Diel variation of larval fish abundance in the Amazon and Rio Negro
Braz. j. biol
;
61(3): 357-362, Aug. 2001. mapas, tab
Article
in English
| LILACS
| ID: lil-305141
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
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Circadian Rhythm
/
Fishes
/
Fresh Water
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Braz. j. biol
Journal subject:
Biology
Year:
2001
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Instituto Nacional de Pesquisas da Amazônia/BR
/
Universidade Federal do Amazonas/BR
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