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| Registros recuperados: 1.204 | |
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| Teresa,Fabrício Barreto; Casatti,Lilian. |
| We assessed the preference of 10 fish species for depth and velocity conditions in forested streams from southeastern Brazil using habitat suitability criteria (HSC curves). We also tested whether preference patterns observed in forested streams can be transferred to deforested streams. We used data from fish sampled in 62 five-meter sites in three forested streams to construct preference curves. Astyanax altiparanae, A. fasciatus, Knodus moenkhausii, and Piabina argentea showed a preference for deep slow habitats, whereas Aspidoras fuscoguttatus, Characidium zebra, Cetopsorhamdia iheringi, Pseudopimelodus pulcher, and Hypostomus nigromaculatus showed an opposite pattern: preference for shallow fast habitats. Hypostomus ancistroides showed a multimodal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Depth; Fish assemblages; Habitat preference; Riparian forest; Velocity. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200395 |
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| Giora,Júlia; Fialho,Clarice B.; Dufech,Ana Paula S.. |
| This study aims to describe the feeding habits of a population of the weakly electric fish Eigenmannia trilineata from Southern Brazil through the monthly frequency variation of replection (RI) and hepatosomatic (HSI) indexes, condition factor (CF) and dietary analysis of the species, besides the comparison of the results with abiotic factors. We collected 428 specimens from June/2002 to May/2003 with a dip net and electric fish detector. Stomach contents were analyzed using three measurements: frequency of occurrence of food items, percentage composition per prey type and feeding importance index. Microcrustacea and autochthonous insects were the dominant food items in the stomachs of E. trilineata. The adults (males larger than 63.5 mm and females larger... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gymnotiformes; Electric-fish; Diet; Southern Brazil. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000200007 |
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| Paiz,Leonardo M.; Baumgärtner,Lucas; Graça,Weferson J. da; Margarido,Vladimir P.; Pavanelli,Carla S.. |
| ABSTRACT We provide cytogenetic data for the threatened species Gymnogeophagus setequedas, and the first record of that species collected in the Iguaçu River, within the Iguaçu National Park’s area of environmental preservation, which is an unexpected occurrence for that species. We verified a diploid number of 2n = 48 chromosomes (4sm + 24st + 20a) and the presence of heterochromatin in centromeric and pericentromeric regions, which are conserved characters in the Geophagini. The multiple nucleolar organizer regions observed in G. setequedas are considered to be apomorphic characters in the Geophagini, whereas the simple 5S rDNA cistrons located interstitially on the long arm of subtelocentric chromosomes represent a plesiomorphic character. Because G.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; Conservation; Iguaçu River; Karyotype; Paraná River. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000200211 |
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| Oyakawa,Osvaldo Takeshi; Fichberg,Ilana; Langeani,Francisco. |
| A new species of Harttia, tribe Harttiini, is described from tributaries of upper portions of rio Paraná drainage. The new species, the smallest known species of the genus, attaining up to 74.0 mm of standard length, can be distinguished from its congeners by the combination of the following characters: abdomen completely covered by plates, a single preanal plate, plates of the gular area in broad contact with the canal plate. Harttia absaberi is the second species of the genus known from the upper portion of rio Paraná drainage. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Harttiini; Loricarioidea; Neotropical fishes; Ostariophysi; Taxonomy. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000400779 |
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| Siqueira,Mayara S.; Leão,Taynara R. F.; Rodrigues,Robson A.; Farias,Karine N. N.; Silva,André L. N.; Marcondes,Sandriely F.; Veiga,Marcelo L.; Franco-Belussi,Lilian; Fernandes,Carlos E.. |
| ABSTRACT Pygocentrus nattereri is a carnivorous fish widely distributed in the Brazilian wetland and occupies different river strata. Based on the sexual maturity, the standard length (SL) has been used to categorize age and physiological attributes. However, hematological parameters and their relationship with age and growth features are unknow. Here, the aim was to evaluate the hematological profile and leukocyte data of juvenile and adult specimens, associating it with SL. Specimens of both sexes were weighted, and SL were measured for classify as juveniles (SL ≤16.0 cm) and adults (SL ≥16.1 cm). Blood was collected to perform the hemogram, for leukocyte quantification and ultrastructural descriptions. In general, hemogram values and leukocyte,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Hematology; Leukocyte ultrastructural morphology; Standard length. |
| Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252021000100216 |
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| Espínola,Luis Alberto; Júlio Junior,Horácio Ferreira; Benedito,Evanilde. |
| The allocation of assimilated energy may be influenced by seasonal changes, growth, and reproductive cycle of fish, food consumption and environmental conditions. The objective of this research was to evaluate the energetic variations of Cichla kelberi in the upper Paraná River floodplain, analyzing the caloric content in muscles, gonadosomatic index (GSI), and the condition factor between assessed systems, sex, and stage of gonadal maturation. The results obtained in the present study permit assuring that this is a species that efficiently converts the resources of the environment into energy. Although presenting higher condition factor in the environment where there is a greater ease in getting food (Paraná subsystem), the energy identified in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Condition factor; Energetic density; Gonadal maturation; Paraná and Baía Rivers. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200015 |
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| Loures,Raquel Coelho; Pompeu,Paulo Santos. |
