Bufo Melanostictus Research Articles

Inter-population variation in thermal sensitivity of the tropical toad Duttaphrynus melanostictus, across a small spatial scale in Sri Lanka.

Inter-population disparities in a species have been shown to occur as an adaptation to different thermal regimes in the environment. We investigated the thermal sensitivities of the tropical toad Duttaphrynus melanostictus (Asia Common Toad) from two populations at different altitudes: Nuwara-Eliya - 1870m, and Polonnaruwa - 25m, above mean sea level. The two locations were separated by what may be considered a short direct distance - 110km. Thermal sensitivity trials were conducted at six temperatures between 12 and 39°C. Assessments were made using the performance indicators jump distance, jump force, contact time on the test plate following stimulus to jump, and righting time after being overturned. Optimum performance is taken to be the greatest jump distance and jump force, the least contact time on the test plate, and the least righting time. The populations at the two altitudes had markedly different thermal sensitivities - toads in the cool area (Nuwara-Eliya) performed at an optimal level under low temperatures, whereas the toads in the warm area (Polonnaruwa) performed optimally under high temperatures. The finding that the thermal optima (i.e., the temperatures at which the optimal performance for the four performance indicators was recorded) of the toads in Polonnaruwa were below the mean maximum ambient temperature at this location suggests that these toads would be more susceptible to global warming than those in Nuwara-Eliya whose thermal optima were above the mean maximum ambient temperature in that location. This was consistent with the narrower thermal safety margin (i.e., difference between the mean optimum temperature and mean ambient temperature) of toads in Polonnaruwa, compared to those in Nuwara-Eliya. Importantly, these findings demonstrate that, although thermal sensitivity is considered a conservative trait, differentiation does occur even over a small spatial scale presumably because it offers an adaptive advantage to the population concerned.

Morphological description of Opalina obtrigonoidea Metcalf, 1923 (Heterokonta, Opalinea) from Duttaphrynus melanostictus and evaluation of the ITS region as a suitable genetic marker for inter-species identification in Opalina.

The redescription of Opalina obtrigonoidea Metcalf, 1923, collected from the rectum of the toads Duttaphrynus melanostictus, is presented in this paper based on detailed morphological information and molecular data. Our results revealed that O. obtrigonoidea varies greatly in body dimensions. Its morphological characteristics allow its differentiation from Opalina undulata. Surprisingly, we sequenced its SSU rDNA-ITS1-5.8S rDNA-ITS2-LSU rDNA (5' end) and found the SSU rDNA of O. obtrigonoidea is nearly identical to that of O. undulata. However, there are differences in both the ITS1 and ITS2 regions that allow their distinction and confirm the morphological differences. Our results indicate that O. obtrigonoidea and O. undulata are closely related species in which morphological and genetic markers have evolved at different speeds. Due to this, the SSU rDNA gene may not be a valid marker for inter-species identification in Opalina, but the ITS is a valid marker for differentiating species in this genus.

Morphological characteristics of tadpole and bioacoustic of species Black-spined toad Duttaphrynus melanostictus (Schneider, 1799) in Vinh City, Nghe An Province

This article showed the results of research on morphological characteristic and metamorphosis of a larval tadpole to juveniles and bioacoustic of adult male individuals of Black-spined toad Duttaphrynus melanostictus (Schneider, 1799) in Nghe An Province. During the reproductive period, the activity of calling a partner happens before it rains from 1 to 3 days, pairing when it rains. The body of tadpoles of Black-spined toad is black, small size, the labial tooth row formula is I(1+1)/III. The time of metamorphosis from stage 34 to stage 46 take from 13 to 16 days, at average temperature of 28.30C. In the reproduction season, adult male make the sound with duration 8.118 ± 3.985 (s), including 68.60 ± 28.08 pulses, the dominant frequency of pulses of 1522.262 ± 59.674 (Hz), the max power of pulses from 92.90 ± 105.10 (dB).

