982 resultados para Ictiologia - Parana, Rio


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Avaliou-se a variabilidade genética dos estoques de reprodutores e dos peixes jovens de Piaractus mesopotamicus de três pisciculturas do estado do Paraná, utilizadas no programa de aumento de estoque de peixes no rio Paranapanema. Foi utilizado o marcador RAPD para avaliar as amostras do estoque de reprodutores e dos peixes jovens das pisciculturas de Palotina, Cambará e Andirá. A porcentagem de fragmentos polimórficos e o índice de diversidade genética de Shannon dos estoques de reprodutores variaram de 75,0% a 71,4% e de 0,434 a 0,376, respectivamente. Os peixes jovens das pisciculturas apresentaram valores mais elevados para ambos os parâmetros, com exceção da piscicultura de Palotina, na qual o índice de diversidade genética de Shannon foi semelhante. Os estoques de reprodutores apresentaram alta variabilidade genética, e esta foi mantida nos peixes jovens.

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The marsh deer is the largest neotropical cervid with morphological and ecological adaptations to wetlands and riparian habitats. Historically, this now endangered species occupied habitats along the major river basins in South America, ranging from southern Amazonia into northern Argentina to the Parana river delta. This particularly close association with wetlands makes marsh deer an excellent species for studying the effects of Pleistocene climatic changes on their demographic and phylogeographic patterns. We examined mitochondrial DNA variation in 127 marsh deer from 4 areas distributed throughout the Rio de]a Plata basin. We found 17 haplotypes in marsh deer from Brazil, Bolivia and Argentina that differed by 1-8 substitutions in a 601 bp fragment of mitochondrial control region sequence, and 486 bp of cytochrome b revealed only 3 variable sites that defined 4 haplotypes. Phylogeny and distribution of control region haplotypes suggest that populations close to the Pantanal area in central Brazil underwent a rapid population expansion and that this occurred approximately 28,000-25,000 years BP. Paleoclimatic data from this period suggests that there was a dramatic increase for precipitation in the medium latitudes in South America and these conditions may have fostered marsh deer's population growth.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Habitat fragmentation and diseases have resulted in a decline of the marsh deer (Blastocerus (dichotomus) throughout its South American range. Our objectives were to determine whether marsh deer intended for translocation from a region of the Rio Parana Basin had been infected previously by foot-and-mouth disease virus (FMDV) and whether they were carrying virus We captured marsh deer from June to October 1998 and collected blood from 108 animals and esophageal-pharyngeal fluid from 53 Serum was tested for antibodies against three FMDV serotypes (O, A, and C) by liquid-phase-blocking sandwich enzyme-linked immunosorbent assay (ELISA) Esophageal-pharyngeal fluid was tested for FMDV RNA by reverse transcription polymerase chain reaction (RT-PCR) and inoculation into three successive baby hamster kidney (BHK-21) cell subcultures, followed by RT-PCR of cultures We detected low log(10) titers (range 1 0-1 5) to FM DV subtype A(24) Cruzeiro in 19 of 108 sampled marsh deer, but failed to isolate FMDV or detect FMDV RNA in any samples we conclude that marsh deer from our study site were unlikely to carry FMDV, however, as a preventive measure, the 19 animals with titers for FMDV were not sent to FMDV-free Brazilian states

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Moenkhausia diamantina, nova espécie, é descrita de tributário do rio Paraguaçu, BA, nordeste do Brasil. Esta espécie é distinguida das demais congêneres por caracteres relacionados ao padrão de coloração do corpo, pela presença de escamas na linha mediana pré-dorsal e número de raios da nadadeira anal.

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

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The aim of this paper was to evaluate the artisanal fisheries in the village of fishermen of Bairro da Ponte, Jurumirim reservoir. Data were collected using production forms which were filled daily by a data collector, in 2005 and 2006. The fishery yield was estimated at 15.7 kg ha(-1) year(-1), the average yield was 12.5 t year(-1) and catch per unit effort (CPUE) was 10.5 kg fisherman(-1) day(-1). We recorded 26 species of landed fish in this activity, being the "traira" (Hoplias malabaricus) the most landed fish in terms of biomass with 6,158.5 kg, representing 24.5%, of the total landed. Seasonally, the CPUE ranged from 14.5 kg fisherman(-1) day(-1) in summer/2005 to 9.0 kg fisherman(-1) day(-1) in spring/2006. The average CPUE by type of fish also showed a marked seasonality. In summer of 2005 and 2006, "curimbata" was the most landed fish, with CPUE kg fisherman(-1) day(-1) of 6.9 and 6.2, respectively. The "piavas" were the most landed fish in autumn with CPUE of 2.4 (year 2005) and 2.3 (year 2006) kg fisherman(-1) day(-1), and "traira" in winter with CPUE ranging from 3.0 to 4.0 kg fishrman(-1) day(-1), in 2005 and 2006, respectively. The mathematical modeling of simple linear regression indicated positive relationships between the monthly fish production and the number of boats in activity and of fishing trips. The study concluded that fishing is sustained only by native species; with marked seasonality for catching fish and that the area of fishing examined of the Jurumirim reservoir is among the most productive areas of the Upper Parana basin.

