Waterborne Exposure of Adult Sand Dollar, Scaphechinus Mirabilis (Agassiz, 1864), to Zinc Ions and Zinc Oxide Nanoparticles Affects Early Development of its Offspring

Early development of the sand dollar, Scaphechinus mirabilis , and damage to DNA molecules in spermatozoa and larval cells were studied after a waterborne exposure of adult individuals to zinc ions (Zn 2+ ) and zinc oxide nanoparticles (ZnO NP). It was found that the proportion of retarded and abnormal larvae increases if the parental individuals have been kept in aqueous solutions containing ionic and nanoform of zinc at concentrations of 100 and 200 μg/L. The percentage of DNA in comet tail and GDI was higher after the exposure to ZnO NP, compared with the Zn 2+ exposure, at a concentration of 200 μg/L. Accumulation of zinc in soft tissues of S. mirabilis was also studied. The zinc concentrations in the soft tissues of both experimental groups of sand dollars proved to be higher than that in control groups. The results of the study have shown that the ionic form of zinc exhibits a lower bioavailability compared with ZnO NP and supported the higher toxic effect of the high concentrations ZnO NP.