Bufo Melanostictus Research Articles

First report of Seuratascaris numidica Seurat, 1917 (Nematoda: Ascarididae) and other helminths from amphibians of West Bengal, India.

Studies on nematode parasites from anuran hosts from Eastern India, particularly West Bengal, are rare. To our knowledge, there is a report of larvae of Monhysterides sp. (a fish parasite) from cysts within the body cavity and musculature of Duttaphrynus melanostictus, Hoplobatrachus tigerinus and Euphlyctis hexadactylus as well as descriptions of Aplectana duttaphryni from D. melanostictus, Aplectana dubrajpuri from H. tigerinus, Cosmocerca microhylae from Microhyla rubra and Rhabdias bulbicauda from D. melanostictus. Here, we report mature individuals of typical anuran parasites, Diplodiscus amphichrus and Seuratascaris numidica, from H. tigerinus and larvae of Acuariidae (a bird parasite) from Fejervarya limnocharis collected in Kulti, West Bengal.

Repeated Detection of an Invertebrate Iridovirus in Amphibians

Abstract Invertebrate iridoviruses (IIVs) (family: Iridoviridae) are known pathogens for invertebrates, causing high mortality and reduced fertility in affected insects. Over the past two decades, IIVs have also been increasingly found in lizards in association with nonspecific clinical signs. It has been hypothesized that IIVs from insects can also infect reptiles. From 2010–11, IIVs were repeatedly detected via polymerase chain reaction testing and virus isolation methods in routine diagnostic samples from different amphibians: three blue poison dart frogs (Dendrobates tinctorius azureus), four edible frogs (Pelophylax kl. esculentus), a giant ditch frog (Leptodactylus fallax), an Amazon milk frog (Trachycephalus resinifictrix), mixed organs from agile frogs (Rana dalmatina), a black-spined toad (Bufo melanostictus), and one Lake Urmia newt (Neurergus crocatus). IIVs were found in skin swabs from apparently healthy animals, as well as in multiple organs of frogs that died of unknown causes. Prey insects...

Effect of Furadan and Malathion on Size and Morphology of Blood Cells of <I>Duttaphrynus melanostictus</I>

Effect of Furadan and Malathion on Size and Morphology of Blood Cells of <I>Duttaphrynus melanostictus</I>

Deep genetic structure and ecological divergence in a widespread human commensal toad

The Asian common toad (Duttaphrynus melanostictus) is a human commensal species that occupies a wide variety of habitats across tropical Southeast Asia. We test the hypothesis that genetic variation in D. melanostictus is weakly associated with geography owing to natural and human-mediated dispersal facilitated by its commensal nature. Phylogenetic and population genetic analyses of mitochondrial and nuclear DNA sequence variation, and predictive species distribution modelling, unexpectedly recovered three distinct evolutionary lineages that differ genetically and ecologically, corresponding to the Asian mainland, coastal Myanmar and the Sundaic islands. The persistence of these three divergent lineages, despite ample opportunities for recent human-mediated and geological dispersal, suggests that D. melanostictus actually consists of multiple species, each having narrower geographical ranges and ecological niches, and higher conservation value, than is currently recognized. These findings also have implications for the invasion potential of this human commensal elsewhere, such as in its recently introduced ranges on the islands of Borneo, Sulawesi, Seram and Madagascar.

Biochemical Modulations in Duttaphrynus melanostictus Tadpoles, Following Exposure to Commercial Formulations of Cypermethrin: An Overlooked Impact of Extensive Cypermethrin use

