Patterns of food resource use by two congeneric species of piranhas (Serrasalmus) on the upper Paraná river floodplain
Braz. j. biol
;
63(2): 177-182, May 2003. tab, mapas, graf
Article
in English
| LILACS
| ID: lil-343813
ABSTRACT
Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments) and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05), with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Diet
/
Fishes
/
Gastrointestinal Contents
Limits:
Animals
Country/Region as subject:
South America
/
Brazil
Language:
English
Journal:
Braz. j. biol
Journal subject:
Biology
Year:
2003
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Fundaçäo Universidade do Tocantins/BR
/
Universidade Estadual de Maringá/BR
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