Archiv Fur Hydrobiologie最新文献

{"title":"Genetic structure of cyclic parthenogenetic zooplankton populations - a conceptual framework","authors":"L. Meester, J. Vanoverbeke, K. D. Gelas, R. Ortells, P. Spaak","doi":"10.1127/0003-9136/2006/0167-0217","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0217","url":null,"abstract":"The genetic structure of cyclic parthenogenetic zooplankton populations is strongly determined by the consequences of combining sexual and asexual reproduction in the same life cycle. Since the pioneering population genetic studies on freshwater zooplankton in the 1970's, a distinction has been made between the genetic structure of permanent and intermittent populations. However, the results of many studies do not fit the expectations of this dichotomous model, for example when large lake populations are considered. In this paper, we present a unifying framework for understanding the genetic structure of cyclic parthenogenetic zooplankton populations, focusing on three factors that determine their degree of clonality and within-population genetic diversity as well as their among-population genetic differentiation: the size of the dormant egg bank, length of the growing season, and strength of clonal selection. We illustrate the importance of each of these factors, and show that our broader concept better explains the variation in genetic structure observed in natural populations of cyclic parthenogens than the earlier implicitly dichotomous model.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"10 1","pages":"217-244"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79103838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking predator kairomones and turbulence: synergistic effects and ultimate reasons for phenotypic plasticity in Daphnia cucullata","authors":"R. Tollrian, C. Laforsch","doi":"10.1127/0003-9136/2006/0167-0135","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0135","url":null,"abstract":"The seasonal change in helmet size in Daphnia cucullata has been studied for over one century. Recently it has been shown that helmets in D. cucullata, which have been found to reduce predator caused mortality, can be induced by chemical cues released by several predatory invertebrates. However, it also has been shown that tur- bulence induces this trait. The relation and interplay of both inducing cues is not known. Here we present results from lab experiments showing that predator cues and turbulence can act synergistically. Both factors in combination induced significantly larger responses, compared to each factor alone, and helmets reached the maximum sizes found in natural lakes. This result might help to explain the observation of large helmets in this species in nature. The ultimate reason behind the turbulence induction is yet unknown. We link both induction factors to predation, as the ultimate reason, by testing the hypothesis that D. cucullata can respond to turbulence produced by swimming invertebrates. We found that helmet growth increased significantly in direct contact to both the heterospecific Daphnia magna and the predator Cyclops sp. Treat- ments which accounted for chemical cues alone did not increase helmet growth in re- sponse to cues from D. magna ,o rCyclops under these conditions. Together, these re- sults indicate that D. cucullata is able to respond to mechanical cues produced by swimming invertebrates. Thus, our study suggests that both chemical cues and turbu- lence generated by predatory invertebrates might act synergistically to induce helmets as effective protection against invertebrate predation.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"39 1","pages":"135-146"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89105364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-density anti-predation refuge in Daphnia and Chaoborus?","authors":"Z. Gliwicz, Piotr Dawidowicz, P. Maszczyk","doi":"10.1127/0003-9136/2006/0167-0101","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0101","url":null,"abstract":"We used a flow-through experimental system (\"plankton organ\") to test if Daphnia hyalina x galeata (Dhg), D. cucullata (Dc) and Chaoborus flavicans (Ch) take higher risks of predation at low population density levels than at high ones, i. e. to test whether or not they select shallower depths with higher temperatures and higher food levels when they do not receive chemical information on crowding (added to the medium with fish kairomones). Neonates of Daphnia and Chaoborus 4 th instar larvae were first grown for 55 h in batch cultures: Daphnia were reared at high food levels (Scenedesmus obliquus) and at two different population densities of 1 and 100 ind. L -1 (Dhg and Dc); Chaoborus were kept at densities of 1 and 10 ind. L -1 without food. After 55 h, individual Daphnia 2 nd instar juveniles were transferred into the narrow vertical tubes of a \"plankton organ\" with constant flow of fresh medium. The medium contained chemical information on either high or low population density; all media had the same food and fish kairomone levels. The same setup was used for individual Chaoborus 4 th instar larvae, but using media without food. Whereas no difference was found in Dc, different depth selection behavior was apparent in Dhg. The daytime depth selected by the animals was greater in the presence of chemical information on high population density, and this behavior became more pronounced with increasing duration of the experiment. The difference was highly significant for the entire dataset. The calculated duration time of egg development was up to 17% longer and the calculated birth rate 12% reduced for Daphnia receiving high-density information, as compared to control animals enjoying higher temperatures of the shallower and warmer strata. Only minor and inconsistent difference was found for Chaoborus.