Extensive application of pesticides in agricultural and domestic zones has contributed to environmental contamination globally. With aquatic bodies being ultimate recipients of pesticide residues, the inhabiting fauna are known to be largely affected due to their proximity and inevitable exposure. The present investigation was aimed to examine the effect of sublethal (1.11 µg/L) concentration of cypermethrin on biochemical cluster of tadpoles of Duttaphrynus melanostictus. Significant changes were observed in total, soluble and structural protein fractions following cypermethrin exposure to subacute (1, 2, 4 and 6 days) durations in whole animal biochemical composition of Duttaphrynus melanostictus. Marked elevation in free amino acid level was observed at all the exposure tenures. Generation of reactive oxygen species with endpoint induction of oxidative stress were evidenced by decrease in activity of catalase, glutathione-S-transferase and increased levels of hydrogen peroxide, reduced glutathione and malodialdehyde levels. The outcome clearly suggests the increased susceptibility of Duttaphrynus melanostictus tadpoles to sublethal concentrations of cypermethrin, thus implicating the toxicant to possess detrimental health effects on Duttaphrynus melanostictus species. The study may contribute in environmental monitoring and assessment of water bodies with possible cypermethrin contamination.

A nano-organo catalyzed route towards the efficient synthesis of benzo[b]pyran derivatives under ultrasonic irradiation

Organocatalyst crafted on silica supported ferrite nanoparticle (Fe2O3@SiO2@VB1) for 4H-benzo[b]pyrans synthesis.

Tadpoles of three common anuran species from Thailand do not prey on mosquito larvae.

Tadpoles are often considered to be predators of mosquito larvae and are therefore beneficial for the control of certain disease vectors. Nevertheless, only a few species have actually been recorded to prey on mosquito larvae. The mosquito larvae predation rates of tadpoles of three common Thai anuran species (Bufo melanostictus, Kaloula pulchra and Hylarana raniceps) were experimentally tested. Tadpoles in varying developmental stages were used to assess a size/age effect on the predation rate. In addition, different instars of Culex quinquefasciatus were used in order to assess a prey size effect on the predation rates. All three species failed to show any evidence of mosquito larvae predation. Neither small nor large tadpoles fed on mosquito larvae. Prey size also did not affect predation. Although tadpoles do not feed on mosquito larvae, there may be other direct or indirect inter-specific interactions that adversely impact the development of larvae in shared habitats with tadpoles.

Sexual dimorphism in baseline urinary corticosterone metabolites and their association with body-condition indices in a peri-urban population of the common Asian toad (Duttaphrynus melanostictus)

Field endocrinology research through the quantification of glucocorticoids or stress hormones in free-living wildlife is crucial for assessing their physiological responses towards pervasive environmental changes. Urinary corticosterone metabolite (UCM) enzyme–immunoassay (EIA) has been validated for numerous amphibian species as a non-invasive measure of physiological stress. Body-condition indices (BCIs) have also been widely used in amphibians as an indirect measure of animal health. Field endocrinology research on amphibian species in Asia is limited. In this study, we validated a UCM EIA in a peri-urban sub-population of the common Asian toad (Duttaphrynus melanostictus) in Pune, Maharashtra, India. We determined the baseline levels of UCMs in male (n=39) and female (n=19) toads. Secondly, we used a standard capture handling protocol to quantify changes in UCMs during short-term captivity. We also determined BCIs in the male and female toads using Fulton's index (K) and residual condition index (RCI). The results showed that mean baseline levels of UCMs were significantly higher in male toads than in females. There was no significant change in mean levels of UCMs of males and females between capture and captivity (0–12h). This highlights plausible habituation of the species to the peri-urban environment. Associations between UCMs with BCIs (K and R) were positive in male toads but negative in females. In conclusion, our UCMs EIA can be applied with BCIs to assess health of the Asian toads. We also suggest that direct fitness parameters such as sperm and oocyte quality, reproductive ecology and immunocompetence measurements should be applied in combination with these conservation physiology tools to quantify the fitness consequences of pervasive environmental changes on native amphibians.

