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Kyungho Choi - One of the best experts on this subject based on the ideXlab platform.

  • ecotoxicological assessment of cimetidine and determination of its potential for endocrine disruption using three test organisms daphnia magna Moina macrocopa and danio rerio
    Chemosphere, 2015
    Co-Authors: Saeram Lee, Byeongwoo Ahn, Pilje Kim, Dawoon Jung, Younglim Kho, Kyungho Choi
    Abstract:

    Abstract Cimetidine is a histamine H2-receptor antagonist used for treatment of gastrointestinal disorders. It is often detected in aquatic environments, but its ecotoxicological effects have not been well studied. Thus, ecotoxicity of cimetidine was evaluated using Daphnia magna and Moina macrocopa , and zebrafish ( Danio rerio ), and a predicted no effect concentration (PNEC) was derived. In D. magna , 48 h immobilization EC 50 was determined at 394.9 mg L −1 . However, reproduction damages in D. magna were not found even at the maximum exposure level (30 mg L −1 ). For M. macrocopa , 48 h EC 50 was found at 175.8 mg L −1 and the 7 d reproduction no observed effect concentration (NOEC) was 1.1 mg L −1 . For D. rerio , 40 d growth NOEC was determined at 100 mg L −1 , the highest experimental concentration. The PNEC of cimetidine was estimated at 0.1 mg L −1 based on M. macrocopa 7 d reproduction NOEC. In 14 d adult zebrafish exposure, endocrine disruption potentials of cimetidine were observed. In male, decrease in plasma 17β-estradiol and testosterone levels, up-regulation of gonadal cyp17 , and down-regulation of hepatic erα were observed at 300 mg L −1 . In female, increase in plasma E2 level and down-regulation of hepatic cyp1a were noted at 3 mg L −1 . Endocrine disruption effects were also observed in early life stage exposure. Up-regulation of erβ at 17 d, and cyp19a and vtg at 40 d post fertilization were detected at 100 mg L −1 , and co-occurrence of ovary and putative testis was observed at as low as 1.1 mg L −1 . The results indicate that there is little evidence for cimetidine to cause direct ecological impact at the current ambient levels in the aquatic environment. However potential consequences of endocrine disruption following long-term exposure in aquatic environment deserves further investigation.

  • sunlight enhances toxicity of fullerene c 60 to freshwater invertebrates daphnia magna and Moina macrocopa
    보건학논집, 2014
    Co-Authors: Kyunghee Ji, Kyungho Choi
    Abstract:

    Manufactured nanomaterials (NMs) are used for various purposes, e.g., as catalysts in chemical reactions, drug delivery devices and consumer products such as sunscreens and cosmetics. Concerns about the potential ecotoxicological effects of NMs are increasing in part because they might have different toxicological characteristics from their larger counterparts. In the present study, we investigated the effects of particle size and UV light on the toxicity of fullerene. Methods: Two aquatic invertebrates, Daphnia magna and Moina macrocopa, were employed for toxicity tests. By exposure to 4 hr/d sunlight exposure, phototoxicity of fullerene by environmental level of ultraviolet (UV) lights was tested. Aquatic toxicities of stable colloidal suspensions of fullerene aggregates in water (aqu/nC 60 ) filtered through a 0.2 ㎛ and 0.45 μm filters were compared. Images of the particle were recorded using transmission-electron microscopy, and changes in catalase (CAT) activity were determined in D. magna juveniles after being exposed to sublethal levels of aqu/nC60 and environmental level of UV lights. Results: Exposure to aqu/nC 60 filtered through 0.2 ㎛ filters under environmental level of ultraviolet light was more detrimental to D. magna and M. macrocopa. Antioxidant enzyme activities were increased by coexposure to aqu/nC 60 and by sunlight. Conclusion: Exposure to fullerene leads to oxidative damage to D. magna and it was aggravated by natural sunlight. Further assessment for sublethal effects of fullerene under environmentally relevant conditions should be followed.

  • toxicity and endocrine disruption in zebrafish danio rerio and two freshwater invertebrates daphnia magna and Moina macrocopa after chronic exposure to mefenamic acid
    Ecotoxicology and Environmental Safety, 2013
    Co-Authors: Hyorin Jung Collard, Kyunghee Ji, Sungeun Kang, Kyungho Choi
    Abstract:

    Abstract Pharmaceuticals have been frequently detected in the aquatic environment. Their potential effects on the endocrine system in wildlife are of special concern because these alterations could lead to impaired reproduction. We evaluated ecotoxicities associated with long-term exposure to mefenamic acid (MFA) and potential endocrine disruption. For this purpose, acute and chronic toxicities of MFA on several aquatic organisms, including two cladocerans, Daphnia magna and Moina macrocopa , and a teleost, Danio rerio were evaluated. The 48 h acute median effective concentration (EC 50 ) of D. magna and M. macrocopa was 17.16 mg/L and 2.93 mg/L, respectively. In chronic toxicity test, D. magna and M. macrocopa showed significant changes in reproduction (number of young per adult) after the exposure to 1.0 mg/L and 0.25 mg/L MFA, respectively. In early life stage exposure using D. rerio , significant decrease of larval survival was observed at 1 mg/L. Changes in vitellogenin (VTG) protein concentrations in 32 day post fertilization fish and vtgI mRNA expression in adult male fish suggest endocrine disruption potentials of MFA. Among the genes of hypothalamus–pituitary–gonad axis, transcriptions of gnrh , gnrhr , cyp19a , and cyp19b increased, supporting estrogenic potential of MFA. Along with histological changes in ovaries, the results of this study provide evidences of endocrine disruption capacity of MFA. However, the effective concentrations are orders of magnitude greater than those occurring in the ambient aquatic environment.

