title: [Species characteristics of the diurnal periodicity of rest and activity in Black Sea fish].
abstract: In 6 species of the Black Sea teleosts differing in habitats and other ecological peculiarities, behavioural and electrophysiological experiments revealed 3 types of the diurnal periodism of motor activity and rest. The first type was most evident in the grey mullet Mugil sp., being characterized by the decrease of the level of the activity at night time. In the second type, motor activity was observed at any time; this type of periodism was typical of the dogfish Squalus acanthias and the hunchback Sciaena umbra. In the third type of periodism, the level of the activity remained also unchanged, but in contrast to the second type, it was practically equal to zero. This type was most evident in the scorpionfish Scorpaena porcus. The data obtained indicate that species peculiarities may be found in the diurnal rhythm of the activity and rest. These periods of rest we consider as "presleep" or "protosleep" (the initial stage of the development of sleep) in vertebrates.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004284:Dogfish / Q000502:physiology; D005399:Fishes / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D013045:Species Specificity; D014586:USSR
vernacular_title: Vidovye osobennosti sutochnoĭ periodiki dvigatel'noĭ aktivnosti i pokoia u chernomorskikh ryb