Evolution of erythrocyte morphology in amphibians (Amphibia: Anura)

We compared the morphology of the erythrocytes of five anurans, two toad species - Bufo gargarizans (Cantor, 1842) and Duttaphrynus melanostictus (Schneider, 1799) and three frog species - Fejervarya limnocharis (Gravenhorst, 1829), Microhyla ornata (Dumeril & Bibron, 1841), and Rana zhenhaiensis (Ye, Fei & Matsui, 1995). We then reconstructed the ancestral state of erythrocyte size (ES) and nuclear size (NS) in amphibians based on a molecular tree. Nine morphological traits of erythrocytes were all significantly different among the five species. The results of principal component analysis showed that the first component (49.1% of variance explained) had a high positive loading for erythrocyte length, nuclear length, NS and ratio of erythrocyte length/erythrocyte width; the second axis (28.5% of variance explained) mainly represented erythrocyte width and ES. Phylogenetic generalized least squares analysis showed that the relationship between NS and ES was not affected by phylogenetic relationships although there was a significant linear relationship between these two variables. These results suggested that (1) the nine morphological traits of erythrocytes in the five anuran species were species-specific; (2) in amphibians, larger erythrocytes generally had larger nuclei.

Temperature-dependent acute toxicity of methomyl pesticide on larvae of 3 Asian amphibian species.

Relative to other animal taxa, ecotoxicological studies on amphibians are scarce, even though amphibians are experiencing global declines and pollution has been identified as an important threat. Agricultural lands provide important habitats for many amphibians, but often these lands are contaminated with pesticides. The authors determined the acute toxicity, in terms of 96-h median lethal concentrations, of the carbamate pesticide methomyl on larvae of 3 Asian amphibian species, the Asian common toad (Duttaphrynus melanostictus), the brown tree frog (Polypedates megacephalus), and the marbled pygmy frog (Microhyla pulchra), at 5 different temperatures (15 °C, 20 °C, 25 °C, 30 °C, and 35 °C) to examine the relationships between temperature and toxicity. Significant interspecific variation in methomyl sensitivity and 2 distinct patterns of temperature-dependent toxicity were found. Because high proportions of malformation among the surviving tadpoles were observed, a further test was carried out on the tree frog to determine effect concentrations using malformation as the endpoint. Concentrations as low as 1.4% of the corresponding 96-h median lethal concentrations at 25 °C were sufficient to cause malformation in 50% of the test population. As the toxicity of pesticides may be significantly amplified at higher temperatures, temperature effects should not be overlooked in ecotoxicological studies and derivation of safety limits in environmental risk assessment and management.

KOMPOSISI MAKANAN (DIET) DUA SPESIES KODOK BUFO MELANOSTICTUS, SCHNEIDER (1799) DAN BUFO ASPER, GRAVENHORST (1829) DI DARATAN TINGGI DAN DATARAN RENDAH SUMATERA BARAT

An abiotic factor is one of the different factors in the composition of food, including frogs. The purpose of this research was to determine the composition of the diet or the food and habitat Two Toads Species Bufo (Phrynoides) asper and Bufo (Duttaphrynus) melanostictus in the Highlands and Lowlands of West Sumatra. The sampling used direct collecting method on the site (Ruler and Iskandar, 2003) and research method refers to methods of Sole et.al. (2005) by analyzing the stomach contents of frogs and counting the number and type of animals eaten. Results of the analysis describes the comparison of animals eaten by frog based on the type and location of the research. The results show that the composition of the highest food contained in the stomach B. melanostictus derived from Plateau. Most insects eaten by frogs are ordo of Hymenoptera of the family Formicidae. Food composition ratio between the two frog species show that B melanostictus has the highest food composition compared to B. asper.

Nematodes of amphibians from Java, Indonesia, with a description of new species, Meteterakis wonosoboensis n. sp. (Nematoda : Heterakoidea).

During a survey on the parasites of amphibians of Indonesia, toads (30 Bufo melanostictus) and 246 frogs (213 Fejervarya cancrivora, 11 F. limnocharis, 22 Rana macrodon from West Java and 68 F. cancrivora from Central Java) were examined for parasitic nematodes. Three species of nematodes were found and described, i.e. Meteterakis wonosoboensis n. sp. from Fejervaria cancrivora; Meteterakis japonica from Bufo melanostictus, F. cancrivora and F. limnocharis; and Chabaudus sp. from F. cancrivora, F. limnocharis and Rana macrodon. Meteterakis wonosoboensis n. sp. is distinguished from other species of the genus by the length and shape of spicules, the number of caudal papillae, the presence of gubernaculum in male and the presence of vulval flap in female. Bufo melanostictus and Java are recorded as new host and locality for M. japonica, respectively.