Comparative Analysis of Anti-predator Behaviour and Life History Traits of the Tadpoles Exposed to Predation Risk and Corticosterone

Anuran tadpoles show behavioural and morphological alterations in the presence of predatory cues (perceived predation risk). Recent studies suggested the possible role of stress hormone corticosterone (CORT) in anti-predator responses. We speculated that the anti-predator responses of prey tadpoles exposed to predation risk and CORT will be similar if they are mediated through CORT. In the present study, we compared behavioural and life history responses of Duttaphrynus melanostictus tadpoles exposed to (i) predatory tadpoles of Hoplobatrachus crassus, and (ii) two concentrations (1 and 10 µg/L) of CORT. The results revealed that exposure of the tadpoles to predation risk and CORT have similar effects on behaviour and life history traits. Tadpoles exposed to predation risk and CORT did not alter behaviour in response to alarm cues. Tadpoles exposed to predation risk and different concentrations of CORT delayed metamorphosis with a reduction in size. CORT influenced metamorphosis and size of the tadpoles in concentration dependent manner. These results suggest that the presence of non-lethal predators affects life history traits possibly through the stress hormone.

Oxidative stress markers and antioxidant defense in hibernating common Asian toads, Duttaphrynus melanostictus

Paper description: In hibernating common Asian toad, in spite of metabolic depression, low body temperature, and slow breathing, oxidative stress was observed. Oxidative stress markers were at higher levels in liver and brain tissues. Increased lipid peroxidation, protein carbonylation and oxidized/reduced glutathione ratio were accompanied by augmented non-enzymatic antioxidant defense which counteracts the oxidative assault in liver and brain tissues during hibernation. Abstract: To assess the oxidative assaults and antioxidant defense, oxidative stress markers, including lipid peroxidation level, protein carbonylation level, GSSG/GSH ratio and nonenzymatic antioxidants such as total glutathione, ascorbic acid and uric acid, in liver and brain tissues of hibernating common Asian toads, Duttaphrynus melanostictus , were compared with toads during active periods. Oxidative stress was found in both liver and brain tissues of hibernating common Asian toads in spite of depressed metabolism and low oxygen consumption. Significantly higher lipid peroxidation, protein carbonylation and an increased GSSG/GSH ratio were found in liver and brain tissues of hibernating toads, indicating oxidative stress. To counteract the stress, ascorbic acid was increased significantly in the liver and brain tissues of hibernating individuals in comparison to individuals during active periods. The uric acid level decreased in both the liver and brain tissues of hibernating toads, which may be due to its decreased rate of synthesis because of low xanthine oxidase activity at low body temperature and hypometabolism. The common Asian toad faced oxidative stress during hibernation, which was counteracted by augmented nonenzymatic antioxidant defense. https://doi.org/10.2298/ABS190605062S Received: June 5, 2019; Revised: August 24, 2019; Accepted: September 9, 2019; Published online: September 25, 2019 How to cite this article: Sahoo DD, Patnaik P. Oxidative stress markers and antioxidant defense in hibernating common Asian toads, Duttaphrynus melanostictus . Arch Biol Sci. 2020;72(1):23-30.

A Comparison of Somatic Condition and Testis Mass in Black-Spectacled Toad (Duttaphrynus melanostictus) between Two Populations at Different Altitudes

A Comparison of Somatic Condition and Testis Mass in Black-Spectacled Toad (Duttaphrynus melanostictus) between Two Populations at Different Altitudes

The first record of the Asian common toad Duttaphrynus melanostictus Schneider, 1799 in Abu Dhabi, United Arab Emirates

The first record of the Asian common toad Duttaphrynus melanostictus Schneider, 1799 in Abu Dhabi, United Arab Emirates

Invasive toads are close to but absent from Komodo National Park

The islands of Komodo National Park in the Wallacea region are the habitats of Komodo dragon (Varanus komodoensis). Although the Wallacea islands have lower species richness compared to the other large islands in Indonesia, they are rich in endemics, and the occurrence of invasive species would therefore threatened the ecological, economic and social balance of the regions. Several papers have hinted at the possibility of the invasion of Komodo National Parks by Asian toads, a situation which would potentially affect the survival of the Komodo dragon. To detect the presence of the invansive toad Duttaphrynus melanostictus in Komodo National Park and its surroundings areas we carried out an amphibian survey using a Visual Encounter Survey method during February to April 2018. The surveyed location consisted of two main islands within Komodo National Park (Rinca island and Komodo island), Flores island (Labuan Bajo and Cumbi village) and Sumbawa island (Sape). Two species of amphibians were found in Komodo National Park (Rinca island and Komodo island), while seven species of amphibians were found across all four locations. No D. melanostictus toads were found in Flores (including in Komodo National Park), however the toad was found to be abundant in Sape (Sumbawa island).

