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| Agostinho,Angelo Antônio; Marques,Elineide Eugênio; Agostinho,Carlos Sérgio; Almeida,Deusimar Augusto de; Oliveira,Rafael José de; Melo,Jussiclene Rodrigues Bezerra de. |
| Fish ladders are generally conceived to reestablish connectivity among critical habitats for migratory species, thus mitigating the impacts of the blockage of migration routes by dams. If this management tool is to be meaningful for conserving fish species, it must provide a fully permeable connection and assure both upward and downward movements. However, because reservoirs have very different hydrodynamics than the original river, it is expected that, at least in the inner area, they may constitute an additional barrier to this movement, especially for descending fish. Thus, the present study sought to determine if migratory fish and their offspring disperse downstream from the dam after ascending a ladder and spawning in the upper reaches of a basin. To... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish passage; Reservoir; Downstream migration; Larvae drift; Rio Tocantins. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000200005 |
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| Bignotto,Thaís Souto; Maniglia,Thiago Cintra; Gomes,Vivian Nunes; Oliveira,Isadora Janolio de; Agostinho,Carlos Sérgio; Prioli,Sônia Maria Alves Pinto; Prioli,Alberto José. |
| Abstract Mitochondrial molecular markers (DNA sequences of D-loop, cytochrome b and cytochrome c oxidase I) were employed to characterize populations of the piranha Serrasalmus maculatus from Upper Paraná, Upper Paraguay and Tocantins River basins. D-loop sequences of S. maculatus population from Paraná-Paraguay River basin exhibited tandem repeats of short motifs (12 base pairs) and variable numbers depending on specimens, accounting for length variation. Concatenated mitochondrial sequences suggested that S. maculatus encompasses different mitochondrial DNA lineages. Although sampling was restricted to three river basins, phylogenetic analysis clearly indicated that the species currently recognized as S. maculatus presents high genetic variability.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cryptic species; Species delimitation; D-loop; Cytochrome b; Cytochrome c oxidase I. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000100801 |
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| Agostinho,Carlos Sérgio; Agostinho,Angelo Antônio; Pelicice,Fernando; Almeida,Deusimar Augusto de; Marques,Elineide Eugênio. |
| Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant) on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Migratory fish; Fish conservation; Biodiversity; Reservoir; Lajeado Dam; Tocantins River. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000200015 |
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| Agostinho,Carlos Sérgio. |
| The viability of an alternative method for estimating the size at sexual maturity of females of Plagioscion squamosissimus (Perciformes, Sciaenidae) was analyzed. This methodology was used to evaluate the size at sexual maturity in crabs, but has not yet been used for this purpose in fishes. Separation of young and adult fishes by this method is accomplished by iterative adjustment of straight-line segments to the data for length of the otolith and length of the fish. The agreement with the estimate previously obtained by another technique and the possibility of calculating the variance indicates that in some cases, the method analyzed can be used successfully to estimate size at sexual maturity in fish. However, additional studies are necessary to detect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Otolith; Sexual maturity; Plagioscion squamosissimus. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132000000400014 |
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