bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colonization, Species Composition, and Conidial Production of Aquatic Hyphomycetes on Chirpine Needle Litter in a Freshwater Kumaun Himalayan Stream
Authors: Sati S. C. , Tiwari N. 
Published: February 2007

AbstractAquatic hyphomycetes colonizing the submerged chirpine (pinus roxburghii SARG.) needle litter in a high altitude, Kumaun Himalayan stream were studied. 15 species belonging to different genera of aquatic Hyphomycetes have been recognized as the colonizers of chirpine needle litter. Clavariopsis aquatica, Heliscus lugdunensis, Lunulospora cymbiformis, Triscelophorus acuminatus and T. monosporus were found with a high frequency of occurrence. The conidial production was highest in Flagellospora penicillioides, however, Campylospora chaetocladia, L. cymbiformis and T. acuminatus had less number of conidia per unit area of pine needles. The chirpine needle litter decomposition in the freshwater habitat is also discussed.
Metacyclops minutus (CLAUS, 1863) ‐ Population Dynamics and Life History Characteristics of a Rapidly Developing Copepod
Authors: Maier Gerhard 
Published: February 2007

AbstractThe cyclopoid copepod Metacyclops minutus, a typical species of temporary pools, shows an unusual life cycle in a small pond in South Germany. The species is present from April/May to December during which period it forms at least 8 generations. Winter and early spring, when the pond is frozen to the bottom, are spent in the bottom mud as C4 or C5 instars. M. minutus shows an extraordinarily low degree of sex size dimorphism (female: male body length ratio) and no significant differences in. copepodite development time between the two sexes. This, together with the exceptionally short durations of embryonic‐ and postembryonic development enables reproduction to start without delay and rapid population growth after harsh conditions. By these means M. minutus is the first species to reproduce after periods of extremely low water level; later, when conditions in the pond become more stable, M. minutus is surpassed in numbers by a coexisting, filterfeeding and parthenogenetically reproducing cladoceran Moina brachiata.
Relationship of Sponge Macrofauna with the Morphology of their Hosts in the North Aegean Sea
Authors: Koukouras A. , Russo A. , Voultsiadou‐Koukoura E. , Dounas C. , Chintiroglou C. 
Published: February 2007

AbstractThe associated macrofauna of four Aegean Sea sponge species (Agelas oroides, Petrosia ficiformis, Ircinia variabilis and Aplysina aerophoba) was compared. The total number of individuals and species was found to be related to sponge volume for all sponge species.The associated macrofaunal weight per individual on all sponge species was negatively correlated with sponge volume. Sponge complexity, as measured by sponge surface area to biomass ratio, was not a consistent predictor of associated macrofauna abundance or diversity. Sponge macrofauna species were not host specific and their relative abundances differed among sponge species.
Comparison of Two Methods of Zooplankton Grazing Measurements
Authors: Nőges Tiina 
Published: February 2007

AbstractA comparison of two methods of zooplankton feeding experiments was performed in the Gulf of Finland. One was the advanced twin‐bathometer method (in situ technique), the other — the “bottle method”. The main difference between the two methods is that it is not necessary to manipulate zooplankton to start an experiment in a twin bathometer, while manipulation is inevitable if the second method is used. In cases when the onset of the grazing experiment requires the manipulation of animals, the adaptation period lasts 2–4 hours and the optimal duration of experiment is 6–10 hours. If animals are not manipulated at the beginning of experiment, the adaptation period does not exist, the exposition time should not exceed 10 hours and the optimal duration of experiment is 2–4 hours. In long‐term experiments (up to 24 hours) the fertilization effect of the excretion of concentrated zooplankton may cause underestimation of grazing rate.
Postglacial Succession in the Subgenus Eubosmina (Crustacea: Cladocera) in the Region of the Unterhavel River (near Berlin, Germany) — Type Changes or Species Immigration?
Authors: Günther Jutta , Lieder Ulrich 
Published: February 2007

