Effects of temperature and hypoxic stress on the oxygen consumption rates of the mudsucker fish Labeo capensis (Smith)

The specific oxygen consumption rate (VO2lMb) of Labeo capensis, the freshwater mudsucker, was determined for small and large fish at winter (8°C) and summer (23°C) temperatures. VO2lMb was also determined during hypoxic conditions of the experimental water. It was found that VO2lMb does not differ substantially compared with other active fish. The VO2lMb for a fish with a body mass of 250 g is 0,053 ml 02 per gram wet body mass per hour for fish acclimated at 8°C and 0,127 ml 02 per gram per hour for fish acclimated at 23°C. The calculated mass exponent, b, is 0,71 at 23°C and 0,68 at 8°C. Hypoxic conditions are relatively well tolerated especially by 23°C- adapted fish