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Donn K. Branstrator - One of the best experts on this subject based on the ideXlab platform.
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the north american invasive zooplanktivore bythotrephes longimanus is less hypoxia tolerant than the native Leptodora kindtii
Canadian Journal of Fisheries and Aquatic Sciences, 2017Co-Authors: Michael L Sorensen, Donn K. BranstratorAbstract:The predatory cladoceran Bythotrephes longimanus (spiny water flea) has been invading lakes and damaging food webs across the central part of North America since the early 1980s. To understand its niche and that of the taxonomically related and native predatory cladoceran Leptodora kindtii, we investigated species survival after 12 h exposures to low dissolved oxygen (DO) concentrations in the laboratory. Bythotrephes longimanus (n = 690) exhibited a hypoxia tolerance limit (LC50) of 1.65 mg·L−1 DO (95% confidence interval: 1.59, 1.72 mg·L−1) and was significantly less tolerant of hypoxia than L. kindtii (n = 380), which exhibited an LC50 of 0.58 mg·L−1 DO (0.51, 0.65 mg·L−1). These lab-based physiological results are consistent with landscape-scale observations that B. longimanus successfully invades primarily mesotrophic and oligotrophic lakes, while L. kindtii inhabits a wider range of lakes that includes eutrophic ones. Climate change throughout the 21st century may increase the occurrence and severit...
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0 199 1, by the American Society of Limnology and Oceanography, Inc Invertebrate pr dation i Lake Michigan: Regulation f Bosmina longirostris by Leptodora kindtii
2015Co-Authors: Donn K. Branstrator, John T. LehmanAbstract:The density of Bosmina longirostris (0. F. Mueller) declined loo-fold between 25 June and 20 August 1985 in Lake Michigan; a similar pattern of changing abundances was observed in 1986 but not in 1987 or 1988. Bosmina collected from periods before and during the decline in 1985 and 1986 were examined for size at maturity and clutch size. Population size-frequency distributions suggest that some animals began to mature at smaller sizes during the decline in 1985. In some cases, the average clutch size for Bosmina of similar body lengths was significantly reduced uring the decline in 1985 and 1986. These data suggest that food limitation was a factor in the species decline in both years. Gut content analyses indicate hat of seven potential predators, Leptodora kindtii (Focke) was probably most responsible for Bosmina mortality. There is ample evidence that Leptodora does not consume strictly f uid from its prey: juvenile L ptodoru ate mainly smaller prey that included Bosmina and the rotifer Conochilus; adults ate a broader size range of prey that included mainly Bosmina, Daphnia, and copepods. In 1987 and 1988, Bythotrephes cederstroemii Schoedler was abundant in Lake Michigan and was contemporaneous with collapse ofthe Leptodora population a d concurrent increase ofthe Bosmina population i August and September. Predatio
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contrasting life histories of the predatory cladocerans Leptodora kindtii and bythotrephes longimanus
Journal of Plankton Research, 2005Co-Authors: Donn K. BranstratorAbstract:The predatory cladocerans, Leptodora kindtii (Focke, 1844) and Bythotrephes longimanus (Leydig, 1860), express markedly different life-history traits. Leptodora produce small-bodied neonates that mature at small sizes but continue to grow throughout life. Bythotrephes produce larger neonates in both relative and absolute terms that grow rapidly to a large size at maturity whereupon they curtail somatic growth and divert resources mainly to reproduction. Despite their remarkable differences, the sets of life-history traits of both species appear to be solutions to the same basic selection pressures imposed by visually discriminating gape-limited fishes and foraging constraints imposed by prey size. Leptodora stresses pre-contact (transparency) while Bythotrephes stresses postcontact (caudal spine) modes of morphological defense against fishes. Mounting these disparate modes of defense has consequences for selection on timing and allocation to body growth that may underlie competitive imbalance between the species. Owing to the production of large-bodied neonates that grow rapidly, Bythotrephes quickly attain body sizes that both admit them to a broader prey base in size and taxonomic variety, and allow shorter prey handling times, in comparison to Leptodora. This provides Bythotrephes with a wider and more exploitable prey base from an earlier age and may explain why Leptodora has declined in density following Bythotrephes invasion into some North American lakes. The divergent sets of life-history traits expressed by Leptodora and Bythotrephes parallel two dominant life-history strategies evolved by phytoplanktivorous species of the order Cladocera.
