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Sample records for brachionus manjavacas rotifera

  1. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera

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    Kubanek Julia

    2009-09-01

    , even at synonymous positions, suggests that the repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Conclusion Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

  2. Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera).

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    Snell, Terry W; Johnston, Rachel K; Rabeneck, Brett; Zipperer, Cody; Teat, Stephanie

    2014-04-01

    The TOR kinase pathway is central in modulating aging in a variety of animal models. The target of rapamycin (TOR) integrates a complex network of signals from growth conditions, nutrient availability, energy status, and physiological stresses and matches an organism's growth rate to the resource environment. Important remaining problems are the identification of the pathways that interact with TOR and their characterization as additive or synergistic. One of the most versatile stress sensors in metazoans is the Jun-N-terminal kinase (JNK) signaling pathway. JNK is an evolutionarily conserved stress-activated protein kinase that is induced by a range of stressors, including UV irradiation, reactive oxygen species, DNA damage, heat, and bacterial antigens. JNK is thought to interact with the TOR pathway, but its effects on TOR are poorly understood. We used the rotifer Brachionus manjavacas as a model animal to probe the regulation of TOR and JNK pathways and explore their interaction. The effect of various chemical inhibitors was examined in life table and stressor challenge experiments. A survey of 12 inhibitors revealed two, rapamycin and JNK inhibitor, that significantly extended lifespan of B. manjavacas. At 1 μM concentration, exposure to rapamycin or JNK inhibitor extended mean rotifer lifespan by 35% and maximum lifespan by 37%. Exposure to both rapamycin and JNK inhibitor simultaneously extended mean rotifer lifespan by 65% more than either alone. Exposure to a combination of rapamycin and JNK inhibitors conveyed greater protection to starvation, UV and osmotic stress than either inhibitor alone. RNAi knockdown of TOR and JNK gene expression was investigated for its ability to extend rotifer lifespan. RNAi knockdown of the TOR gene resulted in 29% extension of the mean lifespan compared to control and knockdown of the JNK gene resulted in 51% mean lifespan extension. In addition to the lifespan, we quantified mitochondria activity using the fluorescent

  3. Moderately lower temperatures greatly extend the lifespan of Brachionus manjavacas (Rotifera): Thermodynamics or gene regulation?

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    Johnston, Rachel K; Snell, Terry W

    2016-06-01

    Environmental temperature greatly affects lifespan in a wide variety of animals, but the exact mechanisms underlying this effect are still largely unknown. A moderate temperature decrease from 22°C to 16°C extends the lifespan of the monogonont rotifer Brachionus manjavacas by up to 163%. Thermodynamic effects on metabolism contribute to this increase in longevity, but are not the only cause. When rotifers are exposed to 16°C for four days and then transfered to 22°C, they survive until day 13 at nearly identical rates as rotifers maintained at 16°C continuously. This persistence of the higher survival for nine days after transfer to 22°C suggests that low temperature exposure alters the expression of genes that affect the rate of aging. The relative persistence of the gene regulation effect suggests that it may play an even larger role in slowing aging than the thermodynamic effects. The life extending effects of these short-term low temperature treatments are largest when the exposure happens early in the life cycle, demonstrating the importance of early development. There is no advantage to lowering the temperature below 16°C to 11° or 5°C. Rotifers exposed to 16°C also displayed increased resistance to heat, starvation, oxidative and osmotic stress. Reproductive rates at 16°C were lower than those at 22°C, but because they reproduce longer, there is no significant change in the lifetime fecundity of females. To investigate which genes contribute to these effects, the expression of specific temperature sensing genes was knocked down using RNAi. Of 12 genes tested, RNAi knockdown of four eliminated the survival enhancing effects of the four-day cold treatment: TRP7, forkhead box C, Y-box factor, and ribosomal protein S6. This demonstrates that active gene regulation is an important factor in temperature mediated life extension, and that these particular genes play an integral role in these pathways. As a thermoresponsive sensor, TRP7 may be

  4. Moderately lower temperatures greatly extend the lifespan of Brachionus manjavacas (Rotifera): Thermodynamics or gene regulation?

    Science.gov (United States)

    Johnston, Rachel K; Snell, Terry W

    2016-06-01

    Environmental temperature greatly affects lifespan in a wide variety of animals, but the exact mechanisms underlying this effect are still largely unknown. A moderate temperature decrease from 22°C to 16°C extends the lifespan of the monogonont rotifer Brachionus manjavacas by up to 163%. Thermodynamic effects on metabolism contribute to this increase in longevity, but are not the only cause. When rotifers are exposed to 16°C for four days and then transfered to 22°C, they survive until day 13 at nearly identical rates as rotifers maintained at 16°C continuously. This persistence of the higher survival for nine days after transfer to 22°C suggests that low temperature exposure alters the expression of genes that affect the rate of aging. The relative persistence of the gene regulation effect suggests that it may play an even larger role in slowing aging than the thermodynamic effects. The life extending effects of these short-term low temperature treatments are largest when the exposure happens early in the life cycle, demonstrating the importance of early development. There is no advantage to lowering the temperature below 16°C to 11° or 5°C. Rotifers exposed to 16°C also displayed increased resistance to heat, starvation, oxidative and osmotic stress. Reproductive rates at 16°C were lower than those at 22°C, but because they reproduce longer, there is no significant change in the lifetime fecundity of females. To investigate which genes contribute to these effects, the expression of specific temperature sensing genes was knocked down using RNAi. Of 12 genes tested, RNAi knockdown of four eliminated the survival enhancing effects of the four-day cold treatment: TRP7, forkhead box C, Y-box factor, and ribosomal protein S6. This demonstrates that active gene regulation is an important factor in temperature mediated life extension, and that these particular genes play an integral role in these pathways. As a thermoresponsive sensor, TRP7 may be

  5. Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A® to the Brachionus plicatilis species complex (Rotifera)

    International Nuclear Information System (INIS)

    Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A®, propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A®:Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10–1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. Corexit 9500A® and oil are similar in their toxicity. However, when Corexit 9500A® and oil are mixed, toxicity to B. manjavacas increases up to 52-fold. Extrapolating these results to the oil released by the Macondo well, suggests underestimation of increased toxicity from Corexit application. We found small differences in sensitivity among species of the B. plicatilis species complex, likely reflecting phylogenetic similarity. Just 2.6% of the water-accommodated fraction of oil inhibited rotifer cyst hatching by 50%, an ecologically significant result because rotifer cyst in sediments are critical resources for the recolonization of populations each Spring. - Highlights: ► We determined LC50's of Corexit 9500A®, propylene glycol, and oil to B. plicatilis. ► Corexit 9500A® and oil are equivalent in toxicity. ► When Corexit 9500A® and oil are mixed, toxicity increases 52-fold to B. plicatilis. ► Results suggest underestimation of increased toxicity due to Corexit application. ► Sensitivity differences are small among species of the B. plicatilis species complex. - Using Brachionus plicatilis acute toxicity tests we estimated Corexit 9500A® and oil toxicity. When these compounds are mixed a 52-fold increase in toxicity was observed.

  6. Cholinergic neuromuscular junctions in Brachionus calyciflorus and Lecane quadridentata (Rotifera:Monogononta)

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    Ignacio Alejandro Prez-Legaspi; Alma Lilin Guerrero-Barrera; Ivn Jos Galvn-Mendoza; Jos Luis Quintanar; Roberto Rico-Martnez

    2014-01-01

    Objective:To identify the presence of joint muscular and cholinergic systems in two freshwater rotifer species, Brachionus calyciflorus and Lecane quadridentata. Methods: The muscle actin fibers were stained with phalloidin-linked fluorescent dye, and acetylcholine was detected with Amplex Red Acetylcholine/Acetylcholinesterase Assay Kit, and then confocal scanning laser microscopy was used. Results:The musculature of Brachionus calyciflorus showed a pattern similar to other species of the same genus, while that of Lecane quadridentata was different from other rotifer genera described previously. The cholinergic system was determined by co-localization of both muscles and acetylcholine labels in the whole rotifer, suggesting the presence of neuromuscular junctions. Conclusions: The distribution pattern of muscular and acetylcholine systems showed considerable differences between the two species that might be related to different adaptations to particular ecological niches. The confirmation of a cholinergic system in rotifers contributes to the development of potential neuro-pharmacological and toxicological studies using rotifers as model organism.

  7. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    International Nuclear Information System (INIS)

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green® analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  8. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

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    Alvarado-Flores, Jesus, E-mail: jalvaflo@hotmail.com [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Ventura-Juarez, Javier, E-mail: jventur@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Morfologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Silva-Briano, Marcelo, E-mail: msilva@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Biologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rubio-Franchini, Isidoro, E-mail: rubio_reyes@hotmail.com [Instituto de Servicios de Salud del Estado de Aguascalientes, Laboratorio Estatal de Salud Publica, Av. Siglo XXI 105, Ciudad Satelite Morelos, C.P. 20270, Aguascalientes, Ags. (Mexico)

    2012-03-15

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green{sup Registered-Sign} analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  9. Brachionidae (Rotifera: Monogononta de la albufera El Paraíso y el reporte de Brachionus ibericusen el Perú

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    Emily Toscano

    2013-12-01

    Full Text Available En este trabajo se reportan las especies de Brachionidae reconocidos en las muestras recogidas en octubre de 2010 en la albufera Laguna El Paraiso, Huacho (11°13' −11° 10'S, 77° 35' −77°40'W. Cinco especies fueron determinadas: Keratella tropica, Brachionus quadridentatus, B. urceolaris, B. angularis y B. ibericusCiros-Pérez 2001. Este último es un nuevo reporte para el Perú y amplía su distribución a nivel mundial.

  10. Light-dependent transcriptional events during resting egg hatching of the rotifer Brachionus manjavacas.

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    Kim, Hee-Jin; Suga, Koushirou; Kim, Bo-Mi; Rhee, Jae-Sung; Lee, Jae-Seong; Hagiwara, Atsushi

    2015-04-01

    Rotifer resting eggs often have to endure harsh environmental conditions during the diapause phase. They are stimulated by light to hatch. In order to study the hatching mechanism, we observed resting eggs and measured their transcriptional expression under different light exposure periods (total darkness, and after 30 min, and 4h light). By using differential-display reverse transcription PCR (DDRT-PCR), we isolated 80 genes that displayed different expression patterns in response to the three light treatments: 20 genes were expressed in total darkness, 40 different genes were differentially expressed under 30 min light, and 20 further genes were expressed after 4h of light. The resting eggs showed no phenotypic differences in embryonic development during the 4h illumination period. In general, the expression patterns of the analyzed genes in resting eggs were differentially modulated by light exposure time. In total darkness, resting eggs mainly expressed genes encoding cell defense and homeostasis functions. In the 30 min illumination group, we found enriched expression of genes encoding fatty acid metabolism-related components, including Acyl-CoA dehydrogenase (ACAD). Genes encoding cellular and embryonic developmental functions were highly observed in the 30 min-illuminated group but were not observed in the 4h-illuminated group. Real-time RT-PCR revealed that several transcripts such as encoding V-type H(+)-translocating pyrophosphatase (V-PPase) and Meckelin had prolonged expression levels when exposed to light for 4h. In the 4h illuminated group, the RecQ protein-like 5 (RECQL5) gene was enriched. This RECQL5 gene may be expressed to protect the developing embryo from continuous light exposure. The data presented in this study indicate that DDRT-PCR-aided gene screening can be helpful to isolate candidate genes involved in the hatching process. PMID:25703093

  11. Zooplankton from a polluted river, Mula (India, with record of Brachionus rubens (Ehrenberg, 1838 epizoic on Moina macrocopa (Straus, 1820

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    Vanjare, A.I.

    2010-06-01

    Full Text Available Rotifera and Cladocera are free living zooplankton elements known to dominate freshwater habitats. Few rotifersare known to be parasitic and epizoic living in association with other organisms. Zooplankton from the polluted river Mula, Pune,Maharashtra was sampled from January to November 2009. Eighteen rotifers and ten cladocerans were recorded during the study.Samples revealed rotifer Brachionus rubens (Ehrenberg, 1838 epizoic on cladoceran Moina macrocopa (Straus, 1820, theoccurrence of which coincided with lower dissolved oxygen (DO content. The rotifers Asplanchnopus multiceps (Schrank,1793, Lacinularia elliptica (Shephard, 1897 and the cladoceran Kurzia longirostris (Daday, 1898 are new records to Maharashtrastate. The present study was an attempt to monitor a polluted habitat for zooplankton fauna. Detailed studies onorganically polluted eutrophic habitats could add new insights into zooplankton diversity and behaviour.

  12. Rotifer assemblages (Rotifera: Eurotatoria of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

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    Bhushan Kumar Sharma

    2014-12-01

    Full Text Available Our plankton and semi-plankton collections from twelve floodplain lakes (beels of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families; these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of  genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region.  Eleven species are new to the study area and we provide an updated list (144 species for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12 species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index, more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters.

  13. Effects of sexual reproduction of the inferior competitor Brachionus calyciflorus on its fitness against Brachionus angularis

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    Li, Chen; Niu, Cuijuan

    2015-03-01

    Sexual reproduction adversely affects the population growth of cyclic parthenogenetic animals. The density-dependent sexual reproduction of a superior competitor could mediate the coexistence. However, the cost of sex may make the inferior competitor more vulnerable. To investigate the effect of sexual reproduction on the inferior competitor, we experimentally paired the competition of one Brachionus angularis clone against three Brachionus calyciflorus clones. One of the B. calyciflorus clones showed a low propensity for sexual reproduction, while the other two showed high propensities. The results show that all B. calyciflorus clones were excluded in the competition for resources at low food level. The increased food level promoted the competition persistence, but the clones did not show a clear pattern. Both the cumulative population density and resting egg production increased with the food level. The cumulative population density decreased with the mixis investment, while the resting egg production increased with the mixis investment. A trade-off between the population growth and sexual reproduction was observed in this research. The results indicate that although higher mixis investment resulted in a lower population density, it would not determinately accelerate the exclusion process of the inferior competitor. On the contrary, higher mixis investment promoted resting egg production before being excluded and thus promised a long-term benefit. In conclusion, our results suggest that mixis investment, to some extent, favored the excluded inferior competitor under fierce competition or some other adverse conditions.

  14. Ingestion of Brachionus plicatilis under different microalgae conditions

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    Zhou, Wenli; Tang, Xuexi; Qiao, Xiuting; Wang, You; Wang, Renjun; Feng, Lei

    2009-09-01

    The effects of four microalgae, Chlorella vulgaris, Platymonas helgolandicavar, Isochrysis galbana, and Nitzschia closterium on the grazing and filtering rates of the marine rotifer, Brachionus plicatilis, were evaluated under laboratory conditions. The grazing rates in separate cultures of the four microalga were as follows: C. vulgaris > P. helgolandicavar > I. galbana > N. closterium. However, the filtering rates occurred in the following order: P. helgolandicavar > N. closterium > C. vulgaris > I. galbana. A mixed diets experiment revealed that P. helgolandicavar was the preferred diet of B. plicatilis. In addition, the grazing rate of B. plicatilis increased gradually as the density of the microalgae increased, until concentrations of 2.5×106 cells mL-1 for C. vulgaris and 1.5×106 cells mL-1 for I. galbana were obtained. Furthermore, the filtering rate increased slightly when the density of the microalgae was low, after which it declined as the microalgal density increased. The grazing rates of B. plicatilis were as follows during the different growth phases: stationary phase > exponential phase > lag phase > decline phase. Additionally, the filtering rates during the growth phases were: exponential phase > lag phase > stationary phase > decline phase. The results of this study provide foundational information that can be used to explore the optimal culture conditions for rotifers and to promote the development of aquaculture.

  15. Ingestion of Brachionus plicatilis under different microalgae conditions

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wenli; TANG Xuexi; QIAO Xiuying; WANG You; WANG Renjun; FENG Lei

    2009-01-01

    The effects of four microalgae, Chlorella vulgaris, Platymonas helgolandicavar, Isochrysis galbana, and Nitzschia closterium on the grazing and filtering rates of the marine rotifer, Brachionus plicatilis, were evaluated under laboratory conditions. The grazing rates in separate cultures of the four microalga were as follows: C. vulgaris > P. helgolandicavar > I. galbana > N. closterium. However, the filtering rates occurred in the following order: P. helgolandicavar > N. closterium > C. vulgaris > I. galbana. A mixed diets experiment revealed that P. helgolandicavar was the preferred diet of B. plicatilis. In addition, the grazing rate of B. plicatilis increased gradually as the density of the microalgae increased, until concentrations of 2.5×106 cells mL-1 for C. vulgaris and 1.5×106 cells mL-1 for I. galbana were obtained. Furthermore, the filtering rate increased slightly when the density of the microalgae was low, after which it declined as the microalgal density increased. The grazing rates of B. plicatilis were as follows during the different growth phases: stationary phase > exponential phase > lag phase > decline phase. Additionally, the filtering rates during the growth phases were: exponential phase > lag phase > stationary phase > decline phase. The results of this study provide foundational information that can be used to explore the optimal culture conditions for rotifers and to promote the development of aquaculture.

  16. The diversity of Indian Brachionidae (Rotifera: Eurotatoria: Monogononta and their distribution

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    B.K. Sharma

    2014-11-01

    Full Text Available We evaluate diversity status of the Brachionidae of India and present an annotated checklist of 46 species excluding dubious and unconfirmed reports. These merit biodiversity value as ~27% of the global diversity of the taxon and ~81% of its Oriental species. We observed two Australasian elements, two Oriental endemics, one Indian endemic, one paleotropical and one cosmo (sub tropical species. The cold-water Keratella serrulata and Notholca squamula are new records from eastern Himalayas. Maximum brachionid diversity (32 species from Assam state of northeast India (NEI is followed by the reports of 27 and 26 species from Tamil Nadu and West Bengal, respectively; 25 species each from Tripura and Maharashtra; and 24 species from Jammu & Kashmir. Brachionus, the most diverse brachionid genus, is widely distributed in India with low richness in hill states of NEI and coastal waters in particular. The Indian brachionid taxonomy is confounded with unconfirmed reports, misidentifications, invalid taxa, and inconsistent treatment of morphological variants, while analysis of cryptic diversity in Brachionus calyciflorus, B. caudatus, B. forficula, B. plicatilis, B. quadridentatus, B. urceolaris, Keratella cochlearis and K. quadrata species-groups awaits attention.

  17. Effects of coal ash pollution on the genetic diversity of Brachionus calyciflorus based on rDNA ITS sequences

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    Xinli Wen; Xianling Xiang; Xin Hu; Yinghao Xue; Yilong Xi; Gen Zhang

    2010-01-01

    In this study, rDNA ITS sequences were analyzed to compare the genetic diversity of Brachionus calyciflorus from the coal ash contaminated (Lake Hui) and two uncontaminated lakes (Lake Tingtang and Lake Fengming). The results showed that two sibling species in Brachionus calyciflorus species complex were defined in both Lake Tingtang and Lake Fengming, but only one sibling species was found in Lake Hui. The coal ash pollution decreased the number of sibling species. Based on the sequences of ...

  18. Peningkatan EPA dan DHA Rotifer (Brachionus plicatilis) oleh Bacillus sp. dengan Periode Pengkayaan Berbeda

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    Budi, Sutia; Zainuddin; Aslamyah, Siti

    2012-01-01

    Brachionus plicatilis memiliki beberapa kelebihan dibanding dengan pakan alami lainnya, seperti ukurannya yang relatif kecil, tetap bertahan di kolom air dan tidak mengendap, bergerak dengan kecepatan yang rendah dan laju perkembangbiakan yang cukup tinggi, merupakan pakan alami yang banyak dipergunakan usaha pembenihan. Penelitian ini bertujuan untuk melihat pengaruh pengkayaan dengan menambahkan Bacillus sp. Pada media kultur terhadap EPA dan DHA Nannochloropsis sp. dengan kepadatan 105 ce...

  19. Relative importance of the trophic and direct pathways on PCB contamination in the rotifer species Brachionus calyciflorus (Pallas)

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    Joaquim-Justo, Célia; Gosselain, V; Descy, Jean-Pierre; Thomé, Jean-Pierre

    1995-01-01

    To determine the contribution of food ingestion (trophic pathway) to PCB contamination of zooplankton in the river Meuse (Belgium), we used 14 C-labelled algae (Dictyosphaerium ehrenbergianum) to measure ingestion and assimilation rates in the rotifer species Brachionus calyciflorus . When the concentration of algae in the culture medium varied from 20 103 to 200 103 algal cells ml -1 (0.12 to 1 .18 mg C 1 - '), the Brachionus calyciflorus ingestion rate varied from 0 .25 ± 0 .12 to 1 .52 ± 0...

  20. Effect of the lecanidae rotifera on the floc size in an activated sludge system; Efecto de rotiferos lecanidos en el tamano de los floculos de un sistema de fangos activos

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    Puigagut, J.; Salvado, H.; Tarrats, X.; Garcia, J.

    2008-07-01

    An activated sludge pilot plant was monitored for 5 months in order to determine the effect of the lecanidae rotifera on both the floc size and the nitrogen removal. Results show that rotifera abundances above 400 individuals/ml{sup -}1 produce a reduction of ca. 50% of the floc average surface. This floc area reduction had, in turn, a great significance on the nitrogen removal efficiency, either in terms of ammonia or nitrates. (Author) 20 refs.

  1. New records of rotifers (Rotifera: Eurotatoria from Deepor Beel - a Ramsar site of India with an update on its rich rotifer diversity.

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    B.K. Sharma

    2015-03-01

    Full Text Available Plankton samples collected from Deepor Beel (a Ramsar site, during July 2011 to June 2013, revealed 155 species of Rotifera, belonging to 35 genera and 20 families.  Of these, 16 species belonging to eight genera and seven families are new records to the rotifer fauna of this wetland of northeast India.  Our observations raise the total richness of the phylum known till date from this important floodplain lake (beel of the Brahmaputra river basin to 171 species and thus highlight its biodiversity value as one of the globally rich Rotifera habitats.  The updated list is interesting for following meta-analyses of rotifer occurrence in this only well sampled freshwater ecosystem of the Indian sub-region. 

  2. Application of rotifer Brachionus plicatilis in detecting the toxicity of harmful algae

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    Yan, Tian; Wang, Yunfeng; Wang, Liping; Chen, Yang; Han, Gang; Zhou, Mingjiang

    2009-05-01

    The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae.

  3. Effect of UV- B radiation on the feeding behavior of the rotifer Brachionus plicatilis

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    FENG Lei; LI Xin; WANG Jinhe; HAN Honglei; TANG Xuexi; CHEN Xiguang

    2007-01-01

    Effect of UV - B radiation on the feeding behaviour of marine zooplankton is important to assessing the health harm of marine ecosystem due to the gradually enhanced UV - B radiation in air. However, there are a few studies on this topic. The feeding behavior of the rotifer, Brachionus plicatilis, under the treatment of UV - B radiation on five species of microalgae, i. e. , Chlorella sp. ,Tetraselmis chuii, Isochrysis galbana Park 8701, Chaetoceros muelleri Lermumerman, and Nitzschia clostertum, was studied. The results showed that the filtering and feeding rates of the rotifer decreased significantly with the dose increase of UV - B radiation when fed with five species of microalgae respectively (P < 0.05 ) which indicates UV - B radiation inhibits the feeding activities of the rotifer on microalage. The mixed culture experiments shows the rotifer preferred to feed Chlorella sp. , then C. muelleri, I.galbana, N. clostertum and T. chuii in turn if without UV - B radiation. Under the highest dose of UV - B radiation treatment (2.70 kJ/m2) , the rotifer preferred to feed C. muelleri, then Chlorella sp. , N. clostertum, I. galbana and T. chuii in turn.Chlorella sp. , I. galbana and C. muelleri became the more favorite foods of the rotifer while T. chuii and N. clostertum became less favorite foods. The change of feeding rate and feeding selectivity of zooplankton driven by the enhanced UV - B radiation will lead to the change in the structure of phytoplankton community.

  4. Effects of diet on population development of the rotifer Brachionus plicatilis in culture

    Science.gov (United States)

    Planas, M.; Estévez, A.

