bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative Analysis of Feeding and Schooling Behaviour of the Cyprinidae Alburnus alburnus (L., 1758), Rutilus rutilus (L., 1758), and Scardinius erythrophthalmus (L., 1758) in a Backwater of the Danube near Vienna
Authors: Haberlehner Elisabeth 
Published: February 2007

AbstractUnderwater observations of the three common fish species Alburnus alburnus (L., 1758), Rutilus rutilus (L., 1758) and Scardinius erythrophthalmus (L., 1758) in a small part of the Danube flood area near Vienna have been made from June to October 1985 and 1986. Particular emphasis has been laid on the partitioning of feeding resources and habitat. It has been established that these species prefer different water zones. Alburnus a. and Scardinius e. are “obligate” schoolers (BREDER, 1967) whereas Rutilus r. is a facultative schooler. While feeding Rutilus r. and Scardinius e. form “aggregations” (BREDER, 1959) and both adopt equivalent feeding techniques. Furthermore Alburnus a. is a quick moving species living near the surface and chasing mostly in schools. While inter‐ and intraspecific aggression is rarely observed for Rutilus r. and Scardinius e., Alburnus a. often show interspecific actions.
The Effect of Food Quantity on Feeding and Metabolic Expenditure in Cladocera
Authors: Philippova Tamara G. , Postnov Andrey L. 
Published: February 2007

AbstractThe effect of Chlorella concentration on total metabolic expenditure, basal metabolism and filtering and ingestion rates was studied in juvenile and adult females of three cladoceran species. No significant influence of food concentration on basal metabolism was found, whereas total metabolic expenditure depended on Chlorella concentration. Total metabolic expenditure in cladocerans was subdivided into: basal metabolism and expenditure on filtration, locomotion and specific dynamic action (SDA). Significant positive correlations were observed between expenditure on filtration and filtering rate and between expenditures on SDA and ingestion rate.
Competitive Exclusion, Harem Behaviour and Host Specificity of the Water MiteUnionicola ypsilophora(Hydrachnellae, Acari) InhabitingAnodonta cygnea(Unionidae)
Authors: Davids Cornelis , Holtslag Johanna , Dimock Ronald V. 
Published: February 2007

AbstractThe co‐occurring freshwater musselsAnodonta cygneaandA. anatinaserve as hosts for the water mitesUnionicola ypsilophoraandU. intermedia, respectively. MaleU. ypsilophoradisplay a territorial behaviour. They fight with other males, and as a result, there is usually only one male per host. As a consequence, this intrasexual aggression results in female‐defence polygyny, or a harem mating system. In contrast,U. intermediashows no antagonistic behaviour between males.A. cygneacan serve as a host forU. intermedia, but this mite species apparently is excluded from the mussel byU. ypsilophora.In this way,U. intermediais restricted by competitive exclusion to the musselA. anatina.
Annual Cycles and Budget of Nutrients in Berre Lagoon (Mediterranean Sea, France)
Authors: Arfi Robert 
Published: February 2007

AbstractThe annual cycles of nutrients in the Etang de Berre were studied in 1985. From measurements twice a month at the input points, daily data for the freshwater flow and from daily measurements at the output point, an estimation is proposed for a nutrient budget. Seasonal variability is important, and a biological control of nutrient availability (locally remineralized products) results in a hydrologically controlled system (nutrients carried by continental waters) which produces the very high microalgal biomass observed in the lagoon. The seasonal halocline brings the euphotic layer very close to the remineralization site: nutrients are then constantly available to the phytoplankton.
Effets du cuivre sur l'ultrastructure de Scenedesmus quadricauda et Chlorella vulgaris. Effect of copper on the ultrastructure of Scenedesmus quadricauda and Chlorella vulgaris
Authors: Bastien Christian , Cǒté Raynald 
Published: February 2007

AbstractA laboratory investigation was conducted to study the effect of various concentrations of copper on the freshwater algae Scenedesmus quadricauda and Chlorella vulgaris. Electron‐dense inclusions were observed in the vacuoles of S. quadricauda, and this alga showed some growth at a dose as high as 2,500 μg.1−1. The occurrence of the electron‐dense inclusions was correlated significantly with the copper concentration and seems to be implicated in the tolerance of the species. C. vulgaris was much more sensitive to copper than S. quadricauda and showed osmotic changes and membrane damage.
Temperature Tolerances and Geographic Distribution of Three Species of Caridina (Decapoda, Atyidae) in Sri Lanka
Authors: de Silva K. H. G. M. 
Published: February 2007

