The Effect of Metal Ions on Survival and Cellular Elements of Coelomic Fluid of Starfish Asterias rubens (Linnaeus, 1758) (Echinodermata: Asteroidea)

Resumo

Toxic effects of various concentrations of cobalt, manganese, iron, lead, cadmium, and copper on the survival and behavioral response of starfish Asterias rubens and changes in cellular elements of its coelomic fluid (CF) have been investigated. The experiments include survival evaluation, evaluation of the righting time, number of cells, and coelomic cell distribution among different groups. Half-lethal concentrations (LC50) of copper (0.98 ± 0.16 μmol), lead (9.6 ± 0.4 μmol), and cadmium (15.1 ± 0.96 μmol) have been determined after 96 h of metal exposure. Exposure of these metals leads to a significant righting time growth, which indicates the increase in behavioral reaction time. All these metals also lead to an increase in the number of cells circulating in CF. The death of starfish followed a significant increase in the number of coelomocytes under the effect of lead, copper, and cadmium. The change in the ratio of the three types of coelomocytes has been studied: with the absence of the metals, the proportion of agranulocytes was 61%, that of granulocytes was 30%, and that of the small cells was 9%. Exposure to lead, copper, and cadmium increased the proportion of agranulocytes while cobalt, manganese, and iron increased the proportion of granulocytes. It has been shown that copper, cadmium, manganese, and cobalt dose-dependently accumulate in the bodies of Asterias rubens starfish. The ability of metals to bioconcentrate from water decreases in the following order: Pb > Cu > Mn > Cd > Co. The results of this work show that A. rubens can potentially be used as a bioindicator of the quality of the marine environment and as a test object for ecological and toxicological studies.