It was clear that the haematology as well as the osmoregulation of o. mossambicus were althered after the exposure to copper at 28-30 and 18-20 respectively. A physiological effect was exerted on mossambicus at both temperatures by causing bhanges in the blood biochemisty such as . Thus any external stressor such as copper even at levels which are considered nonlethal can have a detrimental effect on aquatic organisms.