AbstractThe biokinetic zones of C. fernandoi, C. simoni and C. pristis were found to be 15–29 °C, 15–27 °C and 13–27 °C respectively, while their respective ranges of distribution were found to be in altitudes of 0–700, 0–700 and 450–850 m. Their responses to low temperatures indicate that all three species are unlikely to occur above 1,000 m. The lower limit of distribution of C. fernandoi and C. simoni extends to altitudes in which the temperature rises above their ultimate upper incipient lethal temperatures (UILT). They appear to avoid high temperatures by moving into cooler waters. C. pristis cannot do so since it lives in very shallow streams; the lower level of its distribution appears therefore to be limited by its UILT.
Phytoplankton Fluctuations during an Annual Cycle in the Coastal Lagoon of Cullera (Spain)
Authors: Rojo C. , Miracle M. R. 
Published: February 2007

AbstractThe seasonal variation and the vertical distribution of the phytoplanktonic population of the lagoon of Cullera, an elongated coastal lagoon with estuarine circulation of water, has been studied in three sampling stations: mouth, centre and source. Seasonal variation is determined by a marine‐freshwater interaction. In winter, the sea influence is important, a marine water wedge of anoxic water arrives at the sampling station located at the source and marine and brackish water species dominate the phytoplankton. Also marine species of zooplankton and fish enter the system, which may then be considered as exploited by the sea. In spring the marine wedge retreats from the source but remains in the centre and mouth, salinity diminishes, vertical mixing persists and phytoplankton is dominated by Cyclotella species. From late spring to autumn the freshwater influence prevails and a sharp stratification of the water is produced in the stations at the mouth and the centre, by means of a steep halocline coincident with an oxycline. The phytoplankton in this period follows a typical succession like those described in freshwater eutrophic lakes.Vertical distribution of phytoplankton is determined by the presence of the oxycline, originated by the marine water wedge, whose depth varies seasonally but which is always present in the mouth and centre of the lagoon; only few species of algae can be found below its level.
Studies on the Effect of Cell Division‐inhibiting Herbicides on Unialgal and Mixed Algal Cultures
Authors: Ördög Vince , Kuivasniemi Kaija 
Published: February 2007

AbstractThe effect of two cell division inhibiting herbicides on unialgal and mixed algal cultures was studied in laboratory tests. The herbicides studied were trifluralin (analytical grade) and the active ingredient as well as the preparation (80 % a.i.) of diphenamid. The three green algal species used were Selenastrum capricornutum PRINTZ, Scenedesmus quadricauda (TURP.) BREB., Oocystis parva W. et G. S. WEST. The response of algae to herbicides was determined by cell counting, and measured by turbidity (750 nm) and the 02‐production of some of the treated cultures.The EC50‐value (96 h) of trifluralin to Selenastrum capricornutum was 3.3 mg/l. There were differences in the sensitivity of the three algal strains to the diphenamid; the EC50‐values to Selenastrum, Scenedesmus and Oocystis were 16.7, 10.1 and 6.3 mg/l, respectively. The lag phase observed in the growth of the treated cultures caused by diphenamid was verified by O2‐measurements. The preparation of diphenamid was not as effective as the active ingredient. In mixed cultures the ratio between two different algal strains depended both on the concentration of the diphenamid and the sensitivity of the two strains.
Herbivores and the Spatial Distributions of the Phytoplankton. II. Estimating Grazing in Planktonic Environments
Authors: Wirick Creighton D. 
Published: February 2007

AbstractLarge errors are made when laboratory measurements of the ingestion rate of herbivorous zoo‐plankton are used to estimate grazing in planktonic environments. The errors arise because the spatial heterogeneity in natural plankton distributions is greater than the heterogeneity present in laboratory experiments. Two probability models are developed for extrapolating laboratory measurements of ingestion to planktonic environments. Both models require sample statistics of the plankton distributions, and these are estimated from sampling studies of the small scale distribution of marine plankton. One model predicts laboratory measurements overestimate the ration obtained by an individual copepod by 30 %. A second model predicts errors exceeding ±50 % are possible when laboratory measurements are used to estimate the grazing by a population of cope‐pods.
On the Relations of Vertical Distribution, Diurnal Migration and Nutritional State of Herbivorous Zooplankton in the Northern North Sea during FLEX 1976
Authors: Krause Michael , Radach Gunther 
Published: February 2007