    1989-06-01

    Experiments were conducted in order to observe the effect of five diets on the population development of the rotifer Brachionus plicatilis Müller under laboratory conditions. Diets were based on baker’s yeast ( Saccharomyces cerevisiae) and the algae Tetraselmis suecica and Isochrysis galbana, mixed, or as simple diets. Growth rates, fecundity and biometric parameters were studied for 15 days. The cultures were divided in a logarithmic phase and a harvesting phase. Rotifers fed on Tetraselmis, alone or mixed with yeast or Isochrysis, gave good performances with the best results in all the parameters studied. Average growth rates in all diets were similar during the exponential phase, with values ranging from 0.72 ( Tetraselmis and Tetraselmis + yeast) to 0.47 (yeast). During the harvesting phase there were high differences between diets, with rates highly reduced in the yeast-group (0.17) and good rates when Tetraselmis was ingested (0.65 0.51). This alga had a positive influence on the rotifers, increasing individual growth and fecundity.

  5. Induction of hsp60 in the rotifer, Brachionus plicatilis exposed to dispersed and undispersed crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Wheelock, C.; Tjeerdema, R.; Wolfe, M. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry

    1995-12-31

    The use of chemical dispersants to treat oil spills remains a controversial area. Questions arise as to whether the dispersed oil is in fact more toxic than the original spill, potentially increasing the exposure of organisms in the water column to the dispersed components. Stress proteins, including hsp60, are a group of highly conserved proteins that are induced in response to a wide variety of environmental agents, including UV light, heavy metals, and xenobiotics. They are constitutively expressed, but Brachionus plicatilis has been used to document increased hsp60 levels in response to different environmental stresses. Hsp60 was therefore selected as a sublethal endpoint for B. plicatilis exposed to a range of concentrations of a water accommodated fraction (WAF) of Prudhoe Bay Crude Oil (PBCO), a PCBO/dispersant (Corexit 9527) fraction and a mixture of Corexit 9527 alone. All exposures were done at concentrations below the no observable effect level (NOEL) and at two different salinities, 22 ppt and 34 ppt. Laemmli SDS-PAGE techniques followed by Western Blotting using hsp60 specific antibodies and chemiluminescent detection were used to isolate, identify and measure induced hsp60 as a percentage of control values. Hsp60 induction exhibited a biphasic response with maximal induction occurring at lower concentrations of all three different mixtures, WAF, PBCO/Corexit 9527, and Corexit 9527 alone. Preliminary data found that the dispersed oil is indeed more toxic in terms of hsp60 induction than both the undispersed oil and the dispersing agent alone.

  6. Application of rotifer Brachionus plicatilis in detecting the toxicity of harmful algae

    Institute of Scientific and Technical Information of China (English)

    YAN Tian; WANG Yunfeng; WANG Liping; CHEN Yang; HAN Gang; ZHOU Mingjiang

    2009-01-01

    The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P.donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae.

  7. Morphology and ultrastructure of the freshwater rotifer Brachionus bidentatus (Monogononta: Brachionidae) using scanning and transmission electron microscopy.

    Science.gov (United States)

    Guerrero-Jiménez, Gerardo; Zavala-Padilla, Guadalupe; Silva-Briano, Marcelo; Rico-Martínez, Roberto

    2013-12-01

    The study of sexual reproductive behavior supported by ultrastructural evidence is important in rotifers to describe differences among potential cryptic species. In this research, the morphology of the rotifer Brachionus bidentatus is described at the ultrastructural level, using electronic microscopy, together with a brief description and discussion of its sexual reproductive behavior. The characteristics of the (a) male, (b) the female, (c) the sexual egg or cyst, (d) the partenogenic egg, (e) the no-fecundated sexual egg (male egg), and (f) the trophi, were described. Another part of this research is dedicated to the ultrastructure of the sex cells of the male rotifer B. bidentatus. Samples were obtained from La Punta pond in Cosio, Aguascalientes, Mexico (22 degrees 08' N - 102 degrees 24' W), and a culture was maintained in the laboratory. Fifty organisms, from different stages of the rotifer Brachionus bidentatus, were fixed in Formol at 4% and then prepared; besides, for the trophi, 25 female rotifer Brachionus bidentatus were prepared for observation in a JEOL 5900 LV scanning electronic microscope. In addition, for the observation of male sex cells, 500 males of Brachionus bidentatus were isolated, fixed and observed in a JEOL 1010 transmission microscope. Females of B. bidentatus in laboratory cultures had a lifespan of five days (mean+one SD = 4.69 +/- 0.48; N=13), and produced 4.5 +/- 3.67 (N=6) parthenogenetic eggs during such lifespan. In the case of non-fertilized sexual eggs, they produced up to 18 eggs (mean+one SD = 13 +/- 4.93; N=7). Sexual females produced a single cyst on average (mean +/- one SD = I +/- 0; N=20). For the sexual cycle, the time of copulation between male and female ranged from 10 to 40 seconds (mean +/- one SD = 17.33 +/- 10.55, N=7). The spermatozoa are composed of a celular body and a flagellum, the size of the body is of 300 nm while the flagellum measures 1 700nm. The rods have a double membrane. Their mean length is almost

  8. Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

    DEFF Research Database (Denmark)

    Steenfeldt, Svend Jørgen; Nielsen, Johan W.

    2010-01-01

    holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L−1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L−1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis...... down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe...

  9. Impact of three phthalate esters on the sexual reproduction of the Monogonont rotifer, Brachionus calyciflorus.

    Science.gov (United States)

    Cruciani, V; Iovine, C; Thomé, J-P; Joaquim-Justo, C

    2016-01-01

    Phthalate esters are widespread contaminants that can cause endocrine disruption in vertebrates. Studies showed that molecules with hormonal activities in vertebrates and invertebrates can affect asexual and sexual reproduction in rotifers. We investigated the impact of di-hexylethyl phthalate (DEHP), di-butyl phthalate (DBP) and butylbenzyl phthalate (BBP), on the asexual and sexual reproduction of the freshwater monogonont rotifer Brachionus calyciflorus in order to determine a potential environmental risk for sexual reproduction. We observed that DEHP has no significant impact on both asexual and sexual reproduction up to 2 mg/L. DBP has a positive effect on asexual reproduction at concentrations from 0.05 to 1 mg/L, but depresses it at 2 mg/L. Sexual reproduction is only affected at 2 mg/L and the impact observed is negative. BBP displayed a negative impact on both asexual and sexual reproduction at 1 and 2 mg/L. However we showed that the impacts of BBP on mixis and fertilization rates observed are due to the decrease in population growth rates at these concentrations and not to a direct impact of BBP on the mixis and the fertilization processes. Our results show that sexual reproduction in B. calyciflorus is not more sensitive than asexual reproduction to any of the substances tested which indicates the mode of action of these molecules is related to general toxicity and not to an interference with potential endocrine regulation of sexual reproduction. Comparison of effect concentrations and surface water contamination by phthalate esters suggests these compounds do not constitute a risk for primary consumers in these environments. PMID:26666431

  10. Long-term survival of hydrated resting eggs from Brachionus plicatilis.

    Directory of Open Access Journals (Sweden)

    Melody S Clark

    Full Text Available BACKGROUND: Several organisms display dormancy and developmental arrest at embryonic stages. Long-term survival in the dormant form is usually associated with desiccation, orthodox plant seeds and Artemia cysts being well documented examples. Several aquatic invertebrates display dormancy during embryonic development and survive for tens or even hundreds of years in a hydrated form, raising the question of whether survival in the non-desiccated form of embryonic development depends on pathways similar to those occurring in desiccation tolerant forms. METHODOLOGY/PRINCIPAL FINDINGS: To address this question, Illumina short read sequencing was used to generate transcription profiles from the resting and amictic eggs of an aquatic invertebrate, the rotifer, Brachionus plicatilis. These two types of egg have very different life histories, with the dormant or diapausing resting eggs, the result of the sexual cycle and amictic eggs, the non-dormant products of the asexual cycle. Significant transcriptional differences were found between the two types of egg, with amictic eggs rich in genes involved in the morphological development into a juvenile rotifer. In contrast, representatives of classical "stress" proteins: a small heat shock protein, ferritin and Late Embryogenesis Abundant (LEA proteins were identified in resting eggs. More importantly however, was the identification of transcripts for messenger ribonucleoprotein particles which stabilise RNA. These inhibit translation and provide a valuable source of useful RNAs which can be rapidly activated on the exit from dormancy. Apoptotic genes were also present. Although apoptosis is inconsistent with maintenance of prolonged dormancy, an altered apoptotic pathway has been proposed for Artemia, and this may be the case with the rotifer. CONCLUSIONS: These data represent the first transcriptional profiling of molecular processes associated with dormancy in a non-desiccated form and indicate important

  11. Toxicity of triphenyltin chloride to the rotifer Brachionus koreanus across different levels of biological organization.

    Science.gov (United States)

    Yi, Andy Xianliang; Han, Jeonghoon; Lee, Jae-Seong; Leung, Kenneth M Y

    2016-01-01

    Although triphenyltin (TPT) compounds are ubiquitous pollutants in urbanised coastal environments in Asian regions, their toxicities to marine organisms are still poorly known. This study was designed to investigate the toxicity of triphenyltin chloride (TPTCl) on the rotifer Brachionus koreanus across different levels of biological organisation. Firstly, we concurrently performed a 24 h static-acute toxicity test and a 6-day semi-static multigenerational life-cycle test using the rotifer. Our results demonstrated that the 24-h median lethal concentration of TPTCl for the rotifer was 29.6 μg/L and the 6-day median effect concentration, based on the population growth inhibition, was 3.31 μg/L. Secondly, we examined the expression of 12 heat shock protein (hsp) genes, four glutathione S-transferase (GST) genes, one retinoid X receptor (RXR) gene and 13 cytochrome P450 (CYP) genes in the rotifers after exposure to 20 µg/L TPTCl for 24 h. Among these studied genes, hsp90α2, GST-O and CYP3045C1 were the most significantly up-regulated genes with a relative expression level up to 32.9, 4.4 and 62.6 folds, respectively. The expression of these three genes in the rotifers showed an increasing trend in the first few hours of TPTCl exposure, peaked at 3 h (hsp90α2 and GST-O) and 12 h (CYP3045C1) respectively, and then gradually returned to a lower level at 24 h. Such up-regulations of hsp and GST genes probably offer cellular protection against the TPT-mediated oxidative stress while the accelerated induction of CYP genes possibly facilitates the detoxification of this toxicant in the rotifer. PMID:25045140

  12. Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis.

    Directory of Open Access Journals (Sweden)

    Koushirou Suga

    Full Text Available BACKGROUND: Rotifers are among the most common non-arthropod animals and are the most experimentally tractable members of the basal assemblage of metazoan phyla known as Gnathifera. The monogonont rotifer Brachionus plicatilis is a developing model system for ecotoxicology, aquatic ecology, cryptic speciation, and the evolution of sex, and is an important food source for finfish aquaculture. However, basic knowledge of the genome and transcriptome of any rotifer species has been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We generated and partially sequenced a cDNA library from B. plicatilis and constructed a database of over 2300 expressed sequence tags corresponding to more than 450 transcripts. About 20% of the transcripts had no significant similarity to database sequences by BLAST; most of these contained open reading frames of significant length but few had recognized Pfam motifs. Sixteen transcripts accounted for 25% of the ESTs; four of these had no significant similarity to BLAST or Pfam databases. Putative up- and downstream untranslated regions are relatively short and AT rich. In contrast to bdelloid rotifers, there was no evidence of a conserved trans-spliced leader sequence among the transcripts and most genes were single-copy. CONCLUSIONS/SIGNIFICANCE: Despite the small size of this EST project it revealed several important features of the rotifer transcriptome and of individual monogonont genes. Because there is little genomic data for Gnathifera, the transcripts we found with no known function may represent genes that are species-, class-, phylum- or even superphylum-specific; the fact that some are among the most highly expressed indicates their importance. The absence of trans-spliced leader exons in this monogonont species contrasts with their abundance in bdelloid rotifers and indicates that the presence of this phenomenon can vary at the subphylum level. Our EST database provides a relatively large quantity of transcript

  13. Temperature Effect on the Life History of Three Types of Brachionus calyciflorus Females

    Institute of Scientific and Technical Information of China (English)

    席贻龙; 黄祥飞

    2004-01-01

    The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated individual cultures at 20℃,25℃ and 30℃, and with algae Scenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cycle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20℃, were the longest, and the number of eggs produced by an UMF at 30℃ was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF. Only temperature influenced significantly the mean life-span of the three types of females. The duration of juvenile, reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF.

  14. Effects of Environmental Factors on Growth of Brachionus plicatilis tipicus and Brachionus plicatilis rotundiformis%环境因子对L型、S型褶皱臂尾轮虫生长的影响

    Institute of Scientific and Technical Information of China (English)

    黄翔鹄; 李长玲; 刘楚吾; 郑凤锦; 徐志雄

    2005-01-01

    在实验室条件下,通过种群累积培养的方法,研究了不同盐度和小球藻(Chorella vulgaris)、亚心形扁藻(Platymonas subcordiformis)、微绿球藻(Nannochloris oculata)、波吉卵囊藻(Oocystis borgei)等不同饵料微藻对L型褶皱臂尾轮虫(Brachionus Plicatilis tipicus)和S型褶皱臂尾轮虫(Brachionus Plicatilis rotundiformis)生长的影响,探讨这两种轮虫在生态条件上的差异.结果表明:L型和S型褶皱臂尾轮虫对盐度的适应有显著的差异,生长的最适盐度分别为15和20,大水体培养时,其适宜生长的盐度范围分别是15~20和10~30.饵料微藻对L型和S型褶皱臂尾轮虫生长的影响一致.小球藻培养效果在4种饵料微藻中最好,其生长率明显高于微绿球藻和亚心形扁藻,波吉卵囊藻培养效果较差.

  15. Efficacy of a commercial probiotic relative to oxytetracycline as Gram-negative bacterial control agents in a rotifer (Brachionus plicatilis) batch culture

    Science.gov (United States)

    Two trials were conducted to evaluate two gram-negative bacterial control strategies in batch cultures of the rotifer Brachionus plicatilis. In the first trial, rotifers at an initial density of 47/mL were cultured for 5 d and dosed with a 10-mg/L solution of either oxytetracycline or a commercial p...

  16. Catalogue of type specimens of invertebrates in the collection of the Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil: I. Acanthocephala, Nematoda, and Rotifera Catálogo dos espécimes-tipo de invertebrados da coleção do Instituto Nacional de Pesquisas da Amazônia, Manaus, Brasil: I. Acanthocephala, Nematoda e Rotifera

    Directory of Open Access Journals (Sweden)

    Célio Magalhães

    2006-09-01

    Full Text Available The catalogue of type specimens of the phyla Acanthocephala, Nematoda and Rotifera deposited in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brazil, is presented and updated to July, 2005. A total of three holotypes and six lots of paratypes of three species of Acanthocephala; nine holotypes and 16 lots of paratypes of nine species of Nematoda; and 12 holotypes, six lectotypes, nine lots of paratypes and five lots of paralectotypes of 23 species and subspecies of Rotifera are listed. Specific and subspecific names are listed alphabetically within family, followed by bibliographic citation, original genus name, status of type, collection number, locality data (host and site of infection for parasitic species, and remarks where appropriate. A list of references containing the papers in which the taxa were first described is furnished.É apresentado o catálogo dos espécimes-tipo dos filos Acanthocephala, Nematoda e Rotifera depositados na Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brasil, atualizado até julho de 2005. É relacionado um total de três holótipos e seis lotes de parátipos de três espécies de Acanthocephala; nove holótipos e 16 lotes de parátipos de nove espécies de Nematoda; e 12 holótipos, seis lectótipos, nove lotes de parátipos e cinco lotes de paralectótipos de 23 espécies e subespécies de Rotifera. São listados alfabeticamente em cada família os nomes das espécies e subespécies, seguidos da citação bibliográfica, nome original do gênero, categoria do tipo, número de registro na coleção, dados de localidade (hospedeiro e sítio de infecção no caso de espécies parasitas e comentários quando pertinentes. São relacionados, na lista de referências, os artigos nos quais a descrição original dos táxons foi publicada.

  17. STUDY ON MIXIS POTENTIAL OF ROTIFER RESTING EGGS (BRACHIONUS PLICATILIS) WITH DIFFERENT COLLECTION TIMES AND DIFFERENT PRESERVATION PERIODS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985-1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

  18. STUDY ON MIXIS POTENTIAL OF ROTIFER RESTING EGGS( BRACHIONUS PLICATILIS ) WITH DIFFERENT COLLECTION TIMES AND DIFFERENT PRESERVATION PERIODS

    Institute of Scientific and Technical Information of China (English)

    周利; 郑严; 相建海

    2001-01-01

    The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985 - 1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

  19. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator Growth in Chlorella kessleri (Prey Mass Cultures for Algae Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Vishnupriya Pradeep

    2015-08-01

    Full Text Available A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II. The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm had no effect on downstream fatty acid methyl ester extraction.

  20. Study on feeding ecology of rotifer Brachionus urceus%壶状臂尾轮虫摄食生态的实验研究

    Institute of Scientific and Technical Information of China (English)

    冯蕾; 王进河; 唐学玺

    2009-01-01

    研究了壶状臂尾轮虫(Brachionus urceus)在不同的温度、盐度、饵料种类、pH和光照条件下滤水率(F)和摄食率(G)的变化情况.结果表明:(1)温度对壶状臂尾轮虫的摄食有显著影响(P>小球藻(Chlorella sp.)>牟氏角毛藻(Chaetoceros muelleri Lermumerman)>金藻8701(Isochrysis galbana Park 8701)>扁藻(Tetraselmis chuii);G的顺序为:小球藻>小新月菱形藻>金藻8701>牟氏角毛藻>扁藻;(4)壶状臂尾轮虫适宜的摄食pH范围为6.0~8.0,最适摄食pH为7.0; (5)在条件允许的情况下,黑暗有利于壶状臂尾轮虫的摄食.%The filtering and feeding rate of rotifer Brachionus urceus were studied under different temperature, salinity, food species, pH and light. The results showed that the filtering rate (F) and feeding rate (G) were significantly affected by temperature and salinity. The suitable temperature and salinity for feeding of Brachionus urceus ranged from 25℃ to 30℃ and from 20 to 30, the optimal temperature and salinity were 25℃ and 30. The filtering and feeding rate of Brachionus urceus for 5 strains of microalgae showed a declining gradient of Chaetoceros muelleri Lermumerman > Nitzschia clostertum > Isochrysis galbana Park 8701 >Chlorella sp. > Tetraselmis chuii and Chlorella sp. > Isochrysis galbana Park 8701 >Chaetoceros muelleri Lermumerman > Nitzschia clostertum > Tetraselmis chuii. The suitable pH for feeding of Brachionus urceus ranged from 6.0 to 8.0 and the optimal pH for feeding was 7.0. The darkness was suitable for feeding of rotifer Brachionus urceus.

  1. Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeonghoon; Won, Eun-Ji [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Il-Chan; Yim, Joung Han [Division of Life Sciences, Korea Polar Research Institute, Incheon 406-840 (Korea, Republic of); Lee, Su-Jae [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-10-15

    Highlights: • No mortality within 96 h even at a high intensity (1200 Gy). • A reduced fecundity of Brachionus koreanus at over 150 Gy with a decrease in lifespan. • Dose-dependent ROS increase with GST enzyme activity at sub-lethal doses. • Significant impact on life table parameters, particularly fecundity. • Significant up-regulation of DNA repair-associated genes at sublethal doses. - Abstract: To examine the effects of gamma radiation on marine organisms, we irradiated several doses of gamma ray to the microzooplankton Brachionus koreanus, and measured in vivo and in vitro endpoints including the survival rate, lifespan, fecundity, population growth, gamma ray-induced oxidative stress, and modulated patterns of enzyme activities and gene expressions after DNA damage. After gamma radiation, no individuals showed any mortality within 96 h even at a high intensity (1200 Gy). However, a reduced fecundity (e.g. cumulated number of offspring) of B. koreanus at over 150 Gy was observed along with a slight decrease in lifespan. At 150 Gy and 200 Gy, the reduced fecundity of the rotifers led to a significant decrease in population growth, although in the second generation the population growth pattern was not affected even at 200 Gy when compared to the control group. At sub-lethal doses, reactive oxygen species (ROS) levels dose-dependently increased with GST enzyme activity. In addition, up-regulations of the antioxidant and chaperoning genes in response to gamma radiation were able to recover cellular damages, and life table parameters were significantly influenced, particularly with regard to fecundity. DNA repair-associated genes showed significantly up-regulated expression patterns in response to sublethal doses (150 and 200 Gy), as shown in the expression of the gamma-irradiated B. koreanus p53 gene, suggesting that these sublethal doses were not significantly fatal to B. koreanus but induced DNA damages leading to a decrease of the population size.

  2. Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus

    International Nuclear Information System (INIS)

    Highlights: • No mortality within 96 h even at a high intensity (1200 Gy). • A reduced fecundity of Brachionus koreanus at over 150 Gy with a decrease in lifespan. • Dose-dependent ROS increase with GST enzyme activity at sub-lethal doses. • Significant impact on life table parameters, particularly fecundity. • Significant up-regulation of DNA repair-associated genes at sublethal doses. - Abstract: To examine the effects of gamma radiation on marine organisms, we irradiated several doses of gamma ray to the microzooplankton Brachionus koreanus, and measured in vivo and in vitro endpoints including the survival rate, lifespan, fecundity, population growth, gamma ray-induced oxidative stress, and modulated patterns of enzyme activities and gene expressions after DNA damage. After gamma radiation, no individuals showed any mortality within 96 h even at a high intensity (1200 Gy). However, a reduced fecundity (e.g. cumulated number of offspring) of B. koreanus at over 150 Gy was observed along with a slight decrease in lifespan. At 150 Gy and 200 Gy, the reduced fecundity of the rotifers led to a significant decrease in population growth, although in the second generation the population growth pattern was not affected even at 200 Gy when compared to the control group. At sub-lethal doses, reactive oxygen species (ROS) levels dose-dependently increased with GST enzyme activity. In addition, up-regulations of the antioxidant and chaperoning genes in response to gamma radiation were able to recover cellular damages, and life table parameters were significantly influenced, particularly with regard to fecundity. DNA repair-associated genes showed significantly up-regulated expression patterns in response to sublethal doses (150 and 200 Gy), as shown in the expression of the gamma-irradiated B. koreanus p53 gene, suggesting that these sublethal doses were not significantly fatal to B. koreanus but induced DNA damages leading to a decrease of the population size

  3. TAXAS DE FILTRAÇÃO E INGESTÃO DE UMA MICROALGA POR Philodina roseola (Rotifera: Bdelloidea

    Directory of Open Access Journals (Sweden)

    Raquel Aparecida Moreira

    2016-04-01

    Full Text Available RESUMORotíferos possuem um importante papel nos ciclos biogeoquímicos e na produtividade orgânica dos ecossistemas de água doce em decorrência de suas elevadas taxas metabólicas. Informações sobre a filtração, seu principal processo de aquisição de energia, são relevantes e ainda escassos para a região tropical. Os rotíferos da Subclasse Bdelloidea alimentam-se por filtração ou raspagem consumindo pequenos itens alimentares, como bactérias, algas, leveduras ou matéria orgânica particulada. Sabemos pouco sobre o papel que desempenham na dinâmica trófica dos habitats que ocupam e por isso o objetivo deste estudo foi quantificar em laboratório as taxas de filtração e ingestão do rotífero Philodina roseola, alimentado com Raphidocelis subcapitata. O delineamento experimental consistiu na exposição de 10 rotíferos adultos por tratamento, em cinco concentrações que variaram entre 104 e 107 cels mL-1, mantidos sob temperatura de 25 ± 1 °C. Os experimentos tiveram a duração de 1 hora e as concentrações iniciais e finais da suspensão algal foram quantificadas por contagem numérica das células em câmara de Neubauer. Não foram encontradas diferenças significativas entre as concentrações iniciais e finais de células nos controles indicando não ter ocorrido crescimento algal. As taxas de filtração de P. roseola variaram entre 0,09 e 0,25 mL ind-1 h-1. Tendo em vista que a filtração é o principal processo de aquisição de energia de Philodina roseola, assim como dos demais rotíferos, e que está relacionada a questões importantes da dinâmica trófica dos ecossistemas aquáticos, informações adicionais são desejáveis mas necessitam, no entanto, ser ampliadas para outros tipos de alimento e para diferentes combinações de condições experimentais.Rates of Filtration and Ingestion of a Microalga by Philodina roseola (Rotifera: BdelloideaABSTRACTRotifers play an important role in biogeochemical cycles

  4. Experimental Study on the Interspecific Interactions Between the Two Bloom-Forming Algal Species and the Rotifer Brachionus plicatilis

    Institute of Scientific and Technical Information of China (English)

    XIE Zhihao; XIAO Hui; TANG Xuexi; CAI Hengjiang

    2009-01-01

    The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms (HAB) species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum dong-haiense to support net population increase. With exposure to 2.5×104 cells mL-1 of P. donghaiense, the number of B. plicatilis in-creased faster than it did when exposed to other four algal densities (5, 10, 15 and 20×104 cellsmL-1), and the increase rate of B. plicatilis population (r) at this algal density was 0.104±0.015rd-1. Cell densities ofP. donghaiense decreased due to the grazing of B. plicatilis. In contrast, Heterosigma akashiwo had an adverse effect on B. plicatilis population and its growth was largely unaffected by rotifer grazing. In this case, B. plicatilis population decreased and H. akashiwo grew at a rate similar to that of the control.

