Habitat split and the global decline of amphibians

The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely habitat split- defined as human- induced disconnection between habitats used by different life history stages of a species- which forces forest- associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development ( the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

Vertebrados consumidos por Brycon opalinus (Pisces, Characidae) em rios do Parque Estadual da Serra do Mar, SP

A análise da alimentação da pirapitinga do sul (Brycon opalinus), peixe ameaçado de extinção de rios da Mata Atlântica da Serra do Mar na região Sudeste, revelou a ocorrência de itens alimentares incomuns. As espécies deste gênero são onívoras oportunistas e alimentam-se de itens vegetais e animais, tais como: flores, folhas, frutos e sementes e grande variedade de insetos. em três rios do Parque Estadual da Serra do Mar - Núcleo Santa Virgínia foram encontrados exemplares de B. opalinus que consumiram três itens animais incomuns, os anfíbios Hypsiboas aff. pardalis (Anura, Hylidae) e Eleutherodactylus guentheri (Anura, Leptodactylidae) e o mamífero Oligoryzomys cf. nigripes (Rodentia, Sigmodontinae). O registro do consumo destas espécies de vertebrados foi relacionado com o período de chuvas, quando o material animal ou vegetal carreado até o rio pode ser consumido por B. opalinus, mesmo que não sejam itens habituais para a espécie. A mata ripária preservada, como foi verificado nos três rios do Parque Estadual da Serra do Mar - Núcleo Santa Virgínia (SP), é de suma importância para o fornecimento de itens alimentares animais e vegetais e pela manutenção das condições bióticas e abióticas para a sobrevivência de B. opalinus.

Habitat Split as a Cause of Local Population Declines of Amphibians with Aquatic Larvae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of physical habitat degradation on the stream fish assemblage structure in a pasture region

We compared the fish assemblage structure from streams with different intensities of physical habitat degradation and chemical water pollution by domestic sewage in southeastern Brazil. Eight streams (R1-R8) showing less disturbed or more disturbed conditions of chemical water quality and of physical habitat quality were selected. Cumulative abundance and biomass, combined in ABC plots, revealed (i) biomass curves above the abundance curves, represented by the streams R1-R2 (water and habitat less disturbed) and R5-R6 (water more disturbed and habitat less disturbed), and (ii) biomass curves below the abundance curves, represented by the streams R3-R4 (water less disturbed and habitat more disturbed) and R7-R8 (water and habitat more disturbed). The quantitative structure of the ichthyofauna showed significant correspondence with physical habitat condition but not with chemical water quality. The most significant species to cause the dissimilarity between less disturbed and more disturbed physical habitats was the exotic Poecilia reticulata. Such results indicate that in the focused region-with little influence of industrial pollution, noncritical domestic sewage discharge, and soil predominantly used for pasture-streams with high physical habitat integrity possess a differently structured ichthyofauna than streams with relatively low physical habitat integrity, reinforcing the importance of the physical habitat quality and riparian conservation along these water courses, warranting the conservation of these systems. Indeed, our results also reinforce the importance of including biotic descriptors, particularly of the ichthyo-fauna, in water-monitoring programs designed to reveal signs of human interference.

Biology of a catfish, Trichomycterus sp (Pisces, Siluriformes), in a pristine stream in the Morro do Diabo State Park, southeastern Brazil

The distribution, activity, diet, and reproduction of an undescribed catfish species of the genus Trichomycterus (Trichomycteridae) were studied in the Morro do Diabo State Park, an important conservation area in the Rio Paranapanema basin, State of São Paulo, southeastern Brazil. Trichomycterus sp. is a rheophilic species occurring solely in the riffle areas of the streams and hunts mostly immature aquatic insects during the day by picking them from the substrate. The population has a balanced sex ratio, but females were uncommon in the smallest and largest size classes suggesting that females demonstrate a more accelerated growth pattern. Presence of mature individuals throughout the year represents an opportunistic reproductive tactic for fishes living in fast flowing waters, where the clutches could be shifted by the current, but the high incidence of mature individuals in the wet season may be related to optimal environmental conditions for juveniles during that period. Because of the restriction of Trichomycterus sp. to riffle environments, the conservation of this species depends on the maintenance of the original characteristics of these headwaters. That demands protecting the riparian vegetation and consequently the stream from excessive siltation resulting from runoff and erosion.

