Pub Date : 2006-07-01DOI: 10.1127/0003-9136/2006/0166-0289
J. Larrosa, S. M. Mayeli, E. Mangas-Ramírez, M. A. Rodrigo, C. Rojo
The effect of Daphnia magna invasion on a system with Keratella cochlearis was studied with respect to the competition outcomes between these two planktonic species in cultures lasting for 75 days. Four Daphnia invasion events were carried out at different moments of Keratella population growth curve. We found that D. magna always displaced to + K. cochlearis when it was inoculated during the first period of growth curve (minimum rate was 1 individual of D. magna invading 1000 individuals of K. cochlearis). The ratio of competitors was decisive on the competition outcomes, because when Keratella could develop a large population before the onset of competition, this fact could tip the balance in favour of its persistence. Thus, when D. magna was inoculated during K. cochlearis stationary period (minimum rate in the invasion moment was 1 D: 6000 K in all these treatments) different alternative competitive results were observed: D. magna was excluded or K. cochlearis was excluded or they co-existed, reaching a ratio of 1 D: 300 K. Keratella exhibited two distinct models of growth dynamics and, depending on these dynamics, the competition result varied. We did not find statistically significant differences between population features (growth rate, fecundity, etc.) when comparing them among the different trajectories which promoted different competition outcomes. Although the implied competition mechanisms were known, their effect on competitors, and therefore on the competition outcomes, depended on population history (self-dynamics).
{"title":"Alternative final states when Daphnia magna invades a system with Keratella cochlearis","authors":"J. Larrosa, S. M. Mayeli, E. Mangas-Ramírez, M. A. Rodrigo, C. Rojo","doi":"10.1127/0003-9136/2006/0166-0289","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0289","url":null,"abstract":"The effect of Daphnia magna invasion on a system with Keratella cochlearis was studied with respect to the competition outcomes between these two planktonic species in cultures lasting for 75 days. Four Daphnia invasion events were carried out at different moments of Keratella population growth curve. We found that D. magna always displaced to + K. cochlearis when it was inoculated during the first period of growth curve (minimum rate was 1 individual of D. magna invading 1000 individuals of K. cochlearis). The ratio of competitors was decisive on the competition outcomes, because when Keratella could develop a large population before the onset of competition, this fact could tip the balance in favour of its persistence. Thus, when D. magna was inoculated during K. cochlearis stationary period (minimum rate in the invasion moment was 1 D: 6000 K in all these treatments) different alternative competitive results were observed: D. magna was excluded or K. cochlearis was excluded or they co-existed, reaching a ratio of 1 D: 300 K. Keratella exhibited two distinct models of growth dynamics and, depending on these dynamics, the competition result varied. We did not find statistically significant differences between population features (growth rate, fecundity, etc.) when comparing them among the different trajectories which promoted different competition outcomes. Although the implied competition mechanisms were known, their effect on competitors, and therefore on the competition outcomes, depended on population history (self-dynamics).","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88950537","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}
Pub Date : 2006-07-01DOI: 10.1127/0003-9136/2006/0166-0411
M. Mallory, A. Fontaine, P. Smith, M. Robertson, H. Gilchrist
Abstract: We investigated the water chemistry of 32 small lakes and ponds on South-ampton Island, Nunavut, in July 2001 and 2002. The ponds were generally small andshallow and at low elevation, with half < 20m a.s.l. and within 5km of the coast. Allof the ponds were alkaline (pH range 7.28.1), and shared similar major ion chemis-tries dominated by Ca and Na for cations, and Cl for anions, although there were somedifferences observed among habitats. Nutrients were relatively high compared to otherArctic islands, particularly for total nitrogen, which suggested that ponds on South-ampton Island are P-limited. One pond was located in an eider colony, and waterchemistry underwent a dramatic increase in nutrients, certain ions, and metals over anine week sampling period, presumably the result of ornithogenic inputs from faeces,as well as resuspension of sediments as eiders moved in the pond. Collectively thewater chemistry of ponds on Southampton Island are somewhat similar to those onVictoria and Banks islands, and appear to represent a transition between conditionsfound in sites on the Arctic mainland, and the spartan characteristics of sites on thehigh arctic islands. However, the recent expansion of goose populations and the asso-ciated degradation of lowland habitats on the island may lead to changes in pond che-mistries.Key words: Southampton Island, ponds, nutrients, geese, guano, water chemistry.
