RESUMO
Amphibians are constantly exposed to pollutants and the stress of agricultural activities. We selected three anuran amphibian species Dendropsophus minutus, Boana albopunctata, and Physalaemus cuvieri, totaling 309 individuals. We collected tadpoles in 15 permanent ponds: 5 soybean crops, 3 corn crops, and 7 nonagricultural lands. Our study provides the first comparative data on the genotoxicity and mutagenicity of three common amphibian anurans. Dendropsophus minutus was the most vulnerable species compared with B. albopunctata and P. cuvieri for comet assay and micronuclei test. However, the more significant amount of DNA damage seen in D. minutus does not mean that their populations are threatened once such species adapt well to anthropogenic disturbances. Despite, P. cuvieri was less sensitive than the other two species; the DNA damage was significantly higher in soybean crops. Physalaemus cuvieri is a leptodactylidae species that deposit their eggs in foam nests, which are essential to protect eggs from dehydration. Moreover, the foam reduces the contact of eggs with water; thus, P. cuvieri eggs could be less exposed to contaminants present in pounds, compared with D. minutus and B. albopunctata, which deposit their eggs directly in the water. Therefore, this study was sufficiently sensitive to detect genotoxic and mutagenic effects in tadpoles exposed to agroecosystems. We strongly suggest D. minutus in future biomonitoring studies that involve the comparison of anthropized versus not anthropized environments. Overall, we recommend the comet assay and micronucleus test as effective methods for the detection of genotoxic damage in amphibian anurans to the environmental disturbance, especially in agricultural sites.
Assuntos
Anuros/genética , Ensaio Cometa/métodos , Testes para Micronúcleos/métodos , Agricultura , Animais , Brasil , Dano ao DNA/efeitos dos fármacos , Ecossistema , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Larva/efeitos dos fármacos , Larva/genética , Lagoas , Glycine max , Poluentes Químicos da Água/toxicidade , Zea maysRESUMO
Cytogenetic data can be useful for taxonomic and phylogenetic studies, as well as to provide information about chromosome evolution. Therefore, it may help design conservation priorities for some threatened species, such as anurans. Herein, we describe the karyotypes of Scinax constrictus and Ololygon centralis, native endemic species from the Brazilian Cerrado. Chromosome preparations for both species were stained with Giemsa for morphological analyses and then impregnated by the Ag-NOR method for localization of the nucleolar organizer region (NOR). Both species had 24 chromosomes, as confirmed by meiotic analyses, which showed 12 bivalents. Chromosome morphologies presented the same pattern for Scinax and Ololygon compared to species already karyotyped in both genera. The NOR was interstitially located in the long arm of pair 7 in S. constrictus, whereas in O. centralis it was found near the centromere in the long arm of pair 1, thus diverging from what is commonly found for other Ololygon species. Therefore, we provide the first description of the karyotype of O. centralis and the first report of the localization of the NOR for the karyotype of both species. Our study increases the cytogenetic knowledge in species of the genera Scinax and Ololygon, and provide support for further studies on the taxonomy, ecology, and evolution of hylid anurans.
RESUMO
Worldwide, the indiscriminate and escalating application of pesticides has led to extensive impacts on both the environment and non-target organisms. Phytoremediation, which employs plants to decontaminate environments, is a potential strategy for the mitigation of this damage. The present study assessed the phytoremedial potential of Salvinia auriculata, an aquatic macrophyte known to be effective for the removal of environmental contaminants. In the laboratory, Dendropsophus minutus tadpoles were exposed to different concentrations (0.035, 0.1, 1.0, and 1.5 mg/l) of the commercial insecticide Fipronil 800wg in two treatments - (i) simple exposure for 96 h, and (ii) exposure for 168 h in aquariums containing S. auriculata. In the first experiment, a mortality rate of 33.3 % was recorded at the highest Fipronil concentration (1.5 mg/l), and genotoxic parameters increased at all concentrations except 0.035 mg/L, in comparison with the control. In the second experiment, phytoremediation occurred at all the concentrations tested, with lower frequencies of cells with micronuclei, and binucleated, anucleated, and pyknotic nuclei being observed, in comparison with the first experiment. These findings highlight the potential effectiveness of S. auriculata for the phytoremediation of environments contaminated by pesticides and contribute to the understanding of the benefits of this approach for the protection and preservation of aquatic biodiversity.