  5. Contributions towards a specific DHA enrichment in the live food Brachionus plicatilis and Artemia sp.

    OpenAIRE

    Dhert, Ph.; Sorgeloos, P.; Devresse, B.

    1993-01-01

    This paper reports on enrichment techniques oriented towards a specific DHA accumulation in the live prey Brachionus plicatilis and Artemia sp. The product used in these experiments (DHA7) is an experimental emulsion with a DHA/EPA ratio 6.7:1. Rotifers enriched with this pure DHA7 emulsion contained up to 69 mg/g DW DHA and a DHA/EPA ratio of 1.6. The DHA/EPA ration could be increased to a much higher level by different enrichment techniques. Dilution of the DHA7 emulsion with coconut oil pr...

  6. Impact of several harmful algal bloom (HAB) causing species, on life history characteristics of rotifer Brachionus plicatilis Müller

    Science.gov (United States)

    Lin, Jianing; Yan, Tian; Zhang, Qingchun; Zhou, Mingjiang

    2016-07-01

    In recent years, harmful algal blooms (HABs) have occurred frequently along the coast of China, and have been exhibiting succession from diatom- to dinoflagellate-dominated blooms. To examine the effects of different diatom and dinoflagellate HABs, the life history parameters of rotifers ( Brachionus plicatilis Müller) were measured after exposure to different concentrations of HAB species. The HAB species examined included a diatom ( Skeletonema costatum) and four dinoflagellates ( Prorocentrum donghaiense, Alexandrium catenella, Prorocentrum lima and Karlodinium veneficum). Compared with the control treatment (CT), the diatom S. costatum showed no adverse impacts on rotifers. Exposure to dinoflagellates at densities equivalent to those measured in the field resulted in a reduction in all the life history parameters measured. This included a reduction in: lifetime egg production (CT: 20.34 eggs/ind.) reduced to 10.11, 3.22, 4.17, 7.16 eggs/ind., life span (CT: 394.53 h) reduced to 261.11, 162.90, 203.67, 196 h, net reproductive rate (CT: 19.51/ind.) reduced to 3.01, 1.26, 3.53, 5.96/ind., finite rate of increase (CT: 1.47/d) reduced to 1.16, 1.03, 1.33, 1.38/d, and intrinsic rate of population increase (CT: 0.39/d) reduced to 0.15, 0.03, 0.28, 0.32/d, for the dinoflagellates P. donghaiense, A. catenella, P. lima and K. veneficum, respectively. The results showed that the diatom S. costatum had no detrimental consequences on the reproduction and growth of B. plicatilis, however, the four dinoflagellates tested did show adverse effects. This suggests that dinoflagellate HABs may suppress microzooplankton, resulting in an increase in algal numbers.

  7. Effect of algal food (Chlorella vulgaris concentration and inoculation density on the competition among three planktonic Brachionidae (Rotifera: Monogononta Efecto de la concentración de algas (Chlorella vulgaris y la densidad de inoculación sobre la competencia entre tres Brachionidae (Rotifera: Monogononta planctónicos

    Directory of Open Access Journals (Sweden)

    S.S.S. Sarma

    2008-08-01

    Full Text Available Competitive outcomes among three rotifer species (Anuraeopsis fissa, Brachionus havanaensis and B. angularis were quantified with different inoculation densities of two competing species at a time (0, 25, 50, 75 and 100% and using different algal (Chlorella vulgaris densities (0.2 x 10(6, 0.4 x 10(6 and 0.8 x 10(6 cells ml-1. In control cultures, when each species was grown alone, the population growth of rotifers increased with increasing food availability in the medium, but in mixed cultures, decreased with increasing proportion of the competing species. At low food level, compared to B. havanaensis, B. angularis had stronger negative impact on A. fissa. However, with increasing algal density, both species of Brachionus had similar but reduced impact on A. fissa. Population growth of B. havanaensis was more adversely affected by A. fissa than B. angularis at low and intermediate concentrations. At high food level, the impact of either A. fissa or B. angularis on the growth of B. havanaensis was similar. When grown alone, for a given food density, A. fissa was more numerically (4 to 6 times abundant than the other two species. The rate of population increase (r of rotifers increased with increasing food levels. Depending on the rotifer species and the test conditions, the r varied from -0.001 to 0.34 d-1. Results showed that the competitive outcome in the tested rotifers depended on the initial inoculation density of the competing species, the offered food concentration as well as the interaction of these two factors.Se evaluaron los resultados de la competencia entre tres especies de rotíferos (Anuraeopsis fissa, Brachionus havanaensis y B. angularis usando dos especies a la vez con diferentes densidades de inóculo (0, 25, 50, 75 y 100% y diferentes niveles de alga (Chlorella vulgaris; 0.2 x 10(6, 0.4 x 10(6 y 0.8 x 10(6 células ml-1. En cultivos monoespecíficos, utilizados como control, el crecimiento poblacional de rotíferos aument

  8. The mate recognition protein gene mediates reproductive isolation and speciation in the Brachionus plicatilis cryptic species complex

    Directory of Open Access Journals (Sweden)

    Gribble Kristin E

    2012-08-01

    Full Text Available Abstract Background Chemically mediated prezygotic barriers to reproduction likely play an important role in speciation. In facultatively sexual monogonont rotifers from the Brachionus plicatilis cryptic species complex, mate recognition of females by males is mediated by the Mate Recognition Protein (MRP, a globular glycoprotein on the surface of females, encoded by the mmr-b gene family. In this study, we sequenced mmr-b copies from 27 isolates representing 11 phylotypes of the B. plicatilis species complex, examined the mode of evolution and selection of mmr-b, and determined the relationship between mmr-b genetic distance and mate recognition among isolates. Results Isolates of the B. plicatilis species complex have 1–4 copies of mmr-b, each composed of 2–9 nearly identical tandem repeats. The repeats within a gene copy are generally more similar than are gene copies among phylotypes, suggesting concerted evolution. Compared to housekeeping genes from the same isolates, mmr-b has accumulated only half as many synonymous differences but twice as many non-synonymous differences. Most of the amino acid differences between repeats appear to occur on the outer face of the protein, and these often result in changes in predicted patterns of phosphorylation. However, we found no evidence of positive selection driving these differences. Isolates with the most divergent copies were unable to mate with other isolates and rarely self-crossed. Overall the degree of mate recognition was significantly correlated with the genetic distance of mmr-b. Conclusions Discrimination of compatible mates in the B. plicatilis species complex is determined by proteins encoded by closely related copies of a single gene, mmr-b. While concerted evolution of the tandem repeats in mmr-b may function to maintain identity, it can also lead to the rapid spread of a mutation through all copies in the genome and thus to reproductive isolation. The mmr-b gene is evolving

  9. Studies on elimination of Brachionus plicatilis in culture of Moina mongolica by chemicals Ⅲ. Elimination of Brachionus plicatilis using formaldehyde%在蒙古裸腹溞培养中用药物杀灭褶皱臂尾轮虫的研究Ⅲ.用甲醛控制轮虫的实验

    Institute of Scientific and Technical Information of China (English)

    赵玉明; 何志辉

    2003-01-01

    在毒性试验的基础上,作者继续进行在蒙古裸腹溞Moina mongolica Daday培养中用甲醛控制褶皱臂尾轮虫Brachionus plicatilis的试验.试验结果表明,甲醛不仅可控制褶皱臂尾轮虫的生长,还能降低总氨的浓度,而对溶氧和pH无直接影响.另外,还进行了温度、盐度和总氨对甲醛毒性影响的试验.

  10. Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa) fed Chlorella vulgaris and Scenedesmus acutus cultured on different media.

    Science.gov (United States)

    Morales-Ventura, Jesús; Nandini, S; Sarma, S S S; Castellanos-Páez, Maria Elena

    2012-09-01

    Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold's basal) medium or the commercial liquid fertilizer (Bayfolan). Experiments were conducted at one algal concentration 1.0 x 10(6) cells/mL of C. vulgaris or its equivalent dry weight of 0.5 x 10(6) cells/mL of S. acutus. The population dynamics were tested at 23 +/- 1 degrees C in 100 mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates). For the life table experiments with M. macrocopa, we introduced 10 neonates (<24h old) into each test jar containing the specific algal type and concentration. For the rotifer experiments, we set 5mL tubes with one neonate each and 10 replicates for each algal species and culture medium. We found that the average rotifer life span was not influenced by the diet, but for M. macrocopa fed S. acutus cultured in Bold's medium, the average lifespan was significantly lower than with the other diets. The gross and net reproductive rates of A. fissa (ranging from 18-36 offspring per female) were significantly higher for C vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens

  11. Evidence of WSSV transmission from the rotifer (Brachionus plicatilis to the black tiger shrimp (Penaeus monodon postlarvae and means to control rotifer resting eggs using industrial disinfectants

    Directory of Open Access Journals (Sweden)

    Valeriano Corre, Jr

    2012-06-01

    Full Text Available Rotifers are considered possible vectors of the white spot syndrome virus (WSSV and have been implicated in its recurrence inpond-cultured shrimp. However, direct evidence of the transmission and the pathogenicity of this virus from rotifers to shrimp has been lacking.In the present study, the pathogenicity of WSSV transmitted from infected rotifers (Brachionus plicatilis to post larval black tiger shrimp(Penaeus monodon was investigated. Results show that WSSV transmitted from infected rotifers to post-larval P. monodon caused an 82%cumulative mortality as compared to a 9% mortality in the non-infected control group. We also investigated the possibility of industrial disinfectants(sodium hypochlorite, granulated calcium hypochlorite and formalin as possible means to inhibit the viability of rotifer resting eggs,considered a biological reservoir of WSSV in earthen ponds. Among the disinfectants that were tested, granulated calcium hypochlorite at 5mg/L was the most effective. The present study provides direct evidence of the high pathogenicity of WSSV transmitted from rotifers to postlarval P. monodon and shows the potential use of granulated calcium hypochlorite in pond disinfection. This treatment could be a promisingstrategy to inhibit the spread and recurrence of WSSV outbreaks in P. monodon culture.

  12. Triclosan (TCS) and Triclocarban (TCC) cause lifespan reduction and reproductive impairment through oxidative stress-mediated expression of the defensome in the monogonont rotifer (Brachionus koreanus).

    Science.gov (United States)

    Han, Jeonghoon; Won, Eun-Ji; Hwang, Un-Ki; Kim, Il-Chan; Yim, Joung Han; Lee, Jae-Seong

    2016-01-01

    Triclosan (TCS) and Triclocarban (TCC) are used as antimicrobial agents and have been widely dispersed and detected in the marine environment. However, the toxicities of TCS and TCC have been poorly investigated in marine invertebrates. In this study, the effects of TCS and TCC on mortality, population growth, lifespan, and fecundity were examined in the monogonont rotifer (Brachionus koreanus) using cellular ROS levels, GST enzymatic activity, and gene expression of defensomes. The median lethal concentration (LC50) of TCS (393.1μg/L) and TCC (388.1μg/L) was also determined in the same species. In TCS- and TCC-exposed B. koreanus, growth retardation and reduced fecundity were observed and were shown to have a potentially deleterious effect on the life cycle of B. koreanus. In addition, time-dependent increases in ROS content (%) and GST enzymatic activity were shown in response to TCS and TCC exposure. Additionally, transcript levels of detoxification proteins (e.g., CYPs), antioxidant proteins (e.g., GST-sigma, Cu/ZnSOD, CAT), and heat shock proteins (Hsps) were modulated in response to TCS and TCC exposure over a 24h period. Our results indicate that TCS and TCC induce oxidative stress and transcriptional regulation of detoxification, antioxidant, and heat shock proteins, resulting in changes in lifespan and fecundity. PMID:27067728

  13. Triclosan (TCS) and Triclocarban (TCC) cause lifespan reduction and reproductive impairment through oxidative stress-mediated expression of the defensome in the monogonont rotifer (Brachionus koreanus).

    Science.gov (United States)

    Han, Jeonghoon; Won, Eun-Ji; Hwang, Un-Ki; Kim, Il-Chan; Yim, Joung Han; Lee, Jae-Seong

    2016-01-01

    Triclosan (TCS) and Triclocarban (TCC) are used as antimicrobial agents and have been widely dispersed and detected in the marine environment. However, the toxicities of TCS and TCC have been poorly investigated in marine invertebrates. In this study, the effects of TCS and TCC on mortality, population growth, lifespan, and fecundity were examined in the monogonont rotifer (Brachionus koreanus) using cellular ROS levels, GST enzymatic activity, and gene expression of defensomes. The median lethal concentration (LC50) of TCS (393.1μg/L) and TCC (388.1μg/L) was also determined in the same species. In TCS- and TCC-exposed B. koreanus, growth retardation and reduced fecundity were observed and were shown to have a potentially deleterious effect on the life cycle of B. koreanus. In addition, time-dependent increases in ROS content (%) and GST enzymatic activity were shown in response to TCS and TCC exposure. Additionally, transcript levels of detoxification proteins (e.g., CYPs), antioxidant proteins (e.g., GST-sigma, Cu/ZnSOD, CAT), and heat shock proteins (Hsps) were modulated in response to TCS and TCC exposure over a 24h period. Our results indicate that TCS and TCC induce oxidative stress and transcriptional regulation of detoxification, antioxidant, and heat shock proteins, resulting in changes in lifespan and fecundity.

  14. Effects of UV-B radiation on population growth of rotifer Brachionus urceus%UV-B辐射增强对壶状臂尾轮虫种群增殖的影响

    Institute of Scientific and Technical Information of China (English)

    王进河; 冯蕾; 唐学玺

    2009-01-01

    运用群体累计培养的方法研究了UV-B辐射增强对壶状臂尾轮虫(Brachionus urceus)种群增殖的影响.结果表明:UV-B辐射增强对壶状臂尾轮虫的种群数量、雌体抱卵率和种群增殖率都有显著影响(P<0.05).实验表明,在本实验辐射强度(20μW/cm2)和剂量范围内(0.24、0.48、0.72、0.96和1.20kJ/m2),壶状臂尾轮虫的种群数量和种群增殖率均以对照组最高,各UV-B辐射处理组则随UV-B辐射剂量的增大而呈一致性减小,说明该种群的种群数量和种群增殖率随UV-B辐射的增强显示一致性的影响,两者都可以作为大气UV-B辐射强弱的生物指标.%The effects of UV-B radiation on population growth of rotifer Brachionus urceus were studied using the method of population accumulative culture. The results showed that the population numbers, the percentage of egg-bearing females relative to the total number of females and population growth rate of rotifer Brachionus urceus were significantly affected by UV-B radiation (P<0.05). At the experimental intensity of 20μW/cm2and in the dose range studied (0.00, 0.24, 0.48, 0.72, 0.96 and 1.20kJ /m2), both the population number and growth rate was the highest in the control and decreased with the increment of UV-B radiation. In addition, the population number and growth rate of rotifer Brachionus urceus showed a similar tendency of decrease with the dose increase of UV-B radiation. Both of them could be used as an ideal biomarker for the enhancement of UV-B radiation.

  15. Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

    Directory of Open Access Journals (Sweden)

    José Cristóbal Román-Reyes

    2014-11-01

    Full Text Available La producción de microalgas vivas para cultivar rotíferos constituye uno de los mayores costos de operación en la larvicultura de peces, por lo que se están desarrollando sustitutos comerciales de microalgas para la alimentación y producción de rotíferos. Se desconoce el efecto que tienen las formulaciones comerciales sobre la dinámica poblacional de rotíferos nativos del noroeste de México y en este estudio se evaluó el efecto de cuatro dietas comerciales (Espirulina, RotiMac®, Nanno 3600®, RotiGrow-Plus® y la microalga viva Nannochloropsis sp., sobre el crecimiento poblacional y fecundidad del rotífero Brachionus ibericus (GenBank KJ949043, aislado de una granja de camarón blanco (Litopenaeus vannamei. Se realizaron cinco réplicas por tratamiento alimenticio utilizando recipientes con volumen de 12 L de agua, con temperatura de 29 ± 1°C y salinidad de 35 ± 1, respectivamente. Los resultados mostraron que durante los periodos experimentales, las dietas probadas resultaron adecuadas para alimentar a B. ibericus, con tasas de crecimiento, tiempos de duplicación, densidades máximas y fecundidades que fluctuaron entre 0.20 a 0.27 rotíferos día-1, 2.60 a 3.42 días, 215 a 344 rotíferos mL-1 y de 0.16 a 0.39 huevos hembra-1, respectivamente. Las diferencias entre tratamientos fueron significativas (P 0.05 a las obtenidas con Nanno 3600®.

  16. 轮虫生产中两种益生菌的应用试验%Application test on. two kinds of effective microbes in reproduction of Brachionus plicatilis

    Institute of Scientific and Technical Information of China (English)

    苏跃中; 游岚

    2001-01-01

    During the breeding of Yellow Croaker, baker's yeast is used to culture ratifer (Brachionus plicatilis), by adding two kinds of effective microbes with a primary cencertration 100 ×10-6( VI V). The effects of effective microbes on water quality and ratifer' s reproduction are tested. The experiment results show that these two effective microbes have a good effect on improving culture water quality and reproduction of ratifer, and can be applied in the cultivation of ratifer.%鱼类在工厂化育苗中,用面包酵母进行褶皱臂尾轮虫( Brachionus plicatilis )的培养生产时,添加初始浓度为100×10-6(V/V)的脱氮菌和光合细菌,观察其对水质和轮虫增殖的影响.试验结果表明,该两种益生菌对改善轮虫培养水质及其增殖具有良好效果,可用于育苗的轮虫生产.

  17. Feeding of rotifer Brachionus plicatilis enriched with microalgae.%营养强化时褶皱臂尾轮虫对饵料微藻的摄食

    Institute of Scientific and Technical Information of China (English)

    李磊; 朱小明; 吴洪喜

    2011-01-01

    选取适宜浓度利用单种微藻和混合微藻对轮虫进行营养强化,采用实验生态学方法研究了轮虫滤水率和摄食率的动态变化.结果表明:微藻浓度、微藻种类和培养时间均对轮虫的滤水率和摄食率有显著影响;轮虫对几种单种微藻的滤水率和摄食率均随培养时间的延长而下降,在实验条件下,6h内轮虫对3种微藻的滤水率大小顺序为小球藻>球等鞭金藻>牟氏角毛藻,12h内轮虫对3种和,微藻的滤水率大小顺序则为球等鞭金藻>小球藻>牟氏角毛藻;轮虫在混合微藻中的选择顺序为球等鞭金藻>小球藻>牟氏角毛藻.%By the methods of experimental ecology, this paper studied the dynamic changes of the filtration and ingestion rates of Brachionus plicatilis enriched with single and mixed microalgal diets at optimum concentrations. The microalgal concentration, microalgal species, and culture duration all had significant effects on the filtration and ingestion rates of B. Plicatilis. The filtration and ingestion rates of B. Plicatilis to the diets decreased with increasing culture duration. Under the experimental conditions, the filtration rate of B. Plicatilis to the microalgae within 6 hours was in the order of Chlorella sp- > Isochrysis galbana > Chaetoceros muelleri, while that within the whole experimental duration ( 12 hours) was Isochrysis galbana > Chlorella sp. > Chaetoceros muelleri. The predation of B. Plicatilis fed by mixed microalgal diet was with a preferential order of Isochrysis galbana > Chlorella sp. > Chaetoceros muelleri.

  18. Intracellular haemolytic agents of Heterocapsa circularisquama exhibit toxic effects on H. circularisquama cells themselves and suppress both cell-mediated haemolytic activity and toxicity to rotifers (Brachionus plicatilis).