AbstractAt a fixed station in the northern North Sea the occurrence of herbivorous and omnivorous zooplankton and the changes in its vertical distribution were studied over 2 1/2 months during the spring phytoplankton bloom in 1976.From a sporadical distribution of relative few plankton organisms in the mixed water column at the end of winter, in the middle of April a significant accumulation of organisms began to occur in the upper layers parallel to the development of stratification and the phytoplankton spring bloom. As exceptions, the populations of Microcalanus pusillus and Metridia lucens withdrew to below the thermocline.About ten days after the decline of the phytoplankton bloom, a few zooplankton species—especially wax ester producing copepods like Calanus finmarchicus, Pseudocalanus elongatus, Microcalanus pusillus, aad Metridia lucens—started diurnal vertical migrations. The movements of the species and stages occurred synchronously, leading in the same direction. Nevertheless, the amplitude of the migrations increased with each maturity stage reached.The vertical migrations, characterized by actual locations and velocities of the centers of gravity of the populations, are interpreted in terms of metabolism leading to fat storage, decomposition and reconstruction of lipids and proteins, in terms of a periodical change in the density of the organisms.Further data sets about the vertical distribution of organisms are cited to support the hypotheses stated.
Sedimentation Studies on Gandhisagar Reservoir
Authors: Rao K. S. , Kartha K. N. , Shrivastava S. 
Published: February 2007

AbstractThe sedimentation data of Gandhisagar Reservoir is presented and discussed. About 4.3 % gross capacity of Gandhisagar Reservoir was lost due to accelerated sedimentation from 1962 to 1975. Grain size analysis shows that the sediment consisted of 40.80 percent clay, 51.99 percent silt, 6.30 percent sand, 1.12 percent gravel. Suitable measures to prevent sedimentation are suggested.
Seasonal Dynamics of a Chironomus plumosus (L.) (Diptera, Chironomidae) Population from a Fish Pond in Southern Bohemia
Authors: Maténa Josef 
Published: February 2007

AbstractA population of Chironomus plumosus (L.) from a fish pond has been investigated for two years. Quantitative benthic samples and emergence traps were used to study the seasonal dynamics. Effect of some factors on the duration of development was studied in laboratory experiments. Data on larval abundance, length frequency analysis and emergence of adults suggest a bivoltine life cycle. The population of C. plumosus investigated showed a pronounced tendency to dormancy, even under long‐day conditions. Factors regulating the bivoltine life cycle are discussed.
Experimental Approach to the Role of Different Ecological Types of Protozoa in the Activated‐sludge System
Authors: Macek Miroslav 
Published: February 2007

AbstractRelationship between bacteria and ciliates was investigated in continuous cultures with and without the recycling of flocculated biomass. Monocultures of ciliates of various ecological types were used together with mixed cultures of bacteria or bacteria and flagellates. The effect of ciliates on the distribution of flocculated and dispersed, biomass was tested with respect to characterizing an optimum mixed culture for activated‐sludge treatment. Monoprotozoal populations were not successful in stabilizing the morphology of a bacterial community in a system with recycling of flocculated biomass. Stabilization was observed (with particular ecological types of ciliates) in the system with a high residence time without recycling and/or in the system with the recycling inoculated by both flagellates and ciliates.
The Chydorid Crustacean Alona diaphana (King), Limnetic in Lakes Awasa and Zwai, Ethiopia, with a Discussion of Littoral and Limnetic Zooplankton
Authors: Fernando C. H. , Belay Semeneii , Mengestou Seyoum 
Published: February 2007

AbstractAlona diaphana, a common littoral tropicopolitan cladoceran, occurs in the limnetic of two Ethiopian lakes in considerable numbers and over long periods of time. Our results are presented and the composition of limnetic and littoral zooplankton, in terms of previous records of such incursions, are discussed. The high persistent densities of A. diaphana are due to the extensive littoral areas in the lakes, where it originates, the high intrinsic rates of increase of this species, the low diversity of zooplankton, reducing competition and the low level of predation.
Seasonal Changes in the Chemical Composition ofCeratophyllum demersumL. in a Small Pond
Authors: Pip Eva , Philipp Klaus 
Published: February 2007