Assuntos
Biodegradação Ambiental , Inseticidas , Larva , Pirazóis , Poluentes Químicos da Água , Animais , Larva/efeitos dos fármacos , Pirazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Inseticidas/toxicidade , Anuros/fisiologiaRESUMO
Changes in the natural landscape and the indiscriminate use of pesticides can have a major impact on aquatic environments and have contributed to the worldwide decline of amphibian populations. In the present study, we sampled tadpoles of three anuran amphibians (Boana albopunctata, Physalaemus cuvieri, and Dendropsophus minutus) from ponds in six different agricultural landscapes of the Brazilian Cerrado savanna and evaluated whether and to what extent genotoxic and mutagenic damage was related to land use (the amount of forest and agricultural remnants, and related physicochemical factors) and the presence of pesticides in the water of the study ponds. We also evaluated the hepatotoxicity in P. cuvieri, which was the most abundant species at five of the six sampling points. Clomazone and atrazine were the most common pesticides found in the ponds. The B. albopunctata and P. cuvieri tadpoles presented similar patterns of DNA damage among the sampling points. The least DNA damage was found in the D. minutus tadpoles, although this species was present in only one of the study ponds. More binucleated and anucleated cells were observed in B. albopunctata, but there was no significant variation among species in terms of the number of micronuclei or other erythrocytic nuclear abnormalities. Land use and physicochemical factors did not explain the variation in the DNA damage observed in the three anurans. The hepatotoxicity analyses of P. cuvieri revealed the presence of a series of alterations, including the enlargement of the sinusoids, vacuolization of the hepatocytes, the infiltration of inflammatory cells, hepatic steatosis, and dilation of the blood vessels. The interaction between physicochemical factors and the biomarkers analyzed in the present study is complex. In particular, it will be important to better elucidate which factors are contributing, either directly or indirectly, to the decline of anuran amphibian populations, especially in threatened biomes, such as the Brazilian Cerrado. In this case, we would encourage further in situ studies that assess the ecotoxicology of the landscape, together with the systematic monitoring of aquatic environments, to guarantee the long-term integrity of amphibian populations, and those of other organisms that play an essential functional role in the ecosystem. Environ Toxicol Chem 2023;42:2422-2439. © 2023 SETAC.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Praguicidas , Animais , Brasil , Ecotoxicologia , Ecossistema , Pradaria , Anuros , Larva/genética , BiomarcadoresRESUMO
Global change is predicted to induce shifts in anuran acoustic behavior, which can be studied through passive acoustic monitoring (PAM). Understanding changes in calling behavior requires automatic identification of anuran species, which is challenging due to the particular characteristics of neotropical soundscapes. In this paper, we introduce a large-scale multi-species dataset of anuran amphibians calls recorded by PAM, that comprises 27 hours of expert annotations for 42 different species from two Brazilian biomes. We provide open access to the dataset, including the raw recordings, experimental setup code, and a benchmark with a baseline model of the fine-grained categorization problem. Additionally, we highlight the challenges of the dataset to encourage machine learning researchers to solve the problem of anuran call identification towards conservation policy. All our experiments and resources have been made available at https://soundclim.github.io/anuraweb/ .