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planktivory by bluegill lepomis macrochirus on Leptodora kindti in a small north american lake
Hydrobiologia, 2000Co-Authors: Donn K. Branstrator, Carolyn M HollAbstract:Leptodora kindti (Crustacea: Cladocera) is a large species of zooplankton (2–18 mm length) that is exceptionally transparent. This transparency is believed to be a means by which it successfully coexists in lakes with planktivorous fishes. We investigated the gut remains of bluegill (Lepomis macrochirus) that had been feeding on L. kindti and Daphnia (D. galeata and D. retrocurva) in the wild (Lake Zurich, Illinois) and found that bluegill readily preyed on L. kindti as small as 3–5 mm length, and strongly selected L. kindti over Daphnia galeata and Daphnia retrocurva. The large compound eye of L. kindti is one half to one complete order of magnitude larger than Daphnia's eye, consistent with the hypothesis that eye area is an important visual cue for fishes. Moreover, the slope of the relationship between eye area and body length is an order of magnitude shallower in L. kindti than Daphnia, suggesting that eye area has been under stronger negative selection in L. kindti. Results suggest that L. kindti's large and dark eye compromises the transparent nature of its body.
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predicting diet composition from body length in the zooplankton predator Leptodora kindti
Limnology and Oceanography, 1998Co-Authors: Donn K. BranstratorAbstract:Leptodora kindti and many other species of zooplankton predator range widely throughout temperate-zone lakes, yet these species are rarely included in size-based studies of food webs. This oversight derives mainly from a lack of predictive functions that quantify their effects on prey communities. With laboratory experiments I measured the handling time and phosphorus ingestion of L. kindti fed three cladoceran species radiolabeled with 33 P as a tracer of dry weight (DW). In general, laboratory results show that predator body length exerts strong influence on maximum prey length, on prey handling time (and indirectly predation rate), and on prey profitability (expressed as μg DW ingested time -1 ) in systematic ways that may be useful in predicting predatory effects of L. kindti on natural prey communities. The prey-capturing structure of L. kindti, called the trap basket, constrains the maximum length of prey that is consumable, and handling times on prey increase exponentially as prey length approaches the maximum dimensions of the trap basket. The empirical relationship is given by the following equation: Handling time = 1/[0.067(Trap basket length/Prey length - 1) 0.436 ]. I use handling time and body length data to evaluate the predictive nature of two previously published regression models that relate L. kindti trap basket length to body length. This note offers a length-based approach to analysis of diet composition in L. kindti that will hopefully encourage increased consideration of this species in future studies of food webs.
Takayuki Hanazato - One of the best experts on this subject based on the ideXlab platform.
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egg viability of the rotifer brachionus urceolaris after ingestion by the predatory cladoceran Leptodora kindtii
Hydrobiologia, 2011Co-Authors: Takamaru Nagata, Masaki Sakamoto, Yoshinari Tanaka, Takayuki HanazatoAbstract:Egg resistance against the digestive process of a predator is an effective strategy for zooplankton to compensate population loss due to predation. Parthenogenetic eggs of the rotiferan Brachionus urceolaris, which were ingested by the predatory cladoceran Leptodora kindtii, were expelled from the feeding basket of the predator without digestion. We found a negative correlation between the unconsumed ratio of eggs after ingestion and body length of the predator. As high as 75% of the unconsumed eggs successfully hatched and the hatch ratio was independent of body length of L. kindtii. Our results indicate that the rotifer has an effective strategy to maintain its population in the environment with abundant invertebrate predators.
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the predacious cladoceran Leptodora kindtii as a prey for the cyclopoid copepod mesocyclops sp laboratory observations of predator prey interaction
Journal of Freshwater Ecology, 2005Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:ABSTRACT We observed the behavior of the cyclopoid copepod Mesocyclops sp. as it fed on the cladoceran Leptodora kindtii in the laboratory. The feeding efficiency (capture and ingestion successes) of Mesocyclops sp. was high for smaller L. kindtii (<2.5 mm in body size) but low for larger ones. Mesocyclops sp. ingested small L. kindtii whole, but often consumed parts of larger L. kindtii. The handling time increased as the L. kindtii body size increased, except when Mesocyclops sp. consumed only the second antennae. These laboratory observations suggest that Mesocyclops sp. may be a natural predator of small L. kindtii.
