Common Contracts

License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden

October 24th, 2006

• Filed
  October 24th, 2006

We investigated the physiological responses of cichlids exposed to lifelong hypoxia. Broods of Astatoreochromis alluaudi, Haplochromis ishmaeli and a tilapia hybrid (Oreochromis niloticus X O. mossambicus) were split and exposed to normoxia (80- 90% air saturation) and hypoxia (10% air saturation). Blood and white muscle tissue samples of adults were taken for analysis of physiological parameters for anaerobic metabolism (glycogen and total creatine levels and lactate dehydrogenase activity) and aerobic metabolism (blood haemoglobin concentration, haematocrit, intra- erythrocytic ATP and GTP levels and citrate synthase activity). Total creatine was not significantly different between normoxia-raised and hypoxia-raised siblings in all three species. Glycogen concentrations were significantly elevated in the white muscle of hypoxia-raised tilapia but not in that of A. alluaudi and H. ishmaeli. This indicates an increased anaerobic metabolic capacity in tilapia. The activity of the mitoch