in bufadienolides, peptides and alkaloids. Bufadienolides are cardioactive steroids derived from animals and plants as well. The current study was conducted to investigate the influence of skin secretions of the Egyptian green toad Bufo viridis (SSBV) on the cardiac electrical activity. Isolated toad’s heart was used to reveal the mechanism of action. Application of SSBV (40 μg/ml) into isolated toad’s heart significantly decreased the heart rate (HR) accompanied by an elongation in the conduction time (P–R interval). A pronounced increase of the ventricular contraction (R-wave amplitude) was observed after SSBV application. Marked electrocardiographic changes were induced within minutes (5–20 min) of SSBV perfusion of the isolated hearts; such as sinus arrhythmias, junctional ectopic beats, negative QRS deflection, ventricular tachycardia and heart block. The mechanism of action of SSBV was studied by direct application of different autonomic and ion channels antagonists (atropine sulphate, propranolol and verapamil) to isolated toad’s heart. Neither atropine nor verapamil could attenuate the noticed negative chronotropic and positive inotropic effects. Meanwhile, post-treatment with propranolol decreased R-wave amplitude. Taken together, it can be concluded that: (i) SSBV has a negative chronotropic, dromotropic and positive inotropic effects on isolated toad’s heart; (ii) the reported effects of SSBV could be due to inhibition of Na +–K + ATPase and through ß-adrenergic receptors.

Direct and indirect effects of dragonfly (Anax imperator) nymphs on green toad (Bufo viridis) tadpoles

We conducted an artificial pond experiment to assess the direct and indirect effects of predation on Bufo viridis tadpoles. We ran three treatments: free Anax (unrestrained predatory dragonfly nymph Anax imperator), caged Anax (non-consumptive effects), and control (no Anax). Anax showed both strong consumptive and non-consumptive effects on Bufo tadpoles. Free Anax eliminated all of the tadpoles within six days. Tadpoles preferred the shady side of the ponds. Caged Anax caused tadpoles to increase their spatial preferences. Tadpoles avoided the center of the pond, and in the presence of the caged predator, they were found in the center even less. Tadpoles also showed a strong preference for crowding together, and in the presence of a caged Anax, they tended to crowd more. Moreover, Bufo metamorphosed earlier and at a larger size in the caged Anax ponds, possibly by providing extra food resources due to the extra organic matter excreted by the predators.

Changes in Heat Resistance of the Muscle and Glycerinated Muscle Fibers of Green Toad (Bufo viridis complex)

Heat resistance of muscles and actomyosin proteins was determined at damaging temperatures of 41, 42, and 43 degrees C in three green toad (Bufo viridis complex) populations from different climatic zones of Uzbekistan. The highest muscle and model resistance to these temperatures was revealed in toads living in the warmest plain regions of the country, while the lowest resistance was specific for animals from the piedmont and mountain regions. The variability of heat resistance of the muscle and models was also the highest in toads of the first group. Divergence going in this animal species is proposed.

Distribution of amphibians and reptiles in central Poland: 1980-2000

Based on 3047 records from 97 recorders distribution maps were drawn for the amphibians and reptiles of central Poland (lirom 51°00’N to 52°15’N and from 18°20’E to 20°20’E). The study area was divided into 180 atlas fields based on the geographic grid. All data were gathered in 1980-2000, most of them (67%) however, in 1995-2000. 13 taxa of amphibians were found in 143 atlas fields and 6 species of reptiles were found in 121 atlas fields. The amphibians were (given with the number of atlas fields with the species found): 119 - Common frog Rana temporaria Linnaeus, 1758; 114 - Common toad Bufo bufo (Linnaeus, 1758); 97 - Moor frog Rana arvalis Nilsson, 1842; 94 - Fire-bellied toad Bomhina bombina (Linnaeus, 1761); 93 - Pool frog Rana lessonae Camerano, 1882; 87 - Tree frog Hyla arhorea (Linnaeus, 1758); 85 - Green toad Bufo viriiüs Laurenti, 1768; 72 - Smooth newt Triturus vulgaris (Linnaeus, 1758); 70 - Spadefoot Pelobales fuscus (Laurenti, 1768); 69 - Edible frog Rana kl. esculenia Linnaeus, 1758; 39 - Great crested newt Triturus cristatus (Laurenti, 1768); 30 - Marsh frog Rana ridibunda Pallas, 1771 and 28 - the Natterjack Bufo calamita Laurenti, 1768. The reptile species (given with the number o f atlas fields) were: 94 - Sand lizard Lacerta agilis Linnaeus, 1758; 72 - Slow-worm Anguis fragilis Linnaeus, 1758; 67 - Common lizard Lacerta vivipara Jacquin, 1787; 60 - Grass snake Natrix natrix (Linnaeus, 1758), 57 - Adder Vipera berus (Linnaeus, 1758) and 4 - the Smooth snake Coronella austriaca Laurenti, 1768. Six adult specimens of the European pond terrapin Emys orbicularis (Linnaeus) were also found, but breeding of this species in the area studied was not confirmed.