摘要:

AbstractThe effect ofChlorellaconcentration 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 onChlorellaconcentration. 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 onSDAand ingestion rate.

ISSN:0020-9309    

DOI:10.1002/iroh.19880730602

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

AbstractIn situETS‐activity of size‐fractionated natural phytoplankton communities was studied to determine the relative rate of respiration of different size fractions. Different lakes of varying trophic levels were examined. This study suggested that<35 μm organisms are the major contributes of respiratory‐enzyme activity to the total community respiration. The results of this study indicate that half or more of the losses of primary productivity in different particle sizes are from respiratory activity. The data collected during this research on the photosynthetic rates andP/Rratio of different size particles give better information than primary productivity alone on community metabolic rates for evaluating productivity measur

ISSN:0020-9309    

DOI:10.1002/iroh.19880730603

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

AbstractSediment‐water systems of Lake Balaton mud and tap water were constructed in plexiglass tubes and boxes for evaluation of changes in the nitrogen and phosphorus contents of overlying water as influenced by chironomid density and light conditions.Nitrogen flux from sediment was greatly influenced by denitrification process. The amount of TN released by chironomids amounted to about half of the yearly nitrogen fixation rate in Lake Balaton.Omnivorous chironomids increased the phosphorus content of the overlying water. The rate of release was density dependent. TP release rates ranged between 1–17 mg m−2day−1over a range of densities 500–20,000 larvae m−2.It became evident that aerobic sediment cores can be an important nutrient source in lakes where chironomids inhabit them at densities above 1,000

ISSN:0020-9309    

DOI:10.1002/iroh.19880730604

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

AbstractA one year study on a waste oxidation pond was undertaken to observe the behaviour of four enzymes, viz catalase, phosphatase, protease and amylase with respect to other ecological factors. The increase in solar radiation from March to May enhanced phytoplankton growth resulting in increased pH and DO and considerable reduction in nutrients and BOD. Variations in the activity of enzymes seemed to be directly related to bacterial number. The activity of catalase and phosphatase seemed to be related to the microbial density and nutrient status of the pond. The activity of protease and amylase could be used as a measure of degradation of organic matter.

ISSN:0020-9309    

DOI:10.1002/iroh.19880730605

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

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. anat

ISSN:0020-9309    

DOI:10.1002/iroh.19880730606

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

AbstractBased on the 1958Vemacruise and the 1965Anton Bruuncruise 11 off the west coast of Central America and south through the islands east of the tip of South America, 143 trawl samples were examined for abyssal polychaetous annelida. The cruise tracks designated 7 major areas: Central America (1), Ecuador‐Peru (II), Central and Southern Chile (III), Chile and the Magellan Strait (IV), Tierra del Fuego (V), the Island Complex (Falkland, South Georgia and South Sandwich Islands) (VI), the Drake Strait and Antarctic Peninsula (VII). The collections yielded 7,015 individuals and 322 species from 52 families. The relatively small number of species was attributed mainly to sampling effort, collecting gear and processing techniques.Each major area was characterized in terms of the number of individuals, the number of species, mean number of individuals, mean number of species and meanH′, SR, J′ andDI.Species diversity was significantly higher in Central America (I) than in the other areas. The relationships between biotic and abiotic measures (depth and areas of upwelling) were examined. There were no significant associations for the entire data base with depth. Moreover, there was no association between abundance of polychaetes and areas of upwelling which was hypothesized. In fact, relative abundance was highest in the deepest portions of Central America (I) (Guatemala Basin) and Ecuador—Peru (II) (Milne—Edwards Deep) compared to shallower areas closer to areas of upwelling. Quantitative collecting gear and refined processing techniques will be required to more accurately address these relationships.Dominant families were identified in terms of number of species and number of individuals. These families conformed well with world wide generalizations of dominant families. Dominant species were identified based on the Biological Index Value. The top twenty or dominant species for each major area were identified. A number of these dominant species occurred widely throughout the major areas. The dominant species for the entire data set were determined. In general these species were very eurybathic which was consistent with other worldwide depth distributions of abyssal polychaetes.Based on biotic measures (mean number of species, meanH', SR, J′ andDI) and the Simpson and Dice similarity co‐efficients, several zoogeographic patterns emerged. The polychaete fauna from Central America (I) to southern Chile (II) formed a relatively homogeneous group. Polychaetes from Central America (I) had affinities with faunas studied off western Mexiko. The Chile and Magellan Strait (IV) area seemed to be a transition area which yielded to another relatively homogeneous fauna comprising areas V—VII. The latter fauna belonged to an Antarctic polychaete fauna which was documented earlier in other studies with a larger data base and more sophisticated analysis. It is hoped that the present study will help to provide a start to fill the zoogeographic gap of this enormous and bathymetrical

ISSN:0020-9309    

DOI:10.1002/iroh.19880730607

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

摘要:

AbstractBacteria which are able to store large amounts of phosphorus as polyphosphate (PP) under aerobic conditions and to release it under anaerobic conditions are utilized for the advanced treatment of sewage. This note presents some results which indicate that PP‐accumulating bacteria which possibly participate in the immobilization and release of dissolved phosphate may also be present in lake sediment

ISSN:0020-9309    

DOI:10.1002/iroh.19880730608

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19880730610

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19880730611

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19880730613

出版商:Akademie Verlag, Berlin    

年代:1988

数据来源: WILEY