The Experts below are selected from a list of 85296 Experts worldwide ranked by ideXlab platform
Juergen Geist - One of the best experts on this subject based on the ideXlab platform.
-
Reproduction success of the invasive Sinanodonta woodiana (Lea 1834) in relation to native mussel species
Biological Invasions, 2019Co-Authors: Verena Huber, Juergen GeistAbstract:Invasions of non-native species are major threats for freshwater ecosystems. One of the most invasive freshwater Mussels in Europe is the Asian Sinanodonta woodiana (Chinese pond mussel). It occurs in the same waterbodies as the endangered native species Anodonta cygnea and Anodonta anatina with unknown consequences for them. Thus, the analysis about the host–parasite relationship between the larvae of S. woodiana and host fish species in Europe is important to assess impacts on the native Mussels regarding their competition for hosts. In this study, host suitability of ten different fish species (native and non-native to Europe) for the glochidia of S. woodiana was analyzed by simultaneous infestation of the fish. All fish species were identified as suitable hosts but differed significantly in initial infestation rate as well as duration and rate of juvenile mussel excystment. Surprisingly, the glochidia developed successfully on Rhodeus amarus (bitterling), which cannot use S. woodiana for its own reproduction, and which is an unsuitable host for native anodontines. Compared to both native Anodonta , S. woodiana glochidia developed more successfully resulting in a higher number of excysted juvenile Mussels at similar larval exposure. Metamorphosis was also faster on all tested fish species. These factors, together with the faster growth and higher number of offspring in S. woodiana likely contribute to a competitive advantage over native anodontines. The great likelihood of spreading this mussel on a large number of different possible host fish species deserves attention in fisheries management and stocking programs.
-
exposure of zebra Mussels to extracorporeal shock waves demonstrates formation of new mineralized tissue inside and outside the focus zone
Biology Open, 2018Co-Authors: Katharina Sternecker, Juergen Geist, Sebastian Beggel, Kristin Dietzlaursonn, Matias De La Fuente, Hansgeorg Frank, John P Furia, Stefan Milz, Christoph SchmitzAbstract:The success rate of extracorporeal shock wave therapy (ESWT) for fracture nonunions in human medicine (i.e., radiographic union at six months after ESWT) is only approximately 75%. Detailed knowledge regarding the underlying mechanisms that induce bio-calcification after ESWT is limited. We analyzed the biological response within mineralized tissue of a new invertebrate model organism, the zebra mussel Dreissena polymorpha , after exposure with extracorporeal shock waves (ESWs). Mussels were exposed to ESWs with positive energy density of 0.4 mJ/mm 2 (A) or were sham exposed (B). Detection of newly calcified tissue was performed by exposing the Mussels to fluorescent markers. Two weeks later, the A-Mussels showed a higher mean fluorescence signal intensity within the shell zone than the B-Mussels (p
-
a critical reflection on the success of rearing and culturing juvenile freshwater Mussels with a focus on the endangered freshwater pearl mussel margaritifera margaritifera l
Aquatic Conservation-marine and Freshwater Ecosystems, 2011Co-Authors: Michael Lange, Juergen GeistAbstract:Freshwater Mussels are in decline throughout their range. The lack of natural recruitment in freshwater pearl mussel populations and other freshwater molluscs has led to controversies about the usefulness and applicability of captive breeding techniques for their conservation. The current state of rearing and culturing programmes for freshwater Mussels in Europe and North America is reviewed here with a focus on the endangered freshwater pearl mussel (Margaritifera margaritifera). Different strategies of propagation and the key factors of success are addressed and conservation management decisions are discussed with respect to risk reduction and the intensity of the culturing system. Based on the rearing techniques applied for multiple species in North America, and for the genus Margaritifera in European countries, sufficient numbers of juveniles can be produced to sustain selected populations. However, captive breeding and stocking should be carefully documented and must not replace the restoration of functional stream habitats. From a conservation point of view, captive breeding of endangered mussel species can be a last-minute rescue tool in order to retain the evolutionary potential of priority populations which would not persist long enough to benefit from habitat restoration practices. Copyright © 2011 John Wiley & Sons, Ltd.
Joseph B Rasmussen - One of the best experts on this subject based on the ideXlab platform.
-
impending extinctions of north american freshwater Mussels unionoida following the zebra mussel dreissena polymorpha invasion
Journal of Animal Ecology, 1998Co-Authors: Anthony Ricciardi, Richard J Neves, Joseph B RasmussenAbstract:1. Freshwater Mussels (Order Unionoida) are the most imperiled faunal group in North America; 60% of described species are considered endangered or threatened, and 12% are presumed extinct. Widespread habitat degradation (including pollution, siltation, river channelization and impoundment) has been the primary cause of extinction during this century, but a new stress was added in the last decade by the introduction of the Eurasian zebra mussel, Dreissena polymorpha, a biofouling organism that smothers the shells of other molluscs and competes with other suspension feeders for food. Since the early 1990s, it has been spreading throughout the Mississippi River basin, which contains the largest number of endemic freshwater Mussels in the world. In this report, we use an exponential decay model based on data from other invaded habitats to predict the long-term impact of D. polymorpha on mussel species richness in the basin. 2. In North American lakes and rivers that support high densities (>3000 m−2) of D. polymorpha, native mussel populations are extirpated within 4–8 years following invasion. Significant local declines in native mussel populations in the Illinois and Ohio rivers, concomitant with the establishment of dense populations of D. polymorpha, suggest that induced mortality is occurring in the Mississippi River basin. 3. A comparison of species loss at various sites before and after invasion indicates that D. polymorpha has accelerated regional extinction rates of North American freshwater Mussels by 10-fold. If this trend persists, the regional extinction rate for Mississippi basin species will be 12% per decade. Over 60 endemic Mussels in the Mississippi River basin are threatened with global extinction by the combined impacts of the D. polymorpha invasion and environmental degradation.
