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| Duarte,Silvana; Araújo,Francisco Gerson. |
| The armored catfish Loricariichthys spixii (Steindachner, 1882) is the most abundant member of the Loricariidae family in the Lajes reservoir (22º42'-22º50'S 43º53' -44º05'W), the largest dam in the State of Rio de Janeiro State, but little is known about its biology and life cycle. A standardized fish sampling program in three zones of the reservoir (lower, middle and upper reaches), during three annual cycles: monthly in 1994/1996 and bi-monthly in 1997 was conducted out aiming to assess and add knowledge of the population structure of this species. Fishes were caught using gill nets (50 m long, 3 m depth and 25 to 45 mm meshes), amounting 160 samples. Water temperature, pH and transparency were registered at each sample to correlate with fish abundance.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lajes; Reservoir; Loricariidae; Distribution; Environmental parameters. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000200017 |
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| Duarte,Silvana; Caetano,Carla de Brito; Vicentini,Rafaela Nascimento; Araújo,Francisco Gerson. |
| The catfish Trachelyopterus striatulus Steindachner, 1877 is a very abundant fish species in reservoirs in Southeast Brazil, and its relative abundance seems to be increasing in several lentic environments. Despite of being a very common species, few information is available on its distribution and other aspects of ecology. The Lajes reservoir (22º42'-22º50'S e 43º53'-44º05'W) is the largest manmade lake for hydropower purposes in Rio de Janeiro State, where this species rank among the top abundant fishes, both in number and in biomass. Its relative abundance were compared in three zones of the reservoir (upper, central and lower), based on a standardized program, during three annual periods (monthly sampling in 1994 and bi-monthly sampling in 1996 and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Auchenipteridae; Distribution; Abundance; Environmental parameters; Lajes; Reservoir. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752002000300029 |
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| Duarte,Silvana; Silva,Flávia Cristina de Paula e; Zauli,Danielle Alves Gomes; Nicoli,Jacques Robert; Araújo,Francisco Gerson. |
| The Gram-negative intestinal microbiota of Hypostomus auroguttatus and Pimelodus maculatus, a detritivorous and an omnivorous fish species, respectively, were compared between fishes from the reservoir and the stretch of the river below the dam of the Funil hydroelectric plant, Rio de Janeiro, Brazil. Four selective culture media were used under aerobic and two under anaerobic conditions. The omnivorous species had microbiota with higher population levels compared to the detritivorous species. The number of morphotypes and population levels of total bacteria, vibrio and Bacteroides tended to be higher in summer and autumn in the reservoir, and not different in the river. The number of morphotypes of enterobacteria and total bacteria were higher in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alimentary regimen; Environment; Gut microbiology; Hypostomus auroguttatus; Pimelodus maculatus. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400019 |
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| Santos,Clarice M.; Duarte,Silvana; Souza,Tatiana G. L.; Ribeiro,Thatiana P.; Sales,Armando; Araújo,Francisco G.. |
| As estruturas teciduais do trato gastrintestinal de Pimelodus maculatus La Cepède, 1803, do reservatório de Funil (22º30'-22º35'S; 44º35'- 44º40'W) foram descritas através das técnicas de hematoxilina-eosina (HE), tricômico Gomori, ácido Periódico de Schiff (PAS) e alcian blue (AB) pH 2,5. Objetivou-se a detecção de glicoproteínas (GPs) na mucosa através de uma análise histoquímica e caracterização de possíveis alterações ao longo do trato digestório destes peixes neste sistema de elevado grau de alteração. Cinqüenta e quatro indivíduos adultos, coletados entre abril de 2003 e julho de 2004 (CT=19-38 cm) foram utilizados. Na cavidade bucofaríngea, a mucosa apresenta-se com pregas longitudinais e o epitélio é do tipo estratificado pavimentoso. O esôfago... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Morfologia; Glicoproteínas; Peixes; Pimelodidae. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212007000400009 |
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| Araújo,Francisco Gerson; Duarte,Silvana; Goldberg,Rubens Sterental; Fichberg,Liana. |
| Parauchenipterus striatulus is a representative of the freshwater catfish with wide distribution in the South America region. Despite of being a very abundant fish in rivers and reservoirs of this region, little is known about its biology and ecology. In Ribeirão das Lajes reservoir (22º42'S - 22º50'S, 43º53'- 44º05' W, Rio de Janeiro), the Rio de Janeiro state's largest hydroelectric reservoir, this species is very abundant, representing about 40% of the total experimental fish catches using gill nets. This paper aims to assess aspects of the reproductive cycle of this species describing the gonadal stages, gonadosomatic index, weight-length relationship and condition factor. Fish sampling were carried out bi-monthly, between April 1996 and May 1997. Gill... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Auchenipteridae; Length-weight relationship; Reproduction; Condition factor; Gonadosomatic index; Reservoir. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751999000400016 |
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| Duarte,Silvana; Paiva,Marco A. R.; Lara,Camila C.; Bemquerer,Marcelo P.; Araújo,Francisco Gerson. |
| The enzymatic activities involved in the digestion of proteins and carbohydrates were compared among three organs of the digestive track of two Siluriformes fish species, and between two areas: a reservoir, and an area downriver of it. Our aim was to test the hypothesis that the digestive organs of species with varied feeding habits have different enzymatic activities, and that the enzymatic activity differs among seasons and environmental conditions. The iliophagous/herbivorous species Hypostomus auroguttatus Kner, 1854 had higher trypsin-like, chymotrypsin-like peptidase and β-glucosidase activity in the intestine when compared with the omnivorous species Pimelodus maculatus Lacepède, 1803, whereas the latter had more hepatic trypsin-like activity than... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzymatic activity; Fishes; Physiology; Reservoirs; Siluriformes; Peptidases; Β-glucosidase. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702013000300006 |
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| Duarte,Silvana; Araújo,Francisco Gerson; Bazzoli,Nilo. |
| In this work we describe the gonad morphology and spawning season of Hypostomus affinis (Steindachner, 1877) in a tropical reservoir based on 55 males and 125 females. Our aim was to assess eventual adaptations in reproductive tactics developed by this riverine species inhabiting an oligotrophic reservoir with low habitat complexity, few rocks and few other preferred consolidated substrata. We described the stages of cells of reproductive lineage, gonadal development and some reproductive traits which were compared with information in the available literature. Cells from the spermatogenic lineage were spermatogonia, spermatocytes, spermatids and spermatozoa, and cells from the oocytarian lineage were primary oocytes, previtelogenic oocytes, cortical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brazil; Fish reproduction; Reproductive biology; Reservoirs; Tactics. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000500005 |
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