  • effect of chronic exposure to acetaminophen and lincomycin on japanese medaka oryzias latipes and freshwater cladocerans daphnia magna and Moina macrocopa and potential mechanisms of endocrine disruption
    Chemosphere, 2012
    Co-Authors: Yena Park, Kyunghee Ji, Kyunghee Choi, Jeongim Park, Kyungho Choi
    Abstract:

    Abstract Chronic toxicity of acetaminophen and lincomycin were evaluated using freshwater organisms including two crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). H295R, a human adrenal cell was also used to understand the effects on steroidogenesis. In 21 d D. magna exposure, survival NOEC was found at 5.72 mg L−1 and no reproduction related effects were noted at this level of exposure to acetaminophen, while 21 d survival or growth effects were not observed even at the highest exposure levels (153 mg L−1) for lincomycin. In the chronic fish toxicity test, significant reduction in juvenile survival was observed at 30 d post-hatch (dph) at 95 mg L−1 of acetaminophen, and 0.42 mg L−1 of lincomycin. After the exposure to both pharmaceuticals, vitellogenin levels tended to increase in male fish at 90 dph. In the eggs which were prenatally exposed to 9.5 mg L−1 of acetaminophen, reduced hatchability was observed. The results of H295R cell assay showed that both pharmaceuticals could alter steroidogenic pathway and increase estrogenicity. Endocrine disruption potentials and their ecological implication may deserve further studies. Our observations suggest however that ecological risks of both pharmaceuticals are negligible at the concentrations currently found in the environment.

  • optimal conditions for three brood chronic toxicity test method using a freshwater macroinvertebrate Moina macrocopa
    Environmental Monitoring and Assessment, 2012
    Co-Authors: Sorin Oh, Kyungho Choi
    Abstract:

    Freshwater cladocera such as Daphnia magna and Ceriodaphnia dubia have been used extensively for freshwater toxicity test worldwide. However, these species may not be indigenous in certain geographical regions, which restrict the utility of these organisms as test species. In the present study, we investigated optimal culture and test conditions for an indigenous freshwater macroinvertebrate of Korea, Moina macrocopa. The culture conditions that were evaluated included water temperature (20°C and 25°C), rearing media (moderately hard water or MHW, with or without selenium supplementation, or Elendt M4), and food density (2.5 × 107 and 5 × 107 cells/mL of Selenastrum capricornutum), and their effects on the life history characteristics of M. macrocopa were determined. Population growth rate of M. macrocopa was maximized at 25°C with 5 × 107 cells/mL of algal food density in MHW. A series of chronic three brood reference toxicant tests were conducted under the ideal culture conditions that were identified here, and the results of the tests indicated reliable reproducibility of the test protocol. Optimal culture and test conditions that were identified for M. macrocopa in the present study are suggested for evaluation of chronic toxicity of chemicals and industrial or municipal discharge.

Christian E W Steinberg - One of the best experts on this subject based on the ideXlab platform.

  • algal diets and natural xenobiotics impact energy allocation in cladocerans ii Moina macrocopa and Moina micrura
    Limnologica, 2014
    Co-Authors: Rihab Bouchnak, Christian E W Steinberg
    Abstract:

    Abstract In freshwater lakes, changing mineral and biochemical food qualities as well as exposure to natural xenobiotics, such as humic substances (HSs) are common challenges to life history traits of zooplankters. In this contribution, we tested the bottom-up effect of different food qualities alone and in concert with exposure to increasing HS concentrations in a clone of each Moina micrura (inhabitant of Brazilian coastal lagoons) and Moina macrocopa (invasive species). Carbon, nitrogen, and phosphorus contents, fatty acid (FA) and the amino acid (AA) patterns of three coccal green algae of the summer aspect in the lagoons were analyzed. All algae were deficient in P, differed in their content of α-linolenic acid (ALA), histidine, and arginine and were lacking long-chained polyunsaturated fatty acids (PUFAs >C18). M. micrura did not grow on Desmodesmus armatus. Maximal mean lifespan and total lifespan reproduction were achieved on Pseudokirchneriella subcapitata. M. macrocopa fed all algae offered. Multiple regressions showed that ALA triggered longevity and the P-content reproduction. Exposure to HSs revealed that M. micrura reduced either its lifespan on Monoraphidium minutum or its reproduction on P. subcapitata. Conversely in M. macrocopa, lifespan on M. minutum was extended by a factor of 1.7 and offspring numbers increased by 1.4 upon HS exposure. On D. armatus an originally very low reproductive output increased maximal by a factor 4.6. Relating HS-mediated lifespan and offspring modulations of the 1.08 mM exposure to food components, it appears that ALA controls lifespan modulation even under HS stress, whereas offspring modulation seems to be controlled by C and total AA content. This indicates that, upon HS exposure, the investment of energy in body maintenance or reproduction would depend at least partly on the biochemical composition of the food available. This also shows that even short-chained dietary PUFAs may play a major role in keeping lipid peroxidation low. A comparison of the two Moina species tested revealed that M. macrocopa has the capacity to outcompete M. micrura, since it had the greater clutch size, never reduced the reproductive output upon HS-exposure, and fed all diets offered.

