| Journal: | Brazilian journal of biology |
| Database: | PERIÓDICA |
| System number: | 000275533 |
| ISSN: | 1519-6984 |
| Authors: | Araujo-Lima, C.A.R.M1 Silva, V.V. da Petry, P Oliveira, E.C2 Moura, S.M.L |
| Institutions: | 1Instituto Nacional de Pesquisas da Amazonia, Departamento de Ciencias Medicas, Manaus, Amazonas. Brasil 2Universidade Federal do Amazonas, Manaus, Amazonas. Brasil |
| Year: | 2001 |
| Season: | Ago |
| Volumen: | 61 |
| Number: | 3 |
| Pages: | 357-362 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental |
| English abstract | Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling |
| Portuguese abstract | Em muitos riachos e rios o ictioplâncton é mais abundante à noite do que de dia. Entretanto, em alguns rios isto não acontece e as larvas são igualmente abundantes durante o dia. Essa informação é importante para avaliar a distribuição e a produção de larvas nos rios. O objetivo deste trabalho foi testar se ocorrem diferenças na deriva larval durante os dois períodos do dia no Rio Solimões/Amazonas e no Rio Negro. Testamos esta hipótese comparando as densidades diurna e noturna em larvas de characiformes, clupeiformes e siluriformes durante cinco anos no Rio Solimões/Amazonas e um ano no Rio Negro. Encontramos que as larvas de três espécies de Characiformes e as larvas de Siluriformes de fato não modulavam sua deriva sendo igualmente abundantes durante o dia e à noite. Ao contrário, as larvas de Pellona spp. eram mais abundantes durante o dia. No Rio Negro as larvas eram mais abundantes à noite. Este resultado tem impor-tantes implicações para o planejamento de amostragem de larvas no Rio Solimões/Amazonas, pois indica que coletas diurnas estimam adequadamente a deriva de larvas de algumas espécies de characiformes e siluriformes no Rio Solimões/Amazonas, mas não das larvas de clupeiformes e das larvas do Rio Negro |
| Disciplines: | Biología |
| Keyword: | Ecología, Peces, Río Amazonas, Larvas, Variación diaria |
| Keyword: | Biology, Ecology, Fish, Amazon river, Larvae, Diel variation |
| Full text: | Texto completo (Ver HTML) |