Richard J Neves - One of the best experts on this subject based on the ideXlab platform.
-
acute toxicity of copper ammonia and chlorine to glochidia and juveniles of freshwater Mussels unionidae
Environmental Toxicology and Chemistry, 2007Co-Authors: Ning Wang, Tom Augspurger, Christopher G. Ingersoll, Douglas K Hardesty, Christopher D Ivey, James L Kunz, James F Dwyer, Andy D Roberts, Cynthia M Kane, Richard J NevesAbstract:The objective of the present study was to determine acute toxicity of copper, ammonia, or chlorine to larval (glochidia) and juvenile Mussels using the recently published American Society for Testing and Materials (ASTM) Standard guide for conducting laboratory toxicity tests with freshwater Mussels. Toxicity tests were conducted with glochidia (24- to 48-h exposures) and juveniles (96-h exposures) of up to 11 mussel species in reconstituted ASTM hard water using copper, ammonia, or chlorine as a toxicant. Copper and ammonia tests also were conducted with five commonly tested species, including cladocerans (Daphnia magna and Ceriodaphnia dubia; 48-h exposures), amphipod (Hyalella azteca; 48-h exposures), rainbow trout (Oncorhynchus mykiss; 96-h exposures), and fathead minnow (Pimephales promelas; 96-h exposures). Median effective concentrations (EC50s) for commonly tested species were >58 μg Cu/L (except 15 μg Cu/L for C. dubia) and >13 mg total ammonia N/L, whereas the EC50s for Mussels in most cases were 40 μg/L and above the FAV in the WQC for chlorine. The results indicate that the early life stages of Mussels generally were more sensitive to copper and ammonia than other organisms and that, including mussel toxicity data in a revision to the WQC, would lower the WQC for copper or ammonia. Furthermore, including additional mussel data in 2007 WQC for copper based on biotic ligand model would further lower the WQC.
-
impending extinctions of north american freshwater Mussels unionoida following the zebra mussel dreissena polymorpha invasion
Journal of Animal Ecology, 1998Co-Authors: Anthony Ricciardi, Richard J Neves, Joseph B RasmussenAbstract:1. Freshwater Mussels (Order Unionoida) are the most imperiled faunal group in North America; 60% of described species are considered endangered or threatened, and 12% are presumed extinct. Widespread habitat degradation (including pollution, siltation, river channelization and impoundment) has been the primary cause of extinction during this century, but a new stress was added in the last decade by the introduction of the Eurasian zebra mussel, Dreissena polymorpha, a biofouling organism that smothers the shells of other molluscs and competes with other suspension feeders for food. Since the early 1990s, it has been spreading throughout the Mississippi River basin, which contains the largest number of endemic freshwater Mussels in the world. In this report, we use an exponential decay model based on data from other invaded habitats to predict the long-term impact of D. polymorpha on mussel species richness in the basin. 2. In North American lakes and rivers that support high densities (>3000 m−2) of D. polymorpha, native mussel populations are extirpated within 4–8 years following invasion. Significant local declines in native mussel populations in the Illinois and Ohio rivers, concomitant with the establishment of dense populations of D. polymorpha, suggest that induced mortality is occurring in the Mississippi River basin. 3. A comparison of species loss at various sites before and after invasion indicates that D. polymorpha has accelerated regional extinction rates of North American freshwater Mussels by 10-fold. If this trend persists, the regional extinction rate for Mississippi basin species will be 12% per decade. Over 60 endemic Mussels in the Mississippi River basin are threatened with global extinction by the combined impacts of the D. polymorpha invasion and environmental degradation.
A M Reynolds - One of the best experts on this subject based on the ideXlab platform.
-
Mussels realize weierstrassian levy walks as composite correlated random walks
Scientific Reports, 2015Co-Authors: A M ReynoldsAbstract:Composite correlated random walks (CCRW) have been posited as a potential replacement for Levy walks and it has also been suggested that CCRWs have been mistaken for Levy walks. Here I test an alternative, emerging hypothesis: namely that some organisms approximate Levy walks as an innate CCRW. It is shown that the tri-modal CCRW found to describe accurately the movement patterns of Mussels (Mytilus edulis) during spatial pattern formation in mussel beds can be regarded as being the first three levels in a hierarchy of nested movement patterns which if extended indefinitely would correspond to a Levy walk whose characteristic (power-law) exponent is tuned to nearly minimize the time required to form patterned beds. The Mussels realise this Levy walk to good approximation across a biologically meaningful range of scales. This demonstrates that the CCRW not only describes mussel movement patterns, it explains them.
