Issue 1 Series FISHERIES THE EFFECTS OF METALS ON SWIMBLADDER INFLATION OF COMMON CARP (CYPRINUS CARPIO L.) LARVAE

ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS REFERENCES ABSTRACT The aim of the present study was to evaluate, using the microscope and computer image analysis system MultiScan, the effects of Cu (0.2 mg·dm -3 ) and Cd (0.2 mg·dm -3 ) on swimbladder inflation by common carp (Cyprinus carpio L.) larvae under laboratory conditions. The fish were exposed to metals for 30 days from hatching. The results indicate that heavy metals considerably inhibited inflation of the posterior and anterior chamber of swimbladder. Metals affected inflation of each swimbladder chamber in a different way. They reduced the rate of inflation of first (posterior) chamber, delayed the beginning of inflation of the second (anterior) chamber, and inhibited its growth. Metal exposure resulted in differences among the larvae: some of them inflated the anterior chamber, and the others failed to inflate it. At the end of the experiment, 100% of control fish showed this chamber inflated, while in Cu and Cd-exposed groups 24 and 21%, respectively, lacked the anterior chamber. It was also observed that the anterior chamber is inflated with the gas from the posterior one. Swimbladder inflation is necessary for correct development and good condition of fish. The effect of heavy metals on swim bladder inflation indicates their toxic influence on fish larvae