The effects of temperature and dissolved oxygen on antioxidant defences and oxidative damage in the fathead minnow Pimephales promelas.

Fathead minnows Pimephales promelas maintained at 25° C for 6 h had significantly higher superoxide dismutase (SOD) activity than fish maintained at 7 or 32° C, but hypoxic conditions (3 mg l(-1) O2 ) over the same time period did not affect SOD activity. Fish in better body condition (length-adjusted mass) had higher SOD activity. In a separate experiment, P. promelas maintained at three water temperatures (7, 23 and 32° C) for 31 days did not differ in liver acrolein, a biomarker of oxidative stress.