Die vertikale verteilung und tägliche migration der hydromedusen (Hydrozoa: Coelenterata) in der Bucht von Eilat (Rotes Meer)

During the summer of 1970, plankton samples were made in the Bay of Eilat (Red Sea) to study the vertical distribution and diurnal migration of zooplankton. During this project, three programs of 24 h were carried out with a closing net. The hauls were taken every 2 h in different depths, together with measurements of temperature and salinity. The vertical distribution of hydromedusae, especially of Aglaura hemistoma, Péron and Lesueur, 1809 and Liriope tetraphylla (Chamisso and Eysenhardt, 1821), between the surface and 300 m is described. The diurnal migration for these two species was studied. Presumably temperature and salinity had no direct influence on vertical distribution and diurnal migration, as there was a homogeneous water body. The results are discussed.     

Zonation of the interstitial polychaeteStygocapitella subterranea (Stygocapitellidae) in European sandy beaches

The zonation ofStygocapitella subterranea Knoellner (Polychaeta, Stygocapitellidae) in sandy beaches is compared for several localities along the European coasts. In tidal beaches the species occupies a zone near average high tide level (AHTL), whereas in non-tidal beaches it is found at a fairly long distance from the water line. The regularities observed inS. subterranea indicate that the interstitial fauna may prove well suited for the establishment of a general scheme of zonation in sandy beaches analogous to that for rocky shores proposed byStephenson andStephenson (1949).     

Light,timing of biological rhythms,and chronodisruption in man

This paper reviews abundant evidence suggesting that causes and course of aging and cancers can be considered as being both light- and rhythm-related. We define chronodisruption as a relevant disturbance of orderly biological rhythms over days and seasons and years in man. Light is the primary external mediator and melatonin a primary internal intermediary of such disturbances, which can result in earlier deaths via premature aging and cancers. We conclude that experimental and epidemiological research can provide further insights into common denominators of these chronic processes and may offer novel and uniform targets for prevention.