Print version ISSN 0044-5967
FERREIRA, Marcio Soares; OLIVEIRA, Alzira Miranda de and VAL, Adalberto Luis. Critical swimming speed of matrinxã (Brycon amazonicus) exposed to hypoxia. Acta Amaz. [online]. 2010, vol.40, n.4, pp. 699-704. ISSN 0044-5967. http://dx.doi.org/10.1590/S0044-59672010000400009.
Escape is the first response of fish to stress, that depends on the swimming performance and the physiological adjustments. This study has investigated the critical swimming speed (Ucrit) of matrinxã after exposure to hypoxia. To achieve that, the fishes were exposed to hypoxia and analyzed before and after forced swimming, using Ucrit. The hypoxia caused an increase of lactate, glucose, cortisol and hematocrit. No changes of plasma sodium and potassium levels, as well as the Ucrit, were observed. We suggest that matrinxã is sensitive to hypoxia, but the physiological adjustments are sufficient to keep its swimming performance.
Keywords : Brycon amazonicus; Amazon; swimming performance; hypoxia.