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.

On the classification of lakes and lake-like bodies of the Ukraine [Translation from: Gidrobiologicheskie Zhurnal, Kiev 19(2) 100-101, 1983]

In the Ukraine there are several thousand large, medium and small lakes and lake-like reservoirs, distinguished by origin, salinity, regional position, productivity and by construction a significant number of large and small water bodies, ponds and industrial reservoirs of variable designation. The problem of national systems necessitates the creation of specific schemes and classifications. Classifying into specific types of reservoir by means of suitable specifications is required for planning national measures with the objective of the rational utilisation of natural resources. It is now necessary to consider the present-day characteristics of Ukranian lakes. In the case of the Ukraine it is possible to use two approaches - genetical and ecological. This paper uses the genetical system to classify the lake-like water bodies of the Ukraine.

Observations on the downstream movements of brown trout fry (Salmo trutta L.)in the Lissuraga [Translation from: Bulletin Francais de la Pisciculture No.274 1-17, 1979]

The phenomenon of the downstream movement of brown trout fry has been noticed for a very long time by fish biologists. The work presented here, and taking place in the framework of the hydrobiological research of the INRA, represents the results of three years' observation of the movement downstream in the Lissuraga, a small stream in the French Basque country, in connection with certain environmental factors, which are shown. The authors have used a live experiment to compare, in an artificial stream, the ”descending” (or ”Nomadic”) fry with the ”resident” fry, caught by electric fishing in other parts of the stream.

Ratio of natural isotopes of nitrogen. I. Primary results: soils of Dombes [Translation from: Revue d'Ecologie et de Biologie du Sol 14, 279-287, 1977]

Utilization of the heavy isotope of nitrogen as a tracer has found numerous applications in soil biology. It allows better definition of different stages of the nitrogen cycle, in particular the immobilization-mineralization cycle. In this work, the authors report the results of calculations of natural isotope ratios of nitrogen in samples of water, soil and vegetation prevailing in Dombes and discuss the possibilities of errors and coefficients of fractionation.

Modulation of the effectiveness of 17-alpha-hydroxy-20-beta-dihydroprogesterone or of a gonadotrophic extract on the in vitro intrafollicular maturation of oocytes of the rainbow trout Salmo gairdnerii by various non-maturing steroids [Translation from: Compte Rendu Hebdomadaire des Seances de l'Academie des Sciences, Paris, Series D 281, 811-814, 1975]

The effectiveness of 17 α-hydroxy-20 β-dihydroprogesterone (17 α-20 β Pg) or of a trout hypophyseal gonadotrophic extract on the in vitro intrafollicular maturation of trout oocytes can be modulated by steroids which do not have a direct maturing effect; the effectiveness of the gonadotrophic extract is lowered by oestradiol and oestrone and increased by testosterone. As these steroids have no significant effect on maturation induced by 17 α-20 β Pg, the site of their activity is probably in the follicular envelopes. Corticosteroids, and Cortisol and cortisone in particular increase the effectiveness of the gonadotrophic extract, but increase the effectiveness of 17 α-20 β Pg even more strongly, suggesting that this 'progestagen' has a direct effect on oocyte sensitivity.

Individual growth and seasonal cycle of Daphnia middendorffiana in an Alpine lake [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 26 41-83, 1970]

The problem of the peculiar reproductive biology of the cladoceran Daphnia middendorffiana is investigated from a cytological viewpoint, and by direct observation the meiotic phenomena of the eggs both subitaneous and resting is studied. and during maturation, the true mechanism of the succession of reproductive phases of different ecological significance. Samples were collected in the Italian Alpine Lake of Campo 4°.

Rearing cyprinid fry in cages [conclusions only] [Translation from: Gospodarka rybna, Warszawa 27(8/9) 3-5, 1975]

This short translation presents the conclusions only of a study of the proposed method of rearing cyprinid fry in cages and how this method can increase the amount of material produced of the stocked fry.

A study of the reproductive biology of dace in the middle Ob [introduction , summary and table captions only] [Translation from: Trudy tomsk. gos. Univ. 125, pp.77-91]

The Siberian Dace (Leuciscus leuciscus baicalensis (Dyb)is an important trade fish in Siberian waters. In the Ob basin more than 30,000 centners are produced annually. Catches of dace fluctuate significantly both between different rivers and between years in the Tomsk region. Defining the stocks of dace in the waters of the Tomsk region and explaining the fluctuations over time seems to be a very important and relevant question for the workers of the fishing industry. An answer, however, requires an accurate knowledge of the biology of dace; its reproductive, feeding and migration habits and the conditions of wintering etc. In the following we examine one of the above questions i.e. the biology of the reproduction of dace. The study was carried out in the Middle Ob in May 1951. This tranlations provides the introduction, summary and table captions only of the original article.

Mellum Island (southern North Sea): dynamic processes and sedimentary structures. I. Southern tidal flat, transition zone and high-surface.[p.72 (Blasensand) only][Translation from: Senckenbergiana Maritima 11, 59-113, 1979]

This partial translation of a longer article describes the phenomenon of ”Blasensand”. Blasensand is formed when sedimentation of dried out sand is suddenly flooded from above. A more detailed explanation of Blasensand is given in this translated part of the paper.

Experimental research on the development of Ceratium hirundinella O.F.Muller [Translation from: Z.Bot. 14, 337-371, 1922]

The most important aim of this study lay in filling in the great gap in our knowledge of the processes of germination in the Ceratium cyst and the early developmental stages in the standing stock of Ceratium hirundinella. contained rich cysts, we now succeeded extraordinarily well in pursuing the consistent development of Ceratium from the cyst to the completed cell. A series of experiments were carried out on the cysts and the juvenile stages of Ceratium, which showed very interesting results. The author presents in a general descriptive part the normal processes of germination in Ceratium cysts and the development of the juvenile stages in order to show in an experimental part the changes in form of C. hirundinella under the influence of temperature, light and varying salinities.

The role of ciliates in the pelagic life cycle of the Mediterranean [Translation from: Rapports et Proces Verbaux des Reunions-Conseil International pour l'Exploration de la Mer 17, 511-512, 1963]

During hydrographic and plankton studies carried out since 1960 in the coastal zone between the Ebro and Castellon (western Mediterranean), data has been collected which confirms the importance of ciliates in the composition and activity of the plankton. The ciliates in 413 samples of 100 ml of water were counted, having been examined with the Utermohl microscope after sedimentation. The samples studied were distributed according to the density of their population. subject for study. The author concludes that recognition of the role of ciliates as an important link in the food chain of the sea would simplify the interpretation of certain problems posed by the nutrition of certain groups of planktonic animals.

The role of infusoria and bacteria as food for Cyclopoida in Rybinsk Reservoir [Translation from: Trudy Instituta Biologii Vnutrennykh Vodnany 22(25), 37-42, 1971]

Despite the fact that it is a long time sinc e the methods of collection and quantitative estimatio n of protozoa were worked out data on the abundance of these animals in freshwaters are not very numerous. Nevertheless, Infusoria and Rhizopoda at high densities are widespread in the water and sediments of lakes and reservoirs. In order to find ou t the importance of infusoria as a food source for cyclopoids we carried out experimental investigations using C14. For this three species of cyclopoids, widely distributed in open regions of Rybinsk reservoir were selected: Cyclops vicinus, Mesocyclops oithonoides and Kesocyclops leuckarti. The data presented give evidence that the species investigated are able as predators to consume infusorian plankton arid bacteria in the form of flocs or small clumps of detritus.