Fundamental aspects of the feeding of the amphipod Gammarus (R.) balcanicus (Crustacea, Amphipoda). [Translation from: Nauchn.Dokl.vyssh.Shkoly (Biol.Nauk) 1970(7) 12-16, 1970]

The amphipods are major food items for many commercial fishes, and they are used as protein food for agricultural animals. In the present paper are presented the results of four-year observations on the feeding of Gammarus balcanicus in nature and in an aquarium. Among the studied aspects were the dependence of daily food ration on sex and physiological state (with and without eggs) and feeding on different kinds of plant food. The study concludes that Gammarus balcanicus willingly feed on soft half-decayed plant residues; into their ration also enters food of animal origin. In contrast to other amphipods, G. balcanicus eats representatives of its own species very rarely, and only dead or immobile ones.

On the diel rhythm of motor activity in perch [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.30, 12-14, 1976]

The river perch (Perca fluviatilis L.) is most active in the daytime hours, and displays seasonal changes of diel rhythm with a break of the rhythm in spring and autumn. In the present work data were obtained on the motor activity of 3 perch measuring l8-20 cm, caught by net in the littoral of a reservoir and spawned under laboratory conditions. The degree of intensity of movement of perch was judged by special experiments. The results are summarised in this short paper.

Influence of carbon tetrachloride on the liver of tadpoles of brown frog (Rana temporaria) [Translation from: Trudy leningt.sanit.-gig.med.Inst. 82, 32-36, 1967]

Comparative studies of the structure and regeneration of tissues in different vertebrates make it possible to get ideas from the evolution and regeneration potential of tissues. In this study are considered the reactive changes in the liver of larvae of the amphibian Rana temporaria to CC14 of different concentrations. Tadpoles of different sizes and different growth were placed once each day every day in a vessel with a determined solution of CC14 in water. The liver of tadpoles has a distinctive structure. It is distinguished by structure not only from the liver of higher vertebrates, but also from the liver of the adult frogs. The liver of the latter has an insignificant amount of fat and a whole series of other characters not typical of the liver of the tadpole. Placing the tadpoles in a solution of CCl4 with a concentration of 0.1% did not produce in the liver noticeable morphological changes. The author concludes that the absence of degenerative changes in the liver tadpoles, in spite of a high percentage of death of the experimental animals, tells of the well-known resistance of their liver to the influence of CC14.

A study of the nutrition of the Rotifer Asplanchna, with the help of Carbon 14 [Translation from: Byulleten ' Instituta Biologii Vodokhranilishch, No. 12, pp.17-20, 1962]

Laboratory research was done in order to study the feeding of larval Cricotopus silvestris F. in relation to characters of structure of oral apparatus. Results of the experiments are summarised and the oral apparatus morhologically described.

The efficiency of plankton in the utilization of the sun radiation [Translation from: Briroda, 12, 29-35, 1948]

The efficiency of utilisation of the sun's radiation by natural communities has not been properly demonstrated with what so far has been obtained of reliable values, and it represents a great interest in many respects. A systematic study of the biotic balance of lakes was done in the course of a succession of summers starting in 1932, extensive material was obtained, which permitted to compute a value fear the utilisation of the sun's radiation by plankton in lakes, and to compare this with corresponding values for marine plankton and terrestrial vegetation.

Campagne Chalci 78-01 (30/01/78 - 12/02/78): résultats des chalutages

The aim of this campaign was the trawl exploration of the Ivoirian continental shelf at the depth of 10 to 120 metres.