Summary of the hypotheses tested (in bold) in this study, using three species of freshwater fish with differing lifestyles: Mogurnda adspersa, Hypseleotris sp., and Melanotaenia fluviatilis.

SMR, RMR, MMR and AS refer to standard, routine and maximum metabolic rate, and aerobic scope respectively. Pcrit is critical oxygen tension. Two metabolic reduction variables were measured: (1) ‘Reduction Capacity’ (RC), the logarithm of the ratio of two areas (ln(Ar/Ae)), where Ar is the area between either SMR or RMR and the depressed metabolic rate curves, during gradual hypoxia, and Ae is excess post-hypoxic oxygen consumption; (2) RM, the magnitude of metabolic reduction as measured by the percentage of SMR depressed during hypoxia. Ucrit and Uopt are, respectively, the critical and optimal swimming speeds. COTgross and COTopt are the gross and optimal energetic costs of transport, respectively. Values of SMR and RMR for these three species have already been determined by Dwyer et al. [63], which is why they are not hypotheses tested here. MMR may be linked to lifestyle [26], and so it is included in the set of hypotheses towards improving understanding of how lifestyle affects performance along the FSLC. Interspecific variance in AS is a topic of great current debate and so is included in the analysis, but how its magnitude links with lifestyle isn’t clear [26].Summary of the hypotheses tested (in bold) in this study, using three species of freshwater fish with differing lifestyles: Mogurnda adspersa, Hypseleotris sp., and Melanotaenia fluviatilis.