Assuntos
Anuros , Vocalização Animal , Animais , Acústica , EcossistemaRESUMO
Herbicides improve the productivity of a monoculture by eliminating weeds, although they may also be toxic and have negative effects on non-target organisms, such as amphibians. The present study evaluated the genotoxic, mutagenic, and histopathological hepatic responses of Dendropsophus minutus tadpoles to acute exposure (96 h) to the herbicide glyphosate (GLY, 65, 130, 260 and 520 µg/L) and the surfactant polyoxyethylene amine (POEA, 1.25, 2.5, 5 and 10 µg/L). On average, 174 % more genomic damage was observed in the tadpoles exposed to all concentrations of POEA in comparison with the control, while up to seven times more micronuclei were recorded, on average, at a concentration of 5 µg/L of POEA. All the individuals exposed to 10 µg/L of POEA died. The tadpoles exposed to GLY presented 165 % more DNA damage than the control, on average, at the highest concentrations (260 and 520 µg/L), and up to six times more micronuclei at 520 µg/L. The Erythrocyte Nuclear Abnormality test (ENA) detected a relatively high frequency of cells with lobed nuclei in the tadpoles expose to POEA at 5 µg/L and binucleated cells in those exposed to GLY at 520 µg/L. The hepatic histopathological observations revealed several types of lesions in the tadpoles exposed to both GLY and POEA. Overall, then, the results of the study indicate that both GLY and POEA have potential genotoxic, mutagenic, and hepatotoxic effects in D. minutus tadpoles. We emphasize the need for further studies to monitor the amphibian populations, such as those of D. minutus, which breed in aquatic environments associated with agricultural areas. The release of pollutants into natural habitats may have significant long-term impacts on the survival of anuran tadpoles.
Assuntos
Herbicidas , Poluentes Químicos da Água , Aminas , Animais , Dano ao DNA , Glicina/análogos & derivados , Herbicidas/toxicidade , Humanos , Larva , Mutagênicos/toxicidade , Polietilenoglicóis , Poluentes Químicos da Água/toxicidade , GlifosatoRESUMO
Reptiles are highly susceptible to climate change, responding negatively to thermal and rainfall alterations mainly in relation to their reproductive processes. Based on that, we evaluated the effects of climate change on climatically suitable areas for the occurrence of snakes in the Atlantic Forest hotspot, considering the responses of distinct reproductive groups (oviparous and viviparous). We assessed the species richness and turnover patterns affected by climate change and projected the threat status of each snake species at the end of the century. We also evaluated the effectiveness of the protected areas in safeguarding the species by estimating the mean percentage overlap between snake species distribution and protected areas (PAs) network and by assessing whether such areas will gain or lose species under climate change. Our results showed greater species richness in the eastern-central portion of the Atlantic Forest at present. In general, we evidenced a drastic range contraction of the snake species under climate change. Temporal turnover tends to be high in the western and north-eastern edges of the biome, particularly for oviparous species. Our predictions indicate that 73.6% of oviparous species and 67.6% of viviparous species could lose at least half of their original range by 2080. We also found that existing protected areas of the Atlantic Forest Hotspot have a very limited capacity to safeguard snakes at the current time, maintaining the precarious protection in the future, with the majority of them predicted to lose species at the end of this century. Although oviparous and viviparous snakes have been designated to be dramatically impacted, our study suggests a greater fragility of the former in the face of climate change. We advocated that the creation of new protected areas and/or the redesign of the existing network to harbour regions that maximize the snake species occupancy in the face of future warming scenarios are crucial measures for the conservation of this group.
