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Nunes,Daniela M.; Pellanda,Mateus; Hartz,Sandra Maria. |
Oligosarcus jenynsii (Günther, 1864) and O. robustus Menezes, 1969 are fish species distributed in Rio Grande do Sul, Brazil, Uruguay, and northern Argentina. The reproductive period and recruitment, sex ratio, absolute and relative fecundity, and body length at first gonadal maturation of the two carnivorous species from Fortaleza Lagoon were analized. The specimens were sampled monthly, from May 2000 to April 2001, with fishing effort of 24 hours/month, using stationary gillnets of different mesh sizes and seine net (three samples per edge). The records of each individual included total length, total weight, gonad weight, sex and gonadal maturity stage. The reproductive period of both O. jenynsii and O. robustus ranges from May/June to November/December,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oligosarcus; Reproduction; Characidae; Southern Brazil. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000100001 |
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Becker,Fernando Gertum; Carvalho,Silene de; Hartz,Sandra Maria. |
The present study compares the reproduction, condition and size of the small characiform fish, Characidium pterostictum, sampled at close sites differing in severity of flash flood effects. Data were obtained from seasonal samples in two sites situated 8 km apart in the same stream. In the upstream site, habitat is more severely affected by flash floods than in the downstream site, and this difference was hypothesized to produce differences in life history and individual reproduction trade-off patterns, as predicted by life-history theory. The results provided evidence for small-scale spatial variation in life-history and trade-off patterns within the studied population. At the most severely disturbed site, C. pterostictum displayed a trade-off pattern... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Condition; Reproductive trade-off; Natural disturbance. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400007 |
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Santos,Maria de Fátima M. dos; Pellanda,Mateus; Tomazzoni,Ana Cristina; Hasenack,Heinrich; Hartz,Sandra Maria. |
A survey of carnivore mammals was accomplished in Aparados da Serra National Park from February 1998 to March 2000. The park has 10,250 ha and is considered a biodiversity core area of the Atlantic Forest Biosphere Reserve in the Rio Grande do Sul State, Brazil. The landscape is characterized by relatively well preserved relicts of Araucaria angustifolia (Bertol.) Kuntze forest, grasslands and Atlantic Forest, which have contributed for the survival of endangered carnivore mammals. The National Park was divided in a grid of 16 km² cells using a 1:50,000 scale map. The animals were recorded using indirect methods, by identifying signs (scats, tracks) and direct observation in 2.5 km long and 5 m wide transects, with 10 replicates in each grid cell.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neotropical Mammals; Carnivora; Aparados da Serra; Atlantic Forest. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000300003 |
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De Fries,Lucas; Hahn,Lisiane; Meneses,Bruna Arbo; Câmara,Luís Fernando da; Becker,Fernando Gertum; Hartz,Sandra Maria. |
ABSTRACT We investigated whether the movement and distribution of the migratory fish, Salminus brasiliensis, were affected by a small reservoir. We also examined how movement and distribution were related to water temperature, flow, and rainfall. In December 2011 and January 2012, 24 individuals were captured downstream from the dam, tagged with radio transmitters and released in the reservoir (5.46 km² total area). After being released in the reservoir, 18 of the 24 tagged fish travelled upstream, taking an average of 16.6 days to leave the reservoir, with daily movements varying from < 5 km/day to > 24 km/day. However, only seven tagged specimens (29.16%) returned to the lower reservoir section, while the rest remained in the intermediate and upper... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Environmental impact; Fragmentation; Habitat use; Hydroelectric power; Radio telemetry. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252019000300202 |
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