Brachionus calyciflorus

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T. W. Snell - One of the best experts on this subject based on the ideXlab platform.

  • estimating the toxicity of ambient fine aerosols using freshwater rotifer Brachionus calyciflorus rotifera monogononta
    Environmental Pollution, 2013
    Co-Authors: Vishal Verma, T. W. Snell, Roberto Ricomartinez, Neel Kotra, Corey Rennolds, Rodney J Weber
    Abstract:

    Abstract The toxicity of atmospheric fine particulate matter (PM 2.5 ) in Atlanta is assessed using freshwater rotifers ( Brachionus calyciflorus ). The PM-laden quartz filters were extracted in both water and methanol. Aerosol extracts were passed through a C-18 column to separate the PM components into hydrophobic and hydrophilic fractions. Toxicity data reported in the units of LC 50 (concentration that kills 50% of the test population in 24 h) shows that ambient particles are toxic to the rotifers with LC 50 values ranging from 5 to 400 μg of PM. The methanol extract of the aerosols was substantially more toxic (8 ± 6 times) to the rotifers compared to the water extracts. A sizeable fraction (>70%) of toxicity was found to be associated with the hydrophobic fraction of PM. However, none of the bulk aerosol species was strongly correlated with the LC 50 values suggesting a complicated mechanism of toxicity probably involving synergistic interactions of various PM components.

  • effects of atrazine and carbaryl on growth and reproduction of the rotifer Brachionus calyciflorus pallas
    Journal of Freshwater Ecology, 2012
    Co-Authors: Zhenghe Lu, Jiaxin Yang, Baokun Zhao, T. W. Snell
    Abstract:

    The functioning of freshwater ecosystems can be altered if rotifers are stressed by atrazine and carbaryl. To detect reproductive responses, rotifer (Brachionus calyciflorus) populations were exposed to atrazine and carbaryl at six concentrations ranging from 0 to 5.12 mg L−1 and the 2-d population growth rate, 3-d mictic rate (MR), 7-d resting egg production (RE), and 3-d resting egg hatching rate (HR) were measured. Data showed that the no effect concentration (NOEC) and lowest effect concentration (LOEC) of atrazine and carbaryl were highest for growth rate. In sexual reproduction, the NOEC and LOEC of atrazine for MR were 0.32 and 1.28 mg L−1. However, carbaryl did not show similar results because 0.06 mg L−1 carbaryl increased the MR compared with the control. The NOEC and LOEC of atrazine for RE and HR were the same (0.08 and 0.32 mg L−1) and the NOEC and LOEC of carbaryl for RE were slightly lower. HR was the most sensitive of all indices with NOEC and LOEC of atrazine ranging from 0.02 to 0.32 mg ...

  • Effects of Fenitrothion on Life History Parameters of the Rotifer Brachionus calyciflorus
    Journal of Freshwater Ecology, 2010
    Co-Authors: Linlan Lv, T. W. Snell, Jiaxin Yang, Sungen Li
    Abstract:

    ABSTRACT The effects of fenitrothion on life history parameters, the production of resting eggs and hatching of resting eggs of the rotifer Brachionus calyciflorus were studied on the individual and population level. Neonates (

  • effects of fenitrothion on life history parameters of the rotifer Brachionus calyciflorus
    Journal of Freshwater Ecology, 2010
    Co-Authors: Linlan Lv, T. W. Snell, Jiaxin Yang, Sungen Li
    Abstract:

    ABSTRACT The effects of fenitrothion on life history parameters, the production of resting eggs and hatching of resting eggs of the rotifer Brachionus calyciflorus were studied on the individual and population level. Neonates (<4 h-old) were individually cultured in six concentrations (0.1, 1, 10, 100, 1,000 and 2,000 pg L−1) of fenitrothion. Life history parameters including duration time of the juvenile period, hatching time of the first neonate, reproductive period, post-reproduction period, lifespan, and lifetime reproduction were evaluated. Fenitrothion significantly prolonged the juvenile period at 0.1 μg L−1 and extended hatching time of the first neonate at 1,000 μg L−1 Rotifers exposed to fenitrothion at concentrations of 0.1, 1, 10, and 100 pg L−1 had longer reproductive periods and produced more offspring than controls. Exposure to 1, 000 μg L−1 significantly reduced the number of resting eggs produced. Low concentrations of fenitrothion caused an increase in the duration of the juvenile period...