{"title":"Water chemistry of ponds on Southampton Island, Nunavut, Canada : effects of habitat and ornithogenic inputs","authors":"M. Mallory, A. Fontaine, P. Smith, M. Robertson, H. Gilchrist","doi":"10.1127/0003-9136/2006/0166-0411","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0411","url":null,"abstract":"Abstract: We investigated the water chemistry of 32 small lakes and ponds on South-ampton Island, Nunavut, in July 2001 and 2002. The ponds were generally small andshallow and at low elevation, with half < 20m a.s.l. and within 5km of the coast. Allof the ponds were alkaline (pH range 7.28.1), and shared similar major ion chemis-tries dominated by Ca and Na for cations, and Cl for anions, although there were somedifferences observed among habitats. Nutrients were relatively high compared to otherArctic islands, particularly for total nitrogen, which suggested that ponds on South-ampton Island are P-limited. One pond was located in an eider colony, and waterchemistry underwent a dramatic increase in nutrients, certain ions, and metals over anine week sampling period, presumably the result of ornithogenic inputs from faeces,as well as resuspension of sediments as eiders moved in the pond. Collectively thewater chemistry of ponds on Southampton Island are somewhat similar to those onVictoria and Banks islands, and appear to represent a transition between conditionsfound in sites on the Arctic mainland, and the spartan characteristics of sites on thehigh arctic islands. However, the recent expansion of goose populations and the asso-ciated degradation of lowland habitats on the island may lead to changes in pond che-mistries.Key words: Southampton Island, ponds, nutrients, geese, guano, water chemistry.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79562417","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}
Pub Date : 2006-07-01DOI: 10.1127/0003-9136/2006/0166-0307
K. Muylaert, Luyao Zhao, K. Gucht, S. Cousin, S. Declerck, W. Vyverman
Two fractionation experiments were carried out to study trophic interactions in the microbial food web in the shallow eutrophic lake Visvijver. Despite an order of magnitude difference in biomass of bacteria, heterotrophic nanoflagellates (HNF) and ciliates between the two experiments, the trophic interactions observed were similar. Bacteria were consumed by HNF and oligotrich ciliates, oligotrich ciliates fed on HNF as well as bacteria and cyclopoid copepod nauplii preyed on the oligotrich ciliates. While cyclopoid copepods had no effect on any component of the microbial food web, Daphnia fed on bacteria and HNF. No or a weak and slow trophic cascade occurred from oligotrich ciliates to HNF and bacteria. The lack of a pronounced trophic cascade was ascribed to the importance of the omnivorous oligotrich ciliates in the microbial food web. In both experiments, removal of trophic levels by size fractionation resulted in changes in the identity of the dominant bacterivores, but this had little effect on total bacterial grazing losses. Bacterial community composition (monitored in the second experiment using DGGE analysis), on the contrary, was more strongly influenced by changes in the identity of the dominant bacterivores, suggesting the presence of a 'cryptic trophic cascade'.