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"53 1","pages":"101-114"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74119391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrient and light limitation of reservoir phytoplankton in relation to storm-mediated pulses in stream discharge","authors":"M. Vanni, J. Andrews, W. Renwick, María González, S. Noble","doi":"10.1127/0003-9136/2006/0167-0421","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0421","url":null,"abstract":"We investigated the dynamics of nutrient and light limitation of phytoplank- ton in a reservoir ecosystem in relation to storm-mediated variation in stream dis- charge, and how dynamics differed at a shallow site near stream inflows versus one in deep water near the lake outflow. Storm-mediated discharge events reduced the sev- erity of nutrient limitation and increased the severity of light limitation, as predicted by a model of reservoir resource limitation developed by Kimmel et al. (1990). The sev- erity of nutrient limitation was negatively correlated with discharge to the lake; the correlation was strongest with discharge over the preceding 10-14 day period and wea- ker at shorter and longer time scales. However, discharge events also flushed phyto- plankton from the lake and enhanced light limitation, so it is not clear by which mech- anism(s) discharge events mediate phytoplankton resource limitation. Phytoplankton near stream inflows were less nutrient limited than phytoplankton at the lake outflow, consistent with predictions of the Kimmel et al. (1990) model. However, this was true even when streamflow was negligible, suggesting alternative mechanisms for reduced nutrient limitation near stream inflows. In contrast to predictions of the model, phyto- plankton were not more light limited near stream inflows than at the outflow; shallo- wer depth near inflows compensated for higher turbidity, in terms of the light climate experienced by phytoplankton. Our results show that the mechanisms by which dis- charge events mediate phytoplankton resource limitation are complex and require fur- ther study in reservoirs as well as other aquatic systems subject to a high degree of temporal variation in discharge.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"9 1","pages":"421-445"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91166941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Steps between lakes? Some initial genetic data on the Holarctic planktonic predator Chaoborus flavicans","authors":"F. Wende, L. Lucas, A. Graves, M. C. Swift, T. Berendonk","doi":"10.1127/0003-9136/2006/0167-0169","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0169","url":null,"abstract":"The genetic structure of Chaoborus flavicans was analyzed to start an investigation of the evolutionary status of this Holarctic species and to make inferences about C. flavicans' historical distribution and dispersal. We sequenced a 611 bp fragment of the cytochrome oxidase subunit I and II gene for 26 populations spread across Europe and North America. We found distinct North American and European C. flavicans clades. Chaoborus crystallinus, widely accepted as a sister species of C. flavicans, clustered within the European C. flavicans clade, suggesting potential peripatric speciation. The genetic relationship of the C. flavicans haplotypes within Europe suggests that several glacial refugia existed during the last ice age in southern Europe. European C. flavicans recolonized central and northern Europe from refugia in France and/or Spain after glaciers retreated. This phylogeographic structure was roughly comparable to that of other zooplankton species. The correlation between genetic and geographic distance within Europe was significant, indicating that short distance dispersal in C. flavicans is more common than in other passively dispersing zooplankton species.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"140 1","pages":"169-182"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86639255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"\"Spectral fingerprinting\" for specific algal groups on sediments in situ: a new sensor","authors":"N. Aberle, M. Beutler, C. Moldaenke, K. Wiltshire","doi":"10.1127/0003-9136/2006/0167-0575","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0575","url":null,"abstract":"Currently it is still extremely difficult to adequately sample populations of microalgae on sediments for large-scale biomass determination. We have now devised a prototype of a new benthic sensor (BenthoFluor) for the quantitative and qualitative assessment of microphytobenthos populations in situ. This sensor enables a high spatial and temporal resolution and a rapid evaluation of the community structure and distribution. These determinations are based on the concept that five spectral excitation ranges can be used to differentiate groups of microalgae, in situ, within a few seconds. In addition, because sediments contain a lot of yellow substances, which can affect the fluorescence and optical differentiation of the algae, the device was equipped with a UV-LED for yellow substances correction. The device was calibrated against HPLC with cultures and tested in the field. Our real-time approach can be used to monitor algal assemblage composition on sediments and is an ideal tool for investigations on the large-scale spatial and temporal variation of algal populations in sediments. Apart from the differentiation of algal populations, the BenthoFluor allows instantaneous monitoring of the chlorophyll concentrations and determination of which algae are responsible for this on the uppermost surface of sediments in the field and in experimental set-ups.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"21 1","pages":"575-592"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73193658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining dialysis and dilution techniques to estimate gross growth rate of phytoplankton and grazing by micro- and mesozooplankton in situ","authors":"H. Stibor, Anna Gelzleichter, F. Hantzsche, U. Sommer, M. Striebel, O. Vadstein, Y. Olsen","doi":"10.1127/0003-9136/2006/0167-0403","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0403","url":null,"abstract":"Measurements of in situ phytoplankton growth and grazing by zooplankton normally involve different techniques. We show that a single dilution experiment based on dialysis bags can be used to do these estimates in situ. Dialysis bags allow an estimate of the in situ phytoplankton gross growth rate whereas the dilution gradient allows a simultaneous estimate of microzooplankton grazing. The comparison of the phytoplankton net growth rate outside dialysis bags and the estimated apparent growth rate of phytoplankton in undiluted samples within dialysis bags allows estimating additional loss processes such as mesozooplankton grazing. The method is especially useful in mesocosms experiments.