The New Toad in Town: Distribution of the Asian Toad, Duttaphrynus Melanostictus, in the Toamasina Area of Eastern Madagascar

In March 2014, the Asian toad Duttaphrynus melanostictus was reported from Madagascar's second largest city and main port Toamasina, raising immediate concerns about the invasive nature of the newly introduced toad and its environmental impact should it spread throughout the island. As part of a study on the feasibility of eradication, we conducted 516 interviews and 120 visual encounter surveys between April and November 2014. We found the toad to be widespread to the south and west of city center and estimate its minimum range to include an area of at least 108 km2. Social surveys indicate that the toad may have already been present for some years and potentially introduced prior to 2010, with the site of its introduction likely south of Toamasina near National Route 2 and the Ambatovy Plant. We discuss limitations of our survey methodology, proposed improvements for future work, and the implications of our results on eradication and control measures.

Malathion acute toxicity in tadpoles of Duttaphrynus melanostictus, morphological and behavioural study

The present study was undertaken to evaluate the median lethal concentration (LC50), morphological deformities and changes in behavioural responses caused by commercial formulations of malathion on Duttaphrynus melanostictus tadpoles. The LC50 value was found to be 7.5mg/l and ability of malathion to cause morphological anomalies and changes in behavioural responses in tadpoles were studied at sublethal concentrations of 0.5mg/l (1/15th), 0.75mg/l (1/10th) and 1.5mg/l (1/5th) for a duration of 5days. The morphological defects and changes in behavioural responses like notochord curvature and loss of fright response respectively were witnessed as an important conduct; in addition, other symptoms under both the parameters were known to be time (i.e. developmental stage) and concentration dependent thereby acknowledging the direct cause of damage due to malathion. Thus, based on the present study, care must be taken when this chemical is in use at agricultural sites especially nearby aquatic ecosystems.

Do habitat variables correlate anuran abundance in arid terrain of Rawalpindi–Islamabad Areas, Pakistan?

The quantification of anuran abundance and habitat provides valuable baseline data for future monitoring in areas of planned or anticipated human activities. We carried out the present study to see if anuran abundance is associated with habitat variables (water quality, gravel size and vegetation) in Rawalpindi–Islamabad Area, Pakistan. We used area-constrained searches and quadrat method to gather data on anuran abundance and vegetation diversity, respectively, from September, 2012 to July, 2013. We recorded 28±4.83 (mean number±SE) individuals of six anuran species from the study area. We recorded Euphlyctis cyanophlyctis (10±2.39) as the most abundant anuran species while Microhyla ornata (<1±0.09) as the least abundant species. The Kernel regression revealed strong and statistically significant association between habitat variables and abundance of Hoplobatrachus tigerinus (R2=0.678) and Bufo stomaticus (R2=0.624) but weak and statistically significant association between habitat variables and abundance of E. cyanophlyctis (R2=0.482); Duttaphrynus melanostictus (R2=0. 451); M. ornata (R2=0.223) and Limnonectes limnocharis (R2=0. 006). We concluded that the common frogs and toads in our area belong to families Dicroglossidae and Bufonidae while uncommon frogs are of family Microhylidae. We suggest inclusion of monitoring of water quality (dissolved oxygen and pH) and maintenance of native wild vegetation particularly herbs, shrubs and hydrophytes of the area in the on-going and proposed development schemes of Rawalpindi–Islamabad Areas.

Detection of antidiabetic activity by crude paratoid gland secretions from common Indian toad (bufomelano stictus).