AbstractAnalyses were made of subfossil Eubosmina remains from two Berlin Lakes. The first postglacial eubosminid was B. (E.) longispina. In Tegeler See it occurred from the Alleröd to Atlantic 2. In Lake Unterhavel it disappeared earlier in the Boreal. Bosmina (E.) longicornis occurred in early Atlantic 1 resp. at the end of Atlantic 2 (Tegeler See). Bosmina (E.) c. coregoni appeared in Lake Unterhavel at the end of the Boreal, in Lake Tegeler See at early Boreal. Bosmina (E.) c. thersites occurred only in sediments of Lake Unterhavel beginning in Atlantic 2.No sign of a “morphological transition” between taxa found by HOFMANN could be found in the two investigated lakes. The succession of Eubosmina taxa seems to be mainly the result of immigration.
Zooplankton Migration in Three Lakes of Western New York
Authors: Stewart Kenton M. , Sutherland James W. 
Published: February 2007

AbstractWe examined the diel vertical migration (DVM) of zooplankton in three lakes of western New York; Lakes Conesus, Lime, and McCargo. In all three lakes, the dipteran predator Chaoborus was a more dramatic migrator than any of the cladocerans or copepods. In contrast, another invertebrate predator, Leptodora, seemed to have the least vertical dispersal. In Conesus Lake, following the evening ascent and upper‐water night‐positioning of Chaoborus flavicans, Daphnia pulicaria expanded its own vertical range of dispersal thereby decreasing its degree of overlap with Chaoborus. The vertical distribution of Diaptomus sicilis was mostly below that of Daphnia pulicaria, thus reducing possible competition for food resources. Poor oxygen conditions in the lower waters of Lakes Lime and McCargo restricted all zooplankton (except Chaoborus) to an epilimnetic zone where the regions of niche overlap and predation were narrowed. Such annually‐induced restrictions on vertical dispersal are probably common features of numerous stratified lakes with hypolimnetic reducing conditions. No fixed pattern of vertical dispersal or migration is likely in lakes where stratification and non‐stratification follow each other seasonally. Vertical migration does provide some flexibility in niche separation, but the potential for chaotic behavior in interacting predators and prey may confound simple explanations of DVM.
A Model to Predict Lake Water Colour
Authors: Håkanson Lars 
Published: February 2007

AbstractThis study is an attempt to quantitatively determine variables of significance for predicting colour in small glacial lakes. Lake colour is an important variable in many lake ecological contexts. The data emanate from two extensive data‐sets from Sweden, one of which concerns 1456 lakes, and the other 91 more well‐suited lakes. Four year average values of lake colour were compared to catchment and morphometric parameters to help identify the processes which influence variability in colour between lakes. Various hypotheses concerning the factors regulating colour in lakes were formulated and tested. Various statistical tests were used to separate random influences from causal influences. Those “map parameters” with the most significant influence on colour were the theoretical lake water retention time, the percent of rocks, lakes and mires of the drainage area, the ratio between lake area and drainage area and the lake mean depth. Each model parameter provides only a limited explanation (statistical) of the variability in colour between lakes. The predictability of colour by these models can not be markedly improved by accounting for the distribution of the characteristics in the drainage area. The stability of the final model, which gives an r2‐value of 0.74, has been tested with positive results. The model allows lake colour to be estimated from knowledge of “geological” characteristics of the lake and its drainage area. The variability between lakes from other factors, such as temperature, precipitation and/or contamination of acidifying substances and nutrients, may then be quantitatively differentiated from the impact of these “geological” factors.
Organic Matter, Carbon, Nitrogen and Phosphorus Contents of the Mesozooplankton, Mainly Acartia clausi, in a Tropical Brackish Lagoon (Ebrié Lagoon, Ivory Coast)
Authors: Pagano Marc , Saint‐Jean Lucien 
Published: February 2007

AbstractMesozooplankton samples were collected over a period of one year in five stations of the Ebrié lagoon and analysed for organic, carbon, nitrogen and phosphorus contents. When zooplankton was dominated by A. clausi, body composition was relatively stable compared with the broad variability of environmental factors (mainly salinity, food abundance and composition), although a negative hypothetic influence of salinity may have occurred. Body composition was comparable when zooplankton was dominated by Pseudodiaptomus hessei and freshwater species, but contents were significantly lower for assemblages dominated by more exclusively marine species (Paracalanus spp., Oithona spp., marine cladocerans, chaetognates, etc.).
Acute Toxicity for some Evaporating Aromatic Hydrocarbons for Freshwater Snails and Crustaceans
Authors: Erben Radovan , Pišl Zoran 
Published: February 2007