Assuntos
Biodiversidade , Mudança Climática , Florestas , Modelos Biológicos , Serpentes/fisiologia , Animais , BrasilRESUMO
Our study evaluated 163 individuals, being 74 soybean farmers, occupationally exposed to pesticides, and 89 individuals from Goias municipalities, Central Brazil, with similar conditions to the exposed group, comprising the control group. Of the 74 soybean farmers, 43 exposed directly to pesticides and 31 exposed indirectly. The exposed group consisted of individuals aged 19 to 63 years, 21 women and 53 men, and the control group had ages ranging from 18 to 64 years, being 36 women and 53 men. 18.9% of the exposed group were poisoned by pesticides, and the most common symptoms were headache and gastrointestinal problems. The genotype frequencies of the rs2031920 (T>C) polymorphism in the CYP2E1 gene present significant differences between the exposed and control groups (p = 0.02), showing that 24.3% of the exposed group were heterozygotes against 6.7% in the control group. For the OGG1 gene, two SNPs, rs1052133 (G>C) and rs293795 (T>C), were evaluated and the genotype frequencies were not statistically different between the exposed and control groups. The DNA damage was distinct (p < 0.05) in the three analyzed comet parameters (tail length, Olive tail moment, %DNA) between groups. However, there was no influence of age and alcohol consumption between the groups associated with the polymorphisms in the CYP2E1 and OGG1 genes and DNA damage. We also did not find altered hematological and biochemical parameters in the exposed group. Thus, this pioneering study at Goias State carried out an overview of the health of soybean farmers. We evaluated classic laboratory exams, associated with exposure markers (comet assay) and susceptibility markers (genetic polymorphisms), emphasizing the need to expand the Brazilian health assessment protocol. We found, in soybean farmers, increased DNA damage and a higher number of heterozygotes in CYP2E1 gene, compared with the control group, despite the lack of association with age, educational level, smoking, drinking habits, and genetic polymorphisms.
Assuntos
Citocromo P-450 CYP2E1/genética , Dano ao DNA , DNA Glicosilases/genética , Reparo do DNA , Fazendeiros , Polimorfismo Genético , Adolescente , Adulto , Idoso , Poluentes Ocupacionais do Ar/análise , Poluentes Ocupacionais do Ar/toxicidade , Biomarcadores/sangue , Brasil , Ensaio Cometa , Feminino , Humanos , Inativação Metabólica/genética , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/análise , Praguicidas/análise , Praguicidas/toxicidade , Glycine max/crescimento & desenvolvimento , Adulto JovemRESUMO
Dendropsophus cruzi (Pombal Bastos, 1998) is a small hylid (male snout-to-vent length = 16.3-19.4 mm; female SVL = 21.3-25.0 mm) that is allocated in the D. microcephalus group (Faivovich et al. 2005). It is commonly found in Open and forested areas from Central Brazil to Provincia Velasco, Departamento de Santa Cruz, Bolivia (Frost 2017; Tessarolo et al. 2016). Pombal Bastos (1998) described the advertisement call of D. cruzi as a single pulsed note. Posteriorly, studies uncovered relationships between dominant frequency variation in the advertisement calls of D. cruzi and variation in the SVL and mass of males (Bastos et al. 2003), as well as the existence of a clinal geographic pattern in the variation of acoustic parameters of these calls (Tessarolo et al. 2016). However, the acoustic communication in anurans is usually mediated by more than one vocalization type (Toledo et al. 2015). Due the importance of call types in the social context of anurans (e.g., Reichert 2011; Forti et al. 2017), we expand the vocal repertoire of D. cruzi by describing its aggressive call.
Assuntos
Anuros , Distribuição Animal , Animais , Bolívia , Brasil , Feminino , Masculino , Vocalização AnimalRESUMO
Advertisement calls are often used as essential basic information in studies of animal behaviour, ecology, evolution, conservation, taxonomy or biodiversity inventories. Yet the description of this type of acoustic signals is far to be completed, especially in tropical regions, and is frequently non-standardized or limited in information, restricting the application of bioacoustics in science. Here we conducted a scientometric review of the described adverstisement calls of anuran species of Brazil, the world richest territory in anurans, to evaluate the amount, standard and trends of the knowledge on this key life-history trait and to identify gaps and directions for future research strategies. Based on our review, 607 studies have been published between 1960 to 2016 describing the calls of 719 Brazilian anuran species (68.8% of all species), a publication rate of 10.6 descriptions per year. From each of these studies, thirty-one variables were recorded and examined with descriptive and inferential statistics. In spite of an exponential rise over the last six decades in the number of studies, described calls, and quantity of published metadata, as revealed by regression models, clear shortfalls were identified with regard to anuran families, biomes, and categories of threat. More than 55% of these species belong to the two richest families, Hylidae or Leptodactylidae. The lowest percentage of species with described calls corresponds to the most diverse biomes, namely Atlantic Forest (65.1%) and Amazon (71.5%), and to the IUCN categories of threat (56.8%), relative to the less-than-threatened categories (74.3%). Moreover, only 52.3% of the species have some of its calls deposited in the main scientific sound collections. Our findings evidence remarkable knowledge gaps on advertisement calls of Brazilian anuran species, emphasizing the need of further efforts in standardizing and increasing the description of anuran calls for their application in studies of the behaviour, ecology, biogeography or taxonomy of the species.
