bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthèse et dégradation des composés glucidiques au sein de la communauté planctonique en zone marine eutrophe
Authors: Cahet G. , Crassous P. , Neveux J. , Rassoulzadegan F. 
Published: February 2007

AbstractA general study on the relations between “phytoplanktonic excretion” and “heterotrophic assimilation” has been carried out in eutrophic systems, natural or artificial. In the complex systems of these relations, two types of heterotrophic responses were obtained according to prevailing algal species.High heterotrophic potentials in NW African upwelling show the role of microorganisms in the disappearance of freshly excreted organic substances and in the composition of the remaining organic matter.
The Spawning and Early Life History of the Pollan (Coregonus pollan THOMPSON) in Lough Neagh, Northern Ireland
Authors: Dabrowski Konrad R. 
Published: February 2007

AbstractStudies had been carried out on the local non‐migratory whitefish. Spawning behaviour and light conditions on the spawning ground are recorded. After artificial spawning, embryonal development took place under controlled conditions and the larvae were reared. Detailed characteristics of swim bladder creation and differentiation of the digestive tract are given. Distribution and number of pollan larvae near the spawning area and in the open lake were examined. Data are presented concerning the growth rates of larvae and fry in captivity and under lake conditions. Ecological data related to other coregonids are discussed and compared with the present study.
Stocking Rate Estimations of Tilapia mossambica Fingerlings for some Inland Reservoirs of Sri Lanka
Authors: Wijeyaratne M. J. S. , Costa H. H. 
Published: February 2007

AbstractThe Morphoedaphic Indices for several Sri Lanka inland water bodies (mostly ancient man‐made reservoirs) were calculated using conductivity and depth data. The relationship between Morphoedaphic Index MEI and the annual catch of fish C was found to be

.Using this equation, the annual potential yields were calculated. The stocking densities of Tilapia fingerlings needed to be stocked were then estimated taking into consideration the natural recruitment of fingerlings from the already existing stocks of reproducing Tilapia.
Ecological Distribution of Polychaetous Annelids from the New England Outer Continental Shelf, Georges Bank
Authors: Maurer Don , Leathem Wayne 
Published: February 2007

AbstractFour hundred and eight quantitative grab samples collected during the winter and spring of 1977 from the New England Continental Shelf (Georges Bank) yielded 333 species of polychaetes. Polychaetes comprised 53.8% of the number of all infaunal species, 53% of the density, and 60.5% of the wet weight biomass for all soft‐bodied organisms, at least for the winter. Mean number of species and mean density was significantly higher in the spring than in the winter. Mean values of number of species, H', SDN, density, and biomass were associated with various environmental factors. Based on numerical classification (normal and inverse) five polychaete site groups were identified. To a great extent these site groups were molded by major physical, geologic and biologic processes which influence the productivity of this ecologically and economically important area.
Studies on the Age and Growth of an Air‐breathing Catfish, Clarias batrachus (LINN.)
Authors: Thakur Nirmal K. 
Published: February 2007

AbstractAge and growth of Clarias batrachus have been studied through the checks observed on the transverse sections of the pectoral spines of the fish. It was found that the checks are laid annually during July—August. The relationship between the total length and spine radius of the fish was found to be linear in the logarithmic form. Based on this relationship, a formula for back calculation of lengths at different ages was derived. The growth of the species appeared to conform to the inverse exponential pattern and could be expressed as:

Fairly good agreement was observed to exist between the lengths of the fish at corresponding ages calculated by the spine study, length‐frequency analysis and the empirical growth equation of VON BERTALANFFY.
Adaptation of Bathynellacea (Crustacea, Syncarida) to Life in the Interstitial (“Zoea Theory”)
Authors: Schminke Horst Kurt 
Published: February 2007