    Science.gov (United States)

    Nishiguchi, Tomoki; Cho, Kichul; Yasutomi, Masumi; Ueno, Mikinori; Yamaguchi, Kenichi; Basti, Leila; Yamasaki, Yasuhiro; Takeshita, Satoshi; Kim, Daekyung; Oda, Tatsuya

    2016-10-01

    A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells. Because H. circularisquama showed similar toxicity to rotifers regardless of the light conditions, and because ultrasonic ruptured H. circularisquama cells showed no significant toxicity to rotifers, it was suggested that live cell-mediated light-independent haemolytic activity is a major factor responsible for the observed toxicity to rotifers. Interestingly, the ultrasonic-ruptured cells of H. circularisquama suppressed their own lethal effect on the rotifers. Analysis of samples of the cell contents (supernatant) and cell fragments (precipitate) prepared from the ruptured H. circularisquama cells indicated that the cell contents contain inhibitors for the light-independent cell-mediated haemolytic activity, toxins affecting H. circularisquama cells themselves, as well as light-dependent haemolytic agents. Ethanol extract prepared from H. circularisquama, which is supposed to contain a porphyrin derivative that displays photosensitising haemolytic activity, showed potent toxicity to Chattonella marina, Chattonella antiqua, and Karenia mikimotoi, as well as to H. circularisquama at the concentration range at which no significant toxicity to rotifers was observed. Analysis on a column of Sephadex LH-20 revealed that light-dependent haemolytic activity and inhibitory activity on cell-mediated light-independent haemolytic activity existed in two separate fractions (f-2 and f-3), suggesting that both

  19. Substituição de Artemia sp. pelo rotífero Brachionus plicatilis na larvicultura do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879 Replacement of the Artemia sp. for the rotifer Brachionus plicatilis in the hatchering of the freshwater prawn (Macrobrachium rosenbergii De Man, 1879

    Directory of Open Access Journals (Sweden)

    Luciana Almada Thomaz

    2004-12-01

    Full Text Available Conduziu-se o presente trabalho com o objetivo de avaliar o efeito da substituição dos náuplios de Artemia sp. pelo rotífero enriquecido e congelado (Brachionus plicatilis, O.F. Müller, 1786 sobre a sobrevivência e peso seco das larvas. O experimento foi conduzido em blocos casualizados, sendo testados quatro regimes alimentares na larvicultura do camarão M. rosenbergii, com quatro repetições por tratamento. Nos regimes alimentares, realizaram-se substituições progressivas de náuplios de Artemia sp. (nas pelo rotífero Brachionus plicatilis (rots e testaram-se os seguintes tratamentos: 100% B. plicatilis (30 rots/mL (T1; 100% Artemia sp. (5 nas/mL (T2, 60% Artemia sp. (3 nas/mL + 40% B. plicatilis (12 rots/mL (T3 e 40% Artemia sp. (2 nas/mL + 60% B. plicatilis (18 rots/mL (T4, adicionando-se a estes tratamentos ração úmida. Os resultados da sobrevivência final em pós-larvas foram analisados pelo teste do X² e demonstraram não haver diferenças significativas do tratamento T2 (68,36% sobre os tratamentos T3 (68,76% e T4 (64,60%. O tratamento T1 (100% B. plicatilis apresentou mortalidade total no 14º dia do experimento. O peso seco médio das pós-larvas foi analisado estatisticamente pela ANOVA, não apresentando diferenças significativas entre os valores de 3,29 mg (T2, 3,08 mg (T3 e 3,38 mg (T4. A taxa de mortalidade baseada no número de larvas encontradas mortas diariamente, em relação ao número de larvas estocadas inicialmente, foi maior para todos os tratamentos nos primeiros 15 dias do experimento. Portanto, os resultados demonstraram que a substituição total de rotíferos enriquecidos e congelados acarretou a mortalidade total das larvas, mas a substituição parcial de 40% e 60% dos náuplios de Artemia sp. pelo B. plicatilis foi viável, não apresentando prejuízos significativos em termos de sobrevivência e peso seco das pós-larvas.This work was carried out to identify the replacement of the nauplii Artemia

  20. Effects of the fungicide prochloraz on the rotifer Brachionus calyciflorus%杀真菌剂咪鲜安对萼花臂尾轮虫的影响

    Institute of Scientific and Technical Information of China (English)

    李大命; 陆正和; 封琦; 杨家新

    2011-01-01

    Recent reports suggested that when certain contaminants are present in aquatic ecosystem at levels higher the threshold , they would disrupt endocrine functions of a variety of aquatic invertebrates including rotifers. Prochloraz ( C15 H16C13N3 O2 ) was a new broad-spectrum fungicide developed by England Boots Company ( now called Agro Evo) in 1974 . and launched into the market in 1977. Previous studies have focused mainly on efficacy, toxicity, and fungicidal mechanism of prochloraz; however little information was available about its environmental hormone effect in aquatic ecosystem. This motivated us to use freshwater rotif'er Brachionus calyciflorus , which was distributed widely in lakes , ponds , rivers and other such aquatic ecosystems, as test species to examine whether the fungicide prochloraz can affect the population growth and cumulative egg production in the rotifers and show environmental activity. The effect of prochloraz on reproduction and life cycle characteristics in the rotifer B. calyciflorus was studied by using experimental methods under laboratory conditions. Neonate females of B. calyciflorus were ( 0 - 2 h old) hatched from resting eggs in EPA medium. This rotifer strain was originally collected in Huai-an , Jiangsu Province in China during 2002 ,and since then it has been cultured in the laboratory continuously with periodic collection and storage of resting eggs.ChLorella pyrenoidosa ( cultured in HB4 medium at 25℃) was fed to B. calyciflorus at a density 3. 0x106cells /mL at 25℃.in 3 L bags under fluorescent illumination of 4000 lux and photo period was 16 :8( L :D). The results showed that 24h median lethal concentration ( 24hLC50) value of prochloraz for B. calyciflorus was 7. 09 mg/L, and exhibited a linear regression relationship Y= 20. 6581X- 12. 5673 ( R2 = 0. 93 ) , 95% limits are 6. 95-7. 21 mg/L. Survival curves were lower in treatment groups than that in control, and they decreased with increasing chemical concentrations

  1. Cladocers, Copepods and Rotifers in rice-fish culture handled with metsulfuron-methyl and azimsulfuron herbicides and carbofuran insecticide Cladocera, Copepoda e Rotifera em rizipiscicultura tratada com os herbicidas metsulfuron-metílico e azimsulfuron e o inseticida carbofuran

    Directory of Open Access Journals (Sweden)

    Jaqueline Ineu Golombieski

    2008-11-01

    Full Text Available This study determined the effects of metsulfuron-methyl, azimsulfuron and carbofuran in communities: Cladocers, Copepods and Rotifers that are present in irrigated rice farming with the rice-fish system. The field experiment was conducted in the 2004/05 growing season with eight treatments. The fish species were: Cyprinus carpio, Ctenopharyngodon idella and Aristichthys nobilis, introduced seven days after treatments were applied. Water samples were collected 17 days before and 1st, 3rd, 10th, 18th, 31th, 51th, and 75th days after the agrochemicals were applied for identification and evaluation of the zooplankton. The results indicated that the herbicides did not affect the zooplankton community studied and carbofuran insecticide application provoked negative effects in Cladocers. Copepods and Rotifers were slightly affected by carbofuran.O presente estudo determinou o efeito de metsulfuron-metílico, azimsulfuron e carbofuran nas comunidades: Cladocera, Copepoda e Rotifera presentes em lavouras de arroz irrigado com o sistema de rizipiscicultura. O experimento foi conduzido durante a safra agrícola 2004/05 com oito tratamentos. As espécies de peixes utilizadas foram: Cyprinus carpio, Ctenopharyngodon idella e Aristichthys nobilis, introduzidas sete dias após a aplicação dos tratamentos. Amostras de água foram coletadas 17 dias antes e no(s 1°, 3°, 10°, 18°, 31°, 51° e 75° dias após a aplicação dos tratamentos para a identificação e a avaliação de zooplâncton. Os resultados indicam que os herbicidas estudados não afetaram a comunidade zooplanctônica e a aplicação do inseticida carbofuran provocou efeitos negativos em Cladocera. Copepoda e Rotifera foram pouco afetados pelo carbofuran.

  2. 不同脂肪源对褶皱臂尾轮虫脂类和脂肪酸组成的影响%Effects of dietary lipid sources on fatty acid composition of rotifer Brachionus plicatilis

    Institute of Scientific and Technical Information of China (English)

    成永旭; 王武; 吴嘉敏; 黄显清

    2001-01-01

    Rotifer Brachionus plicatilis was used as the test species. The diets with different lipid sources were as follows: ( 1 ) Baker' s yeast, Saccharomyces cerevisice (control); (2) algae, Nannochlorpsis oculata ( diet A);(3) fish oil(5%) + soybean lecithin (5%) + Baker's yeast(90%)(diet B); (4) fish oil (10%) + Baker's yeast(90 96 )(diet C). The results show that: (1) Considerable difference of fatty acid composition exists in the rotifers fed corresponding diets compared with control, and the highest level of n-3 HUFA fatty acids in the rotifers fed diet C is obtained due to high level of n-3HUFA content in diet. The conclusion is that the HUFA content of diet is a major factor in affecting HUFA levels in the rotifers. (2) The effect of dietary lipid on the fatty acid composition is not only based on dietary level of HUFA, but also the lipid chemical types. (3) The method using dried diet (yeast) mixed with fish oil for the rotifers to enrich n-3HUFA is suitable for large-scale rotifer production mainly for the good effect of HUFA enrichment and avoidance of water contamination.%以褶皱臂尾轮虫(Brachionus plicatilis)为实验动物并设计不同脂肪源饵料,分别为:面包酵母Saccharomyces cerevisice(对照组),微绿球藻Nannochlorpsis oculata(A),5%大豆磷脂+5%鱼油+90%面包酵母(B),10%鱼油+90%面包酵母(C).结果表明:(1)接受不同脂肪源的轮虫的脂肪酸组成显著不同,尤其是高度不饱和脂肪酸(HUFA,20C)含量存在显著差异,说明饵料中HUFA含量对轮虫体内相应脂肪酸的含量有显著影响.投喂饵料C的轮虫具有高含量的n-3HUFA(26.7%),而对照组轮虫的n-3HUFA只有7.56%,所以投喂饵料C使轮虫的脂类HUFA水平得到了强化,提高了轮虫的营养价值.(2)轮虫脂类的HUFA水平不仅由饵料中脂类的相应脂肪酸组成决定,而且轮虫脂类HUFA的提高和强化效果与饵料中HUFA的化学形态密切相关.甘油三酯型饵料HUFA的强化轮

  3. The effect of the causative algae of large-scale HAB in the East China Sea on egg hatching of Argopecten irradians, and population growth of Brachionus plicatilis and Moina mongolica

    Institute of Scientific and Technical Information of China (English)

    CHEN Taoying; YAN Tian; WANG Liping; ZHANG Bin; ZHOU Mingjiang

    2007-01-01

    The impacts of Prorocentrum donghaiense Lu and Alexandrium catenella Balech, causative species of the large-scale HAB in the East China Sea, were studied under laboratory conditions. According to bloom densities, the effects of monoculture and mixture of the two species were examined on the egg-hatching success of Argopecten irradians Lamarck, and the population growth of Brachionus plicatilis Müller and Moina mongolica Daday. The results showed that monoculture of A. catenella had a significant inhibition on the egg hatching success of A. irradians, and the population growth of B. plicatilis and M. mongolica. The median effective densities (EDs0) inhibiting the egg hatching success of A. irradians for 24 h and the population growth of B. plicatilis and M.mongolica for 96 h were 800, 630, and 2 400 cells/cm3, respectively. Monoculture of P. donghaiense has no such inhibitory effect on the egg hatching success of A. irradians; P. donghaiense at lower suitable densities could sustain the population growth of B. plicatilis ( 1 × 104 ~ 3 × 104 cells/cm3 ) and M. mongolica (2 × 104 ~ 5 × 104 cells/cm3 ); P. donghaiense at higher densities had significantly adverse effect on the population growth of B. plicatilis (4 × 104 ~ 10 × 104 cells/cm3 ) and M. mongolica ( 10 ×104 cells/cm3). When the two algae were mixed according to bloom densities, P. donghaiense at suitable densities to some extent could decrease the toxicity of A. catenella to B. plicatilis and M. mongolica. The results indicated that the large-scale HAB in the East China Sea could have adverse effect on zooplankton, and might further influence the marine ecosystem, especially when there was also Alexandrium bloom.

  4. Zooplankton Seasonal Abundance and Vertical Distribution of Highly Alkaline Lake Burdur, Turkey

    OpenAIRE

    Gülle, Iskender; Turna, Ismail Ibrahim; Güçlü, Salim Serkan; Gülle, Pinar; Güçlü, Zekiye

    2010-01-01

    During the period from December 2003 to November 2004 a study has been held to examine the water quality and zooplankton of highly alkaline Lake Burdur. The lake showed thermal stratification between June and October. Six zooplankton taxa were determined, Hexarthra fennica, Brachionus plicatilis from Rotifera and Arctodiaptomus burduricus from Copepoda were the dominant species. Average zooplankton density was 399,074 ind.m-3 and they were 51% H. fennica, 9% B. plicatilis and 40% A. burdu...

  5. 内分泌干扰物氰戊菊酯和有机锡对萼花臂尾轮虫生殖的影响%Effect of endocrine disruptors fenvalerate and TBTC on reproduction of rotifer Brachionus calyciflorus

    Institute of Scientific and Technical Information of China (English)

    朱玮阁; 郭瑞昕; 杨家新

    2009-01-01

    Endocrine disruptors (EDs) are a structurally diverse group of compounds that may adversely affect the health of humans, wildlife and fisheries, or their progeny by interaction with the endocrine system. Many EDs have been detected in aquatic environments, many of which are capable of disrupting endocrine functions of a variety of aquatic invertebrates. In the present study, the estrogenic compound Fenvalerate and androgenic compound TBTC were screened for their effect on the batch carrying eggs every parental rotifer (P),total numbers of eggs, offspring production, and mictic female production of the freshwater rotifer Brachionus calyciflorus. Treatment with Fenvalerate at concentrations (except 3.2μg/L) significantly increased the frequency of carrying 3 eggs (p<0.05).Treatments with Fenvalerate at concentrations of 3.2μg/L to 2000μg/L significantly increased the total number of eggs production compared to controls (p<0.05). Treatment with TBTC at 0.0016,0.04, 0.2 and 1μg/L resulted in a significantly higher frequency of females carrying 3 and 4 eggs compared to control (p<0.05), but the frequency of carrying 1 egg was lower than control. The total number of eggs and offspring were all significantly lower than control (0.0016μg/L excluded) (p<0.05). Moreover, the ratios of mictic female (MF%) of parents and the first generation (F1) were also affected by Fenvalerate and TBTC. MF% of parents and F1 was significantly lower than control only in the two lowest concentrations of Fenvalerate at 0.64μg/L and 3.2μg/L (p<0.01), but there was no difference between treatments and control in higher concentrations, and no effect on MF/AF (mictic females/amictic females) of the F1 as well. The concentrations of TBTC only over 5μg/L significantly affected the MF% of parental compared to control (p<0.01), but MF% of F1 was obviously affected at all concentrations except 0.2μg/L. The MF/AF of parents and F1 were quite similar. TBTC had a negative effect on total number

  6. Persistência na água e influência de herbicidas utilizados na lavoura arrozeira sobre a comunidade zooplanctônica de Cladocera, Copepoda e Rotifera Water persistence and influence of herbicides utilized in rice paddy about zooplankton community of Cladocers Copepods and Rotifers

    Directory of Open Access Journals (Sweden)

    Geovane Boschmann Reimche

    2008-02-01

    Full Text Available Em lavoura de arroz irrigado, é utilizada uma grande quantidade de agroquímicos que, dependendo da sua persistência a campo e toxicidade, podem contaminar corpos d’água e afetar organismos vivos. Com o objetivo de determinar o efeito de concentrações de campo dos herbicidas Clomazone, Quinclorac, Metsulfuron-methyl e Propanil na comunidade zooplanctônica (Cladocera, Copepoda e Rotifera, conduziu-se um experimento em viveiros de aqüicultura, de março a maio de 2005, na estação do outono. Nos dias 1°, 2°, 3°, 7°, 10°, 18°, 31° e 51° após a aplicação dos herbicidas, foram coletadas amostras de água para se determinarem parâmetros físico-químicos da água, concentração dos herbicidas e comunidade zooplanctônica. Os parâmetros médios da qualidade da água foram: oxigênio dissolvido (3,5mg L-1, temperatura (20,1°C, pH (6,0, dureza total (18mg L-1 de CaCO3 e alcalinidade total (9mg L-1 de CaCO3. A ordem decrescente de persistência dos herbicidas na água foi Clomazone = Quinclorac > Propanil > Metsulfuron-methyl, com média de 31, 31, 10 e 7 dias, respectivamente. Os resultados indicaram que os herbicidas provocaram poucas alterações na densidade de organismos dos grupos Rotifera e Copepoda (Adulto e Nauplio. A densidade do grupo Cladocera permaneceu baixa para todo o período experimental.In the rice paddy field it is used a large amount of agrochemical that, depending on their field persistence and toxicity, can contaminate water bodies and may affect living organism. With the objective of determining the effect of field concentrations of Clomazone, Quinclorac, Metsulfuron-methyl and Propanil herbicides on zooplankton community (Cladocers, Copepods and Rotifers, it was carried an experiment in aquaculture ponds, during March to May 2005, in autumn season. In the 1st, 2nd, 3rd, 7th, 10th, 18th, 31th and 51th days after the herbicides application, water samples were collected to evaluate the physical chemical water

  7. 在蒙古裸腹溞培养中用药物杀灭褶皱臂尾轮虫的研究Ⅱ.5种常用药物对蒙古裸腹溞的慢性毒性%Studies on chemicals killing of Brachionus plicatilis in culture of Moina mongolicaby chemicals Ⅱ. The chronic toxicity of five chemicals to Moina mongolica

    Institute of Scientific and Technical Information of China (English)

    赵玉明; 何志辉

    2002-01-01

    试验观察了甲醛、次氯酸钠、次氯酸钙、碘和孔雀石绿对蒙古裸腹m(Moina monggollica)生长、生殖和内禀增长率的影响.得出5种药物对蒙古裸腹m的毒性阈限分别为25.1、0.076、0.085、0.025、0.040 mg/L.这一结果表明,甲醛对蒙古裸腹m的毒性阈限远高于对褶皱臂尾轮虫(Brachionus plicatilis)的24 h LC50,因而,可以作为在m培养液中抑制轮虫的有效药物.

  8. Zooplankton Distribution in Tropical Reservoirs, South China

    Science.gov (United States)

    Lin, Qiu-Qi; Duan, Shun-Shan; Hu, Ren; Han, Bo-Ping

    2003-11-01

    The zooplankton of 18 reservoirs of South China was investigated in 2000. 61 Rotifera species, 23 Cladoceras and 14 Copepodas were identified. The most frequent Rotifera genera were Keratella, Brachionus, Trichocerca, Diurella, Ascomorpha, Polyarthra, Ploesoma, Asplanchna, Pompholyx and Conochilus. Bosmina longirostris, Bosminopsis deitersi, Diaphanosoma birgei, D. brachyurum and Moina micrura were typical of Cladocera in the reservoirs. Phyllodiaptomus tunguidus, Neodiaptomus schmackeri and Mesocyclops leuckarti were the most frequent Copepoda and M. leuckarti dominated Copepoda in most reservoirs. High zooplankton species richness with low abundance was characteristic of the throughflowing reservoir, whereas low species richness with low abundance was found in the reservoir with the longest retention time. Relative high abundance and medium species diversity were the distinction of intermediate retention time reservoirs.

  9. Aporte al conocimiento del zooplancton de agua dulce y estuarina del río Guayas. Guayaquil - Ecuador

    OpenAIRE

    Luzuriaga de Cruz, M.

    1998-01-01

    El presente trabajo corresponde al análisis de zooplancton colectado en cinco estaciones localizadas en el río Guayas. La primera estación estuvo situada 10 km. río arriba de la confluencia del río Babahoyo con el río Daule, en un pozo acuífero. Las otras estaciones se situaron en cuatro sitios consecutivos a lo largo del río Guayas. En este trabajo se han identificado 10 especies: Brachionus plicatilis (O. F. Muller) (Rotifera), Alona cambouei Guerne and Richard, 1893; Moina micrura Kurz, 18...

  10. 秦皇岛海域"褐潮"海水对卤虫、轮虫存活和摄食的影响研究%Effect of "Brown Tide" onsurvival and ingestion of Artemia salina and Brachionus plicatilis in Qinhuangdao

    Institute of Scientific and Technical Information of China (English)

    公晗; 孔凡洲; 王云峰; 颜天; 周名江

    2015-01-01

    为评价秦皇岛褐潮现场海水的毒性, 作者利用HPLC技术及CHEMTAX, 分析了2013年7月2日采自秦皇岛褐潮高峰期微型及微微型浮游植物的色素组成及群落结构;测定了卤虫(Artemia salina)、轮虫(Brachionus plicatilis)存活率和摄食量.研究表明,褐潮海水微型及微微型浮游植物中,海金藻(Pelagophyceae)占主要优势,其生物量占总生物量的72.6%.褐潮海水抑制卤虫存活,卤虫48 h存活率降至77%;对轮虫24 h存活没有显著效应.此外,褐潮海水抑制卤虫、轮虫的摄食,卤虫、轮虫8 h内摄食量分别由(5.5±0.4)ng/个降至(2.4±0.4)ng/个、由(1.5±0.2)ng/个下降至(0.9±0.1)ng/个.该结果与美国的3株褐潮藻的毒性进行了比较.CCMP 1507对卤虫存活有显著抑制作用,其他两株没有显著效应; 3株褐潮藻对轮虫24 h存活都没有显著影响.暴露于3株褐潮藻中,卤虫的摄食量均显著较低;其中CCMP 1507在混合饵料中还抑制卤虫、轮虫对其他藻的摄食.对CCMP 1507各组分分析发现,该藻的毒性主要来源于藻细胞.结合现场试验与室内试验结果分析表明, 秦皇岛褐潮对卤虫、轮虫有一定的毒性,其毒性与CCMP 1507的毒性相当.%To studythe toxicity of the "Brown tide" in Qinhuangdao, the pigment profile and phytoplankton groups of the nano-sized and pico-sized phytoplankton samples collected from the "Brown tide" blooming sea area in Qinhuangdao on July 2rd, 2013 were analyzed using HPLC and CHEMTAX, and the survival and ingestion of Ar-temia salina and Brachionus plicatiliswere tested. It was found that pelagophytes played a predominant role, con-stituting 72.6% of the total phytoplankton biomass. The survival of A. salina decreased to 77% during 48 h expo-sure, while that of rotifer was not affected during 24 h exposure. Additionally, the ingestion of A. Salinaand rotifer in 8 hours was inhibited, reduced from (5.5±0.4)ng/ind to (2.4±0.4) ng/ind, and from (1.5±0.2) ng

  11. Elimination of Brachionus plicatilis in the culturing of Moina mongolica by chemicalsⅠ. Comparative study on the acute toxicity of five chemicals to M. mongolica and B. plicatilis%在蒙古裸腹蟤培养中用药物=杀灭褶皱臂尾轮虫的研究Ⅰ. 5种常用化学药物对蒙古裸腹蟤和褶皱臂尾轮虫的急性毒性

    Institute of Scientific and Technical Information of China (English)

    赵玉明; 何志辉

    2001-01-01

    研究了甲醛、次氯酸纳、次氯酸钙、孔雀石绿、碘对蒙古裸腹蟤(%Moina mongolica% Daday)和褶皱臂尾轮虫(%Brachionus plicatilis%)的急性毒性.得出5种药物对蒙古裸腹蟤的24 h LC-{50}值和48 h LC-{50}值分别为:甲醛,115.50(77.81~171.83) mg/L和73.58(51.14~88.72) mg/L; 次氯酸钠,0.74(0.58~0.94) mg/L和0.38(0.31~0.47) mg/L;次氯酸钙,0.67(0.55~0.83) mg/L和0.58(0.48~0.71)mg/L;碘,0.348(0.303~0.398) mg/L和0.27(0.22~0.32) mg/L;孔雀石绿,0.97(0.69~1.26) mg/L和0.37(0.25~0.54) mg/L.对褶皱臂尾轮虫的相应抑制浓度为:甲醛,10.86(9.00~13.08) mg/L和2.98(2.391~3.711) mg/L;次氯酸钠,0.87(0.67~1.11) mg/L和0.39(0.13~0.46) mg/L;次氯酸钙,0.78(0.59~1.05) mg/L和0.55(0.47~0.64) mg/L;碘,0.41(0.26~0.63) mg/L和0.09(0.055~0.141) mg/L;孔雀石绿,0.84(0.64~1.11) mg/L和0.23(0.21~0.26) mg/L.并将不同蟤龄的蒙古裸腹蟤对甲醛的抗药性同褶皱臂尾轮虫进行了对比.

  12. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

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    Carmen Gabaldón

    Full Text Available Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating. Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as

  13. Morphological similarity and ecological overlap in two rotifer species.

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    Carmen Gabaldón

    Full Text Available Co-occurrence of cryptic species raises theoretically relevant questions regarding their coexistence and ecological similarity. Given their great morphological similitude and close phylogenetic relationship (i.e., niche retention, these species will have similar ecological requirements and are expected to have strong competitive interactions. This raises the problem of finding the mechanisms that may explain the coexistence of cryptic species and challenges the conventional view of coexistence based on niche differentiation. The cryptic species complex of the rotifer Brachionus plicatilis is an excellent model to study these questions and to test hypotheses regarding ecological differentiation. Rotifer species within this complex are filtering zooplankters commonly found inhabiting the same ponds across the Iberian Peninsula and exhibit an extremely similar morphology-some of them being even virtually identical. Here, we explore whether subtle differences in body size and morphology translate into ecological differentiation by comparing two extremely morphologically similar species belonging to this complex: B. plicatilis and B. manjavacas. We focus on three key ecological features related to body size: (1 functional response, expressed by clearance rates; (2 tolerance to starvation, measured by growth and reproduction; and (3 vulnerability to copepod predation, measured by the number of preyed upon neonates. No major differences between B. plicatilis and B. manjavacas were found in the response to these features. Our results demonstrate the existence of a substantial niche overlap, suggesting that the subtle size differences between these two cryptic species are not sufficient to explain their coexistence. This lack of evidence for ecological differentiation in the studied biotic niche features is in agreement with the phylogenetic limiting similarity hypothesis but requires a mechanistic explanation of the coexistence of these species not

  14. How does the 'ancient' asexual Philodina roseola (Rotifera : Bdelloidea) handle potential UVB-induced mutations?

    NARCIS (Netherlands)

    Fischer, Claus; Ahlrichs, Wilko H.; Buma, Anita G. J.; van de Poll, Willem H.; Bininda-Emonds, Olaf R. P.