  • uv b exposure increases acute toxicity of pentachlorophenol and mercury to the rotifer Brachionus calyciflorus
    Environmental Pollution, 1999
    Co-Authors: B. L. Preston, T. W. Snell, R. Kneisel
    Abstract:

    Adverse biological effects of ultraviolet-B (UV-B) radiation have been well documented for phytoplankton and zooplankton in both marine and freshwater ecosystems. However, investigations of interactions between UV-B and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and the toxicant. Here we investigate the potential for UV-B to increase the sensitivity of the rotifer Brachionus calyciflorus to either acute pentachlorophenol (PCP) or mercury toxicity, independent of UV-B effects on these toxicants. UV-B increased the toxicity of PCP and mercury to B. calyciflorus as much as five-fold, depending on duration of UV-B exposure and toxicant concentration. Reductions in the LC50 of up to 60% were also seen for both toxicants. UV-B alone effectively eliminated B. calyciflorus reproduction and reduced ingestion by up to 90%. These results demonstrate the potential for UV-B to increase rotifer sensitivity to anthropogenic stressors independent of photochemical reactions with toxicants.

Yi-long Xi - One of the best experts on this subject based on the ideXlab platform.

  • morphological differentiation of Brachionus calyciflorus caused by predation and coal ash pollution
    Scientific Reports, 2017
    Co-Authors: Xiaoxue Yang, Gen Zhang, Yi-long Xi
    Abstract:

    Different rotifer stains exhibited remarkably morphological differences which could not be eliminated under laboratory conditions. In the present study, we hypothesized that predation pressure and pollution might be two forces driving morphological differentiation of rotifer. To test this hypothesis, rotifers (Brachionus calyciflorus) belonging to two sibling species were collected from three special lakes (with coal ash pollution, high predation pressure or neither) and cultured for more than three months to investigate their potential differentiation in morphology. Twelve morphological parameters were measured and compared among three lakes at four food density (Scenedesmus obliquus). The results showed that most of the tested morphological parameters changed in response to food level and differed among three habitats. Rotifers from the habitat with high predation pressure evolved stable long posterior lateral spine and relatively small body size. Rotifers collected from the polluted habitat was of smaller body size, compared with those from ordinary habitat. Bigger eggs were laid by rotifers from polluted area or lake with high predation pressure, enabling newborns more resistant to pollution or predation, and thus ensuring the survival rate of newborns. Finally, we concluded that both predation and pollution could affect the morphological differentiation and evolution of rotifers.

  • Combined Effects of Temperature and the Microcystin MC-LR on the Feeding Behavior of the Rotifer Brachionus calyciflorus
    Bulletin of Environmental Contamination and Toxicology, 2017
    Co-Authors: Xian-ling Xiang, Ying-ying Chen, Qiu-lei Xu, Yi-long Xi
    Abstract:

    The aim of this study was to investigate the responses in filtration and grazing rates of five rotifer strains of the species Brachionus calyciflorus under different temperatures and MC-LR concentrations. The results showed that strain identity, MC-LR concentration, temperature, and the interactions of these factors significantly affected both response variables, with the exception of the interaction of strain and MC-LR on the grazing rates. At low MC-LR concentrations and for the control group, the filtration and grazing rates increased with increasing temperature. The filtering and grazing rates of B. calyciflorus exposed to higher MC-LR concentrations, however, showed no evident enhancement with increasing of temperature. At high temperatures, the filtration and grazing rates of all rotifer strains decreased significantly with increasing concentration of MC-LR, however B. calyciflorus exhibited a refractory stability in the presence of increased MC-LR levels at lower temperatures.

  • Effects of Multi-metal (Cu, Zn, Cd, Cr, and Mn) Mixtures on the Reproduction of Freshwater Rotifer Brachionus calyciflorus.
    Bulletin of Environmental Contamination and Toxicology, 2015
    Co-Authors: Xiaoping Xu, Yi-long Xi, Lin Huang, Xian-ling Xiang
    Abstract:

    In the field, organisms are usually exposed to mixtures of various metals. However, the effects of multi-metal mixtures on growth and reproduction of rotifers remain unknown. In the present study, effects of multi-metal mixtures (Cu, Zn, Cd, Cr, and Mn) on reproduction of the freshwater rotifer Brachionus calyciflorus were assessed by determining various endpoints, including the ratio of ovigerous females to nonovigerous females, the ratio of mictic to amictic females, the mictic rate, the fertilization rate, the population growth rate, and the resting eggs production. The results demonstrated that reproduction of rotifers was significantly affected by all multi-metal mixtures assessed. Moreover, the ratio of mictic to amictic females was the most sensitive endpoint and might be suitable to evaluate effects of multi-metal mixtures to rotifers.