{"title":"Trophic coupling in the microbial food web of a eutrophic shallow lake (Lake Visvijver, Belgium)","authors":"K. Muylaert, Luyao Zhao, K. Gucht, S. Cousin, S. Declerck, W. Vyverman","doi":"10.1127/0003-9136/2006/0166-0307","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0307","url":null,"abstract":"Two fractionation experiments were carried out to study trophic interactions in the microbial food web in the shallow eutrophic lake Visvijver. Despite an order of magnitude difference in biomass of bacteria, heterotrophic nanoflagellates (HNF) and ciliates between the two experiments, the trophic interactions observed were similar. Bacteria were consumed by HNF and oligotrich ciliates, oligotrich ciliates fed on HNF as well as bacteria and cyclopoid copepod nauplii preyed on the oligotrich ciliates. While cyclopoid copepods had no effect on any component of the microbial food web, Daphnia fed on bacteria and HNF. No or a weak and slow trophic cascade occurred from oligotrich ciliates to HNF and bacteria. The lack of a pronounced trophic cascade was ascribed to the importance of the omnivorous oligotrich ciliates in the microbial food web. In both experiments, removal of trophic levels by size fractionation resulted in changes in the identity of the dominant bacterivores, but this had little effect on total bacterial grazing losses. Bacterial community composition (monitored in the second experiment using DGGE analysis), on the contrary, was more strongly influenced by changes in the identity of the dominant bacterivores, suggesting the presence of a 'cryptic trophic cascade'.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82998490","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0145
K. Anbutsu, T. Nakajima, Y. Takemon, K. Tanida, N. Goto, O. Mitamura
Distributions of biogeochemical constituents in interstitial water and isolated standing water bodies (or pools) were investigated in gravel bars 1 km in length to assess the ability of these waters to serve as a sink or source for nutrients. The temperature and concentration of major ions in interstitial water differed very little from those of river water. DO concentrations in interstitial waters were 5.7 ± 2.2 mg O 2 /l and 3.5 ± 1.8 mg O 2 /l at the side and dried-up channels, respectively. Concentrations of ammonium and nitrite of both interstitial waters at the side (0.50 ± 0.17μM and 0.13 ± 0.09μM, NH 4 + and NO;"") and dried-up channels (0.90 ± 2.14μM and 0.27 ± 0.37μM) were lower than those of river water (1.7 ± 0.8 μM and 0.73 ± 0.22 μM), whereas nitrate (85 ± 25 μM at the side channel and 79 ± 36 μM at the dried-up channel) did not differ on average from those of river water (70 ± 12 μM), though they were often very low (< 10 % of those of river water) at shallow depths of the vegetated areas in the dried-up channel. Soluble reactive phosphorus (SRP) concentrations in interstitial waters at the dried-up channel (0.84 ± 0.53 μM) were lower than those at the side channel (1.9 ± 0.5 μM) and those of river water (1.5 ± 0.5 μM), and decreased downstream. These results suggest that this aerobic hyporheic zone can serve as a sink for ammonium, nitrite and SRP and to a lesser extent of nitrate. Concentrations of these nutrients in pool water varied greatly but did not differ on average from those of river water. Dissolved inorganic nitrogen (DIN) and SRP concentrations were negatively related to the algal biomass. Pool waters also had lower DIN concentrations at the vegetated areas and higher SPR concentrations at the bar head. These results suggest that nutrient concentrations in pool waters are controlled in a complex manner by algal assimilation and surface-subsurface water exchange. Therefore some pools may serve as a sink and others as a source for nutrients.