    2013-01-01

    Like other obligate asexuals, bdelloid rotifers are expected to suffer from degradation of their genomes through processes including the accumulation of deleterious mutations. However, sequence-based analyses in this regard remain inconclusive. Instead of looking for historical footprints of mutatio

  15. Life cycle traits of Philodina roseola Ehrenberg, 1830 (Rotifera, Bdelloidea), a model organism for bioassays.

    Science.gov (United States)

    Moreira, Raquel A; Mansano, Adrislaine S; Rocha, Odete

    2016-01-01

    This paper describes experimental results on the life cycle of the rotifer Philodina roseola cultured in the laboratory. Detailed information on life-cycle parameters of a certain species provides a deep understanding and contributes to a better knowledge of the role of the species in the community, besides providing data that are basic to other ecological investigations such as secondary production estimates and knowledge for applications such as its utilization as test-organism in ecotoxicological studies. The average duration of embryonic development of P. roseola was 23.88 h, the age at maturity of primipara was 3.5 days and the maximum lifespan was 23 days. The average size of the rotifer neonate was 198.77 µm, the mean size of primipara was 395.56 µm and for adults 429.96 µm. The average fecundity was 1.22 eggs per female per day and the mean number of eggs produced per female during the entire life was 22.33. The deceleration of somatic growth from the start of the reproductive stage represents a trade-off between growth and reproduction that is often seen in micrometazoans. The life history of P. roseola follows the strategy of other bdelloid species characterized by a rapid pre-reproductive development and canalization of most assimilated energy to reproduction after reaching maturity. The differences observed in total fecundity and longevity between our P. roseola cultures and those from previous studies were probably due to differences of intrinsic adaptation of this species ecotypes to the conditions of their natural environments. PMID:27168371

  16. Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai, China

    Science.gov (United States)

    Yu, Na; Li, Erchao; Feng, Dexiang; Xiao, Baicai; Wei, Chaoqun; Zhang, Meiling; Chen, Liqiao

    2014-11-01

    Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton ( Brachionus calyciflorus, Microcyclops leuckarti, and Asplanchna priodonta) accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species ( Schmackeria forbesi and Lepadella ovalis) were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.

  17. Zooplankton community of Keibul Lamjao National Park (KLNP) Manipur, India in relation to the physico-chemical variables of the water

    Science.gov (United States)

    Sharma, Aribam Satishchandra; Gupta, Susmita; Singh, N. Rajmuhon

    2016-06-01

    Keibul Lamjao National Park (KLNP), a floating park in Loktak Lake, Manipur (India) was studied from Winter (WIN) to Post Monsoon (POM) for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques-Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA). Analyses of water parameters with PCA revealed that the first PC axis (PC1) accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon (POM) (3 880 ind./L). Spatially, S6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant diff erence in mean zooplankton abundance among the seasons, but there was a statistically significant diff erence among the sites.

  18. VizieR Online Data Catalog: 1.1-2.4um spectra of 7 young M and L dwarfs (Manjavacas+, 2014)

    Science.gov (United States)

    Manjavacas, E.; Bonnefoy, M.; Schlieder, J. E.; Allard, F.; Rojo, P.; Goldman, B.; Chauvin, G.; Homeier, D.; Lodieu, N.; Henning, T.

    2014-02-01

    Our targets were observed with the Infrared Spectrometer And Array Camera (ISAAC) mounted on the Very Large Telescope (VLT) ath the UT3 telescope. The instrument was operated in low-resolution mode with the 0.3" slit at central wavelengths 1.25um, 1.65um, and 2.2um. This setup provides spectra with resolving powers of ~1700, 1600, and 1500 from 1.1-1.4um (J band), 1.42-1.82um (H band), and 1.82-2.5um (K band). (2 data files).

  19. Diel vertical migration and distribution of zooplankton in a tropical Brazilian reservoir

    Directory of Open Access Journals (Sweden)

    Ana M. A. da Silva

    2009-03-01

    Full Text Available Diel vertical migration of zooplankton is a strategy usually employed to reduce the risk of predation, and it can also be associated with the environmental day/night shifts, particularly of light and temperature. The aim of this study was to identify the diel patterns of zooplankton vertical migration and their relationship to the environmental variables in a shallow reservoir in northeastern Brazil. Water samples were taken at a single five-meter depth sampling station (Subsurface, 50% Io, 1% Io and Bottom at four-hour intervals over a period of 24 hours. Two Cladocera species (Moina minuta and Diaphanosoma spinulosum and one Copepoda species (Notodiaptomus cearensis showed similar patterns of nocturnal migration, staying at the bottom during the day and rising toward the surface in the afternoon and during the night. Brachionus falcatus and Hexarthra mira (Rotifera showed no patterns of vertical migration and their vertical distributions were relatively homogenous. Environmental variables were poorly correlated to the species distribution, suggesting that other mechanisms may be responsible of inducing vertical migration.

  20. Distribuição espacial e temporal de Kellicottia bostoniensis (Rousselet, 1908 (Rotifera em um grande reservatório tropical (reservatório de Furnas, Estado de Minas Gerais, Brasil Spatial and temporal distribution of Kellicottia bostoniensis (Rousselet, 1908 (Rotifera in a big tropical reservoir (Furnas Reservoir, state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo Motta Pinto-Coelho

    2002-05-01

    Full Text Available O rotífero Kellicottia bostoniensis é uma espécie planctônica comum na América do Norte, e em anos recentes, ela foi introduzida no Brasil. No sudeste do Brasil ela foi encontrada num pequeno reservatório eutrófico em Belo Horizonte e na bacia do rio Grande, no Reservatório de Furnas (20º 40’S - 46º 19’W. O objetivo do trabalho foi analisar a distribuição espacial e temporal desse rotífero ao longo de um gradiente trófico, em 12 pontos (3 no eixo central do reservatório e (9 em um dos seus principais tributários, o eixo do rio Sapucaí. As amostragens foram feitas em agosto e outubro/99 e março e julho/2000, através de arrastos verticais, com rede cilíndro-cônica de 68µm. Os organismos foram contados em câmara de Sedgwick-Rafter. Esse rotífero apareceu em toda a área amostrada, e os maiores valores de densidade foram observados em outubro e março, estação chuvosa, nos pontos meso e eutróficos. A ocorrência de K. bostoniensis nesse reservatório reflete sua alta adaptabilidade em ambientes tropicais.The rotifer Kellicottia bostoniensis is a common planktonic species in North America. This species has been introduced in Brazil recently. It is found in southeastern Brazil in a small eutrophic reservoir in Belo Horizonte (Minas Gerais state capital and in the Rio Grande Basin, Furnas reservoir (20º 40’ S- 46º 19’W. The aims of this study is to analyze this rotifer spatial and temporal distribution along a trophic gradient in 12 locations (3 in the reservoir central axis and (9 in one of its main tributaries, the Sapucaí River axis. The samplings were taken in August and October, 1999, and in March and July, 2000, through vertical tow, with a 68 µm cylindrical-conical net. The organisms were counted in a Sedgwick-Rafter cell. This rotifer was in the whole sampled area, and the higher densities were observed in October and March, rainy season, in the meso and eutrophic areas. The K. bostoniensis occurrence in this reservoir possibly reflects its high adaptability to tropical environments.

  1. Spatial variations in zooplankton diversity in waters contaminated with composite effluents

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    Asitava CHATTERJEE

    2007-08-01

    Full Text Available Zooplankton species are cosmopolitan in their clean freshwater habitat and are also found in industrial and municipal wastewaters. The present study records for the first time the aspects of zooplankton diversity in relation to physico-chemical environment of five selected sites of the East Calcutta wetlands, a Ramsar site of Kolkata city, India, heavily contaminated by industrial and municipal wastewaters. The study revealed the occurrence of 22 species of zooplankton, among these 3 species of Cladocera, 2 species of Copepoda, 15 species of Rotifera, and 2 species of Ostracoda were recorded. The copepod Mesocyclops leuckarti was found in all the five sites, rotifers Asplanchna brightwelli, Brachionus angularis, B. calyciflorus and Cladocera Ceriodaphnia cornuta were found in four sites; Moina micrura and Diaphanosoma sarsi were found at three sites. Site wise variation in dominance, diversity, evenness and richness were calculated. Site 1, a fish-pond that stabilized composite wastewater, showed the maximum species richness having 17 species, while Site 2, SWF wastewater carrying canal, showed only 4 species. The calculated Jack 1 values of Sites 1 to 5 were 21.78, 3.77, 18.63, 12.5 and 16.95 respectively. Shannon-Wiener species diversity index (H/ values were almost similar for all the three relatively less polluted sites viz, Site 1 (1.959, Site 4 (2.010, Site 5 (2.047. However, at highly polluted sites viz., 2 and 3, H/ value of 1.336 and 0.984 respectively, were calculated. Simpson’s Dominance index (Dsimp value was highest at Site 3 (0.618 indicating maximum dominance, whereas at Site 5 dominance was lowest (0.1680 and diversity was highest. We discuss the role of zooplankton in the amelioration of wastewater.

  2. Effects of experimental eutrophization on zooplankton community

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    Ana Maria Alves de Medeiros

    2013-06-01

    Full Text Available AIMS: The present study evaluated the role that increased nutrient concentrations play on zooplankton community, by employing an experimental laboratory approach. METHODS: Experiments were conducted in the laboratory, where three trophic state conditions were simulated, namely, mesotrophic, eutrophic and hypereutrophic. Each treatment was replicated three times and individuals of Brachionus urceolaris (10 individuals, Hexarthra mira (5 (Rotifera, Latonopsis sp. (10, Moina minuta (10 (Cladocera and Thermocyclops sp. (5 (Copepoda were introduced to each replicate. On the first experiment day, and at 7-day intervals for a 14-day period (totaling three evaluations, all water content was collected from each container and filtered to determine the densities of each zooplankton species. Two-way MANOVA and one-way ANOVA designs were used to determine zooplankton density fluctuations among treatments and throughout the study period. Further, Generalized Linear Models (GLMs were employed to assess how environmental factors affected zooplankton numbers. Phytoplankton composition was also determined in the beginning and in the end of the experiment. RESULTS: B. urceolaris and copepod nauplii, which are typical of eutrophic environments, showed higher densities on the eutrophic and hypereutrophic treatments. Furthermore, cyanobacteria such as Aphanothece sp. and Merismopedia sp. were recorded on the eutrophic and hypereutrophic treatments, respectively. CONCLUSIONS: Similarly to what is frequently observed in the wild, the eutrophic treatment showed higher densities of particular zooplankton species which are known to temporarily benefit from an increase in trophic concentrations. Positive or negative responses from zooplankton dynamics (but also phytoplankton species, provide an important bioindicator framework. Furthermore, results of the present study outline the need for implementing recovery measures on aquatic environments subject to constant nutrient

  3. Development of methods for evaluating toxicity to freshwater ecosystems.

    Science.gov (United States)

    Girling, A E; Pascoe, D; Janssen, C R; Peither, A; Wenzel, A; Schäfer, H; Neumeier, B; Mitchell, G C; Taylor, E J; Maund, S J; Lay, J P; Jüttner, I; Crossland, N O; Stephenson, R R; Persoone, G

    2000-02-01

    This article presents a summary of a collaborative research program involving five European research groups, that was partly funded by the European Commission under its Environmental Research Program. The objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at Level 2 of the Risk Evaluation Scheme for the Notification of Substances as required by the 7th Amendment to EC Directive 79/831/EEC. Currently only a very limited number of test methods have been described that can be used for this purpose and these are based on an even smaller number of test species. Tests based upon algae (Chlamydomonas reinhardi, Scenedesmus subspicatus, and Euglena gracilis), protozoa (Tetrahymena pyriformis), rotifera (Brachionus calyciflorus), crustacea (Gammarus pulex), and diptera (Chironomus riparius) were developed. The tests encompassed a range of end points and were evaluated against four reference chemicals: lindane, 3, 4-dichloroaniline (DCA), atrazine, and copper. The capacity of the tests to identify concentrations that are chronically toxic in the field was addressed by comparing the effects threshold concentrations determined in the laboratory tests with those determined for similar and/or related species and end points in stream and pond mesocosm studies. The lowest no-observed-effect concentrations (NOEC), EC(x), or LC(x) values obtained for lindane, atrazine, and copper were comparable with the lowest values obtained in the mesocosms. The lowest chronic NOEC determined for DCA using the laboratory tests was approximately 200 times higher than the lowest NOEC in the mesocosms. PMID:10648133

  4. EST based phylogenomics of Syndermata questions monophyly of Eurotatoria

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    Bucher Gregor

    2008-12-01

    Full Text Available Abstract Background The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdelloidea is the key to unravel the phylogenetic relations within Syndermata. The syndermatan phylogeny in turn is a prerequisite for reconstructing the evolution of the acanthocephalan endoparasitism. Results Here we present our results from a phylogenomic approach studying i the phylogenetic position of Syndermata within Spiralia, ii the monophyletic origin of monogononts and bdelloids and iii the phylogenetic relations of the latter two taxa to acanthocephalans. For this analysis we have generated EST libraries of Pomphorhynchus laevis, Echinorhynchus truttae (Acanthocephala and Brachionus plicatilis (Monogononta. By extending these data with database entries of B. plicatilis, Philodina roseola (Bdelloidea and 25 additional metazoan species, we conducted phylogenetic reconstructions based on 79 ribosomal proteins using maximum likelihood and bayesian approaches. Our findings suggest that the phylogenetic position of Syndermata within Spiralia is close to Platyhelminthes, that Eurotatoria are not monophyletic and that bdelloids are more closely related to acanthocephalans than monogononts. Conclusion Mapping morphological character evolution onto molecular phylogeny suggests the (partial or complete reduction of the corona and the emergence of a retractable

  5. Global isolation by distance despite strong regional phylogeography in a small metazoan

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    Mills Scott

    2007-11-01

    Full Text Available Abstract Background Small vagile eukaryotic organisms, which comprise a large proportion of the Earth's biodiversity, have traditionally been thought to lack the extent of population structuring and geographic speciation observed in larger taxa. Here we investigate the patterns of genetic diversity, amongst populations of the salt lake microscopic metazoan Brachionus plicatilis s. s. (sensu stricto (Rotifera: Monogononta on a global scale. We examine the phylogenetic relationships of geographic isolates from four continents using a 603 bp fragment of the mitochondrial COI gene to investigate patterns of phylogeographic subdivision in this species. In addition we investigate the relationship between genetic and geographic distances on a global scale to try and reconcile the paradox between the high vagility of this species and the previously reported patterns of restricted gene flow, even over local spatial scales. Results Analysis of global sequence diversity of B. plicatilis s. s. reveals the presence of four allopatric genetic lineages: North American-Far East Asian, Western Mediterranean, Australian, and an Eastern Mediterranean lineage represented by a single isolate. Geographically orientated substructure is also apparent within the three best sampled lineages. Surprisingly, given this strong phylogeographic structure, B. plicatilis s. s. shows a significant correlation between geographic and genetic distance on a global scale ('isolation by distance' – IBD. Conclusion Despite its cosmopolitan distribution and potential for high gene flow, B. plicatilis s. s. is strongly structured at a global scale. IBD patterns have traditionally been interpreted to indicate migration-drift equilibrium, although in this system equilibrium conditions are incompatible with the observed genetic structure. Instead, we suggest the pattern may have arisen through persistent founder effects, acting in a similar fashion to geographic barriers for larger

  6. Responses of the rotifer Brachionus calyciflorus to two tropical toxic cyanobacteria (Cylindrospermopsis raciborskii and Microcystis aeruginosa) in pure and mixed diets with green algae

    NARCIS (Netherlands)

    Soares, M.C.S.; Lürling, M.F.L.L.W.; Huszar, V.M.

    2010-01-01

    Cyanobacteria are known for being inadequate as a food source for zooplankton, whether by their toxicity, large size, lack of essential compounds or due to feeding inhibitors. In eutrophic systems, however, higher abundance of rotifers is often observed with higher abundance of cyanobacteria, which

  7. High Density Cultivation of Rotifer Brachionus plicatilis by Baker's Yeast%用酵母高密度培养褶皱臂尾轮虫

    Institute of Scientific and Technical Information of China (English)

    王鸿鹄; 吴灶和; 瘳永岩

    2009-01-01

    用面包酵母室内高密度培养褶皱臂尾轮虫,结果发现,1.5 g/(106·d)的较高投饵量.适合于接种密度约为50个/ml的褶皱臂尾轮虫培养,而投饵量为1.0~1.2 g/(106·d)时.适合于200个/ml以上较高密度的褶皱臂尾轮虫培养.投饵量为1.5 g/(106·d)时.不适于500个/ml以上接种密度的褶皱臂尾轮虫培养.若褶皱臂尾轮虫密度继续高至1000个/ml以上,投喂量则需进一步降低至1 0 g/(106·d)以下.褶皱臂尾轮虫接种密度低至30个/ml以下时,除酵母外,适当添加一定量(1/3以上体积)的单胞藻.可提高褶皱臂尾轮虫的增殖速度,降低褶皱臂尾轮虫培育的风险.

  8. Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Madsen, C.V.; Riisgard, H.U.

    2008-01-01

    Beating cilia are important organelles for swimming in many zooplanktonic aquatic organisms, including many invertebrate larvae, rotifers and ciliates, but other planktonic organisms, such as copepods and brine shrimps, use muscle-powered swimming appendages. In recent studies we found that the t...

  9. Characterization of Summer Zooplankton (Rotifer and Crustacean)Community and Water Quality Assessment of Three Typical Nanchang Lakes%南昌市3个城中湖泊夏季轮虫和甲壳类群落特征及水质评价

    Institute of Scientific and Technical Information of China (English)

    文媛; 秦海明; 胡旭仁; 胡火玲

    2015-01-01

    >0.02).The community structure was significantly different among the three lakes (P <0.05),character-ized by three obvious groups:Qingshan Lake community,Donghu Lake community and Yueliang Lake community. Canonical correspondence analysis shows that chlorophyll-a,turbidity and dissolved oxygen were the primary factors affecting the distribution of zooplankton (P <0.05).Diversity index of zooplankton and pollution indicator species of Rotifera reveal that Donghu Lake is clean,Qingshan Lake is clean to moderately polluted and Yueliang Lake is lightly to moderately polluted.Overall,Donghu Lake and Qingshan Lake are oligotrophic and Yueliang Lake is me-sotrophic.%为探究城市湖泊浮游动物群落结构特征和分布与水环境因子之间的关系,并评价南昌市典型城市湖泊夏季水质状况,运用多维尺度分析(MDS)和典范对应分析(CCA)方法,对南昌3个城市湖泊———东湖、青山湖、月亮湖的轮虫和甲壳类浮游动物群落进行了研究,分析了浮游动物的多样性指数。结果表明,轮虫是夏季城市湖泊中浮游动物的优势类群,优势度(Y)大于0.02的浮游动物分别为剪形臂尾轮虫(Brachionus forficula)、裂足臂尾轮虫(Brachionus diversicornis)、萼花臂尾轮虫(Brachionus calyciflorus)、桡足类无节幼体(Copepoda nauplii)和卜氏晶囊轮虫(Asplanchna brightwelli);3个湖泊之间浮游动物的群落结构差异显著(P <0.05),明显划分为东湖群落、青山湖群落和月亮湖群落。叶绿素 a 浓度、浊度和溶氧是浮游动物分布的显著影响因子(P <0.05)。多样性指数评价显示,东湖为清洁型水体,青山湖为清洁-中污型水体,月亮湖为轻污-中污型水体。综合评价表明,东湖和青山湖水体为寡营养水平,月亮湖为中富营养水平。

  10. Systematic Study on Nematoda Phylum,Gastrotricha Phylum and Rotifera Phylum%线虫动物门、腹毛动物门及轮虫动物门间的系统学研究

    Institute of Scientific and Technical Information of China (English)

    全仁哲; 贺福德; 陈道富; 范喜顺

    2002-01-01

    用支序分析方法对线虫动物门、腹毛动物门和轮虫动物门三者之间的系统学进行了分析,结论是三者为一单系群,其中腹毛动物门和轮虫动物门为一对姐妹群,线虫动物门则是由三者的共同祖先较早地分出的另一支.由此我们认为,应将这三者合并为一新门合胞体动物门(Syncytia),原来各门分别降为线虫纲、腹毛纲和轮虫纲;原腔动物门这一分类阶元应予废弃.

  11. Water Quality and Planktonic Communities in Al-Khadoud Spring, Al-Hassa, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Adel A. Fathi

    2009-01-01

    Full Text Available Problem statement: Al-Khadoud spring is one of the most important water resources in Al- Hassa Governorate, Saudi Arabia. However, much of its biotic information is still unknown. This study presented preliminary ecological information of this aquatic body. The aim of this research was to study the water characteristics and the planktonic organisms inhibiting Al-Khadoud spring and its irrigational channels for a period of 1 year. Approach: A regular visit was monitoring the spring over a period of 1 year (June 2007 to may 2008. Physico-chemical characteristics of spring water were determined. Quantitative and qualitative analysis of Plankton (Phytoplankton or zooplankton were also investigated. Results: All the water quality variables measured showed considerable seasonal variation. The data of this study showed that there were marked seasonal differences in the quantitative and qualitative composition of the phytoplankton communities in Al-Khadoud spring and its irrigation canal. The changes in total algal counts throughout the investigation coincided closely with in Chlorophyceae abundance. Thirty six species were identified allover the period of the investigation. Out of these, 9 species belong to Chlorophyceae, 17 belong to Bacillariophyceae, 7 to Cyanophyceae and 3 to Euglenophyceae. Cyclotella meneghiniana Kützing, Nitzschia closterium Ehernberg, Fragilaria capucina Desmazieres, Surirella ovalis Breb, Actinastrum sp., Chlorella vulgaris Beyerinck, Scenedesmus quadriquda Breb, Oscillatoria sp. and Oscillatoria subbrevis Schmidle were observed in a high rank of occurrence. The phytoplankton crop showed a remarkable increase as compared with the previous records. The data showed that the zooplanktonic fauna identified in this aquatic body is a typical of the permanent freshwater and brackish water. Eleven species were recorded, 5 belonged to Cladoceran, 4 belonged to Rotifera and 2 belonged to Chironomid. Zooplankton

  12. The Distribution and Seasonality of Zooplankton in Sombreiro River, Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    E.N. Ezekiel

    2011-05-01

    Full Text Available The distribution and seasonality of zooplankton in Sombreiro River of the, Niger Delta area in Nigeria was studied for a period of two years (August, 2007-July, 2009. All the zooplankton species occurred in all the stations except Mysis sp that was not recorded in station 4 (Odiemudie. Also all the stations recorded seventeen species (17 each except station 4 (Odiemudie that had sixteen (16 species. Five species of Cladocera occurred in all the stations and were fairly distributed. In station 2 Alonella costata was the highest (35.7%. This was followed by Moina cacrocapa (34.2% station 2 (Ogbele. Five species of Copepoda were fairly distributed in all the stations. Acanthocyclops, carinetus (53.1% was the highest in station 1. This was followed by Cyclops stenuis (47.2% station 1. Only one specie of Decapod crustacean was recorded. This was recorded in station 1, 2 and 3 but absent in station 4. Station 1 had the highest percentage of 44.9 followed by station 3 with 28.6%. Only one specie of Euphasiacea (Meganicilphanes norvegia was recorded and it occurred in all the stations with station 1 having the highest percentage of 41.8 followed by station 4 (24.1%. Three species of Protozoa were recorded in all the stations. They were fairly distributed. Tintinopsis senensis was the highest in station 3 with a percentage occurance of 45.8. This was followed by Halteria sp. (39.2% in station 3 also. The two species of Rotifera were also fairly distributed in all the stations. Brachionus falcatus was the highest in station 3 followed by Brachionus calyciflorus (32.3 in station 3 also. Annual variation result showed that Paracyclops fimbriatus had the highest mean value 20.417±10.422 (August 2007 - July 2008, 17.333±9.306 (August 2008 - July 2009. This was followed by Cyclops stenuis 18.167±12.494 (August 2007 - July 2008 16.250±10.847 (August 2008 - July 2009 and Meganicliphanes norvegia 17.417±11.540 (August 2007 - July 2008, 14.667±6.596 (August

  13. INFLUENCE OF FRESHWATER DISCHARGE ON ZOOPLANKT COMMUNITY DISTRIBUTION IN THE MUDFLAT WETLANDS OF THE HANGZHOU BAY%淡水排放对杭州湾湿地浮游动物群落分布的影响

    Institute of Scientific and Technical Information of China (English)

    李共国; 屠霄霞; 王佩儿; 王自磐; 廖何朝兴; 杨季芳

    2013-01-01

    In order to understand the spatiotemporal distribution of zooplankton species composition,abundance and biodiversity in the mudflat wetlands of Hangzhou Bay,40 samples were conducted at middle to high tide levels in five sampling stations (S1-S3 for discharge area,and S4-S5 for non-discharge area) in April (spring),July (summer),October (autumn),2010 and January (winter),2011.A total of 38 species of zooplankton (15 Rotifera,4 Cladocera,19 Copepoda) were found.The annual average density (88.89 ind./L) and biomass (0.41 mg/L) of zooplankton in the discharge area were much higher than those,i.e.,4.21 ind./L and 0.10 mg/L,respectively,in the non-discharge area.The dominant species of rotifers and copepods in the discharge area were Brachionus calyciflorus and Sinocalanus dorrii,respectively,and Calanus sinicus dominated copepods in the non-discharge area.Water nutrient concentrations,community density,and biomass of the zooplankton at middle tide level in stations S2-S3 were much higher than those at high tide level.The zooplankton community in the mudflat wetlands,the effects of the freshwater discharge,tidal creek spread,and tidal conditions determined the temporal pattern of the main zooplankton species,and the tidal creek spread and tidal conditions explained differences in composition and structure between the middle and the high tide level.%于2010年4月至2011年1月对杭州湾南岸滩涂湿地5个断面(S1-S3为排水区,S4-S5为非排水区)的高潮位和中潮位分别进行浮游动物群落结构的周年调查,共发现浮游动物38种(轮虫15种,枝角类4种,桡足类19种).排水区浮游动物年平均密度88.89 ind./L,生物量0.41 mg/L,非排水区平均密度仅4.21 ind./L,生物量0.10 mg/L.排水区轮虫和桡足类的第一优势种分别为萼花臂尾轮虫(Brachionus calyciflorus)和汤匙华哲水蚤(Sinocalanus dorrii),而非排水区第一优势种为中华哲水蚤(Calanus sinicus).S2-S3断面中潮位的水体营养盐浓度、

  14. Effects of UV-B radiation on the feeding of the rotifer Brachionus plicatilis%UV-B辐射增强对褶皱臂尾轮虫摄食的影响

    Institute of Scientific and Technical Information of China (English)

    冯蕾; 韩洪蕾; 唐学玺

    2007-01-01

    运用生态毒理学方法,研究了UV-B辐射条件下褶皱臂尾轮虫(Brachinonus plicatilis)对6株海洋微藻:小球藻(Chlorella sp.、绿色巴夫藻(Pauloua uiridis)、扁藻(Tetraselmis chuii)、球等鞭金藻8701(Isochrysis galbana Park 8701)、牟氏角毛藻(Chaetoceros muelleri Lermumerman)和小新月菱形藻(Nitzschia clostertum)的摄食.结果表明:UV-B辐射增强对褶皱臂尾轮虫的摄食有显著的抑制作用.与对照组相比,褶皱臂尾轮虫对每一种饵料单胞藻的滤水率和摄食率都表现出,随UV-B辐射剂量的增大而显著减小(P<0.5).而且对每一种饵料单胞藻的滤水率和摄食率是不相同的,这说明褶皱臂尾轮虫对饵料单胞藻是有选择性的.