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diel vertical migrations of invertebrate predators Leptodora kindtii thermocyclops taihokuensis and mesocyclops sp in a shallow eutrophic lake
Hydrobiologia, 2004Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:We studied vertical distribution patterns of three invertebrate predators – Leptodora kindtii, Mesocyclopssp., and Thermocyclops taihokuensis– in a shallow eutrophic lake, Lake Suwa , Japan. From June to October in 2000 and 2001, we collected samples in the lake center in order to examine the vertical distribution patterns and the densities of the predators in the water column during the day (0900) and at night (2330). We also examined phototactic behavior of Leptodora in the laboratory. The three invertebrate predators showed clear migration patterns. Leptodora and Thermocyclops displayed a typical migration, avoiding the surface and maintaining a high abundance in deeper water during the day, and being distributed uniformly during the night. Mesocyclops, on the other hand, showed no clear vertical distribution pattern in the water column. However, Mesocyclops showed higher densities in the water column during the night than during the day. It suggests that they stayed just above the bottom during the day and migrated upward during the night. Leptodora also showed such a density difference between day and night. In the laboratory, Leptodora showed strong negative phototactic behavior. The observed density changes between day and night in Leptodora and Mesocyclops suggests the possible underestimation of their population density by usual sampling methods, and thus the impact of predation on populations of prey zooplankton species may also be underestimated in shallow water bodies.
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predation impact of Leptodora kindtii on population dynamics and morphology of bosmina fatalis and b longirostris in mesocosms
Freshwater Biology, 2004Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:SUMMARY 1. We assessed the impact of predation by the invertebrate predator Leptodora kindtii on Bosmina longirostris and B. fatalis, which show seasonal and reciprocal succession patterns in Lake Suwa, in a mesocosm experiment using 20-L tanks with or without the predator under different food conditions. We also analysed morphological responses of the two Bosmina species to the predator in the tanks. 2. Bosmina fatalis dominated B. longirostris regardless of predator presence under high food density. However, the presence of Leptodora induced the dominance of B. fatalis more rapidly than its absence. On the contrary, no dominance of B. fatalis was observed in tanks with low food density, irrespective of the presence of the predator. Only B. fatalis showed morphological changes in response to the presence of Leptodora. 3. Mucrone length and antennule shape (angle between body and antennule and angle between antennules) showed marked responses at both high and low food densities, but antennule length responded only at high food density. Mucrone length seems to be a more effective defence against Leptodora. 4. The results suggest that B. fatalis is a superior competitor against B. longirostris and is more resistant to Leptodora predation, especially in good food conditions. The repeatedly observed seasonal succession of the two Bosmina species in the eutrophic Lake Suwa – the replacement of B. longirostris by B. fatalis following the occurrence of abundant Leptodora – seems to be caused by the selective predation of Leptodora on B. longirostris as well as the competitive ability of B. fatalis.
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seasonal and spatial distribution of two bosmina species b longirostris and b fatalis in lake suwa japan its relation to the predator Leptodora
Limnology, 2003Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:In Lake Suwa, Japan, two Bosmina species, B. fatalis and B. longirostris, coexist and show different seasonal succession patterns. To determine the relative importance of factors affecting their succession, the seasonal and spatial distribution of the two Bosmina species and their relation to environmental variables were studied at six near-shore sites on Lake Suwa from May to October 2000, with measurements at each site made at 20 and 80 m from the shore. We analyzed the seasonal and spatial distribution patterns of Bosmina, rotifers, and the major invertebrate predators, cyclopoid copepods and Leptodora kindti. A range of variables (water temperature, dissolved oxygen concentration, and chlorophyll a concentration) was also measured. Multiple stepwise regression analysis was performed between Bosmina and the measured biotic and abiotic variables. Two species of Bosmina showed a marked pattern of seasonal succession, B. longirostris being dominant in May and October and B. fatalis exceeding B. longirostris in summer. However, the densities of both species and their density ratio differed between sites. The ratio of B. fatalis density to total Bosmina density, which indicates the dominance of B. fatalis, was correlated positively with water temperature and Leptodora density and negatively correlated with dissolved oxygen and cyclopoid copepod density. The results suggest that invertebrate predators play an important role in regulating the succession of Bosmina species in Lake Suwa.
Peter R Leavitt - One of the best experts on this subject based on the ideXlab platform.
