Consulta: creatorFacets:"Duarte,Silvana"
Registros recuperados: 9
Data/hora: 16/06/2024 23:12:59

Reproductive plasticity of Hypostomus affinis (Siluriformes: Loricariidae) as a mechanism to adapt to a reservoir with poor habitat complexity
Provedor de dados: 103
Autores: 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

Influence of season, environment and feeding habits on the enzymatic activity of peptidase and β-glucosidase in the gastrointestinal tract of two Siluriformes fishes (Teleostei)
Provedor de dados: 103
Autores: 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

Distribuição e abundância relativa de cumbaca Trachelyopterus striatulus Steindachner (Osteichthyes, Auchenipteridae) no reservatório de Lajes, Rio de Janeiro, Brasil
Provedor de dados: 104
Autores: 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

Indicadores reprodutivos de Parauchenipterus striatulus (Steindachner) (Pisces, Auchenipteridae) na Represa de Ribeirão das Lajes, Rio de Janeiro, Brasil
Provedor de dados: 104
Autores: 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

Abundância relativa e distribuição de Loricariichthys spixii (Steindachner) (Siluriformes, Loricariidae) no reservatório de Lajes, Estado do Rio de Janeiro, Brasil
Provedor de dados: 104
Autores: 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

Morphology of gonads, maturity and spawning season of Loricariichthys spixii (Siluriformes, Loricariidae) in a Subtropical Reservoir
Provedor de dados: 52
Autores: Duarte,Silvana; Araújo,Francisco Gerson; Sales,Armando; Bazzoli,Nilo.
The gonad morphology and spawning season of Loricariichthys spixii in Lajes reservoir were described based on 175 males and 613 females. Cells from the spermatogenic lineage were divided in four phases: spermatogonia (primary and secondary), spermatocytes (primary and secondary), spermatids and spermatozoa, and the cells from the ovocitarian lineage were divided in four phases: primary oocytes (O1), previtellogenic oocytes (O2), cortical vesicle oocytes (O3) and yolk globules or vitellogenic (O4). Five gonadal stages were described for the males/females according to oocytes and spermatogenic lineage cells distribution: resting (1); initial maturation (2a); advanced maturation (2b); partially spent/spawned (4a); totally spent/spawned (4b). Spawning was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Loricariidae; Reservoir; Fish reproduction; Gonad morphology; Brazil.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000700013

Enzymatic Activity in the Gastrointestinal Tract of Pimelodus maculatus (Teleostei, Siluriformes) in Two Neotropical Reservoirs with Different Trophic Conditions
Provedor de dados: 52
Autores: Duarte,Silvana; Bemquerer,Marcelo; Araújo,Francisco Gerson.
Enzymatic activities for digestion of proteins and carbohydrates were compared among three organs of the digestive system of Pimelodus maculatus in two reservoirs with different trophic conditions during the winter of 2006. The aim was to test the hypothesis that enzymatic activity for the digestion of proteins and carbohydrates differed among organs and that such activities differ between the trophic state of the environment. Enzymatic activities were determined through the assays of specificity for trypsin, chymotrypsin and β-glucosidase enzymes. The intestine had higher trypsin-like enzymatic activities compared to the stomach and liver. The highest β-glucosidase activity was found in the liver compared to the stomach and intestine in the oligotrophic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzymes; Catfish; Physiology; Freshwater fishes; Digestive tract.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132015000400605

Gram-negative intestinal indigenous microbiota from two Siluriform fishes in a tropical reservoir
Provedor de dados: 58
Autores: 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

Histologia e caracterização histoquímica do tubo gastrintestinal de Pimelodus maculatus (Pimelodidae, Siluriformes) no reservatório de Funil, Rio de Janeiro, Brasil
Provedor de dados: 76
Autores: 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