{"title":"Distribution of biogeochemical compounds in interstitial and surface standing water bodies in the gravel bar of the Kizu River, Japan","authors":"K. Anbutsu, T. Nakajima, Y. Takemon, K. Tanida, N. Goto, O. Mitamura","doi":"10.1127/0003-9136/2006/0166-0145","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0145","url":null,"abstract":"Distributions of biogeochemical constituents in interstitial water and isolated standing water bodies (or pools) were investigated in gravel bars 1 km in length to assess the ability of these waters to serve as a sink or source for nutrients. The temperature and concentration of major ions in interstitial water differed very little from those of river water. DO concentrations in interstitial waters were 5.7 ± 2.2 mg O 2 /l and 3.5 ± 1.8 mg O 2 /l at the side and dried-up channels, respectively. Concentrations of ammonium and nitrite of both interstitial waters at the side (0.50 ± 0.17μM and 0.13 ± 0.09μM, NH 4 + and NO;\"\") and dried-up channels (0.90 ± 2.14μM and 0.27 ± 0.37μM) were lower than those of river water (1.7 ± 0.8 μM and 0.73 ± 0.22 μM), whereas nitrate (85 ± 25 μM at the side channel and 79 ± 36 μM at the dried-up channel) did not differ on average from those of river water (70 ± 12 μM), though they were often very low (< 10 % of those of river water) at shallow depths of the vegetated areas in the dried-up channel. Soluble reactive phosphorus (SRP) concentrations in interstitial waters at the dried-up channel (0.84 ± 0.53 μM) were lower than those at the side channel (1.9 ± 0.5 μM) and those of river water (1.5 ± 0.5 μM), and decreased downstream. These results suggest that this aerobic hyporheic zone can serve as a sink for ammonium, nitrite and SRP and to a lesser extent of nitrate. Concentrations of these nutrients in pool water varied greatly but did not differ on average from those of river water. Dissolved inorganic nitrogen (DIN) and SRP concentrations were negatively related to the algal biomass. Pool waters also had lower DIN concentrations at the vegetated areas and higher SPR concentrations at the bar head. These results suggest that nutrient concentrations in pool waters are controlled in a complex manner by algal assimilation and surface-subsurface water exchange. Therefore some pools may serve as a sink and others as a source for nutrients.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84233915","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0169
A. Hünken
A method has been developed to calculate the resuspension of small organic particulate matter in various small lowland streams by means of deposition experiments using a mixture of ultra fine and very fine particular organic matter. Hydrodynamic characteristics were modelled from chloride tracer experiments to examine the influence of hydrodynamic stream characteristics on particle resuspension. The rates of resuspension, relative to the seston concentration in the water column, ranged from 0 to 0.05 m -1 and were significantly correlated to the water exchange rate between main channel and transient storage zone. Resuspension rates were higher than deposition rates in most stream reaches, governing the load of suspended small organic particles. The results suggest that the resuspension and deposition of particles alternate within relative short time scales.
本文提出了一种利用超细和极细特定有机物质混合沉积实验的方法来计算各种低地小溪流中小有机颗粒物的再悬浮。通过氯离子示踪剂实验模拟流体动力学特性，考察流体动力学特性对颗粒再悬浮的影响。再悬浮速率相对于水柱中菌落浓度的变化范围为0 ~ 0.05 m -1，且与主河道与暂存区之间的水交换速率显著相关。在大多数河流河段，再悬浮速率高于沉积速率，控制着悬浮小有机颗粒的负荷。结果表明，颗粒的再悬浮和沉积在相对较短的时间尺度内交替发生。
{"title":"Resuspension of particulate organic matter in sand-bed lowland streams","authors":"A. Hünken","doi":"10.1127/0003-9136/2006/0166-0169","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0169","url":null,"abstract":"A method has been developed to calculate the resuspension of small organic particulate matter in various small lowland streams by means of deposition experiments using a mixture of ultra fine and very fine particular organic matter. Hydrodynamic characteristics were modelled from chloride tracer experiments to examine the influence of hydrodynamic stream characteristics on particle resuspension. The rates of resuspension, relative to the seston concentration in the water column, ranged from 0 to 0.05 m -1 and were significantly correlated to the water exchange rate between main channel and transient storage zone. Resuspension rates were higher than deposition rates in most stream reaches, governing the load of suspended small organic particles. The results suggest that the resuspension and deposition of particles alternate within relative short time scales.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81741289","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0185
C. Piscart, P. Usseglio-Polatera, J. Moreteau, J. Beisel
Abstract: Salinity exerts significant pressure on freshwater faunas living in slightlysalted water (i.e. water with salinity < 3gL 1 ). Changes in seven biological and phy-siological characteristics of freshwater taxa belonging to natural invertebrate commu-nities observed along a salinity gradient were investigated. Benthic macroinvertebrateswere sampled from four stations on the Meurthe River, a six-order stream in northeast-ern France with a gradient ranging in concentrations from 0.21g L 1 to 2.60g L oftotal dissolved solids over a distance of only 19km. A fuzzy coding of seven traitsallowed us to quantify the potential physiological requirements or biological traits ofeach species or genus observed. The consideration of whole assemblages highlightedtrends in the use of each modality by communities along the salinity gradient. Achange in many invertebrate traits was observed. Ovoviviparity was important at thestation with the highest salinity, the internal development of eggs in females mostprobably contributing to a better protection of the young. In contrast, this reproductivetype, leading to physiological constraints and limited fecundity, was less adopted inless salted sites.A modification in benthic community feeding habits along the salinitygradient was also discovered.An increase in deposit feeders at the expense of scrapersand piercers was observed. This pattern is in accordance with an energy transfer in theecosystem from water column (i.e. suspended organic material) to river bed (depositedorganic material) along the salinity gradient.Key words: benthic macroinvertebrates, freshwater, biological traits, salinization.