| Damming rivers to generate hydroelectric energy causes a series of changes in the environment, including impacts on the ichthyofauna. Knowledge of the fish community immediately downstream from a hydroelectric dam can help to reduce the negative effects of dam operation, such as fish entrance into the draft tube during turbines maintenance. We evaluated the temporal variation in fish community composition and abundance, near Três Marias Hydroelectric Dam (TMD), and its relationship with abiotic variables. Samples (n = 18) were carried out using gill nets in the tailrace of the dam, over the course of a hydrological year, at six time points during a 24-hour period. Abiotic data were also sampled to assess the relationship with the biotic data. In the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish kill; Ichthyofauna; Impact; Nictemeral; Operation. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000400006 |
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| Anjos,Maeda Batista dos; Zuanon,Jansen. |
| Small streams are important components of the landscape in terra firme forests in central Amazonia and harbor a large number of fish species. Nevertheless, the lack of a common sampling protocol in studies of this ichthyofauna hinders comparisons among available results. This study evaluates how the length of stream reach sampled affects estimates of local fish species density in 1st, 2nd, and 3rd order streams, and proposes a mean minimum sampling length that best approximates the absolute number of species in a given stream segment. We sampled three streams in the Biological Dynamics of Forest Fragments Project's study sites, between May and August 2004. At each stream, one 1st order, one 2nd order, and one 3rd order segment was sampled. We sampled five... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish diversity; Fish abundance; Stream size; Species composition; Species accumulation curves. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000100006 |
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| Basallo,Alexander; Oddone,Maria Cristina. |
| The present study analyzed the sexual development, sizes at maturity and morphometric relationships for both sexes of Sympterygia acutaand S. bonapartii, endemic of south-western Atlantic Ocean. The examined specimens were obtained through research cruises and commercial fishing trips, during 2011 and 2012, along the southern Brazilian coast, in latitudes ranging from 34°28'S to 31°29'S and at depths between 15 and 142 m. Significant differences (p<0.05) in S. bonapartii and in S acutabetween sexes for the relationships total length (cm) - disc width (cm) and total length - total/eviscerated weight (g) respectively, demonstrated sexual dimorphism during the development in both species. The estimated size at maturity for males and females, respectively,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Endemic; Maturity; Morphometric; Oviparity; Reproduction. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000400771 |
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| Azevedo,Pedro G; Melo,Rafael M. C; Young,Robert J.. |
| Knowledge concerning the behavior of wild freshwater fishes in Brazil is restricted to a few studies, despite such studies being able to answer fundamental questions about conservation. Species of Brycon are amongst the most threatened in the Neotropics, particularly in southeast Brazil, due to anthropogenic activities in this region. This study investigated the feeding and social behaviors of the endangered fish, Brycon devillei in the Preto River, Jequitinhonha basin, Minas Gerais State, Brazil. Behavioral data were collected by snorkeling with four spatially separated groups (habituated), and direct observations of shoals were made using an underwater video camera (a total of 448 hours of observations). This species showed diverse tactics to obtain... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feeding association; Feeding tactics; Jequitinhonha basin; Natural history; Underwater observations. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000400011 |
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| Sarmento-Soares,Luisa Maria; Cabeceira,Fernando G.; Carvalho,Lucélia Nobre; Zuanon,Jansen; Akama,Alberto. |
| Centromochlus actually comprises eleven species, being the most problematic genus among the Centromochlinae, including morphologically heterogeneous taxa. The Centromochlus species have a wide distributional area on northern South America. Centromochlus meridionalis, new species, is described from headwaters of rio Teles Pires, contributor of rio Tapajós, Mato Grosso State, Brazil, and represents one of the southernmost records of a centromochlin catfish for Meridional Amazon rivers. Centromochlus meridionalis is promptly distinguished from its congeners by the small orbital diameter (relative to head length), and also by the combination of absence of first nuchal plate, anterior margin of dorsal-fin spine smooth, six branched rays in anal fin, seven pairs... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Centromochlinae; Forest streams; Taxonomy; Teles Pires. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000400797 |
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| Korzelecka-Orkisz,Agata; Szalast,Zuzanna; Pawlos,Dorota; Smaruj,Izabella; Tañski,Adam; Szulc,Joanna; Formicki,Krzysztof. |
| This study describes the egg membrane structures of angelfish (Pterophyllum scalare), morpho-physiological changes during angelfish embryogenesis from activation to hatching under optimal conditions (28°C; pH 6.8), the developing larvae and fry, the effect of alkaline pH on the early developmental stages of the species, the relationship between food item size and fry survival. Egg membranes (thin, transparent, 1.67-2.18 µm thick) are covered by a sticky substance. The amber-coloured angelfish eggs were oval in shape, with average diameters of 1.436 and 1.171 mm, i.e., a mean volume of 1.033 ± 0.095 mm³. The survival rate of embryos and larvae kept in water with an elevated, slightly alkaline pH was very low: as few as 2% of the embryos survived, while in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Egg; Embryogenesis; Embryonic motorics; Larvae morphometry; Membrane structures. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000300010 |
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| Registros recuperados: 1.204 | |
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