Martin Osterling - One of the best experts on this subject based on the ideXlab platform.
-
Recruitment of the threatened mussel Margaritifera margaritifera in relation to mussel population size, mussel density and host density
Aquatic Conservation-marine and Freshwater Ecosystems, 2012Co-Authors: Bjorn Arvidsson, Jens Karlsson, Martin OsterlingAbstract:Anthropogenic, abiotic factors are considered main causes of recruitment failure of unionid Mussels, including the freshwater pearl mussel (Margaritifera margaritifera). In this large-scale investi ...
-
habitat degradation and the decline of the threatened mussel margaritifera margaritifera influence of turbidity and sedimentation on the mussel and its host
Journal of Applied Ecology, 2010Co-Authors: Martin Osterling, Bjorn Arvidsson, Larry GreenbergAbstract:Summary1. Habitatdegradationisamajorreasonforspeciesextinctions.Forparasite–hostinteractions,thedecline of a parasite may not only be related to the parasite’s tolerance to habitat degradation butalsoindirectlythroughthehost’stolerancetothesamedisturbance.2. Our objective was to explore the cause of population declines of the freshwater pearl musselMargaritiferamargaritiferabyrelatingtheagedistribution, densityandgrowthoftheMusselswithturbidity, sedimentation rates and density of the mussel’s host, trout Salmo trutta, in 26 Swedishstreams.3. An analysis of the age structure of nine mussel populations showed that maximum age differedby60 years,withfivepopulationshavinglowproportionsofjuvenileMussels.AdultmusseldensitywashigheratsiteswherejuvenileMusselsoccurredthanatsiteslackingjuvenileMussels.4. Growth of adult Mussels during the past 10 years was lower in the five streams lacking recentrecruitment than in the four streams with recent recruitment, indicating that some environmentalfactormaybenegativelyimpactingthesepopulations.5. Acomparisonamong24populationsindicatedthatturbidityandsedimentationmayberespon-sible for recruitment failure in 58% of the populations. The age of the youngest mussel was posi-tively related to turbidity and sedimentation, and juvenile mussel density was negatively related toturbidity and sedimentation. Incontrast,trout densitywasnot relatedtorecruitment ofMussels orsedimentation, but was positively related to turbidity in all streams, both with and without recentmusselrecruitment.6. Synthesis and applications. Recruitment failure of M. margaritifera appearstoberelatedtoitsown vulnerability to turbidity and sedimentation rather than to its host’s response to this type ofhabitatdegradation.Theresultsfromourstudysuggestthatmanagersmightbeabletoevaluatethepotential viability of mussel populations by measuring stream turbidity. Restoration activities toimprovetheMussels’environmentshouldfocusonreducingfinematerialtransportintostreams.Key-words: habitat degradation, host–parasite, Margaritifera margaritifera, recruitment,Salmo trutta, sedimentation, turbidity, UnionoidaIntroduction
-
Ecology of freshwater Mussels in disturbed environments
2007Co-Authors: Martin OsterlingAbstract:The number of species extinctions is increasing at an alarming rate. Long-lived freshwater Mussels of the order Unionoida, which include a parasitic stage on a host fish, are highly threatened. Habitat degradation by turbidity and sedimentation is thought to be one major reason for their decline. The objective of this thesis was to examine recruitment patterns and identify the causes of the lack of recruitment in the threatened unionoid freshwater pearl mussel (Margaritifera margaritifera). In addition, I investigated the effects of turbidity on non-endangered dreissenid Mussels, where turbidity was manipulated through use of bioturbating mayflies.In a survey of 107 Swedish streams, mussel population size and trout density were both positively correlated to recruitment probability of M. margaritifera. A more in-depth study of the age-structure of nine populations revealed that four of these populations showed no signs of recruitment over the last ten years. Within-stream variation in recruitment was high as both Mussels and trout had patchy distribution, and may be important for population regulation. Moreover, examination of different life stages revealed no differences in the gravid mussel stage or the stage when Mussels infect salmonid fish. Instead, differences were observed for the juvenile, benthic stage, presumably related to differences in turbidity and sedimentation. High turbidity may affect filter-feeding efficiency of Mussels and high sedimentation may reduce survival by clogging sediments, thereby altering, for example, oxygen and food conditions. In the study of the effects of turbidity, bioturbating mayflies increased turbidity and filter-feeding dreissenid Mussels reduced turbidity. Mussel growth both decreased and increased with increasing turbidity, depending on sediment type.Turbidity and sedimentation often impact entire stream systems, and a holistic, catchment-based management strategy may be needed to reduce the effects of sedimentation on freshwater pearl Mussels. The effects of restoration take a long time and must start soon if recruitment of Mussels is to be re-established. Restoration may also be more urgent in some streams than in others, as the maximum age of M. margaritifera populations in my study differed by as much as 60 years. As mussel and trout densities seem to be important for recruitment success, one conservation method may be to concentrate Mussels into sites where trout density is high.