Assuntos
Comunicação Animal , Anuros/fisiologia , Animais , BrasilRESUMO
The potential mutagenic and genotoxic effects of the herbicide atrazine were investigated in different developmental stages of Dendropsophus minutus tadpoles. These animals were exposed to 4 nominal concentrations of atrazine (2.25, 4.5, 9, and 18 mg/L) and 40 mg/L of Cyclophosphamide as a positive control, for 96 h. Negative controls were also added to the experiment. The tadpoles were divided into three groups according to Gosner's developmental stages, namely GS 25-33 as premetamorphic, GS 36-39 as prometamorphic, and GS 42-43 as metamorphic climax. Our results showed that the premetamorphic and metamorphic stages were more sensitive than the prometamorphic stage to the herbicide. A comet assay and micronucleus test for the sensitive stages demonstrated DNA damage in a concentration-dependent curve. Although a dose-response effect was not observed for the prometamorphic stage, a statistically significant difference was found between the treatment of 18 mg/L and the negative control. Moreover, the highest concentration of atrazine showed both the largest amount of DNA damage and the highest micronucleus frequency regardless of the developmental stage of D. minutus. In conclusion, atrazine was genotoxic and mutagenic for D. minutus in a dose-sensitive manner, dependent on larval developmental stages. Considering the prometamorphic stages showed no dose-response effect to atrazine, we suggest caution when using this stage in biomonitoring studies in order to avoid false negative results. Amphibians have been proven to be useful bioindicators, and we suggest replicating biomonitoring studies using different species to represent ecosystems' environmental impacts.
Assuntos
Anuros/crescimento & desenvolvimento , Atrazina/toxicidade , Herbicidas/toxicidade , Larva/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Ensaio Cometa , Dano ao DNA , Monitoramento Ambiental , Testes para Micronúcleos , Mutagênese , MutagênicosRESUMO
Rhinella abei is a medium-sized species (snout-to-vent length 57.0-76.4 mm in males; 60.4-83.9 mm in females-Baldissera et al. 2004) of the Rhinella crucifer species group, distributed in the Brazilian Atlantic Rainforest, from the State of Paraná to northern Rio Grande do Sul (Frost 2016). It is recorded in forested areas (Conte & Rossa-Feres 2007), or while breeding along forest edges and open habitats. Information on advertisement calls of species in the R. crucifer group is available for R. casconi, R. crucifer, R. inopina and R. ornata (Andrade et al. 2015; Heyer et al. 1990; Oliveira et al. 2014; Roberto et al. 2014). Here we describe the advertisement and aggressive calls of R. abei recorded in the municipality of Campo Largo (25.507472° S, 49.376632° W, datum "WGS84"), southeast State of Paraná, Brazil.
Assuntos
Bufonidae/classificação , Bufonidae/fisiologia , Agressão , Distribuição Animal , Animais , Brasil , Feminino , Masculino , Comportamento Sexual Animal , Especificidade da Espécie , Vocalização AnimalRESUMO
Proceratophrys dibernardoi Brandão, Caramaschi, Vaz-Silva & Campos 2013 has recently been described and allocated into the P. cristiceps species group, but no information about its advertisement calls has been provided (Brandão et al. 2013). Here, we describe for the first time the advertisement calls of P. dibernardoi based on specimens from Central Brazil. We also expand P. dibernardoi´s geographic distribution by reporting a new population in the State of Mato Grosso do Sul, Brazil, constituting the westernmost record for this species, and extending its known range approximately 330 km westward of the municipality of Aporé, State of Goiás (P. dibernardoi´s former westernmost record).
