Effects of static magnetic fields on early embryonic development of the sea urchin echinometra mathaei

The influence of static magnetic fields with intensity of 30-50 mT on the early cleavage division of the sea urchin Echinometra mathaei was investigated. The exposure of fertilized eggs to 30, 40, and 50 mT of magnetic fields delayed the onset of early cleavage division. A delay in the first cleavage of 15, 30, and more than 60 min was caused by application of 30, 40, and 50 mT, respectively. The data also showed a significant decrease in cleaved cells for the exposed embryos. Moreover, the exposed eggs to magnetic fields showed more abnormalities compared to the control group. As the intensity of the magnetic field is increased, earlier appearances of abnormalities were observed. That is, deformed fertilization membrane appeared after only 15 min of exposure to 50 mT compared to 30 min in 30 and 40 mT exposures and 90-105 min in the control group.