AbstractSome typical and more frequent freshwater invertebrates of running waters were studied to examine the influence of styrene, xylene and benzene on their mortality. Snails Amphimelania holandri FÉR. and Lymnaea stagnalis L. and crustacenas Asellus aquaticus L. and Gammarus fossarum KOCH., were used in the semi‐static test. Compounds were added in volume concentrations of 0.005 to 0.4% v/v. For all concentrations LC50 was calculated by probit method, which demonstrated that mortality depends much more on increased concentrations (depending on the initial concentration) than on the length of exposure. Styrene was the most toxic, followed by xylene and then benzene. The species G. fossarum showed marked sensitivity, followed by A. aquaticus, and the species A. holandri and L. stagnalis showed less sensitivity.
A Mediterranean Fine‐sand Polychaete Community and the Effect of the Tube‐dwelling Owenia fusiformis DELLE CHIAJE on Community Structure
Authors: Somaschini Alessandra 
Published: February 2007

AbstractSamples were taken in fine‐sand community of the North Latium coast in February and September for two years.Eigthy‐eight species of Polychaetes were identified. The most abundant was Owenia fusiformis which was highly correlated to the clay fraction in the sediments. Species richness and abundance of other polychaete species were related to the abundance of this tubicolous species which provides a spatial refuge from predators and implements sediment stability. There was a persistency in the community structure in spite of seasonal fluctuations in the abundance of dominant species.
A Comparison of Phytoplankton and Algae Growing on Plexiglas Slides in an Oligotrophic Lake
Authors: Rodriguez Marco A. 
Published: February 2007

AbstractThis study compares the composition and dynamics of phytoplankton communities and of periphyton communities growing on Plexiglas slides in a temperate oligotrophic lake. Ordination methods were used in the comparisons, which covered a three‐month period during the summer. Plankton and periphyton communities differed considerably, and shared only six common taxa. An ephemeral Dinobryon pulse occurred simultaneously in both communities, and represented the largest source of variability in community composition. Recovery from the pulse was faster in the phytoplankton than in the periphyton. Attachment to substrata, through its effect on cell turnover times and nutrient cycling, is hypothesized to provide a temporal refuge for plankton species during periods of unfavorable environmental conditions.
Dynamics of Phototrophic Microbial Populations in the Chemocline of a Meromictic Basin of Lake Banyoles
Authors: Garcia‐Gil L. J. , Borrego C. M. , Bañeras L. , Abella C. A. 
Published: February 2007

AbstractThe ecological succession of two microbial planktonic populations in the chemocline of C‐IV, a meromictic basin of Lake Banyoles has been studied during the stratification period of 1989 (June to October). A dense population of deep‐living algae Cryptomonas phaseolus was found growing between 13 and 14 meters depth, forming peaks of 10 to 20 μg.l−1 of chlorophyll a. The physical and chemical properties of the water were continually changing during the studied period and were strongly related to the biological processes developed at the monimolimnion of C‐IV. Although the monimolimnion of the basin was initially anoxic (Eh values were around +300 mV and sulphide was not present at detectable levels) soluble iron and sulphide appeared sequentially, displacing the deep‐living algae population and setting the conditions for the development of a population of brown Chlorobiaceae, Chlorobium phaeobacteroides. Although Cryptomonas population abandons the chemocline (13.75 m.) and decreases its biomass, it does not disappear at all, but moves upwards (8–11 m.) leaving the zone to sulphur phototrophic bacteria which find optimal conditions to grow. The sulphide diffusion coming from sediment and the nutrient limitation were the main responsible factors accounting for the upwards migration and the decrease of growth rate of the algal population respectively.
Biology of Multi Cell Ponds Treating Municipal Wastes
Authors: Patil H. S. , Meti G. M. , Hosetti B. B. 
Published: February 2007

