The aim of the present study was to evaluate, using the microscope and computer image analysis system MultiScan, the effect of 0.2 mg·dm^-3 Cu, Cd or Cu+Cd on yolk sac utilization and growth of common carp larvae Cyprinus carpio under laboratory conditions. According to many authors, yolk sac resorption and growth of larvae may be inhibited by various environmental factors, e.g. heavy metals. The results of the study indicate that heavy metals considerably inhibited utilization of the yolk sac of larvae which was bigger in metal-exposed fish, and some larvae retained it even for 12 days post hatching. Correct yolk utilization is essential for further fish development. Any disturbances reduce fish metabolic rate, which results in reduced growth. In consequence, metal-exposed fish are smaller, weaker, and show higher mortality, which may result in reduction of fish population in polluted waters.

227-236