Abstract
Ivory shells and Pfeffer's whelks were exposed to 10μg/l of cadmium for 20 days, and dis-tribution rates and localization indices of the controls were compared to those of the exposure groups, respectively.
In ivory shells, distribution rates in the viscera decreased from more than 99% in the control to ca. 96% in the exposure group, and consequently, the rates in the muscular tissues increased from nearly 1% to ca. 4%, respectively, In Pfeffer's whelks, distribution rates of the control were ca. 85% in the viscera and ca. 15% in the muscular tissues, while the rates of the exposure groups were ca. 67% in the viscera and ca. 33% in the muscular tissues.
Extremely low values of i-LI were found in the muscular tissues of the ivory shells with ca. -82 in the control, and the values weakened up to ca. -18 in the exposure groups. The i-LI values for the viscera were quite similar in the control (2.28) and the exposure groups (2.19).
In the Pfeffer's whelks the values of i-LI in the muscular tissues weakened from -4.30 in the control to -1.48 in the exposure group, while in the viscera the values were substantially similar, 1.93 in the control and 1.33 in the exposure group.
These results were similar to those obtained previously in the herbivorous gastropods, Haliocis discus and Bacillus cornutus exposed to cadmium.
As shown from the results on localization index of cadmium in the muscular tissues, when gastropod mollusks were exposed to enhanced concentrations of the metal, in shallow water environ-ments, the i-LI values of cadmium in the muscular tissues can vary from negatively high to re-latively low values.
