Cardiorespiratory responses to environmental hypoxia in the yellowtail, Seriola quinqueradiata

Cardiovascular and respiratory responses of fish exposed to environmental hypoxia have on the subject of a number of investigations. Although relatively few species have been examined, generalized responses to ambient hypoxia include an elevation of blood pressure, increased systemic vascular resistance and bradycardia (Fritsche and Nilsson, 1990; Bushnell and Brill, 1991). The degree of bradycardia experienced by fish during hypoxia is highly variable and may depend upon the severity of the hypoxia and the rapidity with which it is imposed. (omitted)