摘要:盐度对生活在盐度< 3gL - 1的微咸水中的淡水动物群具有显著的压力。研究了天然无脊椎动物淡水类群7种生物生理特征沿盐度梯度的变化。底栖大型无脊椎动物的样本来自穆尔特河的四个站点，穆尔特河是法国东北部的一条六阶河流，总溶解固体浓度的梯度从0.21g L - 1到2.60g L，距离仅为19公里。对七个性状的模糊编码使我们能够量化观察到的每个物种或属的潜在生理需求或生物学性状。对整个组合的考虑突出了沿盐度梯度的群落使用每种模式的趋势。许多无脊椎动物的性状发生了变化。卵生在盐度最高的站点很重要，雌性卵的内部发育很可能有助于更好地保护幼崽。相反，这种繁殖类型导致生理限制和有限的繁殖力，在低盐地区较少采用。底栖生物群落摄食习性沿盐度梯度变化也被发现。观察到沉积物喂食器的增加以牺牲刮砂器和穿孔器为代价。这种模式与生态系统中沿盐度梯度从水柱(即悬浮有机质)到河床(沉积有机质)的能量传递相一致。关键词:底栖大型无脊椎动物，淡水，生物学特性，盐碱化
{"title":"The role of salinity in the selection of biological traits of freshwater invertebrates","authors":"C. Piscart, P. Usseglio-Polatera, J. Moreteau, J. Beisel","doi":"10.1127/0003-9136/2006/0166-0185","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0185","url":null,"abstract":"Abstract: Salinity exerts significant pressure on freshwater faunas living in slightlysalted water (i.e. water with salinity < 3gL 1 ). Changes in seven biological and phy-siological characteristics of freshwater taxa belonging to natural invertebrate commu-nities observed along a salinity gradient were investigated. Benthic macroinvertebrateswere sampled from four stations on the Meurthe River, a six-order stream in northeast-ern France with a gradient ranging in concentrations from 0.21g L 1 to 2.60g L oftotal dissolved solids over a distance of only 19km. A fuzzy coding of seven traitsallowed us to quantify the potential physiological requirements or biological traits ofeach species or genus observed. The consideration of whole assemblages highlightedtrends in the use of each modality by communities along the salinity gradient. Achange in many invertebrate traits was observed. Ovoviviparity was important at thestation with the highest salinity, the internal development of eggs in females mostprobably contributing to a better protection of the young. In contrast, this reproductivetype, leading to physiological constraints and limited fecundity, was less adopted inless salted sites.A modification in benthic community feeding habits along the salinitygradient was also discovered.An increase in deposit feeders at the expense of scrapersand piercers was observed. This pattern is in accordance with an energy transfer in theecosystem from water column (i.e. suspended organic material) to river bed (depositedorganic material) along the salinity gradient.Key words: benthic macroinvertebrates, freshwater, biological traits, salinization.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88950166","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0225
V. Rossi, G. Benassi, S. Leonardi, A. Piotti, P. Menozzi
We report the genetic structure of 47 all-female populations of Heterocypris incongruens from Italy. Most populations (34) were collected from ricefields in the Po Plain (Northern Italy). Using three polymorphic allozyme markers (MPI, PGM and GPI) we found 125 different multilocus genotypes (clones) in a total of 3235 studied females. One clone was present almost everywhere (66 % localities) and in about a third (35 %) of all analysed females. Only a few clones (9 or 7 %) were found in more than ten localities while the majority (77 or 62 %) were found in only one population (private clones). Almost half (48 %) of all private clones were from the eight ricefields with the highest clonal richness while 16 % were from isolated temporary pools sampled for comparison. Clonal diversity seems to be the result of the presence of at least two different clonal lineages. One of the two, made up of the largest number of clones, probably had an autochthonous origin, a condition that probably favoured adaptation to local conditions. The other lineage was possibly introduced with imported rice seeds and its descendants carry adaptations to warm