  • Effects of Temperature on Survival, Reproduction, and Morphotype in Offspring of Two Brachionus calyciflorus (Rotifera) Morphotypes
    Journal of Freshwater Ecology, 2010
    Co-Authors: Xian-ling Xiang, Yi-long Xi, Jin-yan Zhang, Qin Ma
    Abstract:

    ABSTRACT Two-spined and unspined Brachionus calyciflorus were cultured at 15°C, 20°C, 25°C, and 30°C to investigate their differences in life expectancy at hatching, average lifespan, generation time, net reproductive rate, intrinsic rate of population increase, proportion of mictic offspring, and proportion of spined offspring. Life history parameters between the two B. calyciflorus morphotypes differed with temperature. At 15°C, the unspined rotifer had a higher intrinsic rate of population increase than the two-spined rotifer. At 20°C, the proportion of spined offspring produced by the two-spined rotifer was higher than that produced by the unspined rotifer. At both 25°C and 30°C, the two-spined rotifer had a longer average lifespan than the unspined rotifer. At 30°C, net reproductive rate of the two-spined rotifer was higher than that of the unspined rotifer. The responses in average lifespan, net reproductive rate, intrinsic rate of population increase, and proportion of spined offspring to increasin...

  • Differences in Asexual and Sexual Reproduction among Eight Geographic Populations of Brachionus calyciflorus (Rotifera) from China
    Journal of Freshwater Ecology, 2009
    Co-Authors: Qin Ma, Yi-long Xi, Jin-yan Zhang, Xian-ling Xiang
    Abstract:

    ABSTRACT Eight geographic populations of Brachionus calyciflorus collected from China were cultured at 18°C, 23°C, and 28°C with 3.0×106 cells/mL of alga Scenedesmus obliquus to investigate their asexual and sexual reproduction. There were significant effects of both temperature and geographic population, independently and in interaction on population growth rate, fertilization rate of mictic females, and resting egg production of the rotifers. Geographic population and interaction between temperature and geographic population influenced significantly mixis rate in the rotifer population.

Lilan Zhang - One of the best experts on this subject based on the ideXlab platform.

  • full life cycle toxicity assessment on triclosan using rotifer Brachionus calyciflorus
    Ecotoxicology and Environmental Safety, 2016
    Co-Authors: Lilan Zhang, Yujuan Wang
    Abstract:

    Abstract Triclosan (TCS) is an antimicrobial and is an aquatic contaminant. Little is known on aquatic toxicity of TCS. Rotifers are common members of freshwater zooplankton. In this study, Brachionus calyciflorus was chosen as a test organism to assess the acute and complete life cycle toxicity of TCS in this study. The acute toxicity results showed that the 24-h median lethal concentration (LC50) of TCS was 345±0.11 μg/L (95% confidence limits of 212–564 µg/L). Reproductive bioassays demonstrated that TCS could inhibit the population growth rate at the concentration higher than 1.0 μg/L. Resting egg production encompasses the full life-cycle of rotifer, and thus its hatching rate were explored to assess the toxicity of TCS towards rotifer population at TCS concentrations ranging from 0.1 to 200 µg/L at two different growth periods. When resting eggs were exposed to TCS during the formation period, 0.1 and 1.0 µg/L of TCS increased the hatching rate from 0.402 to 0.502, and 0.475, respectively. Exposure to 100 and 200 µg/L of TCS reduced the hatching rate to 0.309 and 0.275, respectively. When the resting eggs were formed in the control medium and hatched in medium with TCS, their hatching rates were not significantly influenced by TCS, except that 200 µg/L of TCS decreased the hatching rate from 0.402 to 0.34 significantly. The effects of TCS exposure on the hatching rate during the formation period were greater than those during the resting egg hatching period.