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A small and poorly diversified bivalve fauna from Taciba Formation, Itarare Group, Parana Basin (State of Santa Catarina, Mafra Municipality), is described in this paper for the first time, based on new findings. The fauna is recorded in a 30 cm thick interval of fine sandstone locally at the top of Taciba Formation, in the Butia quarry. The studied fossil-bearing sand-stone bed is a marine intercalation recording a brief eustatic rise in sea-level, probably following glacier retreat and climate amelioration at the end of a broad glacial scenario. The fauna is mainly dominated by productid brachiopods, which are not described here, and rare mollusk shells (bivalves and gastropods). Two bivalve species were identified: Myonia argentinensis (Harrington, 1955), and Aviculopecten multiscalptus (Thomas, 1928). The presence of Myonia argentinensis is note-worthy since this species is also present in the Baitaca assemblage found in marine siltstones (Baitaca assemblage) of the Rio do Sul Formation, cropping out at the Teixeira Soares region, Parana State. This species is also recorded in the bivalve fauna from the Bonete Formation, Pillahinco Group, Sauce Grande Basin, Buenos Aires Province, in Argentina. Hence, the marine bivalves of the Taciba Formation are associated with the transgressive event that characterizes the Eurydesma fauna, indicating a Late Asselian-Sakmarian age for the bivalve fauna. Presence of the Myonia argentinensis megadesmid species reinforces the Gondwanic nature of the studied fauna.

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The deposits of the Permian Teresina Formation are mainly characterized by fi ne-grained siliciclastic rocks and centimetric intercalations of tempestites (bioclastic sandstones and coquinas). Despite the relevance of the bivalve-rich carbonate beds of the Teresina Formation to paleoenvironmental studies, their taphonomy is still poorly studied. The fossil concentration studied in this work was found in a quarry in the city of Irati, Rio Preto district, Parana State. The fossil concentration is located in the middle/upper portion of the unit, far from the top. The studied bed is a bioclastic, intraclastic, peloidal, grainstone/ packstone, with abundant bivalve shell fragments, pelitic and micritic intraclasts, peloids, rare ooids and oncoids, as well as permineralized of Lycophyta microphylles and fish scales. The grains of this carbonate concentration show: high degree of time-averaging, variable degree of packing (dense to disperse), no sorting and chaotic orientation. Notably, the concentration includes a mixture of elements which are indicative of: a) restrictive, low energy, carbonate environment (peloids, ooids and oncoids); b) subaerial environment surrounding the main body of water (Lycophyta microphylles) and c) quiet-water environment punctuated by storm events, where the suspension-feeding bivalves thrived. At least four depositional events caused by storm fl ows were recorded. The amalgamated nature of the bed is a result of storm events in an intracratonic basin with very low seafl oor slope and low rates of sedimentation and subsidence.

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This article presents preliminary information about the reproduction of two species of freshwater stingrays of the genus Potamotrygon, found in the Upper Parana River (Southwest Brazil), where these animals are exotic. Males of P. motoro and P. falkneri become sexually mature around 270 mm and 260 mm of disc width (DW), respectively. Females become sexually mature around 330 mm of DW in P. motoro and 325 mm in P. falkneri. In both species, females are bigger and heavier than males, reaching about 700 mm of DW and 20 kg. Copulating has not been recorded, but one courtship ritual has been observed during the dry season. Mature males present a different dentition from females and young males, which is probably related to their reproductive behavior instead of to their feeding habit. The female fertility has varied from one to three offspring. A miscarriage has been observed at different stages of embryonic development always when pregnant females were captured. In spite of the great history of anthropization of the study area, it seems that hydrological cycles are related to the reproduction of stingrays. Nevertheless, it would be necessary to conduct deeper studies to verify or not this influence.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Microstratigraphic, sedimentological, and taphonomic features of the Ferraz Shell Bed, from the Upper Permian (Kazanian-Tatarian?) Corumbatai Formation of Rio Claro Region (the Parana Basin, Brazil), indicate that the bed consists of four distinct microstratigraphic units. They include, from bottom to top, a lag concentration (Unit 1), a partly reworked storm deposit (Unit 2), a rapidly deposited sandstone unit with three thin horizons recording episodes of reworking (Unit 3), and a shell-rich horizon generated by reworking/winnowing that was subsequently buried by storm-induced obrution deposit (Unit 4). The bioclasts of the Ferraz Shell Bed represent exclusively bivalve mollusks. Pinzonella illusa and Terraia aequilateralis are the dominant species. Taphonomic analysis indicates that mollusks are heavily time-averaged (except for some parts of Unit 3). Moreover, different species are time-averaged to a different degree (disharmonious time-averaging). The units differ statistically from one another in their taxonomic and ecological composition, in their taphonomic pattern, and in the size-frequency distributions of the two most common species. Other Permian shell beds of the Parana Basin are similar to the Ferraz Shell Bed in their faunal composition (they typically contain similar sets of 5 to 10 bivalve species) and in their taphonomic, sedimentologic, and microstratigraphic characteristics. However, rare shell beds that include 2-3 species only and are dominated by articulated shells preserved in life position also occur. Diversity levels in the Permian benthic associations of the Parana Basin were very low, with the point diversity of 2-3 species and with the within-habitat and basin-wide (alpha and gamma) diversities of 10 species, at most. The Parana Basin benthic communities may have thus been analogous to low-diversity bivalve-dominated associations of the present-day Baltic Sea. The 'Ferraz-type' shell beds of the Parana Basin represent genetically complex and highly heterogeneous sources of paleontological data. They are cumulative records of spectra of benthic ecosystems time-averaged over long periods of time (10(2)-10(4) years judging from actualistic research). Detailed biostratinomic reconstructions of shell beds can not only offer useful insights into their depositional histories, but may also allow paleoecologists to optimize their sampling designs, and consequently, refine paleoecological and paleoenvironmental interpretations.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)