Habitat Characteristics and Amphibians Conservation in Lombok Island

The previous study stated that there are 12 species of Amphibians found in Lombok Island, Indonesia. Four of which are the endemic species of Lesser Sunda Islands, namely Oreophryne monticola, Limnonectes kadarsani, Limnonectes dammermani dan Hylarana florensis. However, the information regarding the habitat characteristic which supports animal survival is limited. This study aimed to explore the types of habitat characteristics according to amphibian diversity in the Island of Lombok. The survey study was conducted at 9 locations (3 of habitat type) from March to July 2016. The collected data includes species composition and a sum of individuals of species. Amphibian diversity was analyzed using relative abundance and the Shannon-Wiener index. This study revealed that the nonforest habitat type was appropriate for five species, while secondary and primary forest habitat type was appropriate for seven species. Diversity of species index directly proportional to a natural level of habitat (H’ Nonforest = 1.3; H’ Secondary Forest = 1.7; H’ Primary Forest = 1.8). The highest species abundance was Bufo melanostictus (23.9%), and the lowest species abundance was Oreophryne monticola (0.9%). According to the distribution and relative abundance, the species that require conservation priorities are Oreophryne monticola and Hylarana florensis.

Keanekaragaman katak dan kodok (Amphibia: Anura) di Suaka Margasatwa Paliyan, Gunungkidul, Yogyakarta

Frogs and toads commonly found by human. Frogs and toads could become a bio-indicator of anenvironment. Paliyan Wildlife Sanctuary is a forest area which posses several animal to protect and it’slocated in Gunungkidul Regency, Province of DIY. The diversity of frogs and toads in this wildlifesanctuary is not yet recorded and published. The aim of this research is to understand the diversity of frogsand toads in the area of Paliyan Wildlife Sanctuary. The results there were 9 species of frogs and toads, i.e.,Duttaphrynus melanostictus, Ingerophrynus biporcatus, Fejervarya limnocharis, Kaloula baleata,Occidozyga lima, Occidozyga sumatrana, Microhyla orientalis, Microhyla palmipes and Polypedatesleucomystax. The diversity of frogs and toads in the wildlife sanctuary is moderate according to theShannon-Wiener Index with value: 1,43. Area of Paliyan Wildlife Sanctuary is a suitable habitat for frogsand toads due to its location with dense forest, bushes, rivers, lakes and pools as well as least humanactivities.

INVENTARISASI AMFIBI RESORT CISARUA TAMAN NASIONAL GUNUNG GEDE PANGRANGO BERDASARKAN MUSIM YANG BERBEDA

This study aims to inventory amphibians in the Cimisblung Resort Cisarua Gede Pangrango National Park (TNGGP) the rainy season and dry season. Amphibian data collection was carried out in February - August 2019 in and night (19.00 - 23.00 WIB) days using a visual encounter survey method along 500 meters with the river flow aquatic) and terrestrial among others, below the surface of litter, rock, weathered wood, and in the bush. Amphibians were to view and record their morphology, then matched the images with amphibian identification books. After the next step was identified, the amphibian was photographed for documentation. If amphibians are not identified in the field, the amphibians are taken to the Cibinong Zoology LIPI to be identified. The results obtained were 13 species (Leptobrachium haseltii, Megophrys montana, Duttaphrynus melanostictus, Leptophyryne cruentata, Rhacoporus javanus, Philautus aurifasciatus, dan Nycxtixalus margaritifer, Rana calconata, Huia masonii, Oddorana hosii, Limnonectes kuhlii, Fejevarya limnocharis, Fejevarya limnocharis, and Limnonectes microdiscus) with a difference in the number of species of 5 species between the rainy and dry seasons such as (Leptobrachium haseltii, Duttaphrynus melanostictus, Leptophyryne cruentata, Philautus aurifasciatus, and Nycxtixalus margaritifer).