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mercury elevator in lakes a novel vector of methylmercury transfer to fish via migratory invertebrates
Environmental Science and Technology Letters, 2020Co-Authors: Britt D Hall, Richard J Vogt, Tyler P Cobb, Mark D Graham, Peter R Leavitt, Raymond H Hesslein, Karen A KiddAbstract:Fisheries in highly productive prairie lakes of Canada and the United States frequently have fish consumption advisories due to elevated mercury concentrations. This occurrence is unexpected because such alkaline lakes often exhibit lower methylmercury (MeHg) concentrations in basal trophic levels than those expected in less productive basins with circumneutral pH. As sources of MeHg to fish are largely dietary, components of the food web are expected to be critical controls of the transfer of MeHg to fish. Here, we investigated how Leptodora kindtii, a large (1.5 cm) translucent predatory invertebrate that exhibits pronounced diel vertical migration (in sediments by day, upper water column by night), plays a key role in regulating the contamination of fish with MeHg in a well-studied, eutrophic, prairie lake in western Canada. Estimates of diel fluxes of invertebrate biomass and MeHg revealed that migratory adult Leptodora, but not other adult zooplankton or juvenile Leptodora, acted as a vector, uniquely transferring MeHg from presumptive deepwater sites of methylation to pelagic fish communities. This cryptic process suggests that piscivorous fish may experience greatly elevated exposure to MeHg even in circumstances when biogeochemical features, MeHg sources, and daytime food-web configuration suggest that trophic transfers should be minimal.
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food web consequences of size based predation and vertical migration of an invertebrate predator Leptodora kindtii
Limnology and Oceanography, 2013Co-Authors: Richard J Vogt, B Matthews, Tyler P Cobb, Mark D Graham, Peter R LeavittAbstract:In an intensive study of the vertical and horizontal distribution of zooplankton in a eutrophic lake (Katepwa Lake), we found that only adult Leptodora kindtii (. 5 mm in body size) exhibited diel vertical migration (DVM), whereas juvenile Leptodora (, 5 mm) and other zooplankton species did not. Even though a longitudinal survey of five lakes (1994–2004) indicated that variation in Leptodora density was correlated with several indicators of habitat use (e.g., water temperature) and resource availability (e.g., zooplankton abundance), feeding experiments performed in both lit and unlit conditions demonstrated that a vertebrate predator (perch) strongly reduced Leptodora abundances under all conditions and always preferentially selected large-bodied individuals. Collectively, this evidence suggests that the migratory behavior of large Leptodora is consistent with an antipredator defense strategy. To estimate the ecological significance of Leptodora DVM behavior, we modeled how predation rates on different zooplankton taxa differed between day and night in Katepwa Lake. We found that Leptodora had as much as five-fold higher prey-specific predation rates at night, particularly for intermediatesized prey. We conclude that ignoring the habitat use, size-structure, and vertical migration behavior of Leptodora could considerably underestimate the significance of invertebrate predation in lake food webs, particularly in eutrophic lakes where Leptodora can coexist at high densities with planktivorous fish.
Kwanghyeon Chang - One of the best experts on this subject based on the ideXlab platform.
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the predacious cladoceran Leptodora kindtii as a prey for the cyclopoid copepod mesocyclops sp laboratory observations of predator prey interaction
Journal of Freshwater Ecology, 2005Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:ABSTRACT We observed the behavior of the cyclopoid copepod Mesocyclops sp. as it fed on the cladoceran Leptodora kindtii in the laboratory. The feeding efficiency (capture and ingestion successes) of Mesocyclops sp. was high for smaller L. kindtii (<2.5 mm in body size) but low for larger ones. Mesocyclops sp. ingested small L. kindtii whole, but often consumed parts of larger L. kindtii. The handling time increased as the L. kindtii body size increased, except when Mesocyclops sp. consumed only the second antennae. These laboratory observations suggest that Mesocyclops sp. may be a natural predator of small L. kindtii.
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diel vertical migrations of invertebrate predators Leptodora kindtii thermocyclops taihokuensis and mesocyclops sp in a shallow eutrophic lake
Hydrobiologia, 2004Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:We studied vertical distribution patterns of three invertebrate predators – Leptodora kindtii, Mesocyclopssp., and Thermocyclops taihokuensis– in a shallow eutrophic lake, Lake Suwa , Japan. From June to October in 2000 and 2001, we collected samples in the lake center in order to examine the vertical distribution patterns and the densities of the predators in the water column during the day (0900) and at night (2330). We also examined phototactic behavior of Leptodora in the laboratory. The three invertebrate predators showed clear migration patterns. Leptodora and Thermocyclops displayed a typical migration, avoiding the surface and maintaining a high abundance in deeper water during the day, and being distributed uniformly during the night. Mesocyclops, on the other hand, showed no clear vertical distribution pattern in the water column. However, Mesocyclops showed higher densities in the water column during the night than during the day. It suggests that they stayed just above the bottom during the day and migrated upward during the night. Leptodora also showed such a density difference between day and night. In the laboratory, Leptodora showed strong negative phototactic behavior. The observed density changes between day and night in Leptodora and Mesocyclops suggests the possible underestimation of their population density by usual sampling methods, and thus the impact of predation on populations of prey zooplankton species may also be underestimated in shallow water bodies.
