Background. Chemical substances, including heavy metals, introduced into aquatic ecosystem can disturb the homeostasis of a habitat. The aim of this study was to assess the effects of cadmium compounds on common carp, Cyprinus carpio L. and to follow the toxicodynamics of cadmium elimination from intoxicated fish once they were transferred to a clean ambience. Materials and methods. Common carp were given a single intraperitoneal injection of a sub-lethal cadmium dose (10 μg ּkg-1 body weight) to assess their detoxification potential following transfer to uncontaminated habitat. The 60-day experiment was divided into 8 stages during which various organs and tissues of the fish (liver, kidneys, skin, gills, alimentary tract, and muscles) were examined and subjected to assays for cadmium contents at pre-set times. Cadmium was determined with flameless graphite furnace atomic absorption spectrometry (GF-AAS) in a ZL 4110 Perkin Elmer spectrometer after wet digestion in concentrated HNO3 in CEM MDS 2000 microwave oven. Results. The fish intoxicated with Cd were sluggish, their responses to light and sound were much slower than those of the control fish. The cadmium level was observed to change with time: after initial cadmium accumulation in the tissues, the xenobiotic was eliminated. The experiment explains changes in the intoxicated carp system during the process of detoxification. The highest biological half-life (t1/2) of cadmium was recorded in the muscles (37 days), the lowest being typical of the liver (3.4 days). Conclusion. During detoxification, cadmium was observed to be redistributed among the organs. Metal elimination rate was depended on organ and varied from 0.001 to 0.006 µgּday-1. A long-term effect of sub-lethal intoxication was an about 10-percentage-point reduction of the fish body weight.

fish, carp, Cyprinus carpio, cadmium, intoxication, elimination, dynamics