Effects of Tributyltin-Contaminated Aquatic Environments and Remediated Water on Early Development of Sea Urchin (Hemisentrotus pulcherrimus)

SIMPLE SUMMARY: In this study, the toxicity of tributyltin (TBT) was investigated. Sea urchins (Hemicentrotus pulcherrimus) were used as the experimental animals, and the embryonic toxicity of TBT was investigated by observing the fertilization and embryonic development rates of germ cells exposed to TBT. The fertilization rate exhibited decreasing trends as the concentration of TBT increased. Embryo development was delayed as the TBT concentration increased. Embryos whose development was delayed following TBT exposure progressed well when shifted to fresh media without TBT. The results showed that TBT had a negative effect on embryonic development. Embryonic development was restored on removal of TBT exposure. This result has important implications from the perspective of restoring polluted ecosystems. ABSTRACT: In this study, gametotoxicity and embryotoxicity experiments were performed using Hemicentrotus pulcherrimus to investigate the toxic effects of tributyltin (TBT). The effects of TBT on fertilization and embryogenesis were assessed at various concentrations (0, 0.02, 0.05, 0.09, 0.16, 0.43, 0.73, 4.68, and 9.22 ppb). The fertilization rates decreased in a concentration-dependent manner, with significant reduction following treatment with TBT at 0.05 ppb. Embryos exhibited developmental impairment after TBT exposure at each tested concentration. The frequency of developmental inhibition delay that treatment with TBT delayed embryonic development in a dose-dependent manner, with 100% of embryos exhibiting developmental impairment at 4.68 ppb. During developmental recovery tests, embryos cultured in fresh media without TBT showed advanced embryonic development. Although the observed normal development after transferring the developmentally delayed embryos to fresh media without TBT offers prospects for the restoration of contaminated environments, embryonic development remained incomplete. These results suggest that TBT adversely affects the early embryonic development of H. pulcherrimus.