Assuntos
Anuros/classificação , Anuros/fisiologia , Vocalização Animal/fisiologia , Distribuição Animal , Animais , Brasil , Masculino , Especificidade da EspécieRESUMO
The genus Adelophryne is composed of diminutive frogs occurring in northern Amazonia and the Atlantic Forest. Herein we describe a new species of Adelophryne found in the leaf litter of primary and secondary forests in the mountainous region of Espírito Santo state, southeastern Brazil. The new species is characterized by its small body size, two phalanges in the finger IV, and a glandular ridge line that runs from the posterior part of eye to the insertion of the forelimb. This species is sensitive to edge effect and conversion of native forest into coffee and Eucalyptus plantations and may be listed as Endangered (EN) under B1ab(iii) criteria of the IUCN Red List.
Assuntos
Anuros/anatomia & histologia , Anuros/classificação , Animais , Brasil , Feminino , Pé/anatomia & histologia , Florestas , MasculinoRESUMO
We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.
Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Dano ao DNA , Exposição Ocupacional/análise , Praguicidas/toxicidade , Adulto , Poluentes Ocupacionais do Ar/metabolismo , Brasil , Ensaio Cometa , Feminino , Humanos , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Exposição Ocupacional/estatística & dados numéricos , Praguicidas/metabolismoRESUMO
The Cerrado is a tropical savannah with a diversified anuran assemblage, with 209 to 271 known species, of which approximately 51% are endemic. In this study, we report results of an anuran survey performed in the Extractivist Reserve of the Lago do Cedro, located in the northwestern region of the state of Goiás, Brazil. In this area, we recorded 36 anuran species, distributed in five families, from which five species are Cerrado endemics. This high species richness found in the Extractivist Reserve of the Lago do Cedro could be explain by the different vegetational types within the reserve boundaries that promote a high local heterogeneity. Species richness and representativeness per family are similar to other assemblages reported for different areas in the Cerrado domain, being the local anuran assemblage composed by generalist and widely distributed species. The families Hylidae and Leptodactylidae are the most diversified in the studied area, a common pattern found in neotropical assemblages. The Extractivist Reserve Lago do Cedro is an important area for Cerrado conservation because of the anuran diversity and geographic location, which allows the connection among other protected areas within the Araguaia basin.
O Cerrado é uma savana tropical que abriga uma anurofauna muito diversa, sendo estimado de 209 espécies à 271 espécies conhecidas, das quais a metade (51%) são endêmicas. Neste trabalho, apresentamos o inventário da anurofauna da Reserva Extrativista Lago do Cedro (RELC), noroeste do estado de Goiás. Ao todo, registramos 36 espécies de anuros, distribuídas em cinco famílias, das quais cinco espécies são endêmicas do Cerrado. A alta riqueza de espécies encontrada pode ser explicada pela heterogeneidade de habitats, promovida pelas diferentes fitofisionomias dentro da unidade de conservação. A riqueza de espécies e a representatividade por família apresentam valores semelhantes aos encontrados em outras taxocenoses no Cerrado, com a anurofauna local formada por espécies generalistas e de ampla distribuição. As famílias com maior diversidade de espécies foram Hylidae e Leptodactylidae, padrão frequentemente encontrado nas assembleias neotropicais. A RELC é uma importante unidade de conservação do Cerrado, servindo de abrigo para populações de anuros, sendo representativa da diversidade de anfíbios no bioma, e apresentando localização estratégica devido a posição central com relação a áreas de preservação na bacia do Araguaia.
