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| Vieira,Augusto B. C.; Salvador-Jr.,Luiz F.; Melo,Rafael M. C.; Santos,Gilmar B.; Bazzoli,Nilo. |
| To analyze the reproductive biology of the peacock bass Cichla piquiti, 361 specimens were collected bimonthly in the Itumbiara Reservoir, southeast Brazil, from December 2004 to November 2005. Males and females in reproductive activity occurred during almost the entire year, with reproductive peak occurring before the beginning of the rains when the water temperature remained low, indicating that these environmental variables do not directly influence in the reproduction of C. piquiti. The long reproductive period, partially spent ovaries contained postovulatory follicles and oocytes in all developmental stages, indicate asynchronous development of oocytes and multiple spawning. The mean total lengthand body weigth were, respectively, 38.2 ± 7 cm and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Reproduction; Multiple spawning; Body condition; Phenotypic plasticity. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000400024 |
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| Alvarenga,Érika R. de; Bazzoli,Nilo; Santos,Gilmar B.; Rizzo,Elizete. |
| Reproductive biology and feeding of Curimatella lepidura (Eigenmann & Eigenmann, 1889) were studied in Juramento reservoir, São Francisco River basin, Southeastern Brazil. Histological analyses and gonadosomatic indexes revealed females and males in reproductive activity from October to March and total spawning occurring from January to March coupled with the peak of spermiating males. In the dry season, the fishes accumulated energetic reserves for reproduction during a short rainy season. The species presented sexual dimorphism, being females larger than males and sexual maturation occurring close to 7.7 cm standard length for females and 7.1 cm for males. C. lepidura presented iliophagous feeding habit, ingesting mainly sediment/detritus and a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diet; Gonadal maturation; Reproduction; São Francisco River; Spawning. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752006000200002 |
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| Tupinambás,Taynan H.; Callisto,Marcos; Santos,Gilmar B.. |
| From December 2003 to September 2004, benthic macroinvertebrates (BM), fishes, water and sediment were collected quarterly at six stations in two streams of the upper São Francisco River basin, south-eastern Brazil. We evaluated the ecological conditions, habitat diversity, water quality, composition and structure of BM communities, as well as the food habits of the local fish fauna. By applying a protocol for rapid characterization of ecological conditions and habitat diversity, three of the sampled localities were classified as "pristine" while the others stations were considered "altered". A well oxygenated water with near neutral pH and low electric conductivity (< 0.01 mS/cm) and nutrient concentrations (< 0.08 mg/l total P and < 0.90 mg/l... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bioindicators; Ecological conditions; Human activities; Stomach contents; Water quality. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752007000400005 |
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| Silva,André R. M.; Santos,Gilmar B.; Ratton,Thiago. |
| Many rivers in Brazil as the São Francisco (SFR) have been impounded for reservoirs construction purposes. However, there is a lack of knowledge on their fish fauna in many areas, including headwaters. The present study aimed to describe the fish community structure from Juramento reservoir, located on Juramento River, a branch of SFR basin. Six bimonthly samplings were made in four different sites. Gill and cast nets, beach seines and sieves were used to collect fish. Ecological indexes as well as the relationship between fish abundance and some limnological variables were determined. 3288 fish belonging to 33 species (16.5% of the total described for SFR basin) were captured, being 75.7% Characiformes, 18.1% Siluriformes, 3% Cyprinodontiformes and 3%... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish diversity. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752006000300031 |
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| Thomé,Ralph G.; Bazzoli,Nilo; Rizzo,Elizete; Santos,Gilmar B.; Ratton,Thiago F.. |
| The reproductive biology of the piau-jejo Leporinus taeniatus Lütken, 1875, an endemic species from the São Francisco River basin, was studied by using macroscopical and histological techniques. A total of 121 males and 94 females were captured quarterly, between March 2002 and February 2003 in the Juramento Reservoir. Females were larger than males, indicating sexual dimorphism. Stages of gonadal maturation were defined from histological analyses and gonadosomatic index. Peaks of maturing/mature and spawned/spermiated fishes has occurred in period December-February. L. taeniatus presented total spawning and group-synchronic development of the oocytes. The gonadosomatic index accompanied gonad maturation in both sexes, and coelomic fat presented lower... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Characiformes; Gonadal maturation; Piau-jejo; Reproduction; Total spawning. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752005000300006 |
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| Ribeiro,Vinicius M. A.; Santos,Gilmar B.; Bazzoli,Nilo. |
| The 'saguiru' Steindachnerina insculpta, a small teleost detritivorous fish species in Furnas reservoir, upper rio Paraná basin, Minas Gerais, Brazil, has a prolonged period of reproductive activity that extends from September to March, with fractionated spawning. During gonadal maturation, the females showed a low hepatosomatic index, suggesting that hepatic substances are possibly transferred from liver to ovaries. During the reproductive period, this fish had lower stomach repletion and coelomic fat indexes, indicating that the species eat less and consume more fat reserves. The weight of the ovaries influenced positively the condition factor (K1), since the lowest K2 values (without the gonads weight), were obtained during maturation, confirming the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Freshwater teleost fish; Reproduction; Spawning. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752007000100009 |
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| Guimarães-Cruz,Rodrigo J.; Santos,José E. dos; Santos,Gilmar B.. |
| The gonadal structure and gametogenesis of Loricaria lentiginosa Isbrücker, 1979 were studied through anatomical and histological techniques. Forty two males and ten females in maturation/mature stage were captured in the reservoir of Porto Colombia, Paraná river basin, Minas Gerais, using gill nets, from November 2001 to October 2002 (tri-monthly captures). Examination of the testes revealed that they were paired, elongated and not fringed organs. Histologically, the testes presented three distinct regions: cranial espermatogenic; transistion espermatogenic and secretory; and caudal exclusively secretory. Standard histochemical techniques detected neutral glycoproteins from the secretion of the tubules of the caudal region. Espermatogenesis occurred in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Espermatogenesis; Loricariidae; Ovogenesis; Testes secretion. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752005000300005 |
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