The influence of constant temperature on the embryonic growth of Asellus aquaticus L. (Crustacea) [Translation from: Vestsi Akademii Navuk Belorusskoi SSR, Seriya Biyal. 1979(1) 128-130]

It is known that an adequately large amount of work has been devoted to investigations on the influence of temperature on the growth period of aquatic invertebrates. However, the action of the given factors on the basic biological characteristics of embryonic growth in crustaceans is virtually unknown. An experimental study of the effectiveness of the transformation of matter and energy during the period of embryogenesis in the isopod Asellus aquaticus L. under different constant temperatures was carried out. Specimens were collected in the quarry lakes of the Kurasovshchin zone (city-Minsk). The authors developed a quantitative analysis of the basic energetic properties of animals during one of the physiological stages at different constant temperatures, which allows one to determine the temperature range in which the expenditure of energy, at a given instance during embryonic growth, is minimised. For A. aquaticus this range is represented by the limits 10-22°C, during which the least expenditure of energy is observed between 14.5 and 18.8°C.

Respiration and the efficiency of energy during embryonic development of Asellus aquaticus L. (Crustacea) [Translation from: Vestsi Akademii Navuk Belorusskoi SSR, Seriya Biyal. 1978(5) 112-114, 1978]

Experimental studies were carried out on the transformation of matter and energy during embryonic development of the isopod Crustacea Asellus aquaticus L. under two constant temperatures. Material for the experiments was collected in the quarry lakes of the Kurasovshchin-zone (city-Minsk) at 9°C in April and at 18°C in June, 1977. The rate of consumption of oxygen per specimen by eggs and embryos of Asellus aquaticus was observed and dynamics of the basic biological characteristics during embryonic development studied.

The intensity of photosynthesis in salt lakes of Crimea [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.37 26-29, 1978]

The purpose of this work was the study of phytoplankton production of the salt lakes of the Steppe region of Crimea, during the vegetative period of 1974. From May to October Sakskoe and Sasyk Lakes were examined, and from August to October - Moinakskoe Lake. The density of the salt water was measured and the intensity of photosynthesis was determined. From the data presented, it is apparent that the intensity of photosynthesis in Sakskoe and Sasyk Lakes, on average, is extremely high.

Epidermis differentiation in Salmo irideus Gilb. development [Translation from: Archo ital.Anat.Embriol. 76, 19-30, 1971]

Recent histochemical and histophysiological research on the skin of fish has posed interesting problems both with regard to the presence of specialized types of cell and with regard to the function of this organ. The present paper intends to study the development and the functional differentiation of the trout's skin, both from the histomorphological and the histochemical point of view. The skin of Salmonids is devoid of specialized cells; the granular cells of Petromyzonti, the serous cells of Selacii and the clavate cells described in many other teleosts and it lacks keratin. As such it can be considered a good working model which can be used to show the eventual histomorphological and histochemical changes occurring both in the transformation from the endovular to the aqueous environment. Histomorphological observations were carried out demonstrate the great structural simplicity of the trout's skin at all stages. The article concludes that glycogen increases greatly when the epidermis thickens and therefore when it becomes necessary to guarantee resistance, amongst which is a support mechanism.

On the formation of ephippia in some Cladocera (Crustacea) [Translation from: Zoologicheskie Zhurnal 61, 1425-1427, 1982]

The determination of relative connections between families and genera of Cladocera, necessary for the construction of their natural systems, must be based on various criteria, among them on the structure of the ephippia. Of particular interest is the study of the process of formation and structure of the ephippium in Macrothricidae, different representatives of which differ significantly among themselves according to this criterion. In this article are presented the results of an investigation of the features of formation of the ephippium in seven species of Macrothricidae and in the moinid Moina weismanni Ishikawa (Moinidae).

Comparative drift studies on streams in lower Austria (Flysch, gneiss and chalk formations) [Translation from: Schweizerische Zeitschrift fur Hydrobiologie 30 138-185, 1968.]

Seasonal changes and flooding have an extraordinarily great influence on the drift of organisms. The free water space plays the main part in the provision of food for some fish (Salmo trutta - trout): drift and content of the stomach are balanced here (Simuliidae): whereas others (Thymallus vulgaris) only selectively chose certain animals living at the bottom (molluscs). The total drift, drift of organisms and drift of organic material and minerals, plays a main role in the rate of production in streams. Besides the biology of the organisms living on the river bed, also the geological and hydrographical situation of the area plays a very important role for the composition of the drift. During the years 1964-1966 three streams in the characteristical geological formations flysch, gneiss and chalk of lower Austria were studied in regard to their drift. The Tulln (above St. Christopen), the Krems (above Senftenberg) and the Schwarza (above Hirschwang) seemed to be ideal for this comparative study because they are easy to reach. After summarising the hydrography and chemistry of examined rivers, the author examines the relationship between water level and total drift and the stratification of the total drift before analysing the drift of living organisms. Also considered are seasonal changes of drift of organisms and drift of exuviae.

