RESUMO
Rising habitat loss is one of the main drivers of the global amphibian decline. Nevertheless, knowledge of amphibian diversity needed for effective habitat protection is still highly inadequate in remote tropical regions, the greater part of the Amazonia. In this study we integrated molecular, morphological and bioacoustic evidence to evaluate the species richness of the treefrogs genus Scinax over a 1000 km transect across rainforest of the Purus-Madeira interfluve, and along the east bank of the upper Madeira river, Brazilian Amazonia. Analysis revealed that 82% of the regional species richness of Scinax is still undescribed; two nominal species, seven confirmed candidate species, two unconfirmed candidate species, and one deep conspecific lineage were detected in the study area. DNA barcoding based analysis of the 16s rRNA gene indicates possible existence of three discrete species groups within the genus Scinax, in addition to the already-known S. rostratus species Group. Quantifying and characterizing the number of undescribed Scinax taxa on a regional scale, we provide a framework for future taxonomic study in Amazonia. These findings indicate that the level to which Amazonian anura species richness has been underestimated is far greater than expected. Consequently, special attention should be paid both to taxonomic studies and protection of the still-neglected Amazonian Scinax treefrogs.
Assuntos
Anuros/classificação , Anuros/fisiologia , RNA Ribossômico 16S/genética , Acústica , Animais , Anuros/genética , Brasil , Código de Barras de DNA Taxonômico , Ecossistema , Filogenia , Floresta Úmida , Especificidade da EspécieRESUMO
The neotropical cichlid genus Astronotus currently comprises two valid species: A. ocellatus Agassiz, 1831 and A. crassipinnis Heckel, 1840. The diagnosis is based on color pattern and meristics counts. However, body color pattern is highly variable between regions and the meristic counts show a considerable overlap between populations differing in color patterning. They do not represent true synapomorphies that diagnose species. Purportedly the only truly diagnostic character is the presence or absence of one or more ocelli at the base of the dorsal fin, diagnosing A. ocellatus and A. crassipinnis, respectively. Using the 5' portion of the mitochondrial COI gene and EPIC nuclear markers, the validity of the dorsal ocelli as diagnostic character was tested in individuals sampled from ten localities in the Amazon basin. Analyses rejected the hypothesis that dorsal ocelli are diagnostic at the species level. However, they revealed the existence of five hypothetical, largely allopatrically distributed morphologically cryptic species. The phylogeographic structure is not necessarily surprising, since species of the genus Astronotus have sedentary and territorial habits with low dispersal potential. The distribution of these hypothetical species is coincident with patterns observed in other Amazonian aquatic fauna, suggesting the role of common historical processes in generating current biodiversity patterns.
RESUMO
Eufriesea violacea (Blanchard) is a very seasonal euglossine species, more frequently found in the southern and southeastern regions of Brazil. A number of studies have revealed large variations in the abundance of males of this species present in Atlantic Forest remnants throughout both regions. In this paper, we report variations in the abundance of E. violacea males sampled in several forest patches of different sizes (ranging from 10 to 580 ha), and we propose that this species is possibly sensitive to the reduction in size of forest remnants. Surveys were carried out in nine forest remnants of Atlantic rainforest located in northern Paraná State, southern Brazil. Male euglossine bees were collected with an entomological net when visiting scent-baits, between 10:00 am and 1:00 pm, from October to December of 2001 and 2006. A total of 360 E. violacea males were captured in the nine forest fragments studied. The number of bees attracted to scent baits in each forest patch varied from zero to 261. A very high association (r = 0.993) was detected between the forest patch size and the visitation rate of E. violacea males at different sites, with the highest mean number of males visiting baits/sampling (43.5) being observed for bees from the largest forest remnant. Although alternative hypothesis should not be discharged for the decline in the abundance or absence of E. violacea in small forest patches, our results indicate that populations of this euglossine species need larger forest areas for existing.
Assuntos
Abelhas/fisiologia , Árvores , Animais , Brasil , Masculino , Dinâmica PopulacionalRESUMO
Eufriesea violacea (Blanchard) is a very seasonal euglossine species, more frequently found in the southern and southeastern regions of Brazil. A number of studies have revealed large variations in the abundance of males of this species present in Atlantic Forest remnants throughout both regions. In this paper, we report variations in the abundance of E. violacea males sampled in several forest patches of different sizes (ranging from 10 to 580 ha), and we propose that this species is possibly sensitive to the reduction in size of forest remnants. Surveys were carried out in nine forest remnants of Atlantic rainforest located in northern Paraná State, southern Brazil. Male euglossine bees were collected with an entomological net when visiting scent-baits, between 10:00 am and 1:00 pm, from October to December of 2001 and 2006. A total of 360 E. violacea males were captured in the nine forest fragments studied. The number of bees attracted to scent baits in each forest patch varied from zero to 261. A very high association (r = 0.993) was detected between the forest patch size and the visitation rate of E. violacea males at different sites, with the highest mean number of males visiting baits/sampling (43.5) being observed for bees from the largest forest remnant. Although alternative hypothesis should not be discharged for the decline in the abundance or absence of E. violacea in small forest patches, our results indicate that populations of this euglossine species need larger forest areas for existing.
Eufriesea violacea (Blanchard) é uma espécie de Euglossini bastante sazonal, de ocorrência mais frequente no Sul e Sudeste do Brasil. Vários estudos revelaram grandes variações na abundância de machos de E. violacea em remanescentes de Mata Atlântica dessas duas regiões brasileiras. Neste artigo, relatamos variações na abundância de machos de E. violacea de vários fragmentos florestais de tamanhos distintos (variando de 10 a 580 ha), e sugerimos que a espécie seja provavelmente sensível à redução no tamanho da área do fragmento florestal. As amostragens foram realizadas em nove remanescentes florestais de Mata Atlântica, localizados no Norte do Paraná, Sul do Brasil. Machos euglossíneos foram coletados com rede entomológica durante suas visitas às iscas-odores, entre 10:00h e 13:00h, de outubro a dezembro de 2001 e 2006. O total de 360 machos de E. violacea foi coletado nos fragmentos estudados. O número de abelhas atraídas às iscas em cada área variou de zero a 261 indivíduos. O tamanho do fragmento foi proporcionalmente relacionado (r = 0,993) à taxa de visitação de machos de E. violacea nas diferentes áreas, sendo que o maior número médio de machos (43,5) por amostragem foi observado para abelhas do fragmento florestal maior. Embora hipóteses alternativas para o declínio na abundância ou ausência de E. violacea em fragmentos florestais menores não devam ser descartadas, esses resultados indicam que populações de E. violacea necessitam de áreas florestais maiores para sua sobrevivência.