Echinoderms a wide range of valuable biological processes can be considered and can be relevant for Eco toxicological analyses. As is well known the effects of toxic chemicals and complex mixtures on early developmental stages of aquatic organisms are of great importance in the protection of the natural population’s health. The sea urchin is one of the most sensitive and suitable test organisms for acute bioassay of pollution. The use of sea urchin embryos and gametes in testing developmental, reproductive and cytogenetic effects of chemicals and complex mixtures has been successfully developed by a number of laboratories worldwide. The use of multispecies tests capable of accounting for the differences in sensitivity of different species to different contaminants.