Abundance, biomass, production, and grazing loss rates of phytoplankton, free-living bacteria, Protozoa were assessed during an intense spring phytoplankton bloom in prealpine Lake Constance (Bodensee). More than 50% the primary production was channeled through microbial loop. Bacteria ciliates responded rapidly to increasing biomass production. Maximal growth bacteria slightly lower those dominating species. Averaged over bloom, bacterial C amounted 21% C, 18% particulate Increase...

Functional ecology is a subdiscipline that aims to enable mechanistic understanding of patterns and processes from the organismic ecosystem level. This paper addresses some main aspects process-oriented current knowledge on phagotrophic, i.e. heterotrophic mixotrophic, protists in aquatic food webs. not an exhaustive review; rather, we focus conceptual issues, particular numerical functional response these organisms. We discuss evolution concepts define parameters evaluate predator-prey...

Incident light was manipulated in large plankton towers containing algae, microbes, and herbivores. Paradoxically, food chain production lower with greater energy input. This apparent paradox is resolved by recognizing stoichiometric constraints to production. At high light, elevated algal biomass achieved mainly increases cellular carbon. Consumers have a phosphorus demand for growth, thus excess of carbon inhibited, rather than stimulated, their growth. These experiments may help us...

Journal Article The annual cycle of heterotrophic freshwater nanoflagellates: role bottom-up versus top-down control Get access Thomas Weisse Limnological Institute, University KonstanzPO Box 5560, D-7750 Konstanz, FRG Search for other works by this author on: Oxford Academic Google Scholar Plankton Research, Volume 13, Issue 1, 1991, Pages 167–185, https://doi.org/10.1093/plankt/13.1.167 Published: 01 January 1991 history Received: 17 April 1990 Accepted: 12 September

The vertical distribution, biomass concentrations and growth rates of autotrophic picoplankton (APP) were investigated during the growing season (March-October) in Lake Constance different depths. Cell numbers determined by epifluorescence microscopy varied between 1.0 × 10 3 1.6 times; 5 cells ml −1 depending on water depth. Highest recorded above thermodine late summer. Numerically, APP consisted almost exclusively chroococcoid cyanobactena. During lake stratification several peaks...

ABSTRACT More than 20 Synechococcus and Cyanobium isolates were obtained from central European subalpine lakes sequenced for their 16S rRNA gene part of the phycocyanin operon ( cpc ), specifically intergenic spacer (IGS) between cpcB cpcA , corresponding flanking regions cpcBA -IGS). Maximum-likelihood analyses revealed existence at least six to seven clusters nonmarine picocyanobacteria within picophytoplankton clade support conjecture global dispersal some closely related...

Growth and grazing experiments with free-liv~ng bacteria nano-and microzooplankton were conducted in February-March 1987 the central Red Sea Gulf of Aden using metabolic inhibitors.Results demonstrate existence a dynamic 'microbial loop' which dominates pelagic system terms biomass production.In epipelagial, bacterial abundance ranged from 5.2 to 8.8 X 105 cells ml-l, heterotrophic nanoflagellate (HNF) 0.6 1.2 lo3 ml-l.Bacterial growth rates varied between 0 014 0.097 h-', 0.010 0.108 h-'...

We investigated the effect of pH on growth, cell volume, and production freshwater ciliates Urotricha farcta , U. furcata castalia in laboratory cultures with Cryptomonas sp. as food. Overall, had a significant, species‐specific all parameters investigated. The food alga, sp., showed wide tolerance, positive growth rates between 4.4 9.65. Among ciliates, was most pH‐tolerant pH‐sensitive species, being confined to 6.5‐8.2. optimum derived from cellular rates. optima three ciliate species...

Growth and grazing loss rates of bacteria heterotrophic nanoflagellates were investigated in the northeast Atlantic spring 1989.Experiments conducted 2 different oligotrophic areas at 18"N.30°W 33ON.20°W.Numbers protozoa, namely (HNF), dinoflagellates ciliates, low both areas, average abundance microorganisms euphotic zone varied little.The microbial loop was uncoupled experimentally by differential filtration.Microplankton samples size-fractionated gravity filtration changes numbers their...

Similar to Daphnia, many planktonic ciliates are algivores that occur in vir- tually every natural lake and reproduce primarily asexually. Due their larger popula- tion size shorter generation time, significance as algal consumers second- ary producers may exceed of Daphnia during blooms when averaged over the season. The high reproduction rate, ease culturing, accessibility experimental manipulation, potential apply sophisticated measuring techni- ques such flow cytometry render some...

Abstract Small freshwater bodies are abundant and economically ecologically important on a global scale. Within these, protozoa play an role in structuring planktonic food webs sequestering CO 2 . We hypothesized that short‐term (∼20 days) fluctuations, of 2–10 °C, will significantly alter carbon flux associated with predator–prey interactions within the microbial web. examined model ciliate, Urotricha farcta , which is common; it was fed autotrophic flagellate Cryptomonas sp., also common....

Application of deep sequencing technologies to environmental samples and some detailed morphological studies suggest that there is a vast, yet unexplored rare ciliate biosphere, tentatively defined in terms operational taxonomic units. However, very few complemented molecular phylogenetic data with ecological descriptions the species inventory. This mainly because sampling effort increases strongly decreasing abundance. In spite this limited knowledge, it clear are under certain conditions...

Alpine temperatures have risen at twice the rate compared to northern-hemispheric average during past century. This can be expected affect lake ecosystems via, for example, intensified thermal stratification, shorter ice cover periods, and altered catchment processes. Our study assesses changes in some main constituents of planktic benthic communities five mid-Alpine lakes Niedere Tauern region Austria relation climatic warming, by comparing community environmental data from 1998–1999...