Studies on the complex formation of iron with humic substances [Translation from: Vom Wasser 53, 243-247, 1979]

Most of the humic substances which occur in natural waters have an iron content of a few percent, indicated by the mg/1 content of organically-bonded carbon. This iron is apparently bound in a complex with the humic substances, for it quite plainly differs in its chemical and physico-chemical properties from what one would expect from the purely inorganic iron-water system. The deviations range from the solubility to the redox behaviour, and thus are frequently the basis of analytical and technical difficulties. The key to the solution of most of this problem lies in a better understanding of the aforementioned bonds between the iron and the humic substances. This paper studies the iron content of the humic substance concentration from a bog lake sample and the complexing of iron by humic substances from the surface of the bog lake.

Taxonomic description of Peridinium lomnickii, P.lomnickii var. splendida and P. wierzejskii [Translation from: Flora Slodkowodna Polski. Tom 4. Cryptophyceae, Dinophyceae, Raphidoiphyceae, p326,328-330. Warsaw, 1974]

This partial translation from a larger paper provides taxonomic descriptions of the dinoflagellates Peridinium lomnickii, P.lomnickii var. splendida and P. wierzejskii. Illustrations are included.

On new or insufficiently-known Chytridinae [Translation from: Archiv fur Protistenkunde 54 168-173 + pl.9, 1926]

This partial translation of a larger paper provides taxonomic descriptions of 5 fungal zoospores species: Olpidium vampyrellae, 0. pseudosporearum, 0. leptophrydis, Rhizophidium leptophrydis and Chytridium lateoperculatum.

Calcareous concretions in the Levriere (tributary of the Epte, secondary tributary of the Seine, Eure department) [Translation from: Bull.Ass.fr.Etud.Quaternaire 1973(2), 79-87, 1973]

From research carried, out on a section of the Levriere, concretions (granules, nodules, which were sometimes joined together) partly covering the river ”bottom” were observed. The authors propose to make besides a petrographic examination of the calcareous precipitations and to see if their origin is connected to a biological activity, or if it is purely a case of a physical-chemical precipitation. The hydrological background of the Levriere, a small river of the Normandy Vexin, is given and conditions of the formation of the concretions studied.

On the toxicity of some pesticides for fish [Translation from: Izv.gos.nauchno-issled.Inst.ozern.rybn.Khoz. 121, 95-96, 1977]

In the piscicide laboratory of GosNIORKh over a series of years was carried out the ichthyological evaluation of different agricultural pesticides, used both in our country and abroad. In all more than 300 different chemical substances were tested. Here, it was established that around 10% of them possessed high ichthyotoxic properties. Experiments were conducted under laboratory conditions on aquarium fish in groups, and also on representatives of different species of lake ichthyofauna. The basic criterion of evaluation of toxicity was the death of experimental fish during 120 hours. This short paper summarises the findings of this reasearch and offers a table presenting acute toxicity of pesticides for fish.

Dangeardia sporapiculata n.sp., the term 'apiculus' and the species limitation of some chytrids [Translation from: Sydowia 16 324-330, 1963]

Taxonomic observations are given on Dangeardia sporapiculata n. sp. Furthermore the term 'apiculus' and the species limitation of some chytrids are being discussed. It is concluded that the newly described species Dangeardia sporapiculata does not fit satisfactorily into the present system of phlyctidiacee, because their characteristics do not agree exactly with any genus.

Profile soundings in lakes of the younger morainal area of Sleswick-Holstein with a sediment-echo-sounder of 30 kHz [Translation from: Wass.Boden 26, 135-138, 1974]

To be able to carry out physical, chemical and biological investigations on a lake, one needs a thorough knowledge of the volume of water and the shape of the lake basin. Little is known about the about the morphology of the lakes in Schleswig-Holstein and its ecological consequences. For this research a 30 KHz echo sounder with sediment transceiver was used to carry out profile determinations (echo soundings). This apparatus continuously records on paper the different reflexions and absorptions of the sediment and water body in the corresponding depth. By this, acoustically noticeable layers and different densities in the sediment and 'scattering layers' in the water body due to physical, chemical and biological reasons (e.g. plans and single fish) are made visible. Result are summarised here regarding the echo soundings in Blunker See.

Experiments on the production of a highly dispersible calcium carbonate. ('Experimental section' only) [Translation from: Szklo i Ceramiki 30, 133-136, 1979]

This short translation summarises experiments on the production of a highly dispersible precipitate of calcium carbonate. The translation covers the 'Experimental section' (of the original larger paper) only.

Nitrification in marine ecosystems [Translation from: Rapp.Naturvardsverket SNVPM No.1213, 157-166, 1980]

The nitrification in the ocean is influenced by several environmental factors and the importance of these is more or less known. There are very likely many more to be discovered in the study of the interaction of nitrification bacteria and other micro-organisms in the ocean. Some of the factors to be considered will briefly be dealt with in this paper. Then the authors give the results of an incubation experiment in the Baltic Sea and from a detailed study in Gullmarn.