ricefield conditions. The weak relationship between genetic and geographic distance and the lack of spatial patterns in genetic variability might be due to the species' long-distance dispersal ability and to the persistence of founder effects sustained by large resting egg banks, conditions that blur isolation by distance. The lack of phylogeography in genetic variation may also be due to the spatially stochastic process of initiation and cessation of local ricefield cultivation known to have happened since the 15 th Century in this area of Northern Italy.
{"title":"Clonal diversity of Heterocypris incongruens (Crustacea: Ostracoda) in Northern Italian ricefields","authors":"V. Rossi, G. Benassi, S. Leonardi, A. Piotti, P. Menozzi","doi":"10.1127/0003-9136/2006/0166-0225","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0225","url":null,"abstract":"We report the genetic structure of 47 all-female populations of Heterocypris incongruens from Italy. Most populations (34) were collected from ricefields in the Po Plain (Northern Italy). Using three polymorphic allozyme markers (MPI, PGM and GPI) we found 125 different multilocus genotypes (clones) in a total of 3235 studied females. One clone was present almost everywhere (66 % localities) and in about a third (35 %) of all analysed females. Only a few clones (9 or 7 %) were found in more than ten localities while the majority (77 or 62 %) were found in only one population (private clones). Almost half (48 %) of all private clones were from the eight ricefields with the highest clonal richness while 16 % were from isolated temporary pools sampled for comparison. Clonal diversity seems to be the result of the presence of at least two different clonal lineages. One of the two, made up of the largest number of clones, probably had an autochthonous origin, a condition that probably favoured adaptation to local conditions. The other lineage was possibly introduced with imported rice seeds and its descendants carry adaptations to warm ricefield conditions. The weak relationship between genetic and geographic distance and the lack of spatial patterns in genetic variability might be due to the species' long-distance dispersal ability and to the persistence of founder effects sustained by large resting egg banks, conditions that blur isolation by distance. The lack of phylogeography in genetic variation may also be due to the spatially stochastic process of initiation and cessation of local ricefield cultivation known to have happened since the 15 th Century in this area of Northern Italy.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82818026","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0241
Wiebke J. Boeing, C. Ramcharan, H. P. Riessen
In this laboratory study, we explored the variability of 47 Daphnia pulex clones in migration behavior to predator (Chaoborus and fish) kairomones in 1.6 m long tubes. The preferred mean vertical distribution in control water (no predator kairomone) is diverse among clones and responses to predator kairomone are highly variable. Some migration patterns were opposite to our expectations in clones exhibiting an upward migration in response to fish kairomone. A literature comparison indicated that this is not an unusual finding. In general, more clones responded to Chaoborus than to fish kairomone, stressing the importance of Chaoborus as a predator for Daphnia in nature. Dilution of Chaoborus kairomone led to a reduced upward migration by most Daphnia pulex clones tested and adult Daphnia exhibited a strongly reduced response to Chaoborus in comparison to juvenile Daphnia. This indicates that Daphnia may be able to respond to the actual predation threat.