New aliens in Australia: 18 years of vertebrate interceptions

Abstract ContextAustralia has a high diversity of endemic vertebrate fauna. Yet, transnational human activities continue to increase the rate of transportation, introduction and establishment of new alien vertebrates in Australia, to the detriment of environmental and socioeconomic services. Eradication of invasive vertebrates is often costly and without guarantee of success; therefore, methods for detecting, intercepting and preventing the transport of alien species earlier in the invasion pathway provide substantial benefit. AimTo anticipate emergent threats to Australian biosecurity posed by the transport and introduction of new alien vertebrates over time. MethodsWe collated vertebrate interception data from various mainland Australian State, Territory and Commonwealth government reporting agencies, including data from a previously published study, at both pre-border and post-border stages from 1999 to 2016. Using generalised linear and generalised additive modelling, we predicted trends in interception frequency using predictors such as vertebrate taxa, detection category and alien status. Key resultsInterception frequency increased over time for all vertebrate classes, for pre-border stowaways and for post-border captive and at-large interceptions, with no saturation in the accumulation of new species over time. Five species were responsible for almost half of all incidents, of which red-eared sliders (Trachemys scripta elegans), boa constrictors (Boa constrictor) and corn snakes (Pantherophis guttatus) are prominent in Australia’s illegal alien pet trade. Rose-ringed parakeets (Psittacula krameri) are prominent in the legal alien cage-bird trade, which remains poorly regulated. Asian common toads (Duttaphrynus melanostictus) were frequently detected as stowaways, and most stowaway incidents originated from Southeast Asia, particularly Indonesia, via shipping. Data deficiency for pre-border incidents increased rapidly in 2015 and 2016. ConclusionsAustralia is subject to a persistent and increasing risk of alien vertebrate introductions and incursions over time, owing partly to emergent trends in the alien pet trade as well as increased global trade and tourism. ImplicationsThe future of Australia’s biosecurity remains dependent on stringent border security to prevent the arrival of novel species, but our findings also highlight the importance of ongoing management and control of high-risk species already present, often illegally, within Australia.

Geographic body size variation of a tropical anuran: effects of water deficit and precipitation seasonality on Asian common toad from southern Asia

BackgroundTwo previous studies on interspecific body size variation of anurans found that the key drivers of variation are the species’ lifestyles and the environments that they live in. To examine whether those findings apply at the intraspecific level, we conducted a study of the Asian common toad (Duttaphrynus melanostictus), a terrestrial anuran distributed in tropical regions. The body size of toads from 15 locations, covering the majority of their geographic range, and local environmental data were summarized from published literature. We used a model selection process based on an information-theoretic approach to examine the relationship between toad body size and those environmental parameters.ResultsWe found a positive correlation between the body size of the Asian common toad and the water deficit gradient, but no linkage between body size and temperature-related parameters. Furthermore, there was a positive correlation between the seasonality of precipitation and body size of females from different sampled populations.ConclusionsAs a terrestrial anuran, the Asian common toad should experience greater pressure from environmental fluctuations than aquatic species. It is mainly distributed in tropical regions where temperatures are generally warm and stable, but water availability fluctuates. Therefore, while thermal gradients are not strong enough to generate selection pressure on body size, the moisture gradient is strong enough to select for larger size in both males and females in dryer regions. Larger body size supports more efficient water conservation, a pattern in accordance with the prediction that lifestyles of different species and their local habitats determine the relationship between body size and environment. In addition, larger females occur in regions with greater seasonality in precipitation, which may happen because larger females can afford greater reproductive output in a limited reproductive season.

A food spectrum analysis of three bufonid species (Anura: Bufonidae) from Uttarakhand region of the western Himalaya, India

The ecological diversity of insects and its predators like amphibians are important determinants in ecological balance. A total of 1,222 prey items in 84 specimens were examined to contribute the understanding of the diets of three Duttaphrynus species, viz., himalayanus, melanostictus, and stomaticus from Uttarakhand, the western Himalaya, India. Gut content analysis of three bufonids revealed acceptance of a wide range of terrestrial insects and other invertebrates as their food. The index of relative importance indicated that the most important preys were Formicidae, Coleoptera and Orthoptera. Duttaphrynus melanostictus had the broadest dietary niche breadth, followed by D. himalaynus and D. stomaticus. The wide prey spectrum well indicates that these species are the generalist and opportunist invertebrate feeder. Information pertaining to the food spectrum analysis contributes to understanding the ecological roles and used as a baseline data for future successful amphibian conservation and management programs in the Himalayan ecosystem.

Proteomic analysis of soluble proteins retrieved from Duttaphrynus melanostictus skin secretion by IEx-batch sample preparation