  15. 双酚A对萼花臂尾轮虫毒性及生活史的影响%Effects of bisphenol A on the toxicity and life history of the rotifer Brachionus calyciflorus

    Institute of Scientific and Technical Information of China (English)

    陆正和; 赵宝坤; 杨家新

    2012-01-01

    应用生态毒理学研究方法,研究了双酚A(BPA)对萼花臂尾轮虫毒性及生活史影响.结果表明:BPA对萼花臂尾轮虫24h急性毒性LC50为13.76 mg/L,95%置信限为10.97-17.10 mg/L.生活史研究显示:与对照组相比,0.25-4.0 mg/L的BPA对轮虫胚胎发育历时影响不显著;2.0-4.0 mg/L的BPA显著延迟了轮虫幼体发育时间;当BPA为0.5 mg/L时,轮虫净生殖率(R0)显著上升,但BPA浓度为2.0和4.0 mg/L时R0显著降低;4.0 mg/L的BPA显著缩短世代时间(T);BPA浓度为2.0、4.0 mg/L时,轮虫生命期望值(e0)显著下降;BPA浓度为1.0、2.0、4.0 mg/L时,轮虫内禀增长率(rm)显著下降;BPA浓度为0.5、1.0 mg/L时轮虫所产后代混交率(MR)显著增长.研究结果表明BPA对轮虫的生殖具有干扰作用,其中R0和MR受BPA影响最为显著.

  16. Acute Toxicity Effects of Three Red Tide Algae on Brachionus plicatilis%3种赤潮藻对褶皱臂尾轮虫的急性毒性效应

    Institute of Scientific and Technical Information of China (English)

    周文礼; 肖慧; 王悠; 翟红昌; 唐学玺

    2008-01-01

    应用急性毒性试验方法,研究了可控生态条件下不同密度的东海原甲藻(Prorocentrum donghaiense Lu)、赤潮异弯藻(Heterosigma akashiw0 Hada)和塔玛亚历山大藻(Alexandriumtamarense Bahch)对褶皱臂尾轮虫(Brachionusplicatilis)的致死率和种群增长参数的影响.结果表明,东海原甲藻、赤潮异弯藻和塔玛亚历山大藻对褶皱臂尾轮虫24 h的LC50分别为3.56、1.21和0.49(×104cells/mL);3种赤潮藻在对褶皱臂尾轮虫的致毒过程中均表现了明显的密度效应;104cells/mL的东海原甲藻藻体,105cells/mL的赤潮异弯藻滤液和藻内容物以及103cells/mL的塔玛亚历山大藻滤液、藻内容物和藻体对褶皱臂尾轮虫有显著的抑制效应,且抑制作用随藻密度的增加而增强.

  17. Abundance of Zooplankters on a Rocky Shore of Kasenga, Southen End of Lake Tanganyika

    OpenAIRE

    KONDO, Takaki; KUMEKAWA, Hirokazu; Hori, Michio

    1997-01-01

    Abundance of zooplankters was examined by net collection on a rocky shore at the southern end of Lake Tanganyika. Zooplankters collected were copepoda, Ostracoda, shrimp larvae, Protozoa and Rotifera. No Cladocera was found. The species composition was rather simple and similar to that reported at the northwestern end of the lake. But the density of Rotifera was higher at the southern end. As the density of planktophagous fishes was higher about five times at the northwestern end than at the ...

  18. 澳门4个典型湿地的浮游动物群落特征%Characteristics of the Zooplankton Communities in Four Typical Wetlands of Macao

    Institute of Scientific and Technical Information of China (English)

    陈骞; 何伟添; 刘阳; 黄建荣

    2014-01-01

    5%formalin and concentrated to 50 mL by settling for 24 hours. Metazoan zooplankton samples were taken by passing 50 L water through plankton net (No.13) and preserved with 5%formalin.A total of 110 zooplankton species were identified, along with the dominant population of Protozoa and Rotifera at each sampling site.The number of zooplankton species showed the general tendency of summer>autumn>spring>winter and spatial variation of species number among the four wetlands following the order Fai Chi Kei>Wang de Notre Dame Bay>Lotus Flower Bridge>Nan Vam Lake.The spatial-temporal variations of the zoo-plankton density were shown as follows:winter>spring>autumn>summer and Fai Chi Kei>Lotus Flower Bridge>Wang de Notre Dame Bay>Nan Vam Lake.Strombidium globosaneum, Cyclidium glaucoma, Centropyxis acule-ate, Tintinnidium fluviatile, Brachionus angularis, Synchaeta sp.and Neodiaptomus schmackeri were the most dom-inant species and the zooplankton community in wetlands of Macao reflected obvious properties of tropical aquatic fauna.

  19. SEASONAL CHANGE OF ZOOPLANKTON COMMUNITIES AND ITS RELATIONSHIP WITH AQUATIC ENVIRONMENTS IN THE YONGJIANG RIVER, NINGBO%甬江干流浮游动物群落结构季节动态与水环境的关系

    Institute of Scientific and Technical Information of China (English)

    李共国; 包薇红; 徐石林; 王艳; 谭大鹏; 黄平沙

    2015-01-01

    对采自2011年3月—2012年2月间甬江干流13个断面的水样,按照国家标准测试了9项理化指标,并应用浮游动物定性和定量方法,研究了浮游物群落结构特点和季节变化。研究共记录浮游动物95种,其中轮虫24属72种、枝角类5属10种、桡足类11属13种和4种其他门类无脊椎动物幼虫;优势种主要来自于轮虫动物的臂尾轮虫属(Brachionus)和龟甲轮虫属(Keratella),前者占了浮游动物总丰度的22.1%,后者占总丰度的20.2%。浮游动物的丰度值在各断面均呈明显的季节变化,从断面1至断面6,最大峰值出现在春季,从断面7至断面13,最大峰值多出现在夏季;全干流最大峰值出现在断面5(3160 ind./L)。浮游动物群落生物多样性指数呈上游段低,中、下游河段高的现象;应用中度干扰假说(Intermediate disturbance hy-pothesis)对此结果给予了解释。Two-way ANOSIM相似性分析和Bray-Curtis相似性等级聚类分析显示:不同断面上不同季节的浮游动物群落间均存在显著差异,分别为R=0.264、P=0.1%和R=0.234、P=0.1%,且季节性差异大于断面间差异。在季节性差异中以春季和夏季间的差异性最大。主成分分析(PCA)表明:对不同断面浮游动物群落起作用的理化因子依次为CODCr、TN、DO和BOD5;对不同季节浮游动物群落起作用的理化因子依次为pH、TN/TP、盐度和水温。%In this study, water samples were collected from 13 sections in the Yongjiang River from March 2011 to Febru-ary 2012. Physical and chemical factors were analyzed according to national standards. The structure characteristic and the seasonal changes of the zooplankton communities were measured by the qualitative and quantitative methods. 95 species in water samples were recorded. Among them, 24 genera and 72 species of Rotifera, 5 genera and 10 species of Cladocera, 11 genera and 13 species of Copepoda, and 4 other categories of invertebrate larvae were

  20. 两种桡足类对蟹苗池中轮虫的影响及其控制与利用%Effects of Two Copepod Species on Rotifer Brachionus Plicatilis and Control and Utilization of the Copepods in Mitten-handed Crab Larvae Breeding Earthen Ponds

    Institute of Scientific and Technical Information of China (English)

    张清靖; 周竹君; 朱华

    2005-01-01

    试验结果表明, 细巧华哲水蚤和近亲真宽水蚤严重影响轮虫的存活率;采用1.50、1.75,2.00 mg/L的敌百虫溶液2~3 h能杀死桡足类成体和幼体,但在该浓度下杀灭桡足类的无节幼体则需要7.5~14.5 h.用以上浓度的敌百虫溶液浸泡过的近亲真宽水蚤的卵提前同步萌发,据此提出"二次杀灭法",以有效地控制和利用蟹苗池中的桡足类.

  1. Avaliação dos métodos de amostragem para fauna perifítica em macrófitas na Reserva da Biosfera, Serra do Espinhaço, Estado de Minas Gerais, Brasil - DOI: 10.4025/actascibiolsci.v30i3.377 Evaluation of sampling methods for periphytic fauna in macrophytes at the Espinhaço Mountain Range Biosphere Reserve, Minas Gerais State, Brazil - DOI: 10.4025/actascibiolsci.v30i3.377

    Directory of Open Access Journals (Sweden)

    Cristiane Machado López

    2008-10-01

    Full Text Available Os métodos “Jarra”, “Remocao Manual” e “Draga de Eckman modificada” foram avaliados para amostrar a fauna perifitica associada a macrofitas aquaticas. Foram coletadas 63 amostras em cinco ambientes lenticos e tres loticos na reserva da biosfera da Serra do Espinhaco (Estado de Minas Gerais, Brasil. Os testes estatisticos Anova e Tukey foram feitos para riqueza de Protista, Rotifera e Crustacea, enquanto para a abundancia de Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada e Nematoda foram avaliados os percentuais. Os protozoarios e rotiferos representaram 80% da abundancia e riqueza da comunidade. Nos ecossistemas avaliados todos os metodos foram relevantes para Protista, por outro lado, o metodo da Jarra foi o mais adequado para a analise de Crustacea. Entre os metodos, a Draga foi menos indicada para os grupos de microinvertebrados nos ecossistemas aquaticos. Os metodos Remocao Manual e Draga foram apropriados para analisar Rotifera. A abundancia de Gastrotricha e Tardigrada demonstrou melhores resultados pelo metodo da Jarra e Nematoda pelo metodo da Draga. Os tres metodos sao apropriados para amostragem da fauna perifitica em ambos os sistemas aquaticos. Entretanto, e importante estar ciente de que para cada tipo de ecossistema a amostragem da comunidade faunistica requer um metodo especifico para obter a melhor performance.The methods “Jar”, “Manual Removal” and “modified Ekman`s Dredge” were evaluated for sampling periphyton fauna associated to aquatic macrophytes. Sixty three samples were collected from five lentic and three lotic water bodies at Espinhaço Mountain Range Biosphere Reserve (Minas Gerais, Brazil. ANOVA and Tukey statistical tests were performed for Protista, Rotifera and Crustacea richness, whilst Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada and Nematoda, abundance were evaluate by percentage. Amongst the three methods, Dregde is less indicated for different water bodies systems

  2. Rotifers ingest oocysts of Cryptosporidium parvum

    Science.gov (United States)

    Fayer, R.; Trout, J.M.; Walsh, E.; Cole, R.A.

    2000-01-01

    Six genera of rotifers including Philodina, Monostyla, Epiphanes, Euchlanis, Brachionus, and Asplanchna were exposed to oocysts of Cryptosporidium parvum cleaned of fecal debris. Unstained oocysts and those stained with fluorescein-conjugated monoclonal antibody were added to suspensions of viable rotifers and were examined by phase-contrast, differential interference contrast, and fluorescence microscopy. Rotifers of all six genera were observed ingesting oocysts. A maximum of 25 oocysts was observed in the stomachs of Euchlanis and Brachionus. Euchlanis and Epiphanes were observed excreting boluses containing up to eight oocysts. It was not determined whether rotifers digested or otherwise rendered oocysts nonviable.

  3. USING ROTIFER POPULATION DEMOGRAPHIC PARAMETERS TO ASSESS IMPACTS OF THE DEGRADATION PRODUCTS FROM TRINITROTOLUENE PHYTOREMEDIATION

    Science.gov (United States)

    The objective of this study was to evaluate the aquatic chronic lethal and sublethal toxicity effects from the phytoremediation of water contaminated with 2,4,6-trinitrotoluene (2,4,6-TNT) by the wetland plant species Myriophyllum aquaticum (parrot feather). Rotifers (Brachionus...

  4. Real-time PCR detection and quantification of fish probiotic Phaeobacter strain 27-4 and fish pathogenic Vibrio in microalgae, rotifer, Artemia and first feeding turbot (Psetta maxima) larvae

    DEFF Research Database (Denmark)

    Prol, M.J.; Bruhn, Jesper Bartholin; Pintado, J.;

    2009-01-01

    and in presence of microalgae (Isochrysis galbana), rotifers (Brachionus plicatilis), Artemia nauplii or turbot (Psetta maxima) larvae by real-time PCR based on primers directed at genetic loci coding for antagonistic and virulence-related functions respectively. The optimized protocol was used to study...

  5. Plankton Resting Stages in the Marine Sediments of the Bay of Vlorë (Albania)

    OpenAIRE

    Fernando Rubino; Salvatore Moscatello; Manuela Belmonte; Gianmarco Ingrosso; Genuario Belmonte

    2013-01-01

    In the frame of the INTERREG III CISM project, sediment cores were collected at 2 stations in the Gulf of Vlorë to study the plankton resting stage assemblages. A total of 87 morphotypes were identified and produced by Dinophyta, Ciliophora, Rotifera, and Crustacea. In 22 cases, the cyst belonged to a species absent from the plankton of the same period. The most abundant resting stages were those produced by Scrippsiella species (Dinophyta). Some calcareous cysts were identified as fossil spe...

  6. Invertebrate communities of Nabugabo Lakes: a vital support resource for the fisheries and ecosystem diversity

    OpenAIRE

    Ndawula, L.M.; Kiggundu, V.; Pabire Ghandi, W.

    2005-01-01

    A field study of the invertebrate communities of the Nabugabo lakes(Nabugabo,Kayanja and Kayugi)showed the occurrence of copepoda, cladocera and rotifera(micro-invertebrates or zooplankton); Ephemeroptera and Diptera(macro-invertebrates or zoo-benthos). The most commonly encountered taxa were thermocyclops neglectus, moinamicrura,several rotiferan species(micro-invertebrates);P.adusta,chironomus, tanipodinae and trichoptera(macro- invertebrates). These organisms are assumed to be readily avai...

  7. The Digestive System Content of Mastacembelus mastacembelus (Banks & Solander, 1794) Inhabiting in Karakaya Dam Lake (Malatya-Turkey)

    OpenAIRE

    Pala, Güneş; Tellioğlu, Ayda; EROĞLU, Mücahit; ŞEN, Dursun

    2010-01-01

    In this study, digestive system contents of a total of 126 Mastacembelus mastacembelus (Banks & Solander, 1794) obtained from Karakaya Dam Lake were examined by means of Geometric Index of Importance (GII). In the digestive system content of examined fish, Bacillariophyta (16 taxa), Chlorophyta (6 taxa), Cyanophyta (5 taxa), Dinophyta (1 taxon) and Euglenophyta (1 taxon) which belong to plants and Rotifera (14 taxa), Cladocera (4 taxa), Copepoda (2 taxa) and Pisces (3 taxa) which belo...

  8. Prey selectivity and functional response by larval red-eyed tetra Moenkhausia sanctaefilomenae (Steindachner, 1907 (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Jorge Gallardo Alanis

    2009-10-01

    Full Text Available Studies were carried out to quantify the functional response and prey selectivity of larval (1-5 weeks old of Moenkhausia sanctaefilomenae, a widely cultured ornamental fish, using four rotifers (Brachionus calyciflorus, B. havanaensis, B. patulus and B. rubens as prey. Regardless of larval age, B. havanaensis was not selected, while B. rubens and B. calyciflorus were preferred. B. patulus was selected only after three weeks. When fed B. calyciflorus, the larvae showed increased prey consumption with increasing age, but remained as plateau around 80 prey individuals. M. sanctaefilomenae consumed much lower individuals of both B. havanaensis and B. patulus, while B. rubens was consumed in higher numbers starting from the first week (about 35 ind. larva-1 45 min.-1. Thus, the maximum number of individuals of each Brachionus species consumed by the larval M. sanctaefilomenae showed significant (p<0.05 differences among the prey types.

  9. Evaluation of primary and secondary production using wastewater as a culture medium.

    Science.gov (United States)

    Nandini, S; Ramírez-García, Pedro; Sarma, S S S

    2010-10-01

    The ability of rotifers and cladocerans to convert primary to secondary production in wastewaters was tested. Scenedesmus acutus was cultured on Bold's (defined) medium, wastewater from the tertiary phase of water treatment and a mixture of both. The algal growth rates (µ) ranged from 0.4 to 0.7 day⁻¹, being highest in defined medium. The demographic characteristics of Brachionus rubens and Moina macrocopa were tested using algae at a density of 1.0 x 10⁶ cells mL⁻¹. Into each test jar, we introduced 20 neonates (Moina (0.28-0.57 day⁻¹). Brachionus had significantly higher growth rates on algae cultured on Bold medium than on treated wastewater while Moina grew significantly better on Scenedesmus cultured on Bold medium or a mixture of treated wastewater and Bold medium than on treated wastewater alone. PMID:19748945

  10. Live food mediated vitamin C transfer to Dicentrarchus labraxand Clarias gariepinus

    OpenAIRE

    Merchie, G.; Lavens, P.; Dhert, Ph.; Pector, R.; Mai Soni, A.F.; Nelis, H.; Ollevier, F.P.; De leenheer, A P; Sorgeloos, P.

    1995-01-01

    Live food enrichment techniques, using formulated diets and emulsions for improving the nutritional quality of Brachionus and Artemia , were studied as a tool for transferring ascorbic acid (AA) to fish larvae. Artemia nauplii enriched for 24h with an experimental emulsion containing 20% HUFA and 0%, 10% and 20% ascorbyl palmitate (AP) were administered to catfish larvae in a 20-day feeding trial. Survival was not affected by the dietary AA, but from day 7 onwards a significantly positive eff...

  11. Fecundity, growth, and survival of the angelfish Pterophyllum scalare (Perciformes: Cichlidae) under laboratory conditions

    OpenAIRE

    Armando A. Ortega-Salas; Isabel Cortés G.; Hugo Reyes-Bustamante

    2009-01-01

    The freshwater angelfishes (Pterophyllum) are South American cichlids that have become very popular among aquarists, yet scarce information on their culture and aquarium husbandry exists. We studied Pterophyllum scalare to analyze dietary effects on fecundity, growth, and survival of eggs and larvae during 135 days. Three diets were used: A) decapsulated cysts of Artemia, B) commercial dry fish food, and C) a mix diet of the rotifer Brachionus plicatilis and the cladoceran Daphnia magna. The ...

  12. Ingestion by Japanese Eel Anguilla japonica Larvae on Various Minute Zooplanktons

    OpenAIRE

    Wullur, Stenly; Yoshimatsu, Takao; Tanaka, Hideki; Ohtani, Masataka; Sakakura, Yoshitaka; Kim, Hee-Jin; Hagiwara, Atsushi

    2013-01-01

    We observed the feeding incidence of Japanese eel Anguilla japonica larvae of 6, 7, 8 and 14 days after hatching (DAH) using various minute zooplanktons such as rotifer (Proales similis, Synchaeta sp., Keratella sp., Brachionus rotundiformis, B. angularis) and nauplii of copepod Paracyclopina nana, and compared those results to slurry type diets (i.e., shark eggs for control) to evaluate the usability of these planktons as primary food source for the mass culture of eel larvae. Feeding incid...

  13. ÇAMLIGÖZE BARAJ GÖLÜ (SİVAS-TÜRKİYE) ZOOPLANKTON FAUNASI ÜZERİNE BİR ÇALIŞMA

    OpenAIRE

    Dirican, Seher; Musul, Haldun

    2008-01-01

    Bu çalışma, Sivas ili Suşehri ilçesindeki Kelkit Çayı üzerinde kurulmuş olan Çamlıgöze Baraj Gölü’nün zooplankton faunasının belirlenmesi amacıyla Mayıs ve Kasım 2007 tarihleri arasında yapılmıştır. Çamlıgöze Baraj Gölü’nün zooplankton faunası 3 istasyondan alınan örneklerde incelenmiştir. Çamlıgöze Baraj Gölü’nün zooplankton faunasını başlıca Rotifera şubesi, Cladocera alttakımı ve Copepoda altsınıfı oluşturmaktadır. Bu çalışma sonucunda, Çamlıgöze Baraj Gölü’nde Rotifera şubesinden 11 tür, ...

  14. Beyşehir Gölü Zooplankton Türlerinin Aylık Dağılımı

    OpenAIRE

    DİDİNEN, Hakan; Yunus Ömer BOYACI

    2014-01-01

    Beyşehir Gölü'nde, Mayıs 2009-Nisan 2010 dönem aralığı aylık, 8 ayrı istasyondan su ve zooplankton örneklemesi yapılmıştır. Zooplankton olarak; Rotifera'ya ait 37, Copepoda'ya ait 5, Cladocera'ya ait 4 ve Bivalvia'ya ait 1 tür olmak üzere toplamda 47 tür tespit edilmiştir. Göl geneli toplam zooplankton yoğunluğuna göre; % 95,45'i Rotifera, % 3,66'sı Cladocera, % 0,89'u Copepoda ve < % 0,01'i Bivalvia'ya ait olduğu hesaplanmıştır. Zooplanktonun büyük bir kısmını mikro zooplankton temsil etmişt...

