THE CAUSES AND MECHANISMS OF DIURNAL VERTICAL MIGRATION IN THE SEA.
SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CALIF
Pagination or Media Count:
The close relationship throughout the diurnal cycle between the vertical position of the main sonic-scattering layer in the San Diego region and a particular level of submarine irradiance was demonstrated. Plankton collections made at such depths revealed that the euphausiid crustaceans were preeminently important constituents of the scattering layer population in this region. Biochemical analysis of the photo sensitive pigments in the eyes of these midwater crustaceans presented a close relationship between the absorption spectra of the pigments and the spectral distribution of the light at the depths the animals inhabit. Their spectral sensitivity was measured by electrophysiological experiments, and was shown to be similarly related to environmental light.