  • toxicity assessment of perfluorinated carboxylic acids pfcas towards the rotifer Brachionus calyciflorus
    Science of The Total Environment, 2014
    Co-Authors: Yujuan Wang, Lilan Zhang
    Abstract:

    Abstract The effects of acute toxicity, 3-day population growth and morphological effects of perfluorinated carboxylic acids (PFCAs) with carbon chain lengths of 2–6 on the freshwater rotifer Brachionus calyciflorus were investigated. The results indicated that the 24-h median lethal concentration (LC50) values of trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), perfluorobutanoic acid (PFBA), perfluopentanoic acid (PFPeA), and perfluorohexanoic acid (PFHxA) towards B. calyciflorus were 70, 80, 110, 130 and 140 mg L− 1, respectively. The acute effects of PFCAs decreased with the increase of carbon chain length. The parameters used to determine 3-day population growth on these compounds were the rate of population increase (r) and mictic ratio. With the increase of fluorinated carbon-chain length, the r values of TFA, PFPrA, PFBA, PFPeA and PFHxA decreased by 0.99%, 16.8%, 16.5%, 22.4% and 32.0%, respectively. Mictic ratios ranged from 0.707 to 0.953 for PFCAs with carbon chain lengths of 2–6. In addition, the mictic ratio, body size and egg size exposed to some PFCAs were higher than those of the controls. These results offer a useful method for the ecological risk assessment of these short chain PFCAs.

  • evaluating the sub lethal toxicity of pfos and pfoa using rotifer Brachionus calyciflorus
    Environmental Pollution, 2013
    Co-Authors: Lilan Zhang, Yang Li, Yujuan Wang
    Abstract:

    Abstract The acute and chronic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on the rotifer Brachionus calyciflorus (B. calyciflorus) were investigated at the organismal and the population level. The acute toxicity of PFOS to rotifers was approximately 2.5-fold greater than that of PFOA. From 0.25 to 2.0 mg L−1, PFOS exhibited higher toxicity than PFOA on the F0-generation of B. calyciflorus, including effects on body size, juvenile periods, net reproductive rate, and generation time. Both PFOS and PFOA exposure induced a smaller egg size in B. calyciflorus, suggesting that these risks can be transferred from mother to offspring. The 28-day population growth studies showed that PFOS and PFOA reduced the population density and increased the mictic ratio. Our results demonstrated that both PFOS and PFOA had adverse effects on B. calyciflorus, not only at the individual level but also at the population level.

R. Kneisel - One of the best experts on this subject based on the ideXlab platform.

  • uv b exposure increases acute toxicity of pentachlorophenol and mercury to the rotifer Brachionus calyciflorus
    Environmental Pollution, 1999
    Co-Authors: B. L. Preston, T. W. Snell, R. Kneisel
    Abstract:

    Adverse biological effects of ultraviolet-B (UV-B) radiation have been well documented for phytoplankton and zooplankton in both marine and freshwater ecosystems. However, investigations of interactions between UV-B and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and the toxicant. Here we investigate the potential for UV-B to increase the sensitivity of the rotifer Brachionus calyciflorus to either acute pentachlorophenol (PCP) or mercury toxicity, independent of UV-B effects on these toxicants. UV-B increased the toxicity of PCP and mercury to B. calyciflorus as much as five-fold, depending on duration of UV-B exposure and toxicant concentration. Reductions in the LC50 of up to 60% were also seen for both toxicants. UV-B alone effectively eliminated B. calyciflorus reproduction and reduced ingestion by up to 90%. These results demonstrate the potential for UV-B to increase rotifer sensitivity to anthropogenic stressors independent of photochemical reactions with toxicants.

  • UV-B exposure increases acute toxicity of pentachlorophenol and mercury to the rotifer Brachionus calyciflorus
    Environmental Pollution, 1999
    Co-Authors: B. L. Preston, T. W. Snell, R. Kneisel
    Abstract:

    Adverse biological effects of ultraviolet-B (UV-B) radiation have been well documented for phytoplankton and zooplankton in both marine and freshwater ecosystems. However, investigations of interactions between UV-B and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and the toxicant. Here we investigate the potential for UV-B to increase the sensitivity of the rotifer Brachionus calyciflorus to either acute pentachlorophenol (PCP) or mercury toxicity, independent of UV-B effects on these toxicants. UV-B increased the toxicity of PCP and mercury to B. calyciflorus as much as five-fold, depending on duration of UV-B exposure and toxicant concentration. Reductions in the LC50of up to 60% were also seen for both toxicants. UV-B alone effectively eliminated B. calyciflorus reproduction and reduced ingestion by up to 90%. These results demonstrate the potential for UV-B to increase rotifer sensitivity to anthropogenic stressors independent of photochemical reactions with toxicants. Copyright (C) 1999 Elsevier Science Ltd.