{"title":"Clonal variation in depth distribution of Daphnia pulex in response to predator kairomones","authors":"Wiebke J. Boeing, C. Ramcharan, H. P. Riessen","doi":"10.1127/0003-9136/2006/0166-0241","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0241","url":null,"abstract":"In this laboratory study, we explored the variability of 47 Daphnia pulex clones in migration behavior to predator (Chaoborus and fish) kairomones in 1.6 m long tubes. The preferred mean vertical distribution in control water (no predator kairomone) is diverse among clones and responses to predator kairomone are highly variable. Some migration patterns were opposite to our expectations in clones exhibiting an upward migration in response to fish kairomone. A literature comparison indicated that this is not an unusual finding. In general, more clones responded to Chaoborus than to fish kairomone, stressing the importance of Chaoborus as a predator for Daphnia in nature. Dilution of Chaoborus kairomone led to a reduced upward migration by most Daphnia pulex clones tested and adult Daphnia exhibited a strongly reduced response to Chaoborus in comparison to juvenile Daphnia. This indicates that Daphnia may be able to respond to the actual predation threat.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79125580","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}
Pub Date : 2006-06-01DOI: 10.1127/0003-9136/2006/0166-0199
Marta I. Sánchez, A. Green, E. Castellanos
We studied the temporal variation in abundance and distribution of inverte- brates in the water column in both traditional and industrial salt pans in the Odiel marshes, south-west Spain, in 2001. We selected 12 ponds that were representative of different salinities and stages of salt production. Every two months, invertebrates were sampled within the 0 - 20 cm depth range used by foraging waders. We identified 40 taxa, including 30 aquatic and eight terrestrial metazoan invertebrates. Aquatic inverte- brate taxa richness and diversity decreased significantly with increasing pond salinity, whereas total biomass showed a non-significant increase. Overall, Artemia partheno- genetica constituted 67.6 % of invertebrates by number, and 95.5 % of the biomass. The copepod Cletocamptus retrogressus represented 31.1 % of invertebrates by num- ber, and 0.6 % of the biomass. Invertebrate biomass and dominance of A. parthenogen- etica was highest in September and lowest in November. There was significant spatial and temporal variation in abundance for all aquatic taxa, and for a given pond and month, the depth, distance to shoreline and fetch (wind effects) all had important par- tial effects on invertebrate distribution. Ordination methods showed a strong relation- ship between community structure and water chemistry (salinity, pH and redox poten- tial), with the salinity gradient being the most important. There was a clear separation between low salinity ponds with fish and submerged macrophytes and other ponds. The more intensively managed industrial salines held lower densities and biomass of invertebrates than traditional salines, perhaps owing to greater protection from wind or greater inputs of detritus. The beetle Ochthebius corrugatus was abundant in the tradi-
{"title":"Temporal and spatial variation of an aquatic invertebrate community subjected to avian predation at the Odiel salt pans (SW Spain)","authors":"Marta I. Sánchez, A. Green, E. Castellanos","doi":"10.1127/0003-9136/2006/0166-0199","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0199","url":null,"abstract":"We studied the temporal variation in abundance and distribution of inverte- brates in the water column in both traditional and industrial salt pans in the Odiel marshes, south-west Spain, in 2001. We selected 12 ponds that were representative of different salinities and stages of salt production. Every two months, invertebrates were sampled within the 0 - 20 cm depth range used by foraging waders. We identified 40 taxa, including 30 aquatic and eight terrestrial metazoan invertebrates. Aquatic inverte- brate taxa richness and diversity decreased significantly with increasing pond salinity, whereas total biomass showed a non-significant increase. Overall, Artemia partheno- genetica constituted 67.6 % of invertebrates by number, and 95.5 % of the biomass. The copepod Cletocamptus retrogressus represented 31.1 % of invertebrates