AbstractSeasonal content of total soluble carbohydrate, total soluble protein, free fatty acids and alkaloids were examined in a population ofCeratophyllum demersumgrowing in a pond on the southwestern edge of the Canadian Shield. Total soluble carbohydrate and total soluble protein were inversely correlated. Free fatty acids were dominated by (16:0 + 16:1), 18:2 and 18:3. Relative proportions of the different free fatty acids remained roughly constant throughout the season. Alkaloid concentrations showed large fluctuations, with the highest values found during the first half of the season. Carbohydrate and protein contents of associated periphyton were not correlated with host macrophyte metabolism.
Reliability of Analyses of Hg, Fe, Ca, K, P, pH, Alkalinity, Conductivity, Hardness and Colour from Lakes
Authors: Håkanson Lars , Borg Hans , Uhrberg Roland 
Published: February 2007

AbstractThe aim of this report has been to present results concerning analytical quality controls of Hg analysis of fish and sediment, analyses of Fe, Ca, total‐P, K, pH, alkalinity, conductivity, colour and hardness (Ca + Mg) of lake water samples. Despite the fact that these are standard parameters in many regular water control programs, there are major differences in the reliability with which these parameters can be determined. The focus here is on an overall inter‐laboratory comparison between the parameters. Six laboratories have been involved in the analysis. Selected results: pH gives the lowest (average) relative standard deviation (error), about 2 %; conductivity gives an error of about 5–7 %; alkalinity yields an average error of as much as 13–25 %, which is the largest among the parameters studied here; colour also gives a high error, 9–15 %; hardness gives a relative standard deviation of about 6–7 %. Of the other parameters (i. e., Hg, Fe, Ca and P), Hg gives the best reliability and Fe and P the lowest. To have knowledge of the reliability of the analytical data is of paramount importance in most control programs and research projects.
Growth and Production of Yellow Eels and Glass Eels in Ponds
Authors: Breteler J. G. P. Klein , Dekker W. , Lammens E. H. R. R. 
Published: February 2007

AbstractTwo experiments (I and II) were performed in drainable ponds. Yellow eels Anguilla anguilla (L.) were stocked in early June at three biomasses: 10, 20 and 60 kg · ha−1 in experiment I; and 10, 20 and 40 kg · ha−1 in experiment II. The mean body weights were 27.0 and 24.2 g respectively. Glass eels were stocked only in experiment II at equal densities of 1600·ha−1. In both experiments each biomass of yellow eel was combined in a factorial design with three cyprinid communities differing in biomass and in species‐ and size‐composition. The ponds were drained in autumn. The final body weights at draining ranged from 25.9 to 63.6 g for yellow eel and from 3.9 to 8.8 g for glass eel. The final body weights of yellow eel and of glass eel decreased with increasing biomass of yellow eel. No significant relation was found between the bream Abramis brama (L.) biomass and the growth of eel. The growth rates of yellow eel and glass eel were positively correlated in experiment II. At higher biomasses of yellow eel the percentage females decreased slightly. The recapture rates of yellow eel in experiments I and II amounted to 69.4 ± 9.8 % and 92.2 ± 4.9% (mean ± sd) respectively. The lower recapture rates in experiment I were caused by the inappropriate draining technique used. The glass eels were recaptured with 75.0·5.6% efficiency. The maximum net production of yellow eel occurred at a biomass of 20–40kg·ha−1 and amounted to 19 kg·ha−1.
Comparison of Spectrophotometric, Fluorometric and High Performance Liquid Chromatography Methods for Determination of Chlorophyll a in Aquatic Samples: Effects of Solvent and Extraction Procedures
Authors: Jacobsen Timothy R. , Rai Hakumat 
Published: February 2007

AbstractChlorophyll a determinations were made on lakewater and algal samples by spectrophotometric, fluorometric and high performance liquid chromatographic methods. Acetone, methanol and ethanol solvents were evaluated for their ability to extract photosynthetic pigments from Scenedesmus sp. cultures. Routinely used methods overestimated the chlorophyll a concentrations present in the samples. Significant differences resulted when various standard equations were used to calculate chlorophyll a concentrations. Acetone did not quantitatively extract chlorophyll pigments, even after 24 h. Mechanical disruption was found to be important in assuring complete extraction of the chlorophyll pigments.
Studies of Aquatic Fungi. XIII. Mycoflora of the River Czarna Hańcza and its Tributary, the River Marycha
Authors: Czeczuga Bazyli , Brzozowska Krystyna , Woronowicz Lucyna 
Published: February 2007