AbstractThis study aims at demonstrating that the Bathynellacea arose by neoteny from a zoea‐like ancestor (“Zoea Theory”). Bathynellacea basically have a larval morphology. Their post‐embryonic development passes through phases which are directly comparable with some in the development of primitive Eucarida. These phases are called the parazoeal and bathynellid phase, and correspond to the protozoeal and zoeal phase of Penaeidea, respectively. Running initially parallel to that of Penaeidea, the development of the Bathynellacea breaks off precociously. They reach sexual maturity at a stage which, in the Penaeidea, is followed by metamorphosis. There are reasons to assume that the development of all Syncarida originally passed through a series of free‐living larval stages and underwent metamorphosis. The bathynellaceans reach adulthood at a stage which corresponds to the last larval stage of their ancestor. The ecological path to interstitial life of the Bathynellacea and the bearing of the “Zoea Theory” upon views as to their phylogenetic position are discussed. The classical example of a group of crustaceans thought to have arisen by neoteny, the Cladocera, is critically examined and found to be in need of reevaluation.
A Comparative Study of Primary Production and Related Factors in Four Saline Lakes in Victoria, Australia
Authors: Hammer U. Theodore 
Published: February 2007

AbstractThe purpose of the study was to compare the primary plankton productivities of lakes of different salinities and to determine the causative factors involved in their production rates. Four lakes (specific conductivity —mS cm−1 at 18°C) were initially chosen: Coragulac (9), Red Rock (25), Corangamite (38), Pink (250). Sampling and production measurements were made every two to three weeks.Three lakes were dominated by specific phytoplankton blooms: Red Rock (Anabaena spiroides), Corangamite (Nodularia spumigena). Pink (Dunaliella salina). Coragulac Lake had more diverse populations.Red Rock Tarn had some of the highest production values ever recorded. Extremely high soluble phosphate and inorganic carbon concentrations were the most important causative factors. Pink Lake had very low production rates. High salinity and low nutrient concentrations were limiting factors. The other lakes were intermediate in production and nutrient levels.Zooplankton populations were also determined.
Influence of Temperature, Photoperiod and Trophic Conditions on the Seasonal Cycles of Phytoplankton and Zooplankton in Two Deep Subarctic Lakes of Northern Canada
Authors: Moore James W. 
Published: February 2007

AbstractThe densities of phytoplankton and zooplankton were determined for 12 consecutive months (1978–1979) in two deep oligotrophic lakes in northern Canada. The lakes were situated on the same river system, about 5 km from one another. While they exhibited similar temperature conditions, there were slight differences in the ionic content of the water. Overall, changing temperature was the most important factor influencing the duration of the growth cycles of phytoplankton and zooplankton. Nutrients generally controlled the intensity but not the timing of algal blooms. A similar relationship was recorded for the effects of food supply on the development of the major species of herbivorous zooplankton. Although changing photoperiod likely initiated the growth of several important algal and zooplankton species in the spring and early summer, light had no measurable impact on the development of planktonic communities throughout the remainder of the growing season. The higher ionic content of the water in one lake may have promoted the growth of protozoans during the fall and early winter.
A Quantitative Study of the Comparative Distribution of Non‐parasitic Leeches and Triclads in the Stony Littoral of British Lakes
Authors: Young J. O. , Ironmonger J. W. 
Published: February 2007

AbstractFor each of the three species of leeches and four species of triclads inhabiting the stony littoral of 100 British lakes of diverse trophic status, numbers, biomass and mean weight were correlated against a wide range of physical, chemical and other variables. Very few significant correlations were found between the various biological variables and the non‐chemical variables. Significant, positive correlations were obtained for all leech and triclad variables against all of the chemicals, with the exception of Erpobdella octoculata numbers, Helobdella stagnalis mean weight and all of the Polycelis nigra variables which did not correlate with any. Relationships between biological variables and calcium content are given special consideration. Over the range of lakes investigated, total triclad numbers exceeded leech numbers but the reverse was usually true for total biomass. Correlations between the various leech and triclad variables are examined.
Energy Flows in Populations and Communities of Aquatic Animals
Authors: Alimov A. F. 
Published: February 2007

