RESUMO
In males, large testes size signifies high sperm production and is commonly linked to heightened sperm competition levels. It may also evolve as a response to an elevated risk of sperm depletion due to multiple mating or large clutch sizes. Conversely, weapons, mate or clutch guarding may allow individuals to monopolize mating events and preclude sperm competition, thereby reducing the selection of large testes. Herein, we examined how paternal care, sexual size dimorphism (SSD), weaponry and female fecundity are linked to testes size in glassfrogs. We found that paternal care was associated with a reduction in relative testes size, suggesting an evolutionary trade-off between testes size and parenting. Although females were slightly larger than males and species with paternal care tended to have larger clutches, there was no significant relationship between SSD, clutch size and relative testes size. These findings suggest that the evolution of testes size in glassfrogs is influenced by sperm competition risk, rather than sperm depletion risk. We infer that clutch guarding precludes the risk of fertilization by other males and consequently diminishes selective pressure for larger testes. Our study highlights the prominent role of paternal care in the evolution of testes size in species with external fertilization.
Assuntos
Poder Familiar , Testículo , Humanos , Masculino , Feminino , Animais , Sêmen , Espermatozoides/fisiologia , Reprodução , Comportamento Sexual Animal/fisiologiaRESUMO
The mechanisms of hybridization can be elucidated by analyzing genotypes as well as phenotypes that could act as premating barriers, as the reproductive interactions among heterospecifics can alter the evolutionary history of species. In frogs, hybrids typically occur among species that reproduce explosively (in dense aggregations) with few opportunities for mate selection but are rare in species with elaborate courtship behaviors that may prevent erroneous mating. Using 21 microsatellite markers, we examined hybridization in the prolonged-breeding tree frogs Bokermannohyla ibitiguara and B. sazimai sampled within a contact zone in the Brazilian savanna (72 tadpoles; 74 adults). We also compared acoustic and morphological data. We confirmed both parental species genetically; STRUCTURE results confirmed 14 hybrids, 11 of which were second-generation according to NEWHYBRIDS, all with intermediate values of genetic dissimilarities compared to the parentals. Morphological and acoustic analyses revealed that hybrids showed variable but not necessarily intermediate phenotypes. Moreover, 2 hybrids exhibited call types different from parentals. The reproduction of B. ibitiguara involves territorial and aggressive males, elaborate courtships with acoustic and tactile stimuli, choosy females, and opportunistic strategies. Our study uncovers a rare case of viable hybridization among closely related frogs with such a combination of complex courtship behaviors and mate choice. We discuss the likely directionality and mechanisms behind this phenomenon, and highlight the importance of investigating hybridization even in species that show elaborate reproduction and female choice to advance our understanding of animal diversification.
Assuntos
Corte , Hibridização Genética , Feminino , Masculino , Animais , Agressão , Fenótipo , Reprodução , Anuros/genética , Comportamento Sexual AnimalRESUMO
Despite extensive research on biodiversity in Neotropical forests, biodiversity in seasonally dry, open biomes in South America has been underestimated until recently. We leverage a widespread group, Boana albopunctata, to uncover cryptic lineages and investigate the timing of diversification in Neotropical anurans with a focus on dry diagonal biomes (Cerrado, Caatinga and Chaco) and the ecotone between Amazonia and the Cerrado. We inferred a multilocus phylogeny of the B. albopunctata species group that includes 15 of 18 described species, recovered two cryptic species, and reconstructed the timing of diversification among species distributed across multiple South American biomes. One new potential species (B. aff. steinbachi), sampled in the Amazonian state of Acre, clustered within the B. calcara-fasciata species complex and is close to B. steinbachi. A second putative new species (B. aff. multifasciata), sampled in the Amazonia-Cerrado ecotone, is closely related to B. multifasciata. Lastly, we place a recently identified Cerrado lineage (B. aff. albopuncata) into the B. albopunctata species group phylogeny for the first time. Our ancestral range reconstruction showed that species in the B. albopuctata group likely dispersed from Amazonia-Cerrado into the dry-diagonal and Atlantic Forest. Intraspecies demography showed, for both B. raniceps and B. albopunctata, signs of rapid expansion across the dry diagonal. Similarly, for one clade of B. multifasciata, our analyses support an invasion of the Cerrado from Amazonia, followed by a rapid expansion across the open diagonal biomes. Thus, our study recovers several recent divergences along the Amazonia-Cerrado ecotone in northern Brazil. Tectonic uplift and erosion in the late Miocene and climate oscillations in the Pleistocene corresponded with estimated divergence times in the dry diagonal and Amazonia-Cerrado ecotone. Our study highlights the importance of these threatened open formations in the generation of biodiversity in the Neotropics.