Background:Amphibians have provided a remarkable array of biological active compounds, which are secreted from socalled granular skin glands which serve to protect the amphibians from predators due to its noxious effects on buccal tissue and at least in the case of some peptides, to protect from bacterial (or) protozoan infections. Given the respiratory and antimicrobial functions of amphibian skin, it is likely that some of the novel molecules found in amphibian granular gland secretions might be of use in the treatment of skin and respiratory infections. Secretions from common Indian toad (Bufo melanostictus) a member of Bufonidae family has the history of medicinal use however the anti-diabetic activity is not reported. The present study is aimed to determine whether paratoid gland extract have any influence on the diabetes and the pharmacokinetics and pharmacodynamics of glimepiride (GLM) in normal and diabetic rats.Materials and Methods:An aqueous and methanolic extracts of paratoid glandular secretions were prepared, air dried and used to determine the antidiabetic activity in rats. The blood sampling was done at preset time intervals between 0, 0.5, 1, 2, 4, 6, 8 and 12 h, using heparinized capillaries. The blood glucose levels are estimated by glucose oxidase-peroxidase method, and reversed-phase high-performance liquid chromatography is used to determine the pharmacokinetic parameters of GLM using glibenclamide as an internal standard.Results:Both the aqueous and methanolic extracts produced better glycemic control in diabetic rats, and methanolic extract is better than the aqueous extract. Serum concentrations of GLM increased at 2nd h, and the percentage glucose reduction is maximal at the 4th h with both aqueous and methanolic extracts of paratoid secretions of common Indian toad.Conclusions:Paratoid gland secretions of the common Indian toad is antidiabetic, in addition it has beneficial effects in combination with GLM. Further, it requires the systematic structure elucidation of the compounds and pharmacokinetic studies to explore the beneficial effects.

Influence of Some Environmental Parameters on Some Frog Populations and their Parasitc Fauna

Wild animals, including frogs are usually infected with several species of parasites. Frogs are important for a variety of reasons. Firstly, they control populations of insects and secondly they can act as indicator species to the environment. Studies have shown that frogs can harbor many species of parasites. Worldwide, there were numerous researches carried out on frog parasites but few had been reported from Malaysia. From this study, 300 frogs from 14 species were collected from eight study sites: Duttaphrynus melanostictus, Phrynoidis aspera, Hylarana erythraea, H. labialis, H. nigrovittata, Polypedates leucomystax, Fejervarya cancrivora, F. limnocharis, Limnonectes blythii, L. paramacrodon, L. ibanorum, L. ingeri, Microhylabutleri, and Kaloulapulchra. Eleven (11) helminthic parasites (Heterakis spp., H. vesicularis, Trichostrongylus spp., Pharyngodon spp., Ascaris spp., Oswaldocruzia spp., Rhabdias spp.,Glypthelmins staffordi, Diplodiscusm sacculosus, Manodistomum spp., and Macracanthorynchus spp.), eight blood parasites (a rickettsia, Hepatozoon spp.,Haemogregarina spp., Lankesterella spp., Trypanosoma loricatum, T. rotatorium, T. chattoni, and microfilaria) and one protozoa (Nyctotherus spp.) were recorded from frogs. There were correlations between the presence of helminthic parasites and distribution of rainfall, as well as between blood parasites and Biochemical Oxygen Demand (BOD) of water.

Understanding the ultrastructural aspects of berberine-induced skin-darkening activity in the toad, Bufo melanostictus, melanophores

Berberine is an active compound of Berberis vulgaris (Daruhaldi) with known multiple pharmacological activities, including antimicrobial, antiviral, anti-inflammatory, cholesterol-lowering, and anticancer effects. The present work aimed to study the ultrastructural effects of berberine to determine its skin-darkening potential using Bufo melanostictus melanophores, which has not been done to date. Light and electron microscopic analysis of isolated dorsal skin melanophores of B. melanostictus has been done after treatment with various concentrations of berberine, along with specific antagonists and agonists of β-adrenoceptors in order to explore the mechanism of action of berberine-induced skin darkening. The results showed that the number of melanophores with melanin-loaded dendrites increased in the subepidermal layer significantly in berberine-treated skin pieces in a dose-dependent manner leading to skin darkening. Highly electron-dense melanosomes of Stage IV increased considerably due to the enhanced process of melanization. These effects were found to be antagonized by propranolol, and were also found to be highly potentiated by isoprenaline, which is a specific β-adrenoceptor agonist. The findings show that berberine possesses a skin-darkening potential and could be used as a safe melanogenic agent for the treatment of hypopigmentation disorders or vitiligo.

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