  15. Composition, diversity and short-term temporal fluctuations of zooplankton communities in fish culture ponds (Pindamonhangaba), SP.

    Science.gov (United States)

    Negreiros, N F; Rojas, N E; Rocha, O; Santos Wisniewski, M J

    2009-08-01

    The present study aimed at evaluating the composition, diversity and short-term temporal fluctuations of zooplankton communities in fish ponds. The study was carried out in two fish ponds, with 180 m(2) of water surface (6 x 30 m) each, located in the Aquiculture Centre of the Pindamonhangaba Fisheries Institute - São Paulo. The study was developed over eight weeks, from February 16 to April 6, 1998. The physical and chemical conditions of the water in the fish ponds were adequate for zooplankton development. The zooplanktonic community was characterised by high richness of species and a greater diversity was observed in the first fish pond, with a superior density of Rotifera. Temporal changes in zooplankton composition occurred in both ponds with Cladocera appearing in abundance later, in the fourth week, whereas copepods and rotifers were well represented since the beginning. Many species found are typical of fish ponds and are considered to constitute an excellent food source, showing high nutritional value for fish larvae, a good example being individuals from the Rotifera group and the micro-crustacean species Moina minuta and Thermocyclops decipiens. PMID:19802437

  16. Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    Eliane Maria de Souza Nogueira

    2011-08-01

    Full Text Available The zooplankton of aquatic environments is composed mostly of protozoans, rotifers, cladocerans and copepods, which play an important role in the food chain, transferring mass and energy from primary producers to higher trophic levels. This work was prepared with the objective of contributing to the knowledge of zooplankton biodiversity that occurs in the Sub-basin of Rio Poxim. Water samples were taken at monthly intervals at four sampling stations located along the sub-basin in the period August 2009 to July 2010. To obtain the zooplankton community, 100 L of water were filtered on nylon net with an aperture of 50 mm. Were identified 72 taxa distributed in the following taxonomic categories Rotifera, Protozoa, Porifera, Nematoda, Anellida, Cladocera, Copepoda, Ostracoda, Isopoda and Insecta. In terms of species richness, the phylum Rotifera followed by the Protoctista were the most relevant with forty and fifteen taxa, respectively. The most representative taxa in numerical terms were Arcella vulgaris, Notholca sp. Rotary sp. and nematodes. Regarding the community diversity index, the community was characterized as low diversity, but the taxa were distributed evenly in all monitoring points.

  17. Desempenho larval do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879 submetido a diferentes regimes alimentares Larval performance of the freshwater prawn (Macrobrachium rosenbergii De Man, 1879 submitted to different feeding systems

    Directory of Open Access Journals (Sweden)

    Luciana Almada Thomaz

    2004-12-01

    Full Text Available O desempenho das larvas de Macrobrachium rosenbergii submetidas a quatro diferentes regimes alimentares foi verificado utilizando a observação diária dos subestádios larvais e as primeiras metamorfoses. As larvas foram estocadas em densidade de aproximadamente 100 larvas.l-1, em 16 tanques retangulares, com capacidade de 33 litros. O experimento foi dividido em quatro unidades experimentais (blocos, nos quais foram testados quatro regimes alimentares na larvicultura em circuito aberto, com quatro repetições por tratamento. Os regimes alimentares substituindo progressivamente náuplio de Artemia sp. (nas pelo rotífero Brachionus plicatilis (rots foram os seguintes tratamentos: 100% Brachionus plicatilis (30 rots/mL (T1; 100% Artemia (5 nas/ mL (T2, 60% Artemia (3 nas/mL + 40% Brachionus plicatilis (12 rots/ mL (T3 e 40% Artemia (2 nas/mL + 60% Brachionus plicatilis (18 rots/ mL (T4, sendo adicionada a estes tratamentos ração úmida. Os resultados da mudança dos subestádios larvais demonstraram que não houve diferença significativa entre os tratamentos T2, T3 e T4. No tratamento T1 (100% Brachionus plicatilis houve mortalidade total no 14º dia do experimento. O efeito da ocorrência das primeiras metamorfoses para pós-larvas, ocorreu ao 27º dia nos tratamentos T2, T3 e T4. Conseqüentemente, o ciclo de larvicultura até a metamorfose de 90% para pós-larva (PL1 foi o mesmo nos tratamentos (35 dias. Portanto, a utilização do rotífero enriquecido e congelado no regime alimentar das larvas permitiu desempenho satisfatório em termos de desenvolvimento larval de M. rosenbergii até a passagem para o estádio de pós-larva.The feeding is one of the most important factors to larval development and the sucess of the commercial cultivation of decapod crustacean larvae depends on the efficient and economic utilization of the available food. The performance of Macrobrachium rosenbergii larva submitted to four different feeding systems was

  18. First feeding of Eugerres brasilianus (Carapeva larvae with Acartia tonsa (Copepod nauplii increases survival and resistance to acute stress

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo Costa

    2016-01-01

    Full Text Available The rotifer Brachionus sp. is commonly used for larval feeding in marine fish hatcheries. The aim of this study was to evaluate whether the inclusion of Acartia tonsa nauplii in the initial diet of carapeva larvae improves their survival, growth and resistance to stress when compared to the regimen containing only rotifers. Adult copepods were collected in the wild and cultured with the microalgae Chaetoceros muelleri, Isochrysis galbana and Nannochloropsis oculata to obtain nauplii. Carapeva larvae were grown for 15 days using four treatments and three replicates: 1 Brachionus plicatilis rotifers (10 to 15/mL; 2 A. tonsa nauplii (0.25 to 0.5/mL; 3 Brachionus plicatilis rotifers (5 to 7.5/mL + A. tonsa nauplii (0.12 to 0.25/mL, and 4 no supply of live feed. After 15 days, the carapeva larvae were subjected to stress by exposure to air for 10 seconds and then returned to the source tank to evaluate survival after 24 h. Survival and stress resistance were higher in carapeva larvae fed B. plicatilis + A. tonsa nauplii (P<0.05, 20.9 ± 11.2% and 88.9%, respectively. These results confirm the positive effect of the inclusion of copepod nauplii in the diet of fish larvae. However, more research is needed to validate these results.

  19. Virus-phytoplankton adhesion: a new WSSV transmission route to zooplankton

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The pathogenicity of white spot syndrome virus (WSSV) to zooplankton species, rotifer Brachionus urceus (Linnaeus), copepod Acartia clausi (Giesbrecht) and mysid shrimp Neomysis awatschensis (Brandt), was estimated by immersion challenge and virus-phytoplankton adhesion route to investigate a potential new transmission route of WSSV to zooplankton. WSSV succeeded in infecting these zooplankton species and nested-PCR revealed positive results for the virus-phytoplankton adhesion route, whereas WSSV cannot infect zooplankton by immersion challenge. These results indicated that virus-phytoplankton adhesion route is a successful new transmission route of WSSV to zooplankton and also implied that phytoplankton could be a carrier in WSSV transmission.

  20. Composición taxonómica del zooplancton del embalse de Betania, departamento del Huila, Colombia Composición taxonómica del zooplancton del embalse de Betania, departamento del Huila, Colombia

    Directory of Open Access Journals (Sweden)

    Guillot Monroy Gabriel Hernando

    1999-06-01

    Full Text Available

    Durante el año de 1991 se realizaron muestreos con frecuencia bimestral en el embalse de Betania (alt.: 560 m.s.n.m.; área: 7.4 km2; volumen 1971x106 m3; prof. media: 28 m en el departamento del Huila, con el objetivo de determinar la composición del zooplancton.  En total se registraron 24 taxa: Thermocyclops decipiens (Crustacea, Copepoda, Moina sp., Ceriodaphnia cornuta y Allona sp. (Crustacea, Cladocera; 19 especies de rotíferos, de los cuales 7 corresponden al género Brachionus y larvas del díptero Chaoborus sp.  Se registran por primera vez para Colombia Brachionus havanaensis, B. falcatus falcatus, b. quadridentatus, y Platyias cuadricornis  f. brevispinus.   A partir de la comparación con faunas zooplanctónicas de varios cuerpos de agua tropicales y subtropicales, se concluyó que la composición zooplanctónica del embalse es típica de lagos tropicales cálidos.

    To determine the species composition of the zooplancton in the reservoir Betania (altitude; 560 m.a.s.l.; area: 7.4 km2; vol: 1971 x 106 m3; mean depht 28 m, at seven sites and several depths, bimonthly net samples (100 and 200 microns mesh size were taken during 1991.  Alltogether 24 species were found: Thermocyclops decipiens (Crustacea, Copepoda, Moina sp., Ceriodaphnia cornuta y Allona sp. (Crustacea, Cladocera; 19 species of rotífers, of which 7 belong to the genus Brachionus, as well as larvas of the dipter Chaoborus sp. For the first time Brachionus havanaensis, B. falcatus falcatus, b. quadridentatus, y Platyias cuadricornis  f. brevispinus  were found in Colombia.  The species composition was compared with the composition of other lakes and comparison shows that the Betania reservoir has a typical species composition for warms tropical lakes.

  1. Molecular diversity of eukaryotes in municipal wastewater treatment processes as revealed by 18S rRNA gene analysis.

    Science.gov (United States)

    Matsunaga, Kengo; Kubota, Kengo; Harada, Hideki

    2014-01-01

    Eukaryotic communities involved in sewage treatment processes have been investigated by morphological identification, but have not yet been well-characterized using molecular approaches. In the present study, eukaryotic communities were characterized by constructing 18S rRNA gene clone libraries. The phylogenetic affiliations of a total of 843 clones were Alveolata, Fungi, Rhizaria, Euglenozoa, Stramenopiles, Amoebozoa, and Viridiplantae as protozoans and Rotifera, Gastrotricha, and Nematoda as metazoans. Sixty percent of the clones had <97% sequence identity to described eukaryotes, indicating the greater diversity of eukaryotes than previously recognized. A core OTU closely related to Epistylis chrysemydis was identified, and several OTUs were shared by 4-8 libraries. Members of the uncultured lineage LKM11 in Cryptomycota were predominant fungi in sewage treatment processes. This comparative study represents an initial step in furthering understanding of the diversity and role of eukaryotes in sewage treatment processes.

  2. Marine Meiofauna in Songculan Lagoon, Songculan, Dauis, Bohol Philippines

    Directory of Open Access Journals (Sweden)

    Hongayo, Menelo C

    2013-04-01

    Full Text Available Meiofaunal organisms are small animals found living in the benthic zones of both freshwater and marine habitats and are considered numerically dominant metazoans. Their presence in the benthic zone is important since they serve as links to higher trophic levels in the ecosystems. This study aimed to identify meiofaunal organisms found in Songculan Lagoon, Songculan Dauis, Bohol, Philippines; determine the physico – chemical properties of water and sediments in Songculan Lagoon; and compute and compare for relative abundance of the meiofaunal taxa. This study was limited to meiofaunal taxa identification up to class level. Sampling involves coring method. The results identified eleven (11 meiofaunal taxa namely; Netamoda, Copepod, Ostracod, Turbellaria, Gastropod, Flatworms, Gastroticha, Polychaeta, Oligochaeta, Rotifera and Tardigrada.

  3. Zooplankton communities in the Krenceng Reservoair, Cilegon, Banten

    Directory of Open Access Journals (Sweden)

    Mufti P. Patria

    2005-11-01

    Full Text Available This research was carried out to know the structure of zooplankton communities and relations between the phytoplankton and zooplankton in the Krenceng Reservoair, Cilegon. The zooplankton abundance with used Sedwigck Rafter Counting Method, diversity and evenness were counted. Relations between zooplankton and the environmental factors as well as its relations to phytoplankton calculated with regression. The results showed that are 13 species of the zooplankton found which including in three classes with the highest abundance on Novembers 2002 and March 2003 of the Rotifera. The analysis of regression pointed out that the environmental factors such: pH, BOD5, nitrate, CO2 and abundance of phytoplankton influence the abundance zooplankton in November. While in March, the abundance of zooplankton is influenced by brigthtness, nitrate, orthophosphates and C organic. The abundance of phytoplankton influenced positively by the abundance of zooplankton.

  4. 沙溪竹洲水电站水体富营养化评价%Evaluation on Eutrophication of Zhuzhou Hydroelectri--Station in the Shaxi River

    Institute of Scientific and Technical Information of China (English)

    王钦建

    2009-01-01

    对沙溪竹洲水电站水体的富营养化评价结论:水体总氮超出评价标准,库区具有藻类生长的营养条件,磷是藻类生长限制因子.3种评价方法结果基本一致,表明水体处于贫营养向中营养过渡类型,并现出向富营养化发展的趋势.库区浮游动物种类以轮虫(rotifera)和原生动物(protozoa)为主,浮游植物种类以绿藻门(Chlorophyta)和硅藻门(Bacilariophy-ta)为主,库区应属于中营养类型.

  5. 福建省九龙江江东库区浮游动物的生态研究%The Ecological Research of Zooplankton in Jiangdong Reservoir of Jiulong River in Fujian Province

    Institute of Scientific and Technical Information of China (English)

    干建彗; 郭东晖

    2012-01-01

    The zooplankton community of Jiangdong Reservoir was investigated in Jiulong River,Fujian province from March 2010 to February 2011. The result indicated that ninety-nine species were identified,of which 20 species were Protozoa,29 species were Rotif-era,39 species were Cladocera.and 11 species were Copepoda. The annual average abundance of zooplankton was 5 486. 73 L-1 ,the a-bundance of zooplankton was mainly determined by Protozoa and Rotifera,of which Protozoa was 4 926. 90 L-1,Rotifera was 552. 91 L-1 ,Cladocera was 5. 13 L-1 ,and Copepoda was 1. 79 L-1. The highest zooplankton abundance appeared in November, while the lowest in March. Temperature was the main influence factor of zooplankton community,and the abundance of Rotifera and Copepoda showed a significant positive relationship with Chlorophyll a. Sand mining probably accelerated the development of Protozoa, decreased the Margalef index of zooplankton. The pressure of fish prey and short retention time were the main reasons for low abundance of Cladocera and Copepoda.%于2010年3月-2011年2月对福建省九龙江江东库区的浮游动物进行了生态调查研究.研究结果表明,调查期间共采集到浮游动物99种,其中原生动物20种,轮虫29种,枝角类39种,桡足类11种.浮游动物丰度年均为5 486.73L-1,浮游动物的丰度主要由原生动物和轮虫组成,其中原生动物丰度最高,为4 926.90 L-1,轮虫为552.91L-1,枝角类为5.13 L-1,桡足类丰度最低,年均为1.79 L-1.浮游动物丰度最高值出现在11月,最低值出现在3月.温度是影响浮游动物群落的主要影响因子,轮虫和桡足类丰度分别与叶绿素a(Chl a)浓度存在显著正相关性.挖沙船的频繁活动可能促进了原生动物的生长,降低了浮游动物群落丰富度.短滞留时间和鱼类的捕食压力是造成枝角类和桡足类丰度低下的主要原因.

  6. Zooplankton competition promotes trade-offs affecting diapause in rotifers.

    Science.gov (United States)

    Aránguiz-Acuña, Adriana; Ramos-Jiliberto, Rodrigo; Serra, Manuel

    2015-01-01

    Facultative diapause should be favoured by natural selection in temporary variable habitats. Diapause patterns are evolutionary constrained because producing diapause is resource demanding, which might have implications for competitive dynamics and competitor coexistence through mechanisms such as the storage effect. Besides these implications, competition intensity might affect the quality of the diapausing stages and the reproductive success of the offspring emerging from them. We experimentally analysed traits involved in diapause in the cyclically parthenogenetic rotifer Brachionus calyciflorus, in relation to the presence of its competitor, the cladoceran Moina micrura. Under competition with Moina, Brachionus produced fewer diapausing eggs, most of which possessed visual attributes indicating a higher quality. These diapausing eggs produced under a competitive environment had a higher hatching success; however, the hatchlings exhibited a lower population growth rate. We propose the existence of trade-offs between traits related to diapause: the number of produced eggs, quality of these eggs and hatchling performance. Our results show that interspecific competition may cause fine-tuned changes in the life cycle patterns of the populations. Furthermore, these changes could affect that abundance and performance of competitors and thereby drive back effects on the competitive output. These diapause-driven feedback mechanisms may have strong implications for the dynamics of the natural communities. PMID:25464990

  7. FLUCTUACIÓN DE LOS ENSAMBLES PLANCTÓNICOS EN LA CIÉNAGA DE AYAPEL (CÓRDOBA-COLOMBIA DURANTE UN CICLO SEMANAL FLUCTUATION OF PLANKTON ASSEMBLAGES AT AYAPEL SWAMP IN CÓRDOBA (COLOMBIA DURING A WEEKLY CYCLE

    Directory of Open Access Journals (Sweden)

    Juan Carlos Jaramillo-Londoño

    2012-12-01

    Full Text Available En esta investigación se evaluó la variación espacial y temporal de los ensamblajes fitoplanctónicos y zooplanctónicos, diariamente y durante un ciclo semanal, en seis estaciones de muestreo en la ciénaga de Ayapel (Córdoba, Colombia, tomando muestras integradas de la columna de agua. Ambos ensamblajes presentaron diferencias espaciales y una alta homogeneidad temporal. El fitoplancton estuvo dominado por cianobacterias principalmente Cylindropermopsis raciborskii y Planktolyngbya limnetica, y el zooplancton por rotíferos del género Brachionus.This research was intended to spatially and temporally evaluate phytoplankton and zooplankton assemblages on a daily basis during a weekly cycle, in six sampling stations at Ayapel swamp in Córdoba (Colombia, taking integrated samples of the water column. Both assemblages showed spatial differences and a high temporal homogeneity. Phytoplankton was dominated by cyanobacteria, specifically Cylindropermopsis raciborskii and Planktolyngbya limnetica; and zooplankton was dominated by Brachionus-genus rotifers..

  8. The Spatial Structure of Zooplankton Communities of Pedu Reservoir,Malaysia%The Spatial Structure of Zooplankton Communities of Pedu Reservoir, Malaysia

    Institute of Scientific and Technical Information of China (English)

    Amir Shah Ruddin Md Shah; Johan Ismail; Diana Latief; Wan Maznah Wan Omar

    2012-01-01

    A total of 22 species of zooplankton were identified from 8 sampling stations located in the limnetic zone of Pedu reservoir.The zooplankton community was dominated by rotifers (11 species),followed by cladocerans (9species) and copepods (2 species).Four species of zooplankton comprised of 3 rotifers,Brachionus quadridentata,Brachionus caudatus and Keratella cochlearis and one cladoceran,Ceriodaphnia cornuta were present at all sampling stations.Species richness was highest at Station 2 (17 species) followed by Station 4 and Station 8 (14 species),Station 5 (15 species),Station 7 (11 species),Station 6 (10 species),Station 3 (9 species) and Station 1 (7 species).With an exception of water transparency,all other water quality parameters such as temperature,dissolved oxygen,conductivity,pH and total dissolved solids were not significant when compared between sampling stations.The study found that station 5 which was located in a calm strait,protected from strong wave and wind was a suitable area for zooplankton growth and establishment.Factors supporting the findings included highest water transparency (3.4 m),rich in species numbers (15 species),high diversity index (0.950) and evenness index (0.808).

  9. Rotifer community structure along a stretch under the influence of dams in the Upper Paraná River floodplain

    Directory of Open Access Journals (Sweden)

    Tatiane Mantovano

    2015-07-01

    Full Text Available The construction of reservoirs imposes substantial impact on freshwater ecosystems and changes the ecological aspects of the lotic system downstream of dams. We hypothesized an increasing dissimilarity between communities in the sampling sites according to increasing distance from the Porto Primavera Dam. In addition, we expect that the rotifer community in the last sampling site will be influenced more by environmental variables related to trophic status. Samplings were conducted under the water surface of ten sites on the Paraná River in August 2013. Environmental variables were also determined. The highest number of taxa belonged to families Brachionidae, Lecanidae and Trichocercidae. The most abundant species was observed to Synchaeta oblonga, Keratella cochlearis, Brachionus calyciflorus. The species dissimilarity between sampling sites, tested using the Sorensen index, showed high dissimilarity between sampling sites. Redundancy analysis indicated a significant relationship between environmental variables (total phosphorus and ammonia and abundance of Brachionus calyciflorus and Keratella cochlearis, in the last sampling site. Our results suggest a greater dissimilarity between the rotifer communities according to increasing distance from the Porto Primavera Dam. In addition, a higher influence of the environmental variables related to trophic conditions was observed in the last sampling site, and influenced indirectly the occurrence and abundance of some rotifer species, due to increased availability of food resources, confirming the predicted hypothesis.

  10. 元荡湖水域后生浮游动物群落特征与水质评价%Features of Metazoan Zooplankton and Water Quality Assessment in Yuandang Lake Area

    Institute of Scientific and Technical Information of China (English)

    胡景; 钟俊生; 郁蔚文; 王忆; 陈立婧

    2016-01-01

    Objective] The aim was to study community features of metazoan zooplankton in Yuandang Lake area and evaluate its water quality. [Method] The species, existing quantity, biological diversity of metazoan zooplankton in Yuandang Lake area was investigated in 2013. [Result] There were 20 species of metazoan zooplankton in the lake, belonging to 11 genera, including 11 species of rotifer ,6 species of cladocera and 3 species of copepoda. The dominant species were Brachionus calyciflorus, Brachionus diversicornis, Notholon labis , Asplanchna brightwel, Dicran-ophorus caudatas, Moina micrura, Bosmina longirostris, Bosmina coregoni , Calanus sinicus, Paracyclops fimbriatus and Onychocamptus moham-med. The statistics indicated that the highest density of metazoan zooplankton was in autumn (184. 7 ind/L). The highest biomass was in spring (1. 193 mg/L). [Conclusion] Based on the Shannon-Wiener index, the B/T index of rotifer, the E/O index of metazoan zooplankton and the species sensitive to eutrophication, biological assessment of water quality suggested that the Yuandang Lake area is on mid-eutrophication.%[目的]研究元荡湖水域后生浮游动物群落特征,对元荡湖水域水质进行初步评价。[方法]于2013年对元荡湖水域后生浮游动物的种类组成、现存量、生物多样性等进行了调查研究。[结果]后生浮游动物共有11属20种,包括轮虫11种,枝角类6种,桡足类3种。主要优势种为萼花臂尾轮虫(Brachionus calyciflorus)、裂足臂尾轮虫(Brachionus diversicornis)、唇形叶轮虫(Notholon labis)、卜氏晶囊轮虫(Asplanchna brightwel)、尾猪吻轮虫(Dicranophorus caudatas)、微型裸腹溞(Moina micrura)、长额象鼻溞(Bosmina longirostris)、简弧象鼻溞(Bosmina coregoni)、中华哲水蚤(Calanus sinicus)、毛饰拟剑水蚤(Paracyclops fimbriatus)和模式有爪猛水溞(Onychocamptus moham-med)。调查数据显示,元荡湖后生浮游动物生物密度最高峰出现在秋季,达184

  11. Phototransformation of Amlodipine in Aqueous Solution: Toxicity of the Drug and Its Photoproduct on Aquatic Organisms

    Directory of Open Access Journals (Sweden)

    Marina DellaGreca

    2007-01-01

    Full Text Available The phototransformation of amlodipine in water was investigated under various conditions. A quantum yield ΦS2.2×10−4 and a half-life time t1/2 0.419 days were calculated when the drug in water (10−4 M was exposed to sunlight. The only photoproduct found was its pyridine derivative. Formation of this product was explained on the basis of a radical cation intermediate. The acute and chronic toxicity of the drug and its photoproduct were evaluated on different organisms of the freshwater chain (Brachionus calyciflorus, Thamnocephalus platyurus, Daphnia magna, Ceriodaphnia dubia. The photoproduct exhibited a stronger toxic potential than the parent drug on the long time for C. dubia.