  • algal diets and natural xenobiotics impact energy allocation in cladocerans ii Moina macrocopa and Moina micrura
    Limnologica, 2014
    Co-Authors: Rihab Bouchnak, Christian E W Steinberg
    Abstract:

    Abstract In freshwater lakes, changing mineral and biochemical food qualities as well as exposure to natural xenobiotics, such as humic substances (HSs) are common challenges to life history traits of zooplankters. In this contribution, we tested the bottom-up effect of different food qualities alone and in concert with exposure to increasing HS concentrations in a clone of each Moina micrura (inhabitant of Brazilian coastal lagoons) and Moina macrocopa (invasive species). Carbon, nitrogen, and phosphorus contents, fatty acid (FA) and the amino acid (AA) patterns of three coccal green algae of the summer aspect in the lagoons were analyzed. All algae were deficient in P, differed in their content of α-linolenic acid (ALA), histidine, and arginine and were lacking long-chained polyunsaturated fatty acids (PUFAs >C18). M. micrura did not grow on Desmodesmus armatus. Maximal mean lifespan and total lifespan reproduction were achieved on Pseudokirchneriella subcapitata. M. macrocopa fed all algae offered. Multiple regressions showed that ALA triggered longevity and the P-content reproduction. Exposure to HSs revealed that M. micrura reduced either its lifespan on Monoraphidium minutum or its reproduction on P. subcapitata. Conversely in M. macrocopa, lifespan on M. minutum was extended by a factor of 1.7 and offspring numbers increased by 1.4 upon HS exposure. On D. armatus an originally very low reproductive output increased maximal by a factor 4.6. Relating HS-mediated lifespan and offspring modulations of the 1.08 mM exposure to food components, it appears that ALA controls lifespan modulation even under HS stress, whereas offspring modulation seems to be controlled by C and total AA content. This indicates that, upon HS exposure, the investment of energy in body maintenance or reproduction would depend at least partly on the biochemical composition of the food available. This also shows that even short-chained dietary PUFAs may play a major role in keeping lipid peroxidation low. A comparison of the two Moina species tested revealed that M. macrocopa has the capacity to outcompete M. micrura, since it had the greater clutch size, never reduced the reproductive output upon HS-exposure, and fed all diets offered.

  • culture of the cladoceran Moina macrocopa mortality associated with flagellate infection
    Aquaculture, 2013
    Co-Authors: Sarah L Poynton, Philipp Dachsel, Maik J Lehmann, Christian E W Steinberg
    Abstract:

    Abstract Cladocerans are important food animals in aquaculture, key grazers in freshwater ecosystems, and model animals for ecotoxicological investigations. Their epibiont community, extensively studied in Daphnia , includes filamentous bacteria, fungi, algae, peritrich ciliates, and rotifers; although epibionts are usually benign, heavy infections can be detrimental. During our laboratory culture of female Moina macrocopa Straus, we observed a novel flagellate infection associated with mortality. At day 10, all M. macrocopa were alive in uninfected cultures, whereas in untreated infected cultures, the survival was significantly lower: only 26% of cladocerans were alive. In infected cultures treated with humic substances (as 25 mg L − 1 dissolved organic carbon), mortalities were comparable to those in the untreated infected cultures; in contrast, in the infected cultures treated with 4 g L − 1 sea salt, mortalities were arrested, and 76% of the M. macrocopa were alive at day 10. Moribund cladocerans were transparent, had empty digestive tracts, and greatly reduced motor activity. Free-swimming flagellates moved forward with a wobbling motion, rotating around their long axis; they also attached to cladoceran tissue, the Petri dish, and the glass slide, by the tip of their posterior flagellum. Flagellates preserved for scanning electron microscopy were 6.9 ± 0.7 μm long and 2.1 ± 0.3 μm wide, with a short anterior flagellum (6.8 ± 1.1 μm) and long posterior flagellum (14.1 ± 1.5 μm). Multi-functionality of a flagellum, for locomotion and adhesion, is relatively rare, and previously reported from genera within the Kinetoplastea, suggesting that the flagellate on M. macrocopa may belong to this group. To combat flagellate mass occurrence in Moina cultures, we recommend a treatment with 4 g L − 1 sea salt.