Yujuan Wang - One of the best experts on this subject based on the ideXlab platform.

  • full life cycle toxicity assessment on triclosan using rotifer Brachionus calyciflorus
    Ecotoxicology and Environmental Safety, 2016
    Co-Authors: Lilan Zhang, Yujuan Wang
    Abstract:

    Abstract Triclosan (TCS) is an antimicrobial and is an aquatic contaminant. Little is known on aquatic toxicity of TCS. Rotifers are common members of freshwater zooplankton. In this study, Brachionus calyciflorus was chosen as a test organism to assess the acute and complete life cycle toxicity of TCS in this study. The acute toxicity results showed that the 24-h median lethal concentration (LC50) of TCS was 345±0.11 μg/L (95% confidence limits of 212–564 µg/L). Reproductive bioassays demonstrated that TCS could inhibit the population growth rate at the concentration higher than 1.0 μg/L. Resting egg production encompasses the full life-cycle of rotifer, and thus its hatching rate were explored to assess the toxicity of TCS towards rotifer population at TCS concentrations ranging from 0.1 to 200 µg/L at two different growth periods. When resting eggs were exposed to TCS during the formation period, 0.1 and 1.0 µg/L of TCS increased the hatching rate from 0.402 to 0.502, and 0.475, respectively. Exposure to 100 and 200 µg/L of TCS reduced the hatching rate to 0.309 and 0.275, respectively. When the resting eggs were formed in the control medium and hatched in medium with TCS, their hatching rates were not significantly influenced by TCS, except that 200 µg/L of TCS decreased the hatching rate from 0.402 to 0.34 significantly. The effects of TCS exposure on the hatching rate during the formation period were greater than those during the resting egg hatching period.

  • toxicity assessment of perfluorinated carboxylic acids pfcas towards the rotifer Brachionus calyciflorus
    Science of The Total Environment, 2014
    Co-Authors: Yujuan Wang, Lilan Zhang
    Abstract:

    Abstract The effects of acute toxicity, 3-day population growth and morphological effects of perfluorinated carboxylic acids (PFCAs) with carbon chain lengths of 2–6 on the freshwater rotifer Brachionus calyciflorus were investigated. The results indicated that the 24-h median lethal concentration (LC50) values of trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), perfluorobutanoic acid (PFBA), perfluopentanoic acid (PFPeA), and perfluorohexanoic acid (PFHxA) towards B. calyciflorus were 70, 80, 110, 130 and 140 mg L− 1, respectively. The acute effects of PFCAs decreased with the increase of carbon chain length. The parameters used to determine 3-day population growth on these compounds were the rate of population increase (r) and mictic ratio. With the increase of fluorinated carbon-chain length, the r values of TFA, PFPrA, PFBA, PFPeA and PFHxA decreased by 0.99%, 16.8%, 16.5%, 22.4% and 32.0%, respectively. Mictic ratios ranged from 0.707 to 0.953 for PFCAs with carbon chain lengths of 2–6. In addition, the mictic ratio, body size and egg size exposed to some PFCAs were higher than those of the controls. These results offer a useful method for the ecological risk assessment of these short chain PFCAs.

  • evaluating the sub lethal toxicity of pfos and pfoa using rotifer Brachionus calyciflorus
    Environmental Pollution, 2013
    Co-Authors: Lilan Zhang, Yang Li, Yujuan Wang
    Abstract:

    Abstract The acute and chronic effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on the rotifer Brachionus calyciflorus (B. calyciflorus) were investigated at the organismal and the population level. The acute toxicity of PFOS to rotifers was approximately 2.5-fold greater than that of PFOA. From 0.25 to 2.0 mg L−1, PFOS exhibited higher toxicity than PFOA on the F0-generation of B. calyciflorus, including effects on body size, juvenile periods, net reproductive rate, and generation time. Both PFOS and PFOA exposure induced a smaller egg size in B. calyciflorus, suggesting that these risks can be transferred from mother to offspring. The 28-day population growth studies showed that PFOS and PFOA reduced the population density and increased the mictic ratio. Our results demonstrated that both PFOS and PFOA had adverse effects on B. calyciflorus, not only at the individual level but also at the population level.