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"6 1","pages":"403-419"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87238059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predator-induced shifts in Daphnia life-histories under different food regimes","authors":"J. Pijanowska, Piotr Dawidowicz, A. Howe, L. Weider","doi":"10.1127/0003-9136/2006/0167-0037","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0037","url":null,"abstract":"Abstract: Patterns of growth and reproduction (first, second and third broods) of aDaphnia magna clone were studied in a life-table experiment with and without chemi-cal signals from fish predators, under three different food regimes (0.2, 0.5 and 2.0mgCl –1 ).At high resource levels, predation played a role as a factor synchronizing repro-ductive events. Somatic growth rates increased with increasing food concentration andwere lower under the presence of fish than in the control treatments. Smaller femalesize in the fish treatments was accompanied by reduced number of eggs released in thesecond and third (but not the first) clutch. The effect of decreased cumulative numberof offspring was counterbalanced by the gain in the second fitness component –decreased age in releasing successive broods, which eventually resulted in equivalentintrinsic rates of increase (r) in both, the fish and fish-free environments. Conse-quently, Daphnia life-history performance under the presence of predator cues, with-out accompanying mortality, did not incur fitness costs, across the studied range offood concentrations.Key words: Daphnia magna , phenotypic plasticity, growth rate, predation, reproduc-tive synchrony.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"1 1","pages":"37-54"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84041722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Food niches of cyclopoid copepods in eutrophic Plußsee determined by stable isotope analysis","authors":"B. Santer, N. Sommerwerk, J. Grey","doi":"10.1127/0003-9136/2006/0167-0301","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0301","url":null,"abstract":"Feeding studies have suggested interspecific differences in the food sources and trophic position of cyclopoid copepod species. We measured δ13C and δ15N of five sympatric cyclopoid copepod species and of bulk POM from a eutrophic lake over a one-year period, to determine if stable isotope derived-data from the field supported the hypotheses from feeding studies. Cyclops abyssorum and C. vicinus differed significantly in δ15N but not in δ13C, inferring assimilation from similar carbon sources but differentiation in their trophic position. Cyclops abyssorum δ15N typically was 1– 2‰ higher than C. vicinus, suggesting a more predatory feeding mode compared to its congener. The summer species Mesocyclops leuckarti, Thermocyclops oithonoides and Diacyclops bicuspidatus exhibited considerable differences in δ13C. The lower δ13C of the hypolimnetic D. bicuspidatus compared to the two epilimnetic species indicates a food niche differentiation by vertical separation. All copepod δ13C and δ15N signatures showed seasonal fluctuations, with low values in winter and high values in summer. The δ13C of seston was generally higher than copepod δ13C. We regard selective feeding from the bulk POM, spatial separation of feeding and assimilation of 13C depleted food sources responsible for this phenomenon.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"17 1","pages":"301-316"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86779591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal dynamics of pelagic and benthic (littoral and profundal) bacterial abundances and activities in a deep prealpine lake (L. Constance)","authors":"M. Sala, H. Güde","doi":"10.1127/0003-9136/2006/0167-0351","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0167-0351","url":null,"abstract":"In order to obtain a first insight into the characteristics of pelagic, littoral and profundal bacterial communities and their potential role for the degradation of organic matter in the deep prealpine Lake Constance, we compared the seasonal dynamics of bacterial abundances and activities during the annual cycle in the epilim- netic water of a central station as well as in surface layers of sediments at a central pro- fundal and a littoral site. For this purpose, bacterial abundances (DAPI counts), rates of leucine incorporation, respiration of 14 C-labeled substrates (glucose, phenol) and ectoenzymatic activities were measured biweekly-monthly at the different sampling sites. Bacterial densities in lake sediments generally exceeded those of epilimnetic waters by at least two orders of magnitude with higher values in profundal sediments. A seasonal pattern was well expressed for bacterioplankton, less pronounced for ben- thic littoral bacteria and hardly visible for profundal bacteria. Compared to pelagic bacteria, benthic bacteria exhibited lower specific rates of leucine incorporation, espe- cially during the warmer periods. For profundal benthic communities specific rates of glucose respiration and of enzyme activities were permanently low with little seasonal fluctuation. In contrast, littoral benthic communities showed the highest values for these specific metabolic activities among the three sites tested. Additionally, the capac- ity of metabolism of phenol (used here as a representative of more recalcitrant aro- matic substances) was by far highest respired for littoral communities, and almost lacking for pelagic communities. Evidence from the literature suggests that the qualita- tively and quantitatively enhanced level of degradation capacities observed for littoral bacteriobenthos may be predominantly a result of the combined effect of increased supply of additional organic matter (e. g. allochthonous matter and macrophytes), an enriched bacterial gene reservoir in sediments, and frequent resuspension. Littoral ben- thic communities showed the highest specific metabolic activities exceeding those of bacterioplankton and profundal bacteriobenthos by an order of magnitude. As a whole,","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":"167 1","pages":"351-369"},"PeriodicalIF":0.0,"publicationDate":"2006-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86876969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}