Seasonal development of hypolimnetic ciliate communities in a eutrophic pond

The ciliated protozoan communities in the hypolimnion of a highly produtive pond were investigated over two years. Three physiological groups could be distinguished: stratified water column; (b) anaerobic ciliates with endosymbiotic methanogens; and (c) anaerobes without endosymbiotic methanogens. Both groups of anaerobes were confined to the anoxic zone of the hypolimnion. Community biomass was dominated by microaerobic ciliates which had on average 20 times larger cells than anaerobic ciliates. Abundance and biomass of microaerobic ciliates decreased over the summer, while anaerobic ciliates increased. This reflected a spatial shift in the availability of inorganic nutrients and, as a result, of ciliate food from the epi- and metalimnion to the hypolimnion. The low biomass production of anaerobic ciliates was consistent with the low theoretical growth efficiency of anaerobic metabolism. Ciliate species displayed characteristic spatial and seasonal distribution patterns within the water column which were similar in both years investigated. Spatial and temporal distribution was mainly governed by two factors: (1) the distribution of dissolved oxygen; and (2) the availability of food. Distribution patterns were not related to chemical gradients other than the oxygen gradient, but they were correlated with the distribution of major food sources.

[1]  W. Foissner,et al.  Taxonomische und ökologische Revision der Ciliaten des Saprobiensystems - Band I: Cyrtophorida, Oligotrichia, Hypotrichia, Colpodea. , 1993 .

[2]  B. Finlay,et al.  Anaerobic predatory ciliates track seasonal migrations of planktonic photosynthetic bacteria , 1993 .

[3]  A. Sazhin,et al.  The microplankton organisms at the oxic‐anoxic interface in the pelagial of the Black Sea , 1992 .

[4]  K. J. Clarke,et al.  Anaerobic ciliates from a sulphide-rich solution lake in Spain. , 1991, European journal of protistology.

[5]  T. Fenchel,et al.  Anaerobic free-living protozoa: growth efficiencies and the structure of anaeorobic communities , 1990 .

[6]  N. Pfennig,et al.  Utilization of various chemotrophic and phototrophic bacteria as food by the anaerobic ciliate Trimyema compressum. , 1990, European journal of protistology.

[7]  C. Pedrós-Alió,et al.  In situ specific loss and growth rates of purple sulfur bacteria in Lake Cisó , 1990 .

[8]  G. Vogels,et al.  End products of metabolism in the anaerobic ciliate Trimyema compressum , 1990 .

[9]  G. Bratbak,et al.  High abundance of viruses found in aquatic environments , 1989, Nature.

[10]  K. J. Clarke,et al.  On the abundance and distribution of protozoa and their food in a productive freshwater pond. , 1988, European journal of protistology.

[11]  M. Moore,et al.  Differential use of food resources by the instars of Chaoborus punctipennis , 1988 .

[12]  B. Finlay,et al.  The Spatial Distribution and Ecology of Zoochlorellae-Bearing Ciliates in a Productive Pond1 , 1986 .

[13]  B. Finlay,et al.  FERROUS IRON AND PHOTOTROPHY AS ALTERNATIVE SINKS FOR SULPHIDE IN THE ANOXIC HYPOLIMNIA OF TWO ADJACENT LAKES , 1986 .

[14]  M. Alexander,et al.  Minimum bacterial density for bacteriophage replication: implications for significance of bacteriophages in natural ecosystems , 1985, Applied and environmental microbiology.

[15]  M. Pace.  Planktonic Ciliates: Their Distribution, Abundance, and Relationship to Microbial Resources in a Monomictic Lake , 1982 .

[16]  B. Finlay.  Oxygen Availability and Seasonal Migrations of Ciliated Protozoa in a Freshwater Lake , 1981 .

[17]  K. Porter,et al.  The use of DAPI for identifying and counting aquatic microflora1 , 1980 .

[18]  B. Finlay.  Community production and respiration by ciliated protozoa in the benthos of a small eutrophic loch , 1978 .

[19]  R. Thauer,et al.  Energy conservation in chemotrophic anaerobic bacteria , 1977, Bacteriological reviews.

[20]  R. Goulder.  The seasonal and spatial distribution of some benthic ciliated Protozoa in Esthwaite Water , 1974 .

[21]  M. W. Weatherburn.  Phenol-hypochlorite reaction for determination of ammonia , 1967 .

[22]  D. M. Guthrie,et al.  THE EFFECTS OF THERMAL STRATIFICATION ON THE DISTRIBUTION OF BENTHIC PROTOZOA IN ESTH WAITE WATER , 1961 .

[23]  B. Nixdorf,et al.  Seasonal Changes in the Plankton Dynamics of a Eutrophic Lake Including the Microbial Web , 1993 .

[24]  M. C. Swift.  Prey capture by the four larval instars of Chaoborus crystallinus , 1992 .

[25]  B. Finlay,et al.  Protozoan control of bacterial abundances in freshwater. , 1991 .

[26]  T. Fenchel,et al.  Water column anoxia: vertical zonation of planktonic protozoa , 1990 .

[27]  C. Pedrós-Alió,et al.  Ciliates from a fresh water sulfuretum. , 1986, Bio Systems.

[28]  J. G. Field,et al.  The Ecological Role of Water-Column Microbes in the Sea* , 1983 .

[29]  R. Goulder.  Vertical distribution of some ciliated protozoa in two freshwater sediments , 1971 .