Cadmium, Copper and Tributyltin effects on fertilization of Paracentrotus lividus (Echinodermata)

Marine environments are continuously being threatened by a large number of xenobi- otics from anthropogenic sources. The effect of chemical pollution on living organisms are numerous and may impair reproductive success of adults species of marine invertebrate and vertebrate through effects on gamete quality. Echinoderms are characterized by external fertilizzation and gametes, free of any type of protection, may be in contact with toxic substances so the reproductive success depends largely on the environment conditions. The purpose of this work is to assess the effects on the in vitro fertiliza- tion of exposure of sea urchin Paracentrotus lividus gametes to xenobiotic substances as CuSO4, CdCl2 and TBTCl. The effect of contaminant were assessed by two experimental set in which gametes were treated with different concentration (0, 10-3, 10-5 10-7 10-9 M) of different substances as CdCl2, CuSO4 and TBTCl. The effects were evaluated as percentage of fertilization. The results showed that the gametes exposure to xenobiotic decreased the percentage of fertilization and that more sensitive to treatment were the sperm cells, propably because the toxic effect affected the motility of the sperm. In conclusion, the absence of fertilization (spermiotoxicity) may submit the toxic effects of these substances to the level of body and may candidate the sea urchis as biosensors for the evaluation of environmental quality.