  12. Acute and chronic toxicity testing of bisphenol A with aquatic invertebrates and plants.

    Science.gov (United States)

    Mihaich, Ellen M; Friederich, Urs; Caspers, Norbert; Hall, A Tilghman; Klecka, Gary M; Dimond, Stephen S; Staples, Charles A; Ortego, Lisa S; Hentges, Steven G

    2009-07-01

    Bisphenol A (BPA, 4,4'-isopropylidine diphenol) is a commercially important chemical used primarily as an intermediate in the production of polycarbonate plastic and epoxy resins. Extensive effect data are currently available, including long-term studies with BPA on fish, amphibians, crustaceans, and mollusks. The aim of this study was to perform additional tests with a number of aquatic invertebrates and an aquatic plant. These studies include acute tests with the midge (Chironomus tentans) and the snail (Marisa cornuarietis), and chronic studies with rotifers (Brachionus calyciflorus), amphipods (Hyalella azteca), and plants (Lemna gibba). The effect data on different aquatic invertebrate and plant species presented in this paper correspond well with the effect and no-effect concentrations (NOECs) available from invertebrate studies in the published literature and are within the range found for other aquatic species tested with BPA. PMID:19327838

  13. A Rotifer-Based Technique to Rear Zebrafish Larvae in Small Academic Settings.

    Science.gov (United States)

    Allen, Raymond L; Wallace, Robert L; Sisson, Barbara E

    2016-08-01

    Raising zebrafish from larvae to juveniles can be laborious, requiring frequent water exchanges and continuous culturing of live feed. This task becomes even more difficult for small institutions that do not have access to the necessary funding, equipment, or personnel to maintain large-scale systems usually employed in zebrafish husbandry. To open this opportunity to smaller institutions, a cost-efficient protocol was developed to culture Nannochloropsis to feed the halophilic, planktonic rotifer Brachionus plicatilis; the rotifers were then used to raise larval zebrafish to juveniles. By using these methods, small institutions can easily raise zebrafish embryos in a cost-efficient manner without the need to establish an extensive fish-raising facility. In addition, culturing rotifers provides a micrometazoan that serves as a model organism for teaching and undergraduate research studies for a variety of topics, including aging, toxicology, and predator-prey dynamics. PMID:26886557

  14. Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

    International Nuclear Information System (INIS)

    Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

  15. 药物杀除极大螺旋藻培养液中的轮虫的初步研究%Primary Study on Using Medicine to Exterminate Brachionu plicatilis in the Cultivation Liquid of Spirulina maxima

    Institute of Scientific and Technical Information of China (English)

    赵素芬; 黄壹叁; 官武林

    2005-01-01

    通过向极大螺旋藻(Spirulina maxima)培养液中添加"轮虫克星Ⅰ号"以杀除褶皱臂尾轮虫(Brachionus plicatilis)的试验,表明该药物能有效杀灭藻液中的褶皱臂尾轮虫;后者的死亡时间、死亡率以及杀灭轮虫后螺旋藻的恢复情况与药物的浓度有关;在试验范围内既能杀灭轮虫、对螺旋藻生长的影响又较小的最佳药物浓度为1.25%.

  16. Rotifer community structure and assessment of water quality in Yangcheng Lake

    Institute of Scientific and Technical Information of China (English)

    CHEN Lijing; LIU Qiao; PENG Ziran; HU Zhongjun; XUE Junzeng; WANG Wu

    2012-01-01

    Rotifer community structure was investigated in Yangcheng Lake in 2008.Dominant species and species diversity indices were determined and QB/T was used to assess water quality.The annual average density and biomass of the rotifers in Yangcheng Lake was 2 894± 1 006 ind./L and 12.47± 10.28 mg/L,respectively.The highest densities were observed in the western portion of the lake in March,but the highest biomass occurred in inflowing creeks in September.Within a year of monitoring in Yangcheng Lake,93 species were identified and the dominant species were found to be Polyarthra trigla,Brachionus angularis,Keratella cochlearis,Keratella valga,Brachionus calyciflorus,and Filinia major.Of the species recorded,75 were pollution indicator species.Density and biomass exhibited significant positive correlations with water temperature (R=0.209,P=0.003; R=0.446,P=0.000),but the peak density showed two lags in response to chl a.According to the Jaccard similarity index (SJ),the greatest similarity among dominant species occurred between creeks and the eastern part of the lake.The annual average Shannon-Wiener diversity index H',Margalef richness index D and Pielou evenness index J were 1.96±0.34,1.61 ±0.50and 0.77±0.10,respectively.In all four areas of Yangcheng Lake,β- mesosaprobic species comprised the largest share of pollution indicator species.These data suggest that Yangcheng Lake is mesosaprobic.

  17. Water quality in Lake Xochimilco, Mexico: zooplankton indicators and Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    Sarma Nandini

    2015-08-01

    Full Text Available Lake Xochimilco is a eutrophic water body in Mexico City used by the local population for aquaculture and agriculture. Water level is maintained with inputs of partially treated waste water from the Cerro de la Estrella treatment plant. In this study we analysed the water quality at two sites of Lake Xochimilco, Lake Xaltocan and the Santa Cruz Canal using various indicators such as zooplankton diversity, saprobic indices, bacterial concentrations and physico-chemical variables. Eighty litres of water was filtered from Lake Xochimilco from each site, once a month from March to October of 2012, and the rotifers, cladocerans and copepods were enumerated and identified. Physico-chemical parameters such as temperature, pH, Secchi depth, water depth, nitrogen and phosphorus and chlorophyll a concentrations, and bacterial densities were measured. During the study we recorded 33 species of rotifers, the most abundant being Brachionus angularis, B. calyciflorus and B. havanaensis.  Among the microcrustaceans the most abundant were the cladoceran Moina micrura and the copepods Acanthocyclops americanus and Arctodiaptomus dorsalis. The species diversity was around 2 bits/ind. and the saprobic index between 1.5-2.0, indicating that both sites were β meso-saprobic.  At both sites nitrogen was <1 mg/L and phosphorus ranged between 2.5-7.8 mg/L. Chlorophyll a concentrations were between 66-136 µg/L. The toxigenic (Vibrio cholerae No-O1/No-O139 and the non-toxigenic (Vibrio cholerae No-O135 strains of the bacterium were recorded, closely associated with littoral rotifers and cladocerans particularly Brachionus quadridentatus and  Alona sp. All variables indicate that these sites in Lake Xochimilco are eutrophic and highly contaminated and that the water quality needs to be improved.

  18. Feeding and filtration rates of zooplankton (rotifers and cladocerans) fed toxic cyanobacterium (Microcystis aeruginosa).

    Science.gov (United States)

    Pérez-Morales, Alfredo; Sarma, S S S; Nandini, S

    2014-11-01

    Microcystis aeruginosa is generally dominant in many Mexican freshwater ecosystems interacting with zooplankton species. Hence, feeding and filtration rates were quantified for three cladoceran (Daphnia pulex, Moina micrura and Ceriodaphnia dubia) and three rotifer species (Brachionus calyciflorus, Brachionus rubens and Plationus patulus) using sonicated M. aeruginosa alone or mixed with Scenedesmus acutus in different proportions (25, 50 and 75%, based on cell density), offering a combined initial density of 100,000 cells·ml(-1). All the three cladoceran species ingested M. aeruginosa (100-300 cells ind(-1) min(-1)) when fed exclusively with cyanobacterium. When green alga offered as exclusive diet, the number of cells ingested by the tested cladocerans varied from 80 to 400 cells ind(-1) min(-1). Compared to cladocerans, rotifers in general consumed much lower quantity (< 200 cells ind(-1) min(-1)) of M. aeruginosa and S. acutus. The filtration rate for Daphnia pulex was inversely related to the proportion of green alga in the diet. For other tested cladocerans, no such clear trend was evident. In mixed treatments containing M. aeruginosa, the filtration rate of Daphnia was highest (about 220 μl ind(-1) min(-1)) when the medium contained 75% of S. acutus. Among the rotifer species, P. patulus filtered highest volume (100 μl ind(-1) min(-1) from mixed diets containing higher proportions (50 or 75%) of M. aeruginosa. Thus, there were species-specific differences in the filtration and feeding rates of zooplankton when offered mixed diets of green algae and toxic cyanobacteria. These probably explain the coexistence of different zooplankton species in Microcystis-dominant waterbodies. PMID:25522500

  19. The zooplankton biodiversity of some freshwater environments in Parnaíba basin (Piauí, Northeastern Brazil).

    Science.gov (United States)

    Paranhos, J D N; Almeida, V L S; Silva Filho, J P; Paranaguá, M N; Melo, M; Neumann-Leitão, S

    2013-02-01

    The plankton fauna of the state of Piauí, Northeastern Brazil, especially in the Parnaíba basin, is still poorly known; the results of most studies of the subject have not been published and can only be found in grey literature (unpublished scientific works), such as course completion work and consulting reports. Thus, this paper presents data from samples taken recently from different water bodies in Piauí and represents the second study to be published on the region's zooplankton since the pioneering work of Spandl (1926). A total of 38 species were recorded, including 23 new occurrences of rotifers, 10 of cladocerans and 2 of copepods for the state of Piauí. The greatest richness was observed for the rotifers, of which the genus Brachionus must be highlighted, especially at the Joana reservoir. Among the crustaceans, the greatest richness was observed at the Bezerra reservoir, where cladocerans of the genus Bosmina were prominent. The rotifers Brachionus havanaensis Rousselet, 1911 and Filinia longiseta (Ehrenberg, 1834); the cladocerans Diaphanosoma spinulosum Herbst, 1967 and Moina micrura Kurz, 1874; and the copepods Notodiaptomus cearensis Wright, 1936 and Thermocyclops decipiens Kiefer, 1927 occurred in all or in most environments in which the respective groups were studied. The results presented here expand the taxonomic list of zooplankton for the state of Piauí, including a total fauna of 30 species of rotifers, 15 of cladocerans and 3 of copepods. The zooplankton richness was considered low in the studied reservoirs compared to other freshwater ecosystems from Northeastern Brazil; however, the few studies developed in the Parnaíba basin suggest that the diversity for these organisms should be higher. PMID:23644795

  20. The zooplankton biodiversity of some freshwater environments in Parnaíba basin (Piauí, Northeastern Brazil).

    Science.gov (United States)

    Paranhos, J D N; Almeida, V L S; Silva Filho, J P; Paranaguá, M N; Melo, M; Neumann-Leitão, S

    2013-02-01

    The plankton fauna of the state of Piauí, Northeastern Brazil, especially in the Parnaíba basin, is still poorly known; the results of most studies of the subject have not been published and can only be found in grey literature (unpublished scientific works), such as course completion work and consulting reports. Thus, this paper presents data from samples taken recently from different water bodies in Piauí and represents the second study to be published on the region's zooplankton since the pioneering work of Spandl (1926). A total of 38 species were recorded, including 23 new occurrences of rotifers, 10 of cladocerans and 2 of copepods for the state of Piauí. The greatest richness was observed for the rotifers, of which the genus Brachionus must be highlighted, especially at the Joana reservoir. Among the crustaceans, the greatest richness was observed at the Bezerra reservoir, where cladocerans of the genus Bosmina were prominent. The rotifers Brachionus havanaensis Rousselet, 1911 and Filinia longiseta (Ehrenberg, 1834); the cladocerans Diaphanosoma spinulosum Herbst, 1967 and Moina micrura Kurz, 1874; and the copepods Notodiaptomus cearensis Wright, 1936 and Thermocyclops decipiens Kiefer, 1927 occurred in all or in most environments in which the respective groups were studied. The results presented here expand the taxonomic list of zooplankton for the state of Piauí, including a total fauna of 30 species of rotifers, 15 of cladocerans and 3 of copepods. The zooplankton richness was considered low in the studied reservoirs compared to other freshwater ecosystems from Northeastern Brazil; however, the few studies developed in the Parnaíba basin suggest that the diversity for these organisms should be higher.

  1. Water quality and potamoplankton evaluation of the Nile River in Upper Egypt

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed El-Otify

    2015-06-01

    Full Text Available Aim: The composition, abundance, community structure of potamoplankton and major physical and chemical variables of the Nile water in Upper Egypt were investigated to assess its status in different seasons during 2007.MethodsWater samples were collected seasonally during 2007 from six investigated sites from variable depths at levels of 0, 2.5 and 5 m. The area of this investigation is defined as the southern 120 Km of the main stream of the Nile in Upper Egypt (24° 04’ – 25° 00’ latitudes and 32° 51’ – 32° 54’ longitudes, downstream of Aswan Old Dam.ResultsAltogether, 121 potamoplankton species, of which 85 related to phytoplankton and 36 appertaining to zooplankton were recorded. Most numerous phytoplankton were Chlorophyceae (42 species followed by Bacillariophyceae (30 species. Cyanobacteria and Dinophyceae were less numerous with only 11 and 2 species, respectively. Zooplankton species were mainly belonging to three systematic groups namely; Rotifera (24 species, Copepoda (3 species and Cladocera (9 species. Besides, other rare zooplankton including Platyhelminthes, Nemata and Ciliophora were sparsely encountered. The main hydrological conditions characterizing the investigated area include water level fluctuations (˂82 - ˃85 m above sea level, relatively high current velocity (0.8 - 1.3 m sec–1 and disposal of wastewater. Plankton populations were variably but rather weakly dependent on the major nutrients due to their excessive availability in accessible form for uptake by the producers. For phytoplankton, the community structure was categorized in relation to temperature, pH, SO42– and Mg2+. For zooplankton, the community structure was categorized in relation to conductivity as well as Mg2+. Sampling intervals were inadequate to demonstrate the existing successional pattern of the Nile potamoplankton community. Alterations in the phytoplankton community structure accompanied changes in water temperature represented

  2. A functional difference between native and horizontally acquired genes in bdelloid rotifers.

    Science.gov (United States)

    Barbosa, Elton G G; Crisp, Alastair; Broadbent, Sarah E; Carrillo, Martina; Boschetti, Chiara; Tunnacliffe, Alan

    2016-09-15

    The form of RNA processing known as SL trans-splicing involves the transfer of a short conserved sequence, the spliced leader (SL), from a noncoding SL RNA to the 5' ends of mRNA molecules. SL trans-splicing occurs in several animal taxa, including bdelloid rotifers (Rotifera, Bdelloidea). One striking feature of these aquatic microinvertebrates is the large proportion of foreign genes, i.e. those acquired by horizontal gene transfer from other organisms, in their genomes. However, whether such foreign genes behave similarly to native genes has not been tested in bdelloids or any other animal. We therefore used a combination of experimental and computational methods to examine whether transcripts of foreign genes in bdelloids were SL trans-spliced, like their native counterparts. We found that many foreign transcripts contain SLs, use similar splice acceptor sequences to native genes, and are able to undergo alternative trans-splicing. However, a significantly lower proportion of foreign mRNAs contains SL sequences than native transcripts. This demonstrates a novel functional difference between foreign and native genes in bdelloids and suggests that SL trans-splicing is not essential for the expression of foreign genes, but is acquired during their domestication. PMID:27312952

  3. Ecological factors affecting the distribution of the zooplankton community in the Tigris River at Baghdad region, Iraq

    Directory of Open Access Journals (Sweden)

    Shayma Abdulwahab

    2015-01-01

    Full Text Available Biodiversity of zooplankton in the Tigris River running in Baghdad City, central Iraq, was investigated. Fourteen physical and chemical parameters, were analyzed, these parameters include water and air temperature, pH, EC, turbidity, TDS, DO, BOD5, total hardness, Ca+2, Mg+2, chloride, nitrate and reactive phosphate. Most of these values were within of the Iraqi and international standard limits. In all, 106 taxonomy units of zooplankton were identified, including 65 taxa belonging to rotifers, 25 taxa to copepod and 16 taxa to Cladocera. Values of species richness index of rotifers varied from 1.051 to 12.98, for Cladocera from 1.285 to 3.41 and for copepod from 1.5 to 7.2. The Shannon–Weiner index of Rotifera varied from 0.67 to 3, 0.50–1.72 for Cladocera and from 0.91 to 2.51 for Copepoda. The uniformity index of zooplankton varied from 0.41 to 0.93 for rotifer, 0.33–1 for Cladocera and 0.36–1 for Copepoda. According to statistical analysis, temperature, EC, TDS and dissolved oxygen were observed as major factors which restrict the abundance and diversity of the zooplankton communities in the Tigris River.

  4. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Roque, C.V.; Nascimento, M.R. [Brazilian Nuclear Energy Commission/Pocos de Caldas Laboratory (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Laboratory (Brazil)

    2014-07-01

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m{sup -3}), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  5. Zooplankton community resilience and aquatic environmental stability on aquaculture practices: a study using net cages.

    Science.gov (United States)

    Dias, J D; Simões, N R; Bonecker, C C

    2012-02-01

    Fish farming in net cages causes changes in environmental conditions. We evaluated the resilience of zooplankton concerning this activity in Rosana Reservoir (Paranapanema River, PR-SP). Samples were taken near the net cages installed at distances upstream and downstream, before and after net cage installation. The resilience was estimated by the decrease in the groups' abundance after installing the net cages. The zooplankton community was represented by 106 species. The most abundant species were Synchaeta pectinata, S. oblonga, Conochilus coenobasis, Polyarthra dolichoptera and C. unicornis (Rotifera), Ceriodaphnia cornuta, Moina minuta, Bosmina hagmanni and C. silvestrii (Cladocera) and Notodiaptomus amazonicus (Copepoda). The resilience of microcrustaceans was affected in the growing points as this activity left the production environment for longer, delaying the natural ability of community responses. Microcrustaceans groups, mainly calanoid and cyclopoid copepods, had a different return rate. The net cage installation acted as a stress factor on the zooplankton community. Management strategies that cause fewer risks to the organisms and maximize energy flow may help in maintaining system stability. PMID:22437379

  6. Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

    Directory of Open Access Journals (Sweden)

    Padanillay C. Prabu

    2008-05-01

    Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

  7. Independent origins of parasitism in Animalia.

    Science.gov (United States)

    Weinstein, Sara B; Kuris, Armand M

    2016-07-01

    Nearly half of all animals may have a parasitic lifestyle, yet the number of transitions to parasitism and their potential for species diversification remain unresolved. Based on a comprehensive survey of the animal kingdom, we find that parasitism has independently evolved at least 223 times in just 15 phyla, with the majority of identified independent parasitic groups occurring in the Arthropoda, at or below the level of Family. Metazoan parasitology is dominated by the study of helminthes; however, only 20% of independently derived parasite taxa belong to those groups, with numerous transitions also seen in Mollusca, Rotifera, Annelida and Cnidaria. Parasitism is almost entirely absent from deuterostomes, and although worm-like morphology and host associations are widespread across Animalia, the dual symbiotic and trophic interactions required for parasitism may constrain its evolution from antecedent consumer strategies such as generalist predators and filter feeders. In general, parasitic groups do not differ from their free-living relatives in their potential for speciation. However, the 10 largest parasitic clades contain 90% of described parasitic species, or perhaps 40% of all animal species. Hence, a substantial fraction of animal diversity on the Earth arose following these few transitions to a parasitic trophic strategy. PMID:27436119

  8. Potential pest transfer mediated by international ornamental plant trade

    Science.gov (United States)

    Patoka, Jiří; Bláha, Martin; Kalous, Lukáš; Vrabec, Vladimír; Buřič, Miloš; Kouba, Antonín

    2016-01-01

    In recent years, the keeping of ornamental freshwater animals and plants in garden ponds has been growing in popularity. Water hyacinth (Eichhornia crassipes) is one of the preferred macrophytes seasonally imported mainly from South-eastern Asia throughout the world. This constitutes a secondary introduction inasmuch as the species is native to South America. Although many assemblages of aquatic invertebrates have been described as associated with this plant in the wild, there has been no research focused on their potential introduction via the international plant trade. We examined 216 specimens of water hyacinths imported for ornamental purposes from Indonesia into the Czech Republic. Numerous meio- and macroinvertebrates belonging to at least 39 species were captured. On the total number of individuals, the highest prevalence was of Tubulinea and Rotifera. Most of these were still alive and vital, including a caterpillar of the Indo–Australian invasive moth Spodoptera litura. Water hyacinths are usually placed into outdoor ponds immediately after import, which facilitates the release of non-target alien species. The present paper aims to draw attention to “hitchhikers” associated with the ornamental trade. PMID:27221025

  9. Bacterial and eukaryotic biodiversity patterns in terrestrial and aquatic habitats in the Sør Rondane Mountains, Dronning Maud Land, East Antarctica.

    Science.gov (United States)

    Obbels, Dagmar; Verleyen, Elie; Mano, Marie-José; Namsaraev, Zorigto; Sweetlove, Maxime; Tytgat, Bjorn; Fernandez-Carazo, Rafael; De Wever, Aaike; D'hondt, Sofie; Ertz, Damien; Elster, Josef; Sabbe, Koen; Willems, Anne; Wilmotte, Annick; Vyverman, Wim

    2016-06-01

    The bacterial and microeukaryotic biodiversity were studied using pyrosequencing analysis on a 454 GS FLX+ platform of partial SSU rRNA genes in terrestrial and aquatic habitats of the Sør Rondane Mountains, including soils, on mosses, endolithic communities, cryoconite holes and supraglacial and subglacial meltwater lenses. This inventory was complemented with Denaturing Gradient Gel Electrophoresis targeting Chlorophyta and Cyanobacteria. OTUs belonging to the Rotifera, Chlorophyta, Tardigrada, Ciliophora, Cercozoa, Fungi, Bryophyta, Bacillariophyta, Collembola and Nematoda were present with a relative abundance of at least 0.1% in the eukaryotic communities. Cyanobacteria, Proteobacteria, Bacteroidetes, Acidobacteria, FBP and Actinobacteria were the most abundant bacterial phyla. Multivariate analyses of the pyrosequencing data revealed a general lack of differentiation of both eukaryotes and prokaryotes according to habitat type. However, the bacterial community structure in the aquatic habitats was dominated by the filamentous cyanobacteria Leptolyngbya and appeared to be significantly different compared with those in dry soils, on mosses, and in endolithic habitats. A striking feature in all datasets was the detection of a relatively large amount of sequences new to science, which underscores the need for additional biodiversity assessments in Antarctic inland locations. PMID:26936447

  10. Plankton Resting Stages in the Marine Sediments of the Bay of Vlorë (Albania

    Directory of Open Access Journals (Sweden)

    Fernando Rubino

    2013-01-01

    Full Text Available In the frame of the INTERREG III CISM project, sediment cores were collected at 2 stations in the Gulf of Vlorë to study the plankton resting stage assemblages. A total of 87 morphotypes were identified and produced by Dinophyta, Ciliophora, Rotifera, and Crustacea. In 22 cases, the cyst belonged to a species absent from the plankton of the same period. The most abundant resting stages were those produced by Scrippsiella species (Dinophyta. Some calcareous cysts were identified as fossil species associated with Pleistocene to Pliocene sediment, although they were also found in surface sediments and some of them successfully germinated, thus proving their modern status. Total abundance generally decreased with sediment depth at station 40, while station 45 showed distinct maxima at 3 and 8 cm below the sediment surface. The depth of peak abundance in the sediment varied with species. This paper presents the first study of the plankton resting stages in the Bay of Vlorë. The study confirmed the utility of this type of investigation for a more correct evaluation of species diversity. In addition, the varying distribution with sediment depth suggests that this field could be of some importance in determining the history of species assemblages.

  11. Spatial heterogeneity in a deep artificial lake plankton community revealed by PCR-DGGE fingerprinting

    Science.gov (United States)

    Li, Qiang; Zhao, Yue; Zhang, Xu; Wei, Yuquan; Qiu, Linlin; Wei, Zimin; Li, Fuheng

    2015-05-01

    To explore the spatial heterogeneity of plankton communities in a deep artificial lake (Songhua Lake, China), samples were collected at seven sites. Samples were investigated by denaturing gradient gel electrophoresis (DGGE) analysis of the PCR-amplified 16S and 18S rRNA genes and specific bands were sequenced. Cluster analysis of the DGGE profiles revealed that all of the samples grouped into two distinct clusters, in accordance with sampling site; while in each cluster, the divergence of sub-clusters correlated with sampling depth. Sequence analysis of selected dominant DGGE bands revealed that most sequenced phylotypes (84%) exhibited ≥97% similarity to the closest sequences in GenBank, and were affiliated with ten common freshwater plankton phyