Résumé:
This master's work targets the determination of the sensitivity of embryonic development in the sea urchin "Paracentrotus lividus" in the Mostaganem region .
To this end, we carried out three samplings (March, April, May) from two study stations, namely the port of Salamandre and the station of Sidi El Madjdoub , each known for its different biotic and abiotic properties, at a rate of 10 sea urchins per site per month, which translates to a total of 60 specimens.
Biological assays (bioassays) are a technique frequently used to assess the biological effects of pollutants on marine organisms. These organisms are a good biological tool for studying the environment and the coastal ecosystem in the laboratory. The objective of such tests is to demonstrate toxic effects on populations representative of ecosystems and belonging to different trophic levels. . The sea urchin constitutes a material of choice in the field of environmental toxicology, , larval sea urchin bioassays have been widely used to assess the toxicity of xenobiotics.
The results of exposure of sea urchins to a wide range of pollutants is reflected in our study by developmental arrests, malformations and also growth retardation, for example, at stage two, two unequal blastomeres have been observed, and at the young blastula stage the fertilization membrane is completely torn, thus at the prism stage there is no fourth somatic rod in the polluting site.
