Portrait [Illustration]

Leonid Osipovich Pasternak

Studie [Illustration]

Leonid Osipovich Pasternak

Portait-Studie [Illustration]

Leonid Osipovich Pasternak

Alter Jude [Illustration]

Leonid Osipovich Pasternak

Nach dem Pogrom [Illustration] : Zeichnung

Leonid Osipovich Pasternak

Tolstoi am Schreibtisch [Illustration] : nach einer farbigen Lithographie

Leonid Osipovich Pasternak

Jüdische Musikanten in Polen [Illustration] : (Zeichnung)

Leonid Osipovich Pasternak

Der Dichter Saul Tschernichowsky [Illustration] : (Porträtgemälde)

Leonid Osipovich Pasternak

Porträt des Malers Lovis Corinth [Illustration]

Leonid Osipovich Pasternak

Feeding parameters of copepods from upwelling areas

Feeding patterns of mass herbivorous copepods in upwelling areas are investigated. Daily rations and aspects of their formation are examined in Calanoides carinatus (Benguela upwelling), Calanus pacificus (off the California coast), and Calanus australis (Peru upwelling). Rations were calculated based on gut plant pigment contents obtained at daily stations using laser spectrofluorometry, experimental data on the rate of gut evacuation and data on the carbon/chlorophyll ratio in phytoplankton and particulate matter at the respective stations. When phytoplankton was abundant, diel feeding rhythms were not pronounced and gut pigment level was high during the entire 24-h period. When phytoplankton biomass was low, distinct feeding rhythms were pronounced with a nocturnal maximum. During active upwelling intensive feeding on phytoplankton supports energy (respiration) and plastic (growth, development, reproduction, accumulation of reserves) metabolism of copepods. When upwelling was inactive, the surface part of the population feeds less actively and is able only partially to cover its energy expenditures. The actively growing and reproducing populations of C. pacificus and C. carinatus may consume close to 20% of primary production, whereas the inactive population of C. australis consumed only 0.2% of primary production when upwelling weakened.

(Table 1) Population density and infestation of Paracalanus parvus during the year in the Blue Bay, Black Sea

The life cycle of infusorians belonging to genus Colpoda, dormant cysts of which were found on planktic crustaceans of the Black Sea coastal waters, is described. Population strength of Colpoda is maximum in autumn. The infusorians had no harmful effect on their host. It has been noted that Colpoda enhances decomposition of dead animals.