Аннотация:The electroretinographic responses were measured on the eyecup preparations of the dogfish shark under local photostimulation of white (light-reflecting) and black (light-absorbing) regions of the eyeground. The C-component of the electroretinogram was clearly manifested both under the total illumination of the retina and the local photostimulation of white regions of the eyeground but it was absent under the local photostimulation of black regions of the eyecup. The results indicate the functional differences of the retinal regions localized in white and black areas of the eyecup in deep-sea fish.