  • interaction of temperature and an environmental stressor Moina macrocopa responds with increased body size increased lifespan and increased offspring numbers slightly above its temperature optimum
    Chemosphere, 2013
    Co-Authors: Antonia Engert, Ralph Menzel, Shumon Chakrabarti, Nadine Saul, Michal Bittner, Christian E W Steinberg
    Abstract:

    For organisms, temperature is one of the most important environmental factors and gains increasing importance due to global warming, since increasing temperatures may pose organisms close to their environmental tolerance limits and, thus, they may become more vulnerable to environmental stressors. We analyzed the temperature-dependence of the water-soluble antioxidant capacity of the cladoceran Moina macrocopa and evaluated its life trait variables with temperature (15, 20, 25, 30°C) and humic substance (HS) concentrations (0, 0.18, 0.36, 0.90, 1.79 mM DOC) as stressors. Temperatures below and above the apparent optimum (20°C) reduced the antioxidative capacity. Additions of HSs increased body length, but decreased mean lifespan at 15 and 20°C. There was no clear HS-effect on offspring numbers at 15, 20, and 30°C. At 25°C with increasing HS-concentration, lifespan was extended and offspring numbers increased tremendously, reaching 250% of the control. Although the applied HS preparation possesses estrogenic and antiandrogenic activities, a xenohormone mechanism does not seem plausible for the reproductive increase, because comparable effects did not occur at other temperatures. A more convincing explanation appears to be the mitohormesis hypothesis which states that a certain increase of reactive oxygen production leads to improved health and longevity and, with Moina, also to increased offspring numbers. Our results suggest that at least with the eurythermic M. macrocopa, a temperature above the optimum can be beneficial for several life trait variables, even when combined with a chemical stressor. Temperatures approximately 10°C above its optimum appear to adversely affect the lifespan and reproduction of M. macrocopa. This indicates that this cladoceran species seems to be able to utilize temperature as an ecological resource in a range slightly above its thermal optimum.

  • leaf litter leachates have the potential to increase lifespan body size and offspring numbers in a clone of Moina macrocopa
    Chemosphere, 2012
    Co-Authors: Sylva Hofmann, Ralph Menzel, Nadine Saul, Maxim A Timofeyev, Anke Putschew, Christian E W Steinberg
    Abstract:

    Leaf litter processing is one major pathway of the global organic carbon cycle. During this process, a variety of small reactive organic compounds are released and transported to the aquatic environment, and may directly impact aquatic organisms as natural xenobiotics. We hypothesize that different forest stockings produce different leachate qualities, which in turn, stress the aquatic communities and, eventually, separate sensitive from tolerant species. Particularly, leachates from coniferous trees are suspected to have strongly adverse impacts on sensitive species. We exposed individuals of a clone of the model organism, Moina macrocopa, to comparable concentrations (approximately 2 mM) of litter leachates of Norway spruce, Picea abies, Colorado blue spruce, Picea pungens, black poplar, Populus nigra, and sessile oak, Quercus petraea. The animals were fed ad libitum. The following life trait variables were recorded: growth, lifespan, and lifetime offspring. To identify, whether or not exposure to litter leachates provokes an internal oxidative stress in the exposed animals we measured the superoxide anion radical scavenging capacity via photoluminescence. Except of P. abies, exposure to the leachates reduced this antioxidant capacity by approximately 50%. Leachate exposures, except that of Quercus, increased body size and extended lifespan; furthermore, particularly the leachates of both Picea species significantly increased the offspring numbers. This unexpected behavior of exposed Moina may be based on food supplements (e.g., high carbohydrate contents) in the leachates or on yet to be identified regulatory pathways of energy allocation. Overall, our results suggest that the potentially adverse effects of litter leachates can be overruled by either bacterial-growth supporting fractions in the leachates or an internal compensation mechanism in the Moina individuals.

S S S Sarma - One of the best experts on this subject based on the ideXlab platform.

  • four transgenerational demographic performance of Moina macrocopa exposed to chronic levels of cadmium
    Dose-response, 2017
    Co-Authors: Jose Luis Gamaflores, S S S Sarma, Maria Elena Huidobrosalas, S Nandini
    Abstract:

    : In this study, we quantified intergenerational, demographic variability of Moina macrocopa subjected to cadmium stress. Exposure of M macrocopa to cadmium (0.2, 0.3, and 0.4 mg/L as CdCl2) through 4 consecutive generations revealed changes in demographic responses not only in survivorship variables but also in reproductive parameters. Long-term demographic responses varied differently, depending on the demographic trait and the concentration of heavy metal in the medium. With the exception of generation time, all life history traits were significantly and adversely influenced due to increase in Cd concentrations. The average life span of M macrocopa varied up to 40% depending on Cd level and the generation of exposure. The highest gross reproductive rates were recorded in controls, while the lowest (∼30% less) were recorded at the highest Cd level. Survival-weighted net reproductive rates were reduced by nearly 50% due to Cd toxicity. The rate of population increase per day of M macrocopa was also significantly affected (∼25%) by Cd as compared to controls. This cladoceran showed a dose-response to Cd toxicity with a significance in both magnitude and frequency of offspring production.