Identification of key microhabitats for fish assemblages in tropical Brazilian savanna streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of forest cover and mesohabitat types on functional and taxonomic diversity of fish communities in Neotropical lowland streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Grass-dominated stream sites exhibit low fish species diversity and dominance by guppies: an assessment of two tropical pasture river basins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Plant inhabiting mites (Acari) from the Cerrado biome of Mato Grosso State, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alterações no Código Florestal Brasileiro: impactos potenciais sobre a ictiofauna

É apresentada uma análise dos possíveis impactos que a diminuição da vegetação nativa, notadamente das florestas ripárias, pode causar sobre a ictiofauna. Três conjuntos de aspectos funcionais primordiais desempenhados pelas florestas ripárias são discutidos: transferência de energia solar ao ambiente aquático, interceptação de nutrientes e sedimentos que adentram nos rios e trocas de material orgânico entre o sistema terrestre e aquático. Conclui-se que qualquer alteração que se traduza em mais perdas de vegetação nativa, seja em áreas de preservação permanente ou em reservas legais, pode gerar perdas de espécies, homogeneização faunística e diminuição de biomassa íctica.

Fish assemblages in stream stretches occupied by cattail (Typhaceae, Angiospermae) stands in Southeast Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oportunismo alimentar de Knodus moenkhausii (Teleostei, Characidae): uma espécie abundante em riachos do noroeste do Estado de São Paulo, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Predação de morcegos (Phyllostomidae) pela cuíca d’água Chironectes minimus (Zimmermann, 1780) (Didelphimorphia, Didelphidae) e uma breve revisão de predação em Chiroptera

Bats are predated for some of vertebrates and invertebrates. Some opportunistic species preys these animals' prisoners in nests during procedures of capture in field. This study records the predation of Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) for Chironectes minimus (Zimmermann, 1780) on riparian forest of the brook Talhadinho belonging of the São Paulo, São Paulo, Southeast Brazil, and also presents a lifting previous of mammalian what they present the same one behavior opportunistic predatory, discussing measures simple to avoid this type of predation.

Importância da vegetação ripária em região intensamente desmatada no sudeste do Brasil: um estudo com peixes de riacho

e investigated whether the presence of degraded riparian forests along streams influences the fish communities' composition in comparison with environments completely deforested. Stream stretches (1st to 3rd order) with degraded riparian forest (n = 20) and without riparian forest (n = 20) in the micro-basins of Aguape and Tiete (downstream portion) rivers, northwest of São Paulo, Brazil, were selected for ichthyofauna sampling. Overall, 6,695 individuals, representing six orders, 17 families and 55 species were registered. Forested streams presented higher observed and estimated richness than deforested streams. However, forested streams, on average, had lower total richness and richness of tolerant species than deforested streams, indicating higher beta diversity among forested streams. A difference on the species composition between streams groups was also registered. Most of the unique species to deforested streams, and of those caught in greater abundance and frequency in these streams, are tolerant to structural degradation of the habitat. In contrast, most species that occurred exclusively or preferentially in forested streams have specialized habits and are more dependent on micro-habitats associated with the presence of riparian vegetation. Our results indicate that streams with riparian vegetation, though degraded, are able to maintain distinct communities when compared to those found in completely deforested streams, allowing the occurrence of species with more specialized habits and contributing to the maintenance of communities regionally more diverse.

Fitossociologia e distribuição de espécies arbóreas em uma floresta ribeirinha secundária no município de Rio Claro, SP, Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)