by num- ber, and 0.6 % of the biomass. Invertebrate biomass and dominance of A. parthenogen- etica was highest in September and lowest in November. There was significant spatial and temporal variation in abundance for all aquatic taxa, and for a given pond and month, the depth, distance to shoreline and fetch (wind effects) all had important par- tial effects on invertebrate distribution. Ordination methods showed a strong relation- ship between community structure and water chemistry (salinity, pH and redox poten- tial), with the salinity gradient being the most important. There was a clear separation between low salinity ponds with fish and submerged macrophytes and other ponds. The more intensively managed industrial salines held lower densities and biomass of invertebrates than traditional salines, perhaps owing to greater protection from wind or greater inputs of detritus. The beetle Ochthebius corrugatus was abundant in the tradi-","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74822787","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}
Pub Date : 2006-05-01DOI: 10.1127/0003-9136/2006/0166-0067
D. Toetz
Non-point source pollution by nitrates (NO 3 ) from fertilizers and animal wastes has potential effects on human health and eutrophication of surface waters. Until now one problem in determining sources of NO 3 has been the difficulty of identifying origin. Stable isotopes of nitrogen can be used as a signature of NO 3 to identify origin from animal wastes. NO 3 derived from animal waste has a δ 15 N signature of +10 +20‰, which is uniquely high compared to δ 15 NO 3 from other sources. The purpose of this research was to describe the distribution of δ 15 NO 3 , NO 3 and Cl in wells, springs, seeps and lakes in the vicinity of a concentrated animal feeding operation (CAFO), which was the suspected source of contamination. Nitrate concentrations and δ 15 NO 3 were higher in wells just below the waste spray area of the CAFO than above it. Chloride ion concentrations in wells confirmed a contaminated area below the waste spray area. Surface water samples had a wide range of NO 3 concentrations and were uncontaminated, except for samples from one seep and one spring. However, the mean δ 15 NO 3 in samples from springs were +3.9 to +5.0‰, values that are in a range reported for soil NO 3 . Thus, although data are not available on groundwater movement, both stable isotope signatures and chloride concentrations indicate that animal wastes were the source of NO 3 contamination.
{"title":"Nitrate in ground and surface waters in the vicinity of a concentrated animal feeding operation","authors":"D. Toetz","doi":"10.1127/0003-9136/2006/0166-0067","DOIUrl":"https://doi.org/10.1127/0003-9136/2006/0166-0067","url":null,"abstract":"Non-point source pollution by nitrates (NO 3 ) from fertilizers and animal wastes has potential effects on human health and eutrophication of surface waters. Until now one problem in determining sources of NO 3 has been the difficulty of identifying origin. Stable isotopes of nitrogen can be used as a signature of NO 3 to identify origin from animal wastes. NO 3 derived from animal waste has a δ 15 N signature of +10 +20‰, which is uniquely high compared to δ 15 NO 3 from other sources. The purpose of this research was to describe the distribution of δ 15 NO 3 , NO 3 and Cl in wells, springs, seeps and lakes in the vicinity of a concentrated animal feeding operation (CAFO), which was the suspected source of contamination. Nitrate concentrations and δ 15 NO 3 were higher in wells just below the waste spray area of the CAFO than above it. Chloride ion concentrations in wells confirmed a contaminated area below the waste spray area. Surface water samples had a wide range of NO 3 concentrations and were uncontaminated, except for samples from one seep and one spring. However, the mean δ 15 NO 3 in samples from springs were +3.9 to +5.0‰, values that are in a range reported for soil NO 3 . Thus, although data are not available on groundwater movement, both stable isotope signatures and chloride concentrations indicate that animal wastes were the source of NO 3 contamination.","PeriodicalId":8118,"journal":{"name":"Archiv Fur Hydrobiologie","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77724649","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}
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