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predation impact of Leptodora kindtii on population dynamics and morphology of bosmina fatalis and b longirostris in mesocosms
Freshwater Biology, 2004Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:SUMMARY 1. We assessed the impact of predation by the invertebrate predator Leptodora kindtii on Bosmina longirostris and B. fatalis, which show seasonal and reciprocal succession patterns in Lake Suwa, in a mesocosm experiment using 20-L tanks with or without the predator under different food conditions. We also analysed morphological responses of the two Bosmina species to the predator in the tanks. 2. Bosmina fatalis dominated B. longirostris regardless of predator presence under high food density. However, the presence of Leptodora induced the dominance of B. fatalis more rapidly than its absence. On the contrary, no dominance of B. fatalis was observed in tanks with low food density, irrespective of the presence of the predator. Only B. fatalis showed morphological changes in response to the presence of Leptodora. 3. Mucrone length and antennule shape (angle between body and antennule and angle between antennules) showed marked responses at both high and low food densities, but antennule length responded only at high food density. Mucrone length seems to be a more effective defence against Leptodora. 4. The results suggest that B. fatalis is a superior competitor against B. longirostris and is more resistant to Leptodora predation, especially in good food conditions. The repeatedly observed seasonal succession of the two Bosmina species in the eutrophic Lake Suwa – the replacement of B. longirostris by B. fatalis following the occurrence of abundant Leptodora – seems to be caused by the selective predation of Leptodora on B. longirostris as well as the competitive ability of B. fatalis.
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seasonal and spatial distribution of two bosmina species b longirostris and b fatalis in lake suwa japan its relation to the predator Leptodora
Limnology, 2003Co-Authors: Kwanghyeon Chang, Takayuki HanazatoAbstract:In Lake Suwa, Japan, two Bosmina species, B. fatalis and B. longirostris, coexist and show different seasonal succession patterns. To determine the relative importance of factors affecting their succession, the seasonal and spatial distribution of the two Bosmina species and their relation to environmental variables were studied at six near-shore sites on Lake Suwa from May to October 2000, with measurements at each site made at 20 and 80 m from the shore. We analyzed the seasonal and spatial distribution patterns of Bosmina, rotifers, and the major invertebrate predators, cyclopoid copepods and Leptodora kindti. A range of variables (water temperature, dissolved oxygen concentration, and chlorophyll a concentration) was also measured. Multiple stepwise regression analysis was performed between Bosmina and the measured biotic and abiotic variables. Two species of Bosmina showed a marked pattern of seasonal succession, B. longirostris being dominant in May and October and B. fatalis exceeding B. longirostris in summer. However, the densities of both species and their density ratio differed between sites. The ratio of B. fatalis density to total Bosmina density, which indicates the dominance of B. fatalis, was correlated positively with water temperature and Leptodora density and negatively correlated with dissolved oxygen and cyclopoid copepod density. The results suggest that invertebrate predators play an important role in regulating the succession of Bosmina species in Lake Suwa.
Yuwei Chen - One of the best experts on this subject based on the ideXlab platform.
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restoration of a subtropical eutrophic shallow lake in china effects on nutrient concentrations and biological communities
Hydrobiologia, 2013Co-Authors: Feizhou Chen, Tingting Shu, Erik Jeppesen, Zhengwen Liu, Yuwei ChenAbstract:While numerous reports exist on the results of lake restoration initiatives in temperate regions, only a few exist from subtropical lakes. We present results of the lake restoration of shallow, subtropical Lake Wuli, China, conducted between 1999 and 2010. After restoration, annual average concentrations of total nitrogen, total phosphorus (TP), and chlorophyll a and the chemical oxygen demand declined significantly, though summer TP remained high. Suspended solids increased significantly over the years, whereas transparency decreased, though not significantly so. The contribution of cryptophytes to total phytoplankton biomass decreased, while the proportion of cyanobacteria, especially potentially N2-fixing species, increased. Rotifers were superseded by crustaceans as the dominant taxon of the zooplankton community. Enhanced abundance of Daphnia spp., appearance of Leptodora kindti, and increased biomass ratios of zooplankton to phytoplankton, calanoids to cyclopoids, and nauplii to copepods in the post-restoration period indicate reduced fish predation and stronger top-down control of phytoplankton. However, the increase in non-algal turbidity, probably caused by the higher biomass of benthivorous fish, apparently prevented the re-establishment of submerged macrophyte communities. We conclude that removal of fish, particularly benthivorous species, will further improve water quality in this and other subtropical shallow lakes.