  • Effects of predation by Hydra (Cnidaria) on cladocerans (Crustacea: Cladocera)
    PAGEPress Publications, 2016
    Co-Authors: Ligia Rivera-de La Parra, S S S Sarma, S Nandini
    Abstract:

    Planktonic cladocerans have evolved different strategies to avoid predation from vertebrates; these include changes in morphology, behavior, physiology, and/or life-history traits. However, littoral cladocerans are better adapted to avoid invertebrate predation particularly from insect larvae by evolving morphological and physiological adaptations. Nevertheless, this has not been proven for some littoral predators such as Hydra. In this study, we provide quantitative data on how Hydra affects its zooplankton prey. We studied the predation behavior on Alona glabra, Ceridodaphnia dubia, Daphnia pulex, Daphnia cf. mendotae, Diaphanosoma birgei, Macrothrix triserialis, Moina macrocopa, Pleuroxus aduncus, Scapholeberis kingi, Simocephalus vetulus, Elaphoidella grandidieri, Brachionus rubens and Euchlanis dilatata. We also tested the indirect effect of allelochemicals from Hydra on the demography of Daphnia cf. mendotae. Littoral cladocerans are specially adapted to resist nematocyst injection and discharge of toxic substances from Hydra. A significant decrease in the population growth rate from 0.21 to 0.125 d-1 was observed at densities of 2 ind. ml-1. The role of carapace thickness as an adaptive strategy of littoral cladocerans against Hydra predation is discussed

  • temperature and age affect the life history characteristics and fatty acid profiles of Moina macrocopa cladocera
    Journal of Thermal Biology, 2015
    Co-Authors: Jose Luis Gamaflores, S S S Sarma, S Nandini, Maria Elena Huidobrosalas, Ricardo Zepedamejia, R D Gulati
    Abstract:

    Demographic responses and fatty acid profiles of Moina macrocopa were quantified under different temperature regimes (20 °C, 25 °C and 30 °C and diurnally variable 20–30 °C) and at fixed ration (10.65 µg DW ml−1) of Chlorella. Highest constant temperature (30 °C) reduced the density of M. macrocopa. The cladocerans under the fluctuating temperature regime too had lower population growth (about 50% lower than that at constant 25 °C). The survivorship of M. macrocopa was higher at 20 °C than that at 25 °C and 30 °C or at variable temperature regime. Gross and net reproductive rates were higher at 25 °C. At 20 °C, neonates had the highest proportion (67%) of myristic, palmitic and stearic acids while the adults had the lowest (26%) proportion. For both adults and neonates, palmitoleic, linoleic and linolenic comprised of 15–35% of the total fatty acids. Higher percentage (19%) of linoleic acid was present in adults than neonates (7%). Adults had linolenic acid level which was 3-times higher than in neonates. Linoleic and linolenic fatty acids decreased with increasing temperature for neonates and adults from 20 °C to 30 °C. The demographic responses and fatty acid profiles of M. macrocopa were discussed in relation to level and mode of temperature exposure.

  • effect of paracetamol and diclofenac on population growth of plationus patulus and Moina macrocopa
    Journal of Environmental Biology, 2014
    Co-Authors: S S S Sarma, Brenda Karen Gonzalezperez, Rosa Martha Morenogutierrez, S Nandini
    Abstract:

    Two non-steroidal anti-inflammatory commonly used in Mexico are paracetamol and diclofenac. These drugs reach natural waterbodies transport through the hydrological areas of agriculture and effluent treatment plants and can affect plankton. In this study, we quantified the chronic effects of paracetamol and sodium diclofenac on the population dynamics of the rotifer and the cladoceran under laboratory conditions. Both these species of zooplankton are common in freshwaters and are sensitive to chemicals in the medium. Our results showed that densities of both and decreased with increasing levels of both the analgesic drugs. Both zooplankton species did not survive beyond when paracetamol was applied at 32 mg l in the medium. Diclofenac in general had more adverse effect than paracetamol for either zooplankton species. was more sensitive than to both analgesic drugs. When diclofenac was present in the medium at 12.5 mg l , rotifer reproduction was inhibited, while the tested cladocerans continued to grow but to lower densities compared to control. The rate of population increase (r) per day of and was significantly and inversely related to the concentration of paracetamol and diclofenac in the medium. However, the relationship between r and drug concentration differed depending on the zooplankton species and drug. In controls, the r of was 0.18 d , for

  • effect of water quality on the feeding ecology of axolotl ambystoma mexicanum
    Journal of Limnology, 2013
    Co-Authors: D J Chaparroherrera, S Nandini, S S S Sarma
    Abstract:

    Ambystoma mexicanum , a highly endangered species, is endemic to lake Xochimilco (Mexico City, Mexico) which currently is being negatively affected by the introduction of Oreochromis niloticus (Tilapia) and water pollution. During the first weeks of development, when mortality is the highest, Ambystoma mexicanum depends on a diet of zooplankton. The aim of this study was to check whether contamination levels in lake Xochimilco influence zooplankton consumption by similar size classes of A. mexicanum and Oreochromis niloticus . In this study, we analysed changes in the functional responses and prey preference of A. mexicanum and larval Tilapia in two media, one with filtered lake Xochimilco water and another one with reconstituted water. As prey we used cladocerans (Moina macrocopa , Alona glabra , Macrothrix triserialis and Simocephalus vetulus) and ostracods (Heterocypris incongruens) . Zooplankton was offered in 5 different densities, 10, 20, 40, 80, 160 ind./mL. Prey consumption by A. mexicanum varied in relation to the species offered and age of the larvae. From the first week to the eighth week prey consumption by A. mexicanum increased by 57%. Our functional response tests showed that regardless of the prey type, prey consumption by A. mexicanum was lower in the contaminated water from lake Xochimilco. Among the zooplankton offered in the contaminated environment predators preferred smaller and slower moving microcrustaceans such as Alona glabra and Heterocypris incongruens . Furthermore, O. niloticus preferred prey such as Moina macrocopa and Macrothrix triserialis in the contaminated medium and was more voracious than the axolotl. Our results indicate that both water quality of the lake and the presence of the more resistant exotic fish adversely impact the survival of this endangered amphibian.