Assuntos
Anuros , Florestas , Animais , Anuros/genética , Biodiversidade , Brasil , Filogenia , FilogeografiaRESUMO
Amphibians may be more vulnerable to climate-driven habitat modification because of their complex life cycle dependence on land and water. Considering the current rate of global warming, it is critical to identify the vulnerability of a species by assessing its potential to acclimate to warming temperatures. In many species, thermal acclimation provides a reversible physiological adjustment in response to temperature changes, conferring resilience in a changing climate. Here, we investigate the effects of temperature acclimation on the physiological performance of tadpoles of a stream-breeding savanna tree frog (Bokermannohyla ibitiguara) in relation to the thermal conditions naturally experienced in their microhabitat (range: 18.8-24.6°C). We quantified performance measures such as routine and maximum metabolic rate at different test (15, 20, 25, 30, and 34°C) and acclimation temperatures (18 and 25°C). We also measured heart rate before and after autonomic blockade with atropine and sotalol at the respective acclimation temperatures. Further, we determined the critical thermal maximum and warming tolerance (critical thermal maximum minus maximum microhabitat temperature), which were not affected by acclimation. Mass-specific routine and mass-specific maximum metabolic rate, as well as heart rate, increased with increasing test temperatures; however, acclimation elevated mass-specific routine metabolic rate while not affecting mass-specific maximum metabolic rate. Heart rate before and after the pharmacological blockade was also unaffected by acclimation. Aerobic scope in animals acclimated to 25°C was substantially reduced, suggesting that physiological performance at the highest temperatures experienced in their natural habitat is compromised. In conclusion, the data suggest that the tadpoles of B. ibitiguara, living in a thermally stable environment, have a limited capacity to physiologically adjust to the highest temperatures found in their micro-habitat, making the species more vulnerable to future climate change.
RESUMO
Trachycephalus cunauaru é um hilídeo amazônico que utiliza fitotelmatas para se reproduzir. Existem relativamente poucas informações sobre a espécie, principalmente devido à dificuldade de acesso aos seus sítios reprodutivos. Nesse trabalho, reunimos dados de ecologia e história natural de T. cunauaru em uma área da Amazônia meridional, no estado de Mato Grosso, Brasil. Além de fitotelmatas naturais, utilizamos baldes instalados a uma altura de 10 m como fitotelmatas artificiais. Comparamos características físicas e químicas, bem como a presença e ausência de girinos, entre fitotelmatas naturais e artificiais. Também coletamos dados sobre o comportamento reprodutivo da espécie por meio de armadilhas fotográficas. Registramos uma densidade de 14,1 sítios reprodutivos por km2 . Os parâmetros ambientais diferiram significativamente entre fitotelmatas artificiais e naturais. Em sítios artificiais a presença de girinos esteve diretamente relacionada à árvores com maior diâmetro. Registramos, pela primeira vez, oofagia para a espécie e observamos que machos podem utilizar mais de um fitotelmata. Também registramos a presença de cobras nos sítios reprodutivos. Constatamos que sítios artificiais e armadilhas fotográficas representam uma alternativa satisfatória para registros comportamentais para T. cunauaru e, possivelmente, para outras espécies com hábitos similares. (AU)
Assuntos
AnfíbiosRESUMO
Parental care is costly, thus theory predicts that parents should avoid caring for unrelated offspring. However, alloparenting has been reported in many taxa because it may increase the caregiver mating success or offspring survival. We experimentally investigated the existence of allopaternal care in two glassfrog species, Hyalinobatrachium chirripoi and Centrolene peristicta, and discussed possible costs and benefits. Males mated with multiple females and cared for clutches, while continued to call. In the field, we randomly placed unrelated clutches in the territory of males already caring for their clutches and in the territory of non-attending males. Attending males adopted unrelated clutches, whereas non-attending males abandoned their territories. Once males adopted unrelated offspring, they cared for all clutches in a similar frequency and gained new clutches. Alloparenting was context-dependent, as only males already caring for their clutches adopted unrelated ones. We suggest that steroid hormonal levels might mediate the adoption of unrelated offspring by attending males. Additionally, our results suggest that males do not directly discriminate between related and unrelated offspring. Alloparenting has been widely investigated in different vertebrates, except for amphibians. Thus, our study sheds light on the roles of alloparenting for offspring survival and mating success in this group.
Assuntos
Anuros/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Masculino , Reprodução/fisiologiaRESUMO
Trachycephalus cunauaru is an Amazonian hylid that uses phytotelmata to reproduce. There is relatively little information about the species, mainly due to the difficulty of accessing their reproductive sites. In this study, we gathered data on the ecology and natural history of T. cunauaru in the southern Amazon, in the state of Mato Grosso, Brazil. In addition to natural phytotelmata, we used buckets installed at a height of 10 m as artificial phytotelmata. We compared physical and chemical characteristics, as well as the presence of tadpoles between natural and artificial phytotelmata. We also collected data on the reproductive behavior of the species through the use of camera traps. We recorded a density of 14.1 reproductive sites per km². Environmental parameters differed significantly between artificial and natural phytotelmata. In artificial sites, the presence of tadpoles was directly related to trees with a larger diameter. We registered oophagy for the first time for the species and observed that males can use more than one phytotelm. We also recorded the presence of snakes within the reproductive sites. We determined that artificial sites and digital camera traps are a satisfactory alternative for behavioral observations of T. cunauaru and possibly for other species with a similar habit.(AU)
Trachycephalus cunauaru é um hilídeo amazônico que utiliza fitotelmatas para se reproduzir. Existem relativamente poucas informações sobre a espécie, principalmente devido à dificuldade de acesso aos seus sítios reprodutivos. Nesse trabalho, reunimos dados de ecologia e história natural de T. cunauaru em uma área da Amazônia meridional, no estado de Mato Grosso, Brasil. Além de fitotelmatas naturais, utilizamos baldes instalados a uma altura de 10 m como fitotelmatas artificiais. Comparamos características físicas e químicas, bem como a presença e ausência de girinos, entre fitotelmatas naturais e artificiais. Também coletamos dados sobre o comportamento reprodutivo da espécie por meio de armadilhas fotográficas. Registramos uma densidade de 14,1 sítios reprodutivos por km2. Os parâmetros ambientais diferiram significativamente entre fitotelmatas artificiais e naturais. Em sítios artificiais a presença de girinos esteve diretamente relacionada à árvores com maior diâmetro. Registramos, pela primeira vez, oofagia para a espécie e observamos que machos podem utilizar mais de um fitotelmata. Também registramos a presença de cobras nos sítios reprodutivos. Constatamos que sítios artificiais e armadilhas fotográficas representam uma alternativa satisfatória para registros comportamentais para T. cunauaru e, possivelmente, para outras espécies com hábitos similares.(AU)
Assuntos
Animais , Anuros/classificação , Ecologia , Comportamento ReprodutivoRESUMO
Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.(AU)
Assuntos
Animais , Anuros/fisiologia , Ecologia , Comportamento Sexual AnimalRESUMO
ABSTRACT Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.
RESUMO
Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.(AU)
Assuntos
Animais , Arvicolinae/parasitologia , Nociceptividade/fisiologia , Analgesia/efeitos adversos , Estações do Ano , Cadeia AlimentarRESUMO
Amphibians are among the most threatened vertebrate groups in the world, and the main causes include climate change, habitat destruction, and emerging diseases. Herein, we investigated the occurrence and characterized molecularly Apicomplexa in anurans from southeastern Brazil. Forty individuals from seven anuran species were sampled in São Paulo state. In the molecular analyses, one Leptodactylus latrans and one Rhinella diptycha were positive in PCR assays for species of Hepatozoon. Two L. latrans were also positive for coccidian infections (Lankesterella sp. and an unidentified coccidian species). Phylogenetic analysis based on 18S rDNA clustered the sequences detected in anurans from the present study with Hepatozoon spp. detected in reptiles and other anurans from Brazil, albeit they were separate from Hepatozoon haplotypes detected in frogs from Africa and North America. Our study showed, for the first time, the molecular detection of Lankesterella sp. and another coccidian in L. latrans. Additionally, co-infection by different species of Hepatozoon haplotypes and an unidentified coccidian in anurans from Brazil was documented.
Assuntos
Anuros/parasitologia , Apicomplexa/genética , Apicomplexa/isolamento & purificação , Infecções Protozoárias em Animais/parasitologia , Animais , Anuros/classificação , Apicomplexa/classificação , Brasil/epidemiologia , Coccídios/classificação , Coccídios/genética , Coccídios/isolamento & purificação , Coccidiose/epidemiologia , Coccidiose/parasitologia , Coccidiose/veterinária , DNA de Protozoário/genética , DNA Ribossômico/genética , Filogenia , Infecções Protozoárias em Animais/epidemiologiaRESUMO
Amphibian species from Mato Grosso do Sul state were compiled and checked for the first time. A total of 97 species were recorded, representing more than 10% of the known Brazilian amphibians. Twenty five anuran genera in nine families and only one caecilian were recorded. Cerrado was the richest area followed by semideciduous forests, Chaco, and veredas (palm swamps). It was recorded 56 species in floodplain areas and 92 in the surrounding cerrados. The Serra da Bodoquena National Park and some Pantanal areas were better sampled than other regions in Mato Grosso do Sul, resulting in sampling gaps across the state. Important areas for future inventories were identified: mountainous regions in Serra de Maracaju and those bordering the Apa river, Brazilian chacoan areas, the Taquari river alluvial fan, the broad Taquari-Itiquira flat area, the Central Plateau scarps, wet areas from Parana river bordering São Paulo state, and inland areas from Pantanal.(AU)
A fauna de anfíbios do estado de Mato Grosso do Sul foi compilada e elaborada pela primeira vez, totalizando 97 espécies, o que representa pouco mais de 10% das espécies que ocorrem no Brasil. Nove famílias e 25 gêneros de Anura e apenas uma espécie de Gymnophiona foram registradas. As áreas de Cerrado apresentaram a maior riqueza, seguidas pelas florestas estacionais semideciduais, Chaco e veredas. Em relação às macrorregiões consideradas, foram registradas 56 espécies para a planície de inundação (majoritariamente representada pelo Pantanal) e 92 para o planalto. As regiões mais amostradas em Mato Grosso do Sul são o Parque Nacional da Serra da Bodoquena e algumas áreas do Pantanal, o que resulta em lacunas de amostragens por todo o estado, principalmente nas regiões norte, leste/sudeste e parte do oeste/sudoeste. Foram identificadas áreas consideradas importantes para amostragens em decorrência da complexidade de fitofisionomias e relevos encontrados no estado: Maciço do rio Apa, Serra de Maracaju, grande parte do Chaco brasileiro, leque do rio Taquari, planalto do Taquari-Itiquira, escarpas do planalto Central, áreas úmidas/florestas estacionais da planície do rio Paraná e áreas interioranas do Pantanal, onde o acesso é difícil.(AU)
Assuntos
Animais , Anfíbios , Grupos de População Animal , BrasilRESUMO
ABSTRACT Amphibian species from Mato Grosso do Sul state were compiled and checked for the first time. A total of 97 species were recorded, representing more than 10% of the known Brazilian amphibians. Twenty five anuran genera in nine families and only one caecilian were recorded. Cerrado was the richest area followed by semideciduous forests, Chaco, and veredas (palm swamps). It was recorded 56 species in floodplain areas and 92 in the surrounding cerrados. The Serra da Bodoquena National Park and some Pantanal areas were better sampled than other regions in Mato Grosso do Sul, resulting in sampling gaps across the state. Important areas for future inventories were identified: mountainous regions in Serra de Maracaju and those bordering the Apa river, Brazilian chacoan areas, the Taquari river alluvial fan, the broad Taquari-Itiquira flat area, the Central Plateau scarps, wet areas from Parana river bordering São Paulo state, and inland areas from Pantanal.
RESUMO A fauna de anfíbios do estado de Mato Grosso do Sul foi compilada e elaborada pela primeira vez, totalizando 97 espécies, o que representa pouco mais de 10% das espécies que ocorrem no Brasil. Nove famílias e 25 gêneros de Anura e apenas uma espécie de Gymnophiona foram registradas. As áreas de Cerrado apresentaram a maior riqueza, seguidas pelas florestas estacionais semideciduais, Chaco e veredas. Em relação às macrorregiões consideradas, foram registradas 56 espécies para a planície de inundação (majoritariamente representada pelo Pantanal) e 92 para o planalto. As regiões mais amostradas em Mato Grosso do Sul são o Parque Nacional da Serra da Bodoquena e algumas áreas do Pantanal, o que resulta em lacunas de amostragens por todo o estado, principalmente nas regiões norte, leste/sudeste e parte do oeste/sudoeste. Foram identificadas áreas consideradas importantes para amostragens em decorrência da complexidade de fitofisionomias e relevos encontrados no estado: Maciço do rio Apa, Serra de Maracaju, grande parte do Chaco brasileiro, leque do rio Taquari, planalto do Taquari-Itiquira, escarpas do planalto Central, áreas úmidas/florestas estacionais da planície do rio Paraná e áreas interioranas do Pantanal, onde o acesso é difícil.
RESUMO
Amphibian species from Mato Grosso do Sul state were compiled and checked for the first time. A total of 97 species were recorded, representing more than 10% of the known Brazilian amphibians. Twenty five anuran genera in nine families and only one caecilian were recorded. Cerrado was the richest area followed by semideciduous forests, Chaco, and veredas (palm swamps). It was recorded 56 species in floodplain areas and 92 in the surrounding cerrados. The Serra da Bodoquena National Park and some Pantanal areas were better sampled than other regions in Mato Grosso do Sul, resulting in sampling gaps across the state. Important areas for future inventories were identified: mountainous regions in Serra de Maracaju and those bordering the Apa river, Brazilian chacoan areas, the Taquari river alluvial fan, the broad Taquari-Itiquira flat area, the Central Plateau scarps, wet areas from Parana river bordering São Paulo state, and inland areas from Pantanal.
A fauna de anfíbios do estado de Mato Grosso do Sul foi compilada e elaborada pela primeira vez, totalizando 97 espécies, o que representa pouco mais de 10% das espécies que ocorrem no Brasil. Nove famílias e 25 gêneros de Anura e apenas uma espécie de Gymnophiona foram registradas. As áreas de Cerrado apresentaram a maior riqueza, seguidas pelas florestas estacionais semideciduais, Chaco e veredas. Em relação às macrorregiões consideradas, foram registradas 56 espécies para a planície de inundação (majoritariamente representada pelo Pantanal) e 92 para o planalto. As regiões mais amostradas em Mato Grosso do Sul são o Parque Nacional da Serra da Bodoquena e algumas áreas do Pantanal, o que resulta em lacunas de amostragens por todo o estado, principalmente nas regiões norte, leste/sudeste e parte do oeste/sudoeste. Foram identificadas áreas consideradas importantes para amostragens em decorrência da complexidade de fitofisionomias e relevos encontrados no estado: Maciço do rio Apa, Serra de Maracaju, grande parte do Chaco brasileiro, leque do rio Taquari, planalto do Taquari-Itiquira, escarpas do planalto Central, áreas úmidas/florestas estacionais da planície do rio Paraná e áreas interioranas do Pantanal, onde o acesso é difícil.
Assuntos
Animais , Anfíbios , Brasil , Grupos de População AnimalRESUMO
Male calls play different roles in anuran social organization, such as spacing, territoriality and female attraction. However, calls and associated behaviors remain poorly described for many anuran species. Here we describe the advertisement and release calls of the tree frog Phyllomedusa ayeaye (Lutz, 1966) and report on the social context of emissions and a physical combat. Approximately 35 minutes of digital recordings were obtained from 34 hours of observations at one breeding site in the state of Minas Gerais, southeastern Brazil. Bioacoustic analysis showed that males emitted two types of advertisement calls: 1) simple call (a sequence of short pulsed notes) and 2) composite call (a sequence of short pulsed notes followed by a long pulsed note). Composite calls were emitted more frequently during more intense chorus activity, with various active males at the breeding site. The release call was also composed by short pulsed notes, with a wider spectrum of frequencies and emitted more rapidly than the advertisement calls. Our results suggest that the composite call of P. ayeaye may represent a mixed advertisement call. Long notes might be the aggressive part directed to males, whereas short notes directed to females. Our description of call types, their functions, and male physical interactions will be useful for studies investigating the systematics and behavior of Phyllomedusa species.(AU)
Assuntos
Animais , Anuros , Comportamento Animal , Acústica , Vocalização AnimalRESUMO
Male calls play different roles in anuran social organization, such as spacing, territoriality and female attraction. However, calls and associated behaviors remain poorly described for many anuran species. Here we describe the advertisement and release calls of the tree frog Phyllomedusa ayeaye (Lutz, 1966) and report on the social context of emissions and a physical combat. Approximately 35 minutes of digital recordings were obtained from 34 hours of observations at one breeding site in the state of Minas Gerais, southeastern Brazil. Bioacoustic analysis showed that males emitted two types of advertisement calls: 1) simple call (a sequence of short pulsed notes) and 2) composite call (a sequence of short pulsed notes followed by a long pulsed note). Composite calls were emitted more frequently during more intense chorus activity, with various active males at the breeding site. The release call was also composed by short pulsed notes, with a wider spectrum of frequencies and emitted more rapidly than the advertisement calls. Our results suggest that the composite call of P. ayeaye may represent a mixed advertisement call. Long notes might be the aggressive part directed to males, whereas short notes directed to females. Our description of call types, their functions, and male physical interactions will be useful for studies investigating the systematics and behavior of Phyllomedusa species.
Assuntos
Animais , Acústica , Anuros , Comportamento Animal , Vocalização AnimalRESUMO
Sexual size dimorphism (SSD) varies in animals from male biased to female biased. The evolution of SSD is potentially influenced by a number of factors, such as territoriality, fecundity, and temporal breeding patterns (explosive vs. prolonged). In general, frogs show female-biased SSD with broad variance among species. Using comparative methods, we examine how different selective forces affect male and female sizes, and we test hypotheses about size-dependent mechanisms shaping SSD in frogs. Male size was weakly associated with SSD in all size classes, and we found no significant association among SSD, male size, temporal breeding pattern, and male territoriality. In contrast, female size best explained SSD variation across all size classes but especially for small-bodied species. We found a stronger evolutionary association between female body size and fecundity, and this fecundity advantage was highest in explosively breeding species. Our data indicate that the fecundity advantage associated with female body size may not be linear, such that intermediate and large females benefit less with body size increases. Therefore, size-dependent selection in females associated with fecundity and breeding patterns is an important mechanism driving SSD evolution in frogs. Our study underscores the fact that lineage-specific ecology and behavior should be incorporated in comparative analyses of animal SSD.
Assuntos
Anuros/anatomia & histologia , Anuros/genética , Tamanho Corporal , Caracteres Sexuais , Animais , Evolução Biológica , Feminino , Fertilidade , Masculino , Reprodução , Seleção Genética , TerritorialidadeRESUMO
Chytridiomycosis, an infectious disease of amphibians, is caused by the fungus Batrachochytrium dendrobatidis (Bd) and has been linked to declining amphibian populations worldwide. The susceptibility of amphibians to chytridiomycosis-induced population declines is potentially influenced by many factors, including environmental characteristics, differences among host species and the growth of the pathogen itself. We investigated the effects of elevation and breeding habitat on Bd prevalence and individual infection intensity (zoospore loads) in 3 anuran assemblages of the Atlantic Coastal Forest of Brazil. Bd infection intensity was strongly influenced by elevation and breeding habitat, but we found no evidence of an interaction between those 2 variables in explaining the number of zoospores sampled from individual frogs. In contrast, Bd infection odds were predicted by elevation and by an interaction between elevation and breeding habitat, such that frogs had a higher probability of Bd infection in lotic habitats at low elevations. Our results indicate that Bd persists across a wide variety of habitats and elevations in the Atlantic Coastal Forest. Prevalence and infection intensity of Bd are highest at high elevations where overall environmental conditions for Bd are most favorable. In addition, at low elevations amphibian host habitat choice is also an important determinant of infection. Our study highlights the need to investigate interacting variables of host ecology and the environment simultaneously.
Assuntos
Altitude , Anuros/microbiologia , Anuros/fisiologia , Cruzamento , Quitridiomicetos/fisiologia , Ecossistema , Micoses/veterinária , Animais , Brasil/epidemiologia , Micoses/epidemiologia , Micoses/microbiologia , Reprodução , Fatores de RiscoRESUMO
Diversification of South American species endemic to open habitats has been attributed to both Tertiary events and Pleistocene climatic fluctuations. Nonetheless, phylogeographical studies of taxa in these regions are few, precluding generalizations about the timing and processes leading to differentiation and speciation. We inferred population structure of Hypsiboas albopunctatus, a frog widely distributed in the Brazilian Cerrado. Three geographically distinct lineages were recovered in our phylogeny. The Chapada dos Guimarães (CG) clade was the first to diverge from other populations and contains multiple haplotypes from a single population in western Cerrado, probably representing a cryptic species. The southeast clade (SE) includes populations along the southeastern limit of the range within the historical distribution of the Brazilian Atlantic forest. Finally, the Central Cerrado (CC) group includes haplotypes from the interior of Brazil that are paraphyletic relative to the SE clade. Analyses of historical demography indicate significant population expansion in the CC and SE populations, likely associated with colonization of newly formed open habitats. The divergence of populations in the CG clade occurred in the late Miocene, concordant with the uplift of the central Brazilian plateau. Divergence of the SE clade from the CC occurred during the mid-Pleistocene. Thus, both Tertiary geological events and Pleistocene climatic fluctuations promoted divergences among lineages. Our study reveals a complex history of diversification in the Cerrado, a morphoclimatic domain highly threatened because of anthropogenic habitat alteration. We identified surprisingly deep divergences in a widely distributed frog, indicating that the Cerrado is not a barrier-free habitat and that its diversity is likely underestimated.