AbstractThe energy assimilated by single individuals of aquatic animals throughout their life times and by populations and communities of aquatic animals during the growth season has been studied with due regard for the definitive weight of the single individual and the mean biomass of populations and communities. Energy assimilated throughout life by invertebrates of different systematic positions, definitive size and life duration is about 2.5 times as high as the energetic content of their definitive mass. The energy flow in populations of benthic animals is about 5 times as high as the seasonal average biomass, and in populations of planktonic animals it is 40 times as high. The energy flow in bottom communities is almost 10 times and in planktonic ones 35 times as high as the average seasonal biomass of communities. Specific production (P/B coefficient per 24 h) for communities of bottom animals was 0.013 per 24 h. The average value of the K2 coefficient (net growth efficiency) calculated for an individual's life time is about 0.4 in populations of bottom animals, the K2 for vegetation seasons is 0.26, and for communities it is 0.2 (per vegetation season). Increasing complexity of the biological systems is accompanied by an increase in the specific energy flow and a decline in the efficiency of food energy utilization for production.
Macrobenthic Communities of the Lower Chesapeake Bay. II. Lynn‐haven Roads, Lynnhaven Bay, Broad Bay, and Linkhorn Bay
Authors: Tourtellotte Gary H. , Dauer Daniel M. 
Published: February 2007

AbstractBased on 96 grab samples at 16 sites the composition and distribution of macrobenthic fauna were examined in a small coastal basin of lower Chesapeake Bay. Normal classification analysis of dominant species produced five site groups. Site groups were divided into clean sand sites, fine sand sites with varying amounts of silt‐clay, and mud sites. Dominant species of the clean group were primarily restricted to this sediment type, while the dominant species of the other groups were widespread in the study area.
Oxygen Consumption and Dissolved Inorganic Nutrient Production in Marine Coastal and Shelf Sediments of the Middle Atlantic Bight
Authors: Florek Robert J. , Rowe Gilbert T. 
Published: February 2007

AbstractThe benthic oxygen demand and inorganic nutrient release have been investigated in the coastal zone of the Mid‐Atlantic Bight of the United States using in situ and ship‐board incubations to estimate fluxes across the sediment‐water interface. Oxygen demand ranged from ca. 70 ml m−2 hr−1 nearshore in warm (25°C) muddy sediments to ca. 4 ml m−2 hr−1 in cold (6°C), coarse‐grained sediments offshore. Ammonium ion flux was out of the sediments in all but 4 of 29 incubations, while nitrate was often found to be utilized within or on the sediments, decreasing in 10 of 29 incubations. Those locations with fluxes of nitrate out of the sediment had concentrations in the pore water that were generally high, sometimes up to several mM l−1. Nitrate fluxes were always well below those of ammonia, even where high almost equivalent concentrations of both NH4 and NO3 were found at the same locale.On George's Bank only 13 % of total N demand by the phytoplankton was estimated to be supplied by the benthos, whereas in New York Bight the supply amounted to 42 % of the demand. This difference can be attributed to higher pelagic biological and advective (mixing and upwelling) inputs to George's Bank compared to the relatively well stratified New York Bight in late summer and autumn.
Sensitivity of Lakes to Inorganic Enrichment Stress ‐ Some Results of Experimentally Induced Fertilization
Authors: Hillbricht‐Ilkowska Anna , Zdanowski Bogusław 
Published: February 2007

AbstractThe introduction of P and N loads exceeding 4‐14 and 1‐2 times, respectively, the amount of these nutrients stored in the waters of four lakes (dystrophic and eutrophic, stratified and unstratified) resulted in stronger, two‐phased changes in Ptot standing stock and in rather insignificant and non‐directed changes in Ntot in all lakes. In the waters there was the immediate increase of Ptot followed by a decrease (together with a decrease in the N : P ratio) but the final level was still higher than in the control. In the top layer of off‐littoral sediments there was a temporary accumulation of nutrients followed by their release to a level significantly lower than that in the control year. Visible changes in the nutrient content and total biomass of above‐ground parts of macrophytes were noted only in the lake which was previously highly dystrophic, after it had been limed. This lake reacted strongest to the P load, and the release of nutrients from its deposits started simultaneously with fertilization. It is hypothesized that the reduction in the N : P ratio in the lake waters was mainly responsible for the lack of assimilation of further doses of P and that the acceleration of denitrification process caused by the higher overall lake productivity was responsible for the stabilization and removal of the N load. The activation of bacterial decomposition in the sediments due to the increase in lake productivity and sedimentation rate was considered as the probable reason for the acceleration of the nutrients release from the top layers of the sediments and their further physical transport to deeper layers.
The Natural History of a Nearctic Temporary Pond in Ontario with Remarks on Continental Variation in such Habitats
Authors: Williams D. Dudley 
Published: February 2007