Amphibians display a toxic secretion that works as chemical defenses against predators and/or microorganisms that is stored in specialized glands located in the tegument. For some animals, such glands have accumulated in specific regions of the body and formed prominent structures known as macroglands. The Bufonidae family displays conspicuous macroglands in a post-orbital position, termed parotoids, which secretions are known to be extremely viscous and rich in alkaloids and steroids. Few proteins have been described in this material, though. Mainly, because of the difficulties to handle such biological matrix. In this context, we have performed a proteomic study on the parotoid macrogland secretion of the Asian bufonid Duttaphrynus melanostictus. By employing the Ion-Exchange (IEx)-batch chromatography (anionic, cationic and both) we obtained six fractions - bound and unbound – that were submitted to an in solution-trypsin digestion followed by LC-MS/MS. Proteins related to: antioxidant activity, binding processes (carbohydrate/lipid/protein), energy metabolism, hydrolases, lipid metabolism and membrane traffic were identified. Moreover, IEx was able to preserve the biological activity of the retrieved proteins (peptidasic). The current study increases the knowledge on the proteins present in the bufonids parotoid macrogland secretion, providing a better understanding of the physiological role played by such molecules. SignificanceThe current approach allowed a detailed proteomic analysis of the several proteins synthesized in the D. melanostictus parotoid macrogland (Bufonidae) that are secreted into the skins, but embedded within a complex viscous biological matrix. Moreover, our results aim to increase the knowledge on the biological role played by such proteins at the skin.

The protection of indolealkylamines from LPS-induced inflammation in zebrafish

Ethnopharmacological relevanceToad skin came from Bufo bufo gargarizans Cantor and Bufo melanostictus Schneider. As the traditional Chinese medicine, it had the effect of clearing away heat and detoxification. In traditional applications, toad skin was often used for the treatment of cancer and inflammation. Total indolealkylamines (IAAs) from this medicine were proved the main compounds exert anti-inflammatory activity in our previous research. Aim of the studyIn the present study, we aimed to investigate the potential mechanism of anti-inflammatory activity of IAAs on LPS induced zebrafish. Materials and methodsLPS induced zebrafish was applicated as an in vivo inflammation model to clarify the structure-activity relationship of 4 major IAAs (N-methyl serotonin, bufotenine, dehydrobufotenine and bufothionine) from toad skin. Quantitative RT-PCR was applied to detect key cytokines and members of the MyD88-dependent signaling pathway. In addition, the targeted lipidomics was conducted to find out the potential biomarkers in the inflammatory zebrafish. Network pharmacology was used to unveil the main enzymes closely related to the target lipids. ResultsOur results showed that the anti-inflammatory activity of free IAAs (N-methyl serotonin, bufotenine and dehydrobufotenine) was more potent than that of combined IAAs (bufothionine). RT-PCR demonstrated that 4 IAAs exerted antiendotoxin inflammatory effect via suppressing the TLR4/MyD88/NF-κB and TLR4/MyD88/MAPKs signaling pathway. A total of 33 possible inflammatory biomarkers, including 14 SM, 6 Cer, 11 PC and 2 GlcCer, triggered by LPS were screened out. The levels of most of candidates could be regulated toward a normal level by IAAs, especially in N-methyl serotonin and dehydrobufotenine groups. Enzymes especially LBP, PLA2, CERK, SMPD and SGMS were found closely associated with the regulation of most lipid markers. ConclusionsOverall, the mechanism underlying the anti-inflammatory activity of IAAs probably attributed to their capability to suppress NF-κB and MAPKs inflammatory pathway. Meanwhile, IAAs could also interfere the metabolism of SM, Cer and PC probably by regulating LBP, PLA2, CERK, SMPD and SGMS.

Record of Some Digeneans, Infecting Freshwater Fishes, Snails, and Amphibians in India, Using 28S Ribosomal DNA Marker

Eleven species of digenetic trematodes are recorded herein in an attempt to chart the trematode biodiversity in Kakraiya Lake of District Barabanki, U.P., infecting freshwater fishes, snails, and frogs. The species are Opisthorchis attuai and Isoparorchis hypselobagri from Wallago attu; Diplostomulum minutum from Heteropneustes fossilis; Buchephalopsis karvai from Xenentodon cancila; Cephalogonimus mukerjius, and Kaurma sp. from Pila globosa; Pseudodiplodiscoides murtyi from Bellamya bengalensis; Mesocoelium sociale from Duttaphrynus melanostictus; Diplodiscus amphichrus, Halipegus mehransis, and Halipegus barabankiensis n.sp. from Euphlyctis cyanophlyctis. Among the eight species considered as valid so far O. attuai, I. hypselobagri, M. sociale, B. karvai, P. murtyi, D. amphichrus, H. mehransis and C. mukherjius have been described well only at the adult stage, whereas the morphology of D. minutum, and Kaurma sp. at the metacercarial stage has been described, which further awaits to trace their life cycle. The present results show that H. barabankiensis represents distinct entities from a molecular and morphological point of views, which leads to the description of a new species. All these trematode species were subjected to morphological, morphometric, and molecular analysis. Partial nucleotide sequences of the 28S ribosomal gene were obtained from these trematode species and deposited in the GenBank. The phylogenetic reconstruction based on the 28S rRNA gene placed the studied species within the respective families, and their validity is discussed.

