Spatial orientation of trout (Salmo trutta L.) and rainbow trout (Oncorhynchus mykiss Walb.) embryos in natural and artificial magnetic fields

Trout (Salmo trutta L.) and rainbow trout (Oncorhynchus mykiss Walb.) embryos developing in eggs incubated in the geomagnetic field are oriented NW-SE. Artificial horizontal magnetic fields of 0.5 and 1.0 mT, i.e., higher than that of the natural one but of the same direction resulted in a changed alignment of the embryos examined. The embryos placed in those artificial fields were aligned N-S and NE-SW. A 90° clockwise rotation of the artificial horizontal magnetic field poles, relative to the geomagnetic one, resulted in embryos′ orientation being changed to N-S and NE-SW.