RESUMO
A diversidade de anfíbios no Cerrado é ameaçada principalmente pelo aumento das atividades antrópicas. A legislação vigente exige de empreendimentos potencialmente impactantes a implantação de programas ambientais que incluem a recuperação de áreas degradadas e o estudo dos mecanismos ecológicos associados à recolonização de áreas alteradas. Os objetivos deste estudo foram: avaliar possíveis diferenças na composição de espécies em assembléias de anuros entre áreas de topografia modificada (ATM) e áreas de topografia não modificada (ATNM); e comparar a riqueza de anuros entre ATM e ATNM. Apesar do maior número de espécies registradas na ATM (28 espécies) em relação à ATNM (22 espécies), não houve diferença na riqueza quando comparamos as curvas de rarefação ou a riqueza estimada (jackknife1). Entretanto, as duas assembléias diferiram quanto às curvas de abundância relativa, especialmente quanto ao padrão das espécies mais abundantes. Localmente, a análise de co-ocorrência demonstrou que as espécies na ATM co-ocorrem menos do que o esperado ao acaso, o que indica a partilha dos ambientes para reprodução mediada por interações competitivas. A presença de corpos d'água artificiais com alta heterogeneidade estrutural, associados a fragmentos florestais em bom estado de conservação são fatores que contribuem para a manutenção de uma alta diversidade de anfíbios na área.
Assuntos
Anuros , Meio Ambiente , Biodiversidade , Eucalyptus , Recuperação e Remediação AmbientalRESUMO
Studies about the organization of the genetic variability and population structure in natural populations are used either to understand microevolutionary processes or the effects of isolation by human-inducted landscape modifications. In this paper, we analyzed patterns of genetic population structure using 126 RAPD loci scored for 214 individuals of Physalaemus cuvieri, sampled from 18 local populations. Around 97% of these loci were polymorphic. The among-population variation component (Phi(ST)) obtained by AMOVA was equal to 0.101 and theta B obtained using a Bayesian approach for dominant markers was 0.103. Genetic divergence, analyzed by Mantel spatial correlogram, revealed only a short-distance significant correlation between genetic and geographic distances. This is expected if low levels of population differentiation, due to high abundance buffering the effect of stochastic processes, are combined with low spatially restricted gene flow. Although this may be consistent with the current knowledge of species' biology, the spatial distribution of local populations observed in this study also suggest that, at least in part, recent human occupation and habitat fragmentation may also explain part of the interpopulational component of the genetic variation.
Assuntos
Anuros/genética , Animais , Teorema de Bayes , Brasil , DNA/genética , Ecossistema , Variação Genética , Genética Populacional , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
O Cerrado é o segundo maior bioma brasileiro e é considerado um dos mais importantes hotspots de biodiversidade. Neste bioma foram registradas cerca de 150 espécies de anuros, das quais 30 por cento são endêmicas. Entretanto, existem muitas áreas ainda não inventariadas, nas quais não se conhece quase nada sobre a diversidade de anuros. Assim, neste estudo apresentamos informações referentes a anurofauna do sudoeste do Estado de Goiás (Brasil Central), a qual vem sendo modificada principalmente pela agropecuária. Nesta região, 45 corpos d'água foram amostrados entre os meses de novembro/2007 a fevereiro/2008 e novembro/2008 a março/2009, localizados próximos a plantações de soja, cana-de-açúcar, pastagem e vegetação nativa. No total, foram registrados adultos e girinos de 36 espécies de anuros, a maioria comum de áreas abertas. As curvas de acumulação de espécies, tanto para adultos quanto para girinos, apresentaram a formação de uma assíntota, o que indica uma baixa probabilidade de registro de novas espécies mesmo com a amostragem de outros corpos d'água. Nesta área com forte influência de impactos agrícolas, a riqueza encontrada representa aproximadamente 1/4 do total de espécies conhecidas para o bioma Cerrado.