AbstractThe seasonal succession of members of the invertebrate community of a temporary vernal pond in southern Ontario is described. Although succession was essentially continuous, 5 faunal groups are suggested, based on time of appearance and duration of active forms in the pond. Some species were found during virtually the entire aquatic phase, while others completed their life cycles in only 2‐3 weeks. Analysis of growth rates revealed many different patterns between species and groups. Analysis of community structure in terms of trophic status indicated shifts which coincided with the seasonal occurrence of the pond's potential food resources. Comparison of this fauna with that of a similar pond on Vancouver Island, British Columbia (some 2,400 km to the west) showed many similarities in niche occupancy, including 6 species in common. The biological characteristics leading to the success of these cosmopolitan species in temporary aquatic habitats is discussed.
Birth and Death Rates of a Littoral Filter Feeding Microcrustacean, Sida crystallina (Cladocera), in Cochran Lake, Michigan
Authors: Fairchild G. Winfield 
Published: February 2007

AbstractPopulation changes of Sida crystallina, a filter feeding microcrustacean which attaches to aquatic macrophytes, were examined in Cochran Lake, Michigan during June and July, 1979. Population estimates were derived from organisms present in 10 samples of leaves of the water lily Nymphaea odorata collected every 3 days.Population densities of Sida responded both to food and predation by fish. Declines in average clutch size were associated with decreasing phytoplankton biomass and the increasing dominance of colonial green and blue‐green algae, but were not significantly influenced by the densities of invertebrates on the plants. Largemouth bass fry (Micropterus salmoides) dramatically reduced the numbers of Sida and altered the age structure of the population in late June.
Studies on Stabilization Ponds for Domestic Sewage in India
Authors: Rao A. V. 
Published: February 2007

AbstractFor one year a single cell stabilization pond, T. T. Nagar, Bhopal (August, 1968 to July, 1969) and series stabilization ponds, Shahpur, Bhopal (January, 1969 to December, 1969) were studied. Climatological conditions in Bhopal were favourable for the treatment of sewage in stabilization ponds. There was a considerable reduction in BOD, total nitrogen, phosphate, coliforms and enterococci during the process of treatment. The reductions were highest in series ponds. Studies on diurnal variations showed that highest pH, dissolved oxygen, algal cell number and lowest alkalinity values occurred around 4.00 p.m. Algal flora present in the single cell pond consisted of 31 species representing 27 genera. In the series ponds 33 species belonging to 30 genera and 37 species belonging to 33 genera were recorded for the primary and secondary ponds, respectively.
Standardgewichte der Copepoden in der Pommerschen Bucht. Standard Weights of the Pomeranian Bay Copepods
Authors: Chojnacki Juliusz 
Published: February 2007

AbstractThe length weight relationship was determined for Pseudocalanus minutus elongatus, Temora longicornis, Acartia bifilosa, and Acartia longiremis caught in the Pomeranian Bay (Baltic Sea). To determine the weights of the individuals a geometrical method was used and the formula.
Studies on Chaetophoraceae from Southern Iraq
Authors: Islam A. K. M. Nurul , Haroon A. K. Yousuf 
Published: February 2007

AbstractCloniophora macrocladia (NORDST) BOUR. var. macrocladia, Stigeoclonium curvirostrum SKUJA, St. fasciculare KÜTZ. var. glomerata (HAZEN) ISLAM and St. stagnatile (HAZEN) COLLINS fa. are reported from Iraq.
The Spatial and Temporal Distribution of Epipelic Algae in a Shallow Eutrophic Prairie‐parkland Lake, Alberta, Canada
Authors: Jenkerson C. G. , Hickman M. 
Published: February 2007

AbstractInvestigations were conducted upon the epipelic algal community of a shallow eutrophic lake in central Alberta, Canada. The lake was Hastings Lake (longitudes 112° 50′ and 113° 00′ W; latitudes 53° 15′ and 53° 50′ N). The epipelic algae displayed both spatial and temporal distributions for species composition, standing crop as well as productivity.In situcross incubation experiments showed the potential photosynthetic viability of epipelic algae living below the 1% irradiance level.
The Natural Feeding and Resource Partitioning of Erpobdella octoculata L. and Erpobdella testacea SAV. in Lake Esrom, Denmark
Authors: Dall Peter C. 
Published: February 2007