S Nandini - One of the best experts on this subject based on the ideXlab platform.

  • four transgenerational demographic performance of Moina macrocopa exposed to chronic levels of cadmium
    Dose-response, 2017
    Co-Authors: Jose Luis Gamaflores, S S S Sarma, Maria Elena Huidobrosalas, S Nandini
    Abstract:

    : In this study, we quantified intergenerational, demographic variability of Moina macrocopa subjected to cadmium stress. Exposure of M macrocopa to cadmium (0.2, 0.3, and 0.4 mg/L as CdCl2) through 4 consecutive generations revealed changes in demographic responses not only in survivorship variables but also in reproductive parameters. Long-term demographic responses varied differently, depending on the demographic trait and the concentration of heavy metal in the medium. With the exception of generation time, all life history traits were significantly and adversely influenced due to increase in Cd concentrations. The average life span of M macrocopa varied up to 40% depending on Cd level and the generation of exposure. The highest gross reproductive rates were recorded in controls, while the lowest (∼30% less) were recorded at the highest Cd level. Survival-weighted net reproductive rates were reduced by nearly 50% due to Cd toxicity. The rate of population increase per day of M macrocopa was also significantly affected (∼25%) by Cd as compared to controls. This cladoceran showed a dose-response to Cd toxicity with a significance in both magnitude and frequency of offspring production.

  • Effects of predation by Hydra (Cnidaria) on cladocerans (Crustacea: Cladocera)
    PAGEPress Publications, 2016
    Co-Authors: Ligia Rivera-de La Parra, S S S Sarma, S Nandini
    Abstract:

    Planktonic cladocerans have evolved different strategies to avoid predation from vertebrates; these include changes in morphology, behavior, physiology, and/or life-history traits. However, littoral cladocerans are better adapted to avoid invertebrate predation particularly from insect larvae by evolving morphological and physiological adaptations. Nevertheless, this has not been proven for some littoral predators such as Hydra. In this study, we provide quantitative data on how Hydra affects its zooplankton prey. We studied the predation behavior on Alona glabra, Ceridodaphnia dubia, Daphnia pulex, Daphnia cf. mendotae, Diaphanosoma birgei, Macrothrix triserialis, Moina macrocopa, Pleuroxus aduncus, Scapholeberis kingi, Simocephalus vetulus, Elaphoidella grandidieri, Brachionus rubens and Euchlanis dilatata. We also tested the indirect effect of allelochemicals from Hydra on the demography of Daphnia cf. mendotae. Littoral cladocerans are specially adapted to resist nematocyst injection and discharge of toxic substances from Hydra. A significant decrease in the population growth rate from 0.21 to 0.125 d-1 was observed at densities of 2 ind. ml-1. The role of carapace thickness as an adaptive strategy of littoral cladocerans against Hydra predation is discussed

  • temperature and age affect the life history characteristics and fatty acid profiles of Moina macrocopa cladocera
    Journal of Thermal Biology, 2015
    Co-Authors: Jose Luis Gamaflores, S S S Sarma, S Nandini, Maria Elena Huidobrosalas, Ricardo Zepedamejia, R D Gulati
    Abstract:

    Demographic responses and fatty acid profiles of Moina macrocopa were quantified under different temperature regimes (20 °C, 25 °C and 30 °C and diurnally variable 20–30 °C) and at fixed ration (10.65 µg DW ml−1) of Chlorella. Highest constant temperature (30 °C) reduced the density of M. macrocopa. The cladocerans under the fluctuating temperature regime too had lower population growth (about 50% lower than that at constant 25 °C). The survivorship of M. macrocopa was higher at 20 °C than that at 25 °C and 30 °C or at variable temperature regime. Gross and net reproductive rates were higher at 25 °C. At 20 °C, neonates had the highest proportion (67%) of myristic, palmitic and stearic acids while the adults had the lowest (26%) proportion. For both adults and neonates, palmitoleic, linoleic and linolenic comprised of 15–35% of the total fatty acids. Higher percentage (19%) of linoleic acid was present in adults than neonates (7%). Adults had linolenic acid level which was 3-times higher than in neonates. Linoleic and linolenic fatty acids decreased with increasing temperature for neonates and adults from 20 °C to 30 °C. The demographic responses and fatty acid profiles of M. macrocopa were discussed in relation to level and mode of temperature exposure.