The Cerrado is the second largest biome in Brazil and is considered one of most important among the biodiversity hotspots. In this biome can be found about 150 anurans species, from which 30 percent are endemic. However, there are many Cerrado areas that have little information gathered about the anuran biodiversity. Thus, in this study we present the result of an inventory of anurans species from the southwest region of Goiás State (Central Brazil). In this region, we sampled 45 water bodies, located near soybean and sugar-cane cultures, pastures and natural vegetation, from November/2007 to February/2008 and from November/2008 to March/2009. Altogether, adults and tadpoles of 36 species were registered, with the majority of species registered in association to open areas. The rarefied curve of species richness show an asymptote formation, which indicates that the chance to add species to the inventory is low, even with additional habitats sampling. Therefore, our results reveal high species richness in the present sampled region, which represented almost one fourth of all species found in Cerrado.
RESUMO
O Cerrado representa um dos maiores domínios fitogeográficos da América do Sul, sendo o segundo maior domínio de vegetação no Brasil e um dos 34 hotspots de biodiversidade do planeta. No presente estudo, a diversidade e distribuição espacial e temporal de anfíbios anuros foram estudadas entre outubro de 2005 e agosto de 2006, em três áreas de Cerrado no município de Niquelândia, estado de Goiás. Foram registradas 29 espécies pertencentes a oito famílias: Bufonidae (uma espécie), Cyclorhamphidae (três espécies), Dendrobatidae (uma espécie), Hylidae (dez espécies), Leiuperidae (uma espécie), Leptodactylidae (nove espécies), Microhylidae (duas espécies) e Strabomantidae (duas espécies). As Áreas 1 e 2 apresentaram as maiores riquezas com 21 e 18 espécies, respectivamente. Todavia, maior diversidade foi encontrada na Área 2, que apresentou uma alta equitabilidade. Dentre os sítios reprodutivos, a estabilidade do corpo d'água permanente que mantém água durante todo o ano favoreceu a ocorrência de espécies com padrões de reprodução intermediário e prolongado, contribuindo para a maior riqueza de espécies nesse ambiente. A distribuição temporal das espécies foi influenciada tanto pelo regime de chuvas quanto pela temperatura, pois os machos da maioria das espécies (86 por cento) vocalizaram na estação chuvosa. Physalaemus cuvieri utilizou seis dos 14 sítios estudados para reprodução, sendo considerada uma espécie generalista. Por outro lado, Hypsiboas lundii, Barycholos ternetzi, Leptodactylus gr. marmoratus, Leptodactylus cf. martinezi e Ameerega flavopicta apresentam limitações impostas por modos reprodutivos específicos ficando restritas a um determinado hábitat.
The Cerrado is one of the largest phytogeographic domains of South America, being the second largest Brazilian phytogeographic domain and one of the 34 most endangered regions on the planet. In this study, the spatio-temporal distribution of frogs were studied between October 2005 and August 2006 in three Cerrado areas of Niquelândia, Goiás State, central Brazil. Twenty-nine anuran species were recorded, belonging to eight families: Bufonidae (one species), Cyclorhamphidae (three species), Dendrobatidae (one species), Hylidae (ten species), Leiuperidae (one species), Leptodactylidae (nine species), Microhylidae (two species) and Strabomantidae (two species). Areas 1 and 2 showed the greatest richness, with 21 and 18 species respectively. However, greater diversity was found in Area 2 which showed high evenness. Among breeding sites, those that hold water throughout the year favored the occurrence of species with intermediate and prolonged reproductive activity, which contributed for an increase in the species richness in these sites. The temporal distribution of species was influenced by rainfall and temperature, with males of most species (86 percent) vocalizing in the rainy season. Physalaemus cuvieri used six of the 14 sites studied for reproduction, and is considered a generalist species. However, Hypsiboas lundii, Barycholos ternetzi, Leptodactylus gr. marmoratus, Leptodactylus cf. martinezi and Ameerega flavopicta have limitations imposed by specific reproductive modes, being restricted to localized habitats.