Hypoxic environments as refuge against predatory fish in the Amazonian floodplains

Brazilian Journal of Biology

Mb. Anjos²  Rr. De Oliveira²  J. Zuanon¹ 

[1] ,Universidade Federal do Amazonas Instituto Nacional de Pesquisas da Amazônia Programa Integrado de Pós-Graduação em Biologia Tropical e Recursos NaturaisManaus AM ,Brazil

关键词: hypoxia;    dissolved oxygen;    piscivory;    Amazonia;    hipóxia;    oxigênio dissolvido;    piscivoria;    Amazônia;   

DOI  :  10.1590/S1519-69842008000100007

来源: SciELO

【 摘 要 】

Several groups of Amazonian fishes exhibit behavioral, morphological and physiological characteristics that allow occupying hypoxic environments, despite the energetic costs of living in such harsh conditions. One of the supposed advantages of occupying hypoxic habitats would be a lower predation pressure resulting from a lower number of piscivorous fishes in those environments. We tested this hypothesis in an area of the Amazon River floodplain through gill net fishing in normoxic and hypoxic habitats. From the 103 species caught, 38 were classified as piscivores. We found no difference in the number of piscivorous species captured in hypoxic and normoxic habitats (chi2 = 0.23; p = 0.63; df = 1) but piscivorous individuals were more numerous in normoxic than in hypoxic sampling stations (chi2 = 104.4; p < 0.001; df = 1). This indicates that environments submitted to low oxygen conditions may in fact function as refuges against piscivorous fishes in the Amazonian floodplains.

【 授权许可】

CC BY   
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