AbstractThe authors investigated the mycoflora and the environmental factors in the River Czarna Hańcza (10 stations) and its tributary River Marycha (1 station) as well as Lakes Hańcza (2 stations) and Wigry (2 stations) on the occurrence of various aquatic fungi.At the stations investigated the presence of 45 aquatic fungi species was noted. The following fungi, up to now unknown in Poland, were found:Monoblepharis hypogyna, Rozellopsis inflata, Cladolegnia eccentrica, Apostemidium guernisaci, Anguillospora gigantea, Geniculospora grandis, Clavariopsis aquatica, Lemonniera aquaticaandLemonniera terrestris.
The Variation in the Acidity of Ground and Surface Waters in Northern Ireland
Authors: Jordan C. , Enlander I. J. 
Published: February 2007

AbstractThe distribution of surface and ground waters in Northern Ireland were mapped with respect to pH and total hardness and the distributions discussed in relation to the regional geology and pedology. These waters were grouped into 3 categories depending on their vulnerability to acidification. Three upland areas, the Mournes, the western Sperrins and the northern Glens of Antrim, were identified as being vulnerable to acidification. Concentrations of total and labile aluminium in these areas were high and, in the Mournes and Sperrin areas, exceeded the EC directive on total aluminium in drinking water. However, because of their differing geology and pedology, only the Mournes area had labile aluminium levels which gave cause for concern. A fish survey in a reservoir in the Mournes catchment showed that it supported a small but self‐sustaining population of brown trout (Salmo trutta) which, although small in size, showed no signs of deformity.
Les Invertébrés Planctoniques du Lac Volvi (Macédoine, Grèce). The Planktonic Invertebrates of Lake Volvi (Macedonia, Greece)
Authors: Zarfdjian M. H. , Vranovský M. , Economidis P. S. 
Published: February 2007

AbstractThe planktonic invertebrates found in Lake Volvi are presented. There are 26 species of Rotifera, 1 Bivalve (larva), 13 Cladocera, 5 Copepoda, 1 Branchiura and 1 Diptera (larva). Many of these are new for the Greek fauna, though they are common in Europe. The discovery of some other species extends the knwown bounds of their geographical distribution in Greece.The lack of large‐sized forms is considered to be due to strong predation by Alosa macedonica. (Pisces, Clupeidae). A comparison is given to the planktonic invertebrates of other Balkan lakes. There is a remarkable similarity with the fauna of Lake Doïrani.
Growth of Blue‐Green Algae in the Saidenbach Reservoir and its Relationship to the Silicon Budget
Authors: Horn Heidemarie 
Published: February 2007

AbstractThe phytoplankton succession during the summer in the mesotrophic reservoir Saidenbach since 1975 may well be explained by the resource ratio hypothesis. Until 1980, only phosphorus controlled the phytoplankton growth, and diatoms prevailed, because an excesses of silicon existed. From 1981 to 1986, the ratio Si:P often was smaller than 90, a value, critical for the development of the diatom Fragilaria crotonensis. Its reduced growth caused an increased occurrence of blue‐greens (mostly Aphanothece clathrata) immediately after the diatom mass development. During these years at first silicon limited phytoplankton growth in summer, later on the growth again was limited by phosphorus.Because of increased Si and P load since 1987 a simultaneous limitation of both nutrients occurs. This leads now to parallel mass developments of diatoms and blue‐greens.In order to maintain the positive effect of diatoms (phosphorus transport into the sediment), it is to guarantee a sufficiently high Si:P ratio. If a reduction of P load isn't possible, Si remobilization from the sediment could be increased by artificial changes of the water level.
Biomass and Functional Distribution According to the Feeding Modes of Two Freshwater Protozoan Communities
Authors: Fernandez‐Leborans Gregorio , de Zaldumbide Mercedes Castro , Perales Carolina 
Published: February 2007

AbstractThe study has been made concerning the composition of and the relationships among: physico‐chemical factors, abundance, number of species, biomass, heterotrophic and photoautotrophic components, and functional groups with regard to the feeding patterns of a river‐reservoir system. The most outstanding results concerning the system as a whole are: 1, a relationship exists between the biomass of protozoa and the biomass of ciliates; 2, the most important functional groups, in terms of the number of species, are group III (ciliate “downstream” filter feeders) and group IV (ciliate “upxtream” filter feeders), and in terms of the abundance of specimens, the most important ones are groups III and V (raptorial feeders); 3, the division into functional groups according to feeding modes is similar in the river and the reservoir studied. This correlation is quite significant with regard to the number of species, the abundance of specimens, and between the samples taken from the two areas.