*4.3. Sea Urchin Embryos Development Test*

The preliminary fertilized eggs (2.5 × 103 cell mL−1) were stored in seawater, with different concentrations of the tested Ech (10 to 40 μg mL−1) and its complexes with CRGs, for 30 min, after which a suspension of native sperm was added. The number of embryos developed up to the stage of 2–4 blastomeres and of early blastula, in the presence of the test compounds, was evaluated using a microscope.