Urinary corticosterone metabolite responses to capture and visual elastomer tagging in the Asian toad (Duttaphrynus melanostictus)

Herpetological research involving amphibians is increasingly using mark and recapture methods, employing various techniques such as toe-clipping and visible implant alphanumeric tags. Visual Implant Elastomer (VIE) is a new method available for herpetological surveys, involving a coloured dye inserted into the epidermal skin surface of frogs. Previously, there has been only one study which demonstrated that the VIE method does not generate a significant physiological stress response (using a faecal glucocorticoid method) in a captive amphibian species. Physiological stress can also be quantified non-invasively using urinary corticosterone metabolite (UCM) enzyme-immunoassay in amphibians. In this study, we tested the physiological stress response of a common amphibian species, wild caught Asian toads (Duttaphrynus melanostictus), by comparing UCM responses to capture handling, sham control or VIE marking method. Adult males (n = 38) were captured and sampled for baseline UCM (t = 0 h) then marked either using the VIE or sham (saline control), or only handled during capture. Subsequently, urine samples were collected at t = 2, 12 and 24 h for toads within each group. UCM levels were quantified using an enzyme immunoassay (EIA) to determine differences among treatment groups and over time following capture. Toads generated acute stress responses to all three groups, showing a change in UCMs between baseline samples, 12 h, and 24 h samples. The mean UCM levels were not significantly different between the VIE method and the control groups (capture handling or sham operated). These results indicate that VIE method of tagging is no more stressful than routine handling of amphibians, hence in this context, the method does not have any additional welfare implications. Future research should explore the limitations of VIE tagging for long-term mark recapture studies, however, our current findings support its application as a minimally-invasive method for marking amphibians.

Assemblage and Diversity of Anurans in Two Forests of the Western Ghats

The Western Ghats of India being a hotspot of biodiversity, amphibian population deserves precise and systematic exploration. In the present study, we evaluated the pattern of occurrence of anurans (during monsoon, post-monsoon and summer) in two forest ecosystems (evergreen and semi-evergreen) of the Western Ghats of Karnataka. Abiotic factors (air/water/soil temperature, humidity, illumination, canopy cover and litter thickness) in the forests chosen were assessed. The frequency of occurrence, diversity, evenness and expected number of species of anurans were calculated by standard methods. A total of 22 and 15 species of anurans was recorded in the evergreen and semi-evergreen forests, respectively. Species richness and diversity were higher in the evergreen forest than semi-evergreen forest. The diversity of anurans was higher during wet seasons (monsoon and post-monsoon) than dry season (summer). The rarefaction indices also revealed higher expected number of species during monsoon and or post-monsoon seasons than summer season. The anuran population composed of widespread, endemic and endangered species. The most frequent species of anurans recorded in this study include Clinotarsus curtipes, Duttaphrynus melanostictus, Euphlyctis cyanophlyctis, Fejervarya sahyadris, Hoplobatrachus tigerinus and Sylvirana temporalis. Among the anuran assemblage, Fejervarya sahyadris, Pseudophilautus wynaadensis, Raorchestes charius and Rhacophorus lateralis have been considered as the endangered species. The present study constitutes a baseline data on the anurans of Western Ghats of Karnataka.

Effect of controlled Nickel exposure on Duttaphrynus melanostictus oxidative stress and its management

This study mainly focuses on the effect of a common heavy metal poisoning and how the oxidative stress is managed in Duttaphrynus melanostictus during Nickel poisoning. The subject, Duttaphrynus melanostictus was exposed to Nickel in regular frequency with a very small amount by creating moist environment which imitates the presence of Nickel in soil due to pollution and then the body weight analysis (by ANOVA and Post Hoc analysis (using SPSS package 16.0)) and skin coloration and pigmentation were checked at 24 hours interval to study the oxidative stress and its management by the animal's physiological system. The initial change in skin color at early stages of nickel exposure and then its restoration was observed. Similarly the loss of body weight at initial exposure and then its stabilization after some days was noted. The analysis and observations revealed that the antioxidant system of Duttaphrynus melanostictus is well developed to sustain against the oxidative stress due to nickel exposure.