  • effect of paracetamol and diclofenac on population growth of plationus patulus and Moina macrocopa
    Journal of Environmental Biology, 2014
    Co-Authors: S S S Sarma, Brenda Karen Gonzalezperez, Rosa Martha Morenogutierrez, S Nandini
    Abstract:

    Two non-steroidal anti-inflammatory commonly used in Mexico are paracetamol and diclofenac. These drugs reach natural waterbodies transport through the hydrological areas of agriculture and effluent treatment plants and can affect plankton. In this study, we quantified the chronic effects of paracetamol and sodium diclofenac on the population dynamics of the rotifer and the cladoceran under laboratory conditions. Both these species of zooplankton are common in freshwaters and are sensitive to chemicals in the medium. Our results showed that densities of both and decreased with increasing levels of both the analgesic drugs. Both zooplankton species did not survive beyond when paracetamol was applied at 32 mg l in the medium. Diclofenac in general had more adverse effect than paracetamol for either zooplankton species. was more sensitive than to both analgesic drugs. When diclofenac was present in the medium at 12.5 mg l , rotifer reproduction was inhibited, while the tested cladocerans continued to grow but to lower densities compared to control. The rate of population increase (r) per day of and was significantly and inversely related to the concentration of paracetamol and diclofenac in the medium. However, the relationship between r and drug concentration differed depending on the zooplankton species and drug. In controls, the r of was 0.18 d , for

  • effect of water quality on the feeding ecology of axolotl ambystoma mexicanum
    Journal of Limnology, 2013
    Co-Authors: D J Chaparroherrera, S Nandini, S S S Sarma
    Abstract:

    Ambystoma mexicanum , a highly endangered species, is endemic to lake Xochimilco (Mexico City, Mexico) which currently is being negatively affected by the introduction of Oreochromis niloticus (Tilapia) and water pollution. During the first weeks of development, when mortality is the highest, Ambystoma mexicanum depends on a diet of zooplankton. The aim of this study was to check whether contamination levels in lake Xochimilco influence zooplankton consumption by similar size classes of A. mexicanum and Oreochromis niloticus . In this study, we analysed changes in the functional responses and prey preference of A. mexicanum and larval Tilapia in two media, one with filtered lake Xochimilco water and another one with reconstituted water. As prey we used cladocerans (Moina macrocopa , Alona glabra , Macrothrix triserialis and Simocephalus vetulus) and ostracods (Heterocypris incongruens) . Zooplankton was offered in 5 different densities, 10, 20, 40, 80, 160 ind./mL. Prey consumption by A. mexicanum varied in relation to the species offered and age of the larvae. From the first week to the eighth week prey consumption by A. mexicanum increased by 57%. Our functional response tests showed that regardless of the prey type, prey consumption by A. mexicanum was lower in the contaminated water from lake Xochimilco. Among the zooplankton offered in the contaminated environment predators preferred smaller and slower moving microcrustaceans such as Alona glabra and Heterocypris incongruens . Furthermore, O. niloticus preferred prey such as Moina macrocopa and Macrothrix triserialis in the contaminated medium and was more voracious than the axolotl. Our results indicate that both water quality of the lake and the presence of the more resistant exotic fish adversely impact the survival of this endangered amphibian.

Kyunghee Choi - One of the best experts on this subject based on the ideXlab platform.

  • combined effects of the cyanobacterial toxin microcystin lr and environmental factors on life history traits of indigenous cladoceran Moina macrocopa
    Environmental Toxicology and Chemistry, 2014
    Co-Authors: Jungkon Kim, Jungkwan Seo, Hyojung Yoon, Pilje Kim, Kyunghee Choi
    Abstract:

    Environmental factors are important in that they might interact with toxicants and could affect the concentration–response relationship of the toxicants in the water environment. Microcystins (MCs) produced by algal blooming are natural toxins that exert severe impacts on aquatic organisms. Despite the possibility of interaction effects between environmental factors and MCs, very few studies have been carried out to date. In the present study, the authors evaluated the effect of 3 environmental factors on chronic toxicity of MC-leucine-arginine (MC-LR; 0 µg/L, 0.8 µg/L, 4 µg/L, 20 µg/L, 100 µg/L, 500 µg/L) to the freshwater invertebrate Moina macrocopa. Three environmental factors were determined to reflect the reasonable worst conditions of the water body in South Korea: high water temperature (25 °C), the highest concentration of nutrients (ammonia-nitrogen [NH3-N] = 3.8 mg/L; nitrate-nitrogen [NO3-N] = 8.5 mg/L) during the occurrence of algal bloom, and 2 pH conditions of 7.0 and 9.0, which satisfy the test acceptance criteria for the Daphnia test. Among the various environmental factors being tested, high water temperature and NO3-N elevated chronic toxicity of MC-LR, whereas NH3-N reduced toxicity. Water pH did not influence chronic toxicity of MC-LR to M. macrocopa. This observation suggests that those environmental factors are responsible for changing the trend of MC-LR toxicity. Environ Toxicol Chem 2014;33:2560–2565. © 2014 SETAC

  • effect of chronic exposure to acetaminophen and lincomycin on japanese medaka oryzias latipes and freshwater cladocerans daphnia magna and Moina macrocopa and potential mechanisms of endocrine disruption
    Chemosphere, 2012
    Co-Authors: Yena Park, Kyunghee Ji, Kyunghee Choi, Jeongim Park, Kyungho Choi
    Abstract:

