Estudio de caso: el sistema de la cuenca del río Bogotá: resumen = Case study: the Bogota river basin: summary

Incluye Bibliografía

Feeding ecology of Dash-dot Tetra Hemigrammus belottii (Steindachner 1882) (Characiformes: Characidae) in the streams of the Urucu River basin, central Amazonia, Brazil

O presente estudo descreve a dieta da espécie Hemigrammus belottii (Characiformes: Characidae) coletados na bacia do Rio Urucu no município de Coari, Amazonas, (Brasil), buscando responder o seguinte questionamento: Qual a influência dos períodos hidrológicos (seco e chuvoso) e da distribuição espacial na dieta de H. belottii? Os espécimes tiveram seus estômagos retirados e os itens alimentares pesados e identificados para posteriores análises relacionadas à intensidade alimentar, pelo Índice de Repleção (IR%) e pelo índice de importância alimentar (IAi%). Foi analisado um total de 227 espécimes, com comprimento padrão médio de 16,54 mm ± 5,6 mm. Baseado no IR% verificou-se para H. belottii uma maior intensidade alimentar durante o período da seca. A dieta da espécie foi composta predominantemente pelos itens Formicidae (IAi% = 69,6), fragmento de exoesqueleto alóctone (IAi% = 17,7) e Coleoptera (IAi% = 6,0), com sua composição se mostrando independente de períodos hidrológicos e de sua distribuição espacial, que pode ser atribuído à alta disponibilidade de itens alimentares utilizados pela espécie durante o ano todo. De um modo geral H. belottii evidenciou um hábito alimentar insetívoro generalista, com predomínio de itens de origem alóctone.

A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon river basin, Brazil

Uma nova espécie de hilídeo do gênero Scinax é descrita e ilustrada. O novo táxon foi encontrado na Amazonia, região norte do Brasil, municípios de Maués e Careiro da Várzea, Estado do Amazonas. A nova espécie é caracterizada pelo tamanho moderado (machas com media de comprimento rostro-cloacal de 36.3mm); corpo robusto; mancha axiliar e inguinal grande, laranja bordeada de preto; e saco vocal bilobado. Essa nova espécie foi encontrada em floresta primária e secondária sobre ramos de arbustos e árvores sobre ou próximo a poças permanentes ou áreas alagadas.

DNA barcode of Parodontidae species from the La Plata river basin - applying new data to clarify taxonomic problems

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

Reproductive migration of fish and movement in a series of reservoirs in the Upper Parana River basin, Brazil

AbstractThis study evaluates the effectiveness of two fish passes at two hydropower dams (Canoas I and II) in the Upper Parana basin, which form part of a cascade of three reservoirs. Fish from 12 migratory species (3089 specimens) were captured during their ascending, reproductive migration and were tagged with hydrostatic tags. The recapture data (294 specimens over two consecutive years) showed that there is a strong tendency for the maintenance of ascending migration through reservoirs with fish passes but with differences in migratory activity within the same species. No eggs, larvae or juveniles of these species were found in samples collected over 5 years in the reservoirs above the fish passes. These data suggest that fish passes have contributed to the restoration of the migratory routes of adult fish but that in the absence of suitable spawning or nursery habitats for these species; they probably act as ecological traps and do not contribute to the recruitment of the species.

Trends in planktonic copepod diversity in reservoirs and lotic stretches in a large river basin in South America

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

The fish fauna in tropical rivers: The case of the Sorocaba river basin, Sao Paulo, Brazil

A survey was carried out on the fish species in the Sorocaba. River basin, the main tributary of the left margin of the Tiete River, located in the State of Sao Paulo, Brazil. The species were collected with gill nets. After identification of the specimens, their relative abundance, weight and standard length were determined. Up to the present moment there are not any studies that focus this subject in this hydrographic basin. Fifty-three species, distributed in eighteen families and six orders were collected. Characiformes were represented by twenty-eight species, Siluriformes by seventeen species, the Gymnotiformes by three species, Perciformes and Cyprinodontiformes by two species, and the Synbranchiformes by one species. Among the collected species there were two exotic. The most abundant species were Astyanax fasciatus and Hypostomus ancistroides. In relation to total weight the most representative species were Hoplias malabaricus and Hypostomus ancistroides. Cyprinus carpio, Prochilodus lineatus, Schizodon nasutus and Hoplias malabaricus were the most representative species in relation to average weight. Largest standard length were recorded for Sternopygus macrurus, Steindachnerina insculpta, Eigenmannia aff. virescens and Cyprinus carpio.

Life-history strategies associated to reproduction of three Hyphessobrycon species (Characidae) in lentic environments of upper Paraná River basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The stream fish fauna from three regions of the Upper Paraná River basin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Identification guide to some Diaptomid species (Crustacea, Copepoda, Calanoida, Diaptomidae) of "de la Plata" River Basin (South America)

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

Erosion rates and landscape evolution of the lowlands of the Upper Paraguay river basin (Brazil) from cosmogenic Be-10

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pb-210 and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Regulation of the abundance and turnover of copepod species by temperature, turbidity and habitat type in a large river basin

Freshwater copepods were sampled in the La Plata River basin to identify the processes that affect beta diversity and to determine the main factors influencing their geographical distribution and patterns of endemism. Beta diversity patterns exhibited strong dissimilarity between locations; the turnover process was predominant and indicated a replacement of species along the basin. Redundancy analysis indicated the presence of two large sets of species separated geographically by a boundary zone, with several associated variables. Northern species were associated with water transparency and temperature, mean air temperature, mean air temperature during winter and minimum air temperature of coldest month, indicating that these species are not tolerant to low temperatures and are abundant in reservoirs that are common in the upper stretch of the Paraná River basin. Southern species were related with amplitude of air temperature, turbidity, total phosphorus and total suspended matter, indicating that these species are polythermic and have adapted to live in river stretches. From 20 environmental variables analyzed in our study, partial least squares analysis indicated four variables with increased retention of effects on copepod abundance: air temperature, minimum temperature of coldest month, turbidity and transparency. Because almost all of the species found in this study occurred across a wide range of habitat types, the cause of the separation between river and reservoir species could be considered to be more anthropogenic than natural, and it primarily affected species abundance. For certain members of the northern group of copepod species, distribution was dependent on high temperatures, whereas the distribution of the southern group indicated that the species were polythermic.

Knodus dorsomaculatus (Characiformes: Characidae), a new species from Teles Pires River, Tapajos River basin, Brazil

Knodus dorsomaculatus, a new species, is described from Teles Pires River, a tributary of the Tapajos River, Brazil. It can be distinguished from its congeners by the presence of a conspicuous dark blotch on the base of the first five branched dorsal fin rays and the presence of ii,9 dorsal fin rays. Additional comparisons between K. dorsomaculatus and its congeners are presented.