AbstractThe natural feeding and competitive interactions between populations of Erpobdella ostoculata and Erpobdella testacea were investigated in Lake Esrom, Denmark, during 1979/80. Statistical analysis revealed that the size of the leeches was the main factor involved in resource utilization. Size‐specific feeding included differences in the numerical composition of diets and the size of individual prey. Five weight classes of Erpobdella spp. were distinguished. The number of prey per leech increased from 1.63‐2.84 for the first to the fifth weight class, whereas diversity in feeding averaged 1.71 prey per leech. Quantification of competitive interactions indicated that the temporal differences in weight class composition of the two species were sufficient to explain coexistence, although both species have an annual life cycle, and neither species showed taxonomic food refuges.
Estimates of Microbial Populations Involved in the N Cycle and their Activity in Water and Sediments of Fish Farming Ponds under Mono and Polyculture Systems in India
Authors: Jana B. B. , Roy S. K. 
Published: February 2007

AbstractThe population sizes of ammonifying, protein mineralizing, nitrogen fixing and nitrifying bacteria, and the rates of ammonification and nitrification (natural and potential) were measured in water and sediments of four fish ponds being used for traditional, mono‐ and polyculture systems of fish farming. Spatial differences in the microbial density in these ponds were related to the fish culturing practices adopted. The seasonal variation of ammonifying bacteria was found to be positively correlated with the NH4‐N level in the water. The natural and potential capacity to generate both nitrite and nitrate in these water bodies was strongly correlated with the concentrations of the different forms of inorganic nitrogen present. The rates of NO2‐N and NO3‐N formation occurring in these fish ponds were directly proportional to the amount of dissolved oxygen and pH of the environment, respectively.
The Proportion of Empneuston and Total Atmospheric Inputs of Carbon, Nitrogen and Phosphorus in the Nutrient Budget of a Small Mesotrophic Lake (Piburger See, Austria)
Authors: Psenner Roland 
Published: February 2007

AbstractLitter and wet traps were employed to determine the inputs of coarse organic matter (empneuston), total organic carbon, total nitrogen and phosphorus through dry fallout and precipitation to a soft‐water, mesotrophic lake. The dispersal of airborne material over the lake surface was investigated, and a method for the calculation of total input was developed. The component of the particulate matter larger than 1 mm contained the largest proportion of organic carbon, while the dissolved and the fine particle (smaller than 1 mm) fractions made greater contributions to the inputs of nitrogen and phosphorus compounds. The importance of the large particle fraction of the airborne organic matter in the lake's nutrient budget during the autumnal fall of litter was confirmed. However, the maximum total airborne input seems to occur during spring and summer. The input of phosphorus compounds through the atmosphere to small forest lakes is large compared to that from other sources. Airborne material accounts for 39% of the total phosphorus loading.
Prehistoric pH Trends in Kejimkujik Lake, Nova Scotia
Authors: Delorme L. Denis , Esterby Sylvia R. , Duthie Hamish 
Published: February 2007

AbstractKejimkujik Lake in Nova Scotia has an average pH of 4.8 and receives wet precipitation with a weighted mean pH of 4.62. The lake is situated in a drainage basin where organic rich soils and bogs rest upon poorly buffered igneous and metamorphic rocks. Fossil diatoms from a sediment core reveal that since 21.7cm the pH trend has been to a lower pH. The flora of the lake between 13.0 and 10.7cm indicate a climatic change to a dryer period followed by a return to a more moist and humid climate. Colonization by European settlers, around 1850 A.D. drastically altered the pH of Kejimkujik Lake through deforestation and burning of lumbering refuse. The effect of potassium hydroxide, by leaching potassium from wood ash, on the lake continued to 2.2cm (about 1950) when the acidity began to drop to lower more normal levels. The overriding effect on the lake appears to have been the presence of organic soils and bogs which have contributed organic acids to the system since at least 21.7cm.