    Abstract Chronic toxicity of acetaminophen and lincomycin were evaluated using freshwater organisms including two crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). H295R, a human adrenal cell was also used to understand the effects on steroidogenesis. In 21 d D. magna exposure, survival NOEC was found at 5.72 mg L−1 and no reproduction related effects were noted at this level of exposure to acetaminophen, while 21 d survival or growth effects were not observed even at the highest exposure levels (153 mg L−1) for lincomycin. In the chronic fish toxicity test, significant reduction in juvenile survival was observed at 30 d post-hatch (dph) at 95 mg L−1 of acetaminophen, and 0.42 mg L−1 of lincomycin. After the exposure to both pharmaceuticals, vitellogenin levels tended to increase in male fish at 90 dph. In the eggs which were prenatally exposed to 9.5 mg L−1 of acetaminophen, reduced hatchability was observed. The results of H295R cell assay showed that both pharmaceuticals could alter steroidogenic pathway and increase estrogenicity. Endocrine disruption potentials and their ecological implication may deserve further studies. Our observations suggest however that ecological risks of both pharmaceuticals are negligible at the concentrations currently found in the environment.

  • endocrine disruption and consequences of chronic exposure to ibuprofen in japanese medaka oryzias latipes and freshwater cladocerans daphnia magna and Moina macrocopa
    Aquatic Toxicology, 2010
    Co-Authors: Sunyoung Han, Kyungho Choi, Kyunghee Choi, Byeongwoo Ahn, Jungkon Kim, Sunmi Kim, Junheon Yun, Jong Seong Khim, Xiaowei Zhang, John P Giesy
    Abstract:

    Despite frequent detection of ibuprofen in aquatic environments, the hazards associated with long-term exposure to ibuprofen have seldom been investigated. Ibuprofen is suspected of influencing sex steroid hormones through steroidogenic pathways in both vertebrates and invertebrates. In this study, the effect of ibuprofen on sex hormone balance and the associated mechanisms was investigated in vitro by use of H295R cells. We also conducted chronic toxicity tests using freshwater fish, Oryzias latipes, and two freshwater cladocerans, Daphnia magna and Moina macrocopa, for up to 144 and 21d of exposure, respectively. Ibuprofen exposure increased 17beta-estradiol (E2) production and aromatase activity in H295R cells. Testosterone (T) production decreased in a dose-dependent manner. For D. magna, the 48 h immobilization EC50 was 51.4 mg/L and the 21 d reproduction NOEC was <1.23 mg/L; for M. macrocopa, the 48 h immobilization EC50 was 72.6 mg/L and the 7d reproduction NOEC was 25mg/L. For O. latipes, 120 d survival NOEC was 0.0001 mg/L. In addition, ibuprofen affected several endpoints related to reproduction of the fish, including induction of vitellogenin in male fish, fewer broods per pair, and more eggs per brood. Parental exposure to as low as 0.0001 mg/L ibuprofen delayed hatching of eggs even when they were transferred to and cultured in clean water. Delayed hatching is environmentally relevant because this may increase the risk of being predated. For O. latipes, the acute-to-chronic ratio of ibuprofen was estimated to be greater than 1000. Overall, relatively high acute-to-chronic ratio and observation of reproduction damage in medaka fish at environmentally relevant ranges of ibuprofen warrant the need for further studies to elucidate potential ecological consequences of ibuprofen contamination in the aquatic environment.

  • endocrine disruption and consequences of chronic exposure to ibuprofen in japanese medaka oryzias latipes and freshwater cladocerans daphnia magna and Moina macrocopa
    Aquatic Toxicology, 2010
    Co-Authors: Kyungho Choi, Kyunghee Ji, Kyunghee Choi, Jong Seong Khim, Xiaowei Zhang, John P Giesy
    Abstract:

    Despite frequent detection of ibuprofen in aquatic environments, the hazards associated with long-term exposure to ibuprofen have seldom been investigated. Ibuprofen is suspected of influencing sex steroid hormones through steroidogenic pathways in both vertebrates and invertebrates. In this study, the effect of ibuprofen on sex hormone balance and the associated mechanisms was investigated in vitro by use of H295R cells. We also conducted chronic toxicity tests using freshwater fish, Oryzias latipes, and two freshwater cladocerans, Daphnia magna and Moina macrocopa, for up to 144 and 21 d of exposure, respectively. Ibuprofen exposure increased 17-estradiol (E2) production and aromatase activity in H295R cells. Testosterone (T) production decreased in a dose-dependent manner. For D. magna, the 48 h immobilization EC50 was 51.4 mg/L and the 21 d reproduction NOEC was <1.23 mg/L; for M. macrocopa, the 48 h immobilization EC50 was 72.6 mg/L and the 7 d reproduction NOEC was 25 mg/L. For O. latipes, 120 d survival NOEC was 0.0001 mg/L. In addition, ibuprofen affected several endpoints related to reproduction of the fish, including induction of vitellogenin in male fish, fewer broods per pair, and more eggs per brood. Parental exposure to as low as 0.0001 mg/L ibuprofen delayed hatching of eggs even when they were transferred to and cultured in clean water. Delayed hatching is environmentally relevant because this may increase the risk of being predated. For O. latipes, the acute-to-chronic ratio of ibuprofen was estimated to be greater than 1000. Overall, relatively high acute-to-chronic ratio and observation of reproduction damage in medaka fish at environmentally relevant ranges of ibuprofen warrant the need for further studies to elucidate potential ecological consequences of ibuprofen contamination in the aquatic environment.