Respiratory Metabolism as a Function of Oxygen Tension at Different Life Stages of Blue Morph, Pseudotropheus lombardoi

Oxygen consumption per unit weight is an objective and versatile characteristic describing the level of metabolism. The metabolic rate gives an indication of energy expenditure on the life supporting functions associated with growth, feeding and reproduction. The present study was conducted to determine the effect of oxygen tension on respiratory metabolism on different life stages of Pseudotropheus lombardoi and the cost of parental care in mouth brooding is estimated by their metabolic rate during their oral incubation. Metabolic rate decreased linearly at statistically significant rate with increasing biomass. In relation to sex, the metabolic rates of males were higher than in females. During mouth brooding, metabolic rate of P. lombardoi was 70% more than the non-mouth brooding female fish and 40% more than the spent fish.