AbstractObservations were made over a period of one year on the performance of multi stage stabilization ponds treating domestic waste waters. The unit is composed of Primary anaerobic (P1) and two consecutive Secondary (P2) and Tertiary (P3) facultative ponds. The overall reduction in BOD, bacteria, PO4, SO4, NH3N, Cl− and total solids were 89.4, 99.8, 76.2, 47.7, 79.7, 18.6 and 74.0 percent, respectively. Elimination of H2S was 84.8% in the final effluents. Chlorella vulgaris was found to be the dominant alga followed by Euglena, Ankistrodesmus, Phacus and Synedra as subdominant forms. 9 species of protozoa have been recorded in the first pond and their number declined in the successive ponds.
Lake Müggelsee and its Environment — Natural Conditions and Anthropogenic Impacts
Authors: Driescher Eva , Behrendt Horst , Schellenberger Günter , Stellmacher Rita 
Published: February 2007

AbstractLake Müggelsee, a polymictic eutrophic lake at the eastern border of the city of Berlin (area: 7.3 km2, mean depth: 4.9m) is mainly influenced by the River Spree (flowing through the lake) and subject to various usages, especially to municipal water supply and recreation. Geomorphologic development, morphometric features, climatic conditions, hydrological regime, and position in the hydrographic net are described. Short information is given on fauna and flora of the lake, and on characteristics of the catchment area. Water quality parameters are summarized as 12 year average (1979–1990) and the eutrophic state is compared to other lakes. Finally, a short report on scientific research activities is given.
Lake Müggelsee and the Inflowing River Spree; Comparison of Phytoplankton Communities 1980–1990
Authors: Köhler Jan , Nixdorf Brigitte , Hoeg Sigrid 
Published: February 2007

AbstractBiomass and community structure of phytoplankton have been analysed in the eutrophic, shallow, polymictic Müggelsee and in the inflowing Spree since 1980. In both lake and river, mean biomass and vitality of phytoplankton were similar. A regular annual succession of planktonic algae was found in both the river and the lake. The same species were found to be dominant, although the actual biomass of single phytoplankton populations differed normally from inflow to lake. Lake phytoplankton was characterized by higher proportions of Cyanobacteria (45.9 ± 11.3% resp. 34.5 ± 8.2%) and lower proportions of centric diatoms (35.1 ± 9.5% resp. 41.9 ± 10.3%, average April‐October, 1980–90). The less abundant Pennales, Chlorophytes, and unidentified planktonic algae < 10 μm had attained a relatively higher importance in the river than in the lake. In the last decade, a pronounced shift from Cyanobacteria to diatoms (mainly Centrales) has been observed in the river.
Phenomenological Description of Polymixis and Influence on Oxygen Budget and Phosphorus Release in Lake Müggelsee
Authors: Behrendt Horst , Nixdorf Brigitte , Pagenkopf Wolf‐Gunter 
Published: February 2007

AbstractThe polymictic properties of a shallow eutrophic lake (Lake Müggelsee, Berlin) are described by the water column stability (N2) and vertical differences in oxygen saturation at the deepest site (7 m) of the lake from 1979 to 1990. Mixing and stratification changed irregularly up to seven times from April to October. Thermally stable conditions generally lasted 1–2 weeks. A maximum of 5 weeks stratification was observed in 1982. Although the oxygen content above the sediment depleted during stratification periods the lake is well supplied with oxygen in general. As a consequence of oxygen depletion, considerable amounts of phosphate can be released from the sediment leading to differences in the concentration of phosphate between the deepest point and subsurface of more than 1000 μg 1−1. The release of dissolved reactive phosphate from the sediment is mainly controlled by the rate of change of oxygen in the deepest layers of the lake.
The Carbon Balance of Phytoplankton Production and Loss Processes Based on in situ Measurements in a Shallow Lake
Authors: Behrendt Horst , Nixdorf Brigitte 
Published: February 2007

AbstractThe balance of phytoplankton biomass was studied during spring and early summer 1986 and 1987 in Lake Müggelsee, a eutrophic polymictic lake. It is assessed as the result of biomass changes, gross primary production (14C‐method) and physiological or internal and ecological or external losses. Biomass changes, primary production, grazing, dark carbon losses and exudation were estimated from in situ measurements. The remaining light carbon losses and net sedimentation were calculated from the phytoplankton balance of the lake. On average the physiological losses of algae ranged between 80.5 of primary production in 1986 and 72% in 1987. Dark carbon losses by respiration ranged between 15 and 20%, and grazing losses between 24.5 and 21.9% of gross primary production in 1986 and 1987, respectively. The remaining 16.6 and 23.6% of primary production which were lost in 1986 and 1987, respectively, are mainly attributed to sedimentation.
The Cost of Reproduction in the Rotifer Brachionus calyciflorus Pallas
Authors: Guisande C. , Galindo M. D. , Galan F. M. , Oliveros F. 
Published: February 2007

AbstractA study of lifespan, fecundity, and reproductive schedules was carried out with the rotifer Brachionus calyciflorus under different food concentrations.At high food densities (6.1 to 12.4 μg · ml−1, dry mass) there was an increase in offspring number but the reproductive investment remained constantly. This was possible because Brachionus calyciflorus invested a smaller amount of energy one egg volume being able to increase offspring number. Although egg volume was reduced, this was compensated by the greater amount of energy available to the neonates. The length of the prereproductive period remained constant throughout this range of food concentrations. Within this range a reduction in lifespan was observed. This, however, was not due to a total higher reproductive investment, but to an increased offspring rate production resulting in a shortening of the reproductive period. The length of the post‐reproductive period was not different at all food concentrations.
Free Fatty Acids of Surface Film of Water in the Sydinsky Bay of the Krasnoyarsk Reservoir
Authors: Gladyshev Michail I. , Kalachova Galina S. , Sushchik Nadezhda N. 
Published: February 2007

AbstractDuring the summer of 1990 composition and concentrations of free fatty acids (FFA) in the surface film of water were investigated. 23 FFA species were identified. Using cluster analysis in conjunction with ANOVAR correspondence of FFA contents in the surface film with seasonal patterns of pelagic plankton was proved. Three different groups of FFA were revealed, acids of every group had similar seasonal dynamics and presumably were of similar origination. Data obtained gave a chance to suppose that main part of FFA were originated by exudation of living cells of phytoplankton as well as postmortal exudation of bacterioplankton. On the basis of FFA contents in a single sample from the surface film identification of sign of derivatives of phytoplankton biomass was suggested. This express‐assay may be useful for monitoring.
Redescription of Mesocyclops leuckarti (Copepoda, Cyclopoida), Including a Study of its Naupliar Development
Authors: Dahms H.‐U. , Fernando C. H. 
Published: February 2007

AbstractThe female and male of Mesocyclops leuckarti (CLAUS, 1857) from a European population are redescribed in detail. New diagnostic characters are described which have passed unnoticed so far. All six naupliar stages of this species are studied as well. Characters of the adult and naupliar external morphology are discussed with respect to previous studies.
Inorganic Turbidity and the Failure of Fishery Models
Authors: Lind O. T. , Dávalos‐Lind L. O. , Chrzanowski T. H. , Limón J. G. 
Published: February 2007

AbstractModels for the prediction of fishery production and/or harvest based on primary production, algal biomass, or nutrients and morphometry have been effective in many lakes and reservoirs. Lake Chapala, México's largest, is located on the Río Lerma, one of México's principal rivers. It was made a reservoir in 1903 by the construction of a hydroelectric dam on the out‐flowing Rio Santiago. For the first half of this century Lake Chapala was famous for its native white‐fish (Chirostoma lucius) fishery. This fishery has collapsed. The present fishery consists of small Chirostoma species and the introduced Oreochromis. During the past 17 years the water level has fallen by over 3 meters. Now very shallow, clay resuspension creates low visibility (Secchi < 1 m). Nutrients are abundant with total phosphorus exceeding 1 mg 1−1 and inorganic nitrogen exceeding 0.5 mg 1−1. Photosynthesis is limited by light and especially the unfavorable mixing depth to photic depth ratio. Models based on phytoplankton production or biomass underestimate the fishery by about one order of magnitude while a morphoedaphic model overestimates the fishery to the same extent. We sought to explain alternate pathways to support the realized fishery. Experiments suggest that bacterial prodution, with a bypass of the microbial loop, may offer a partial explanation. Management practices to increase the fishery based on an increased autotrophic base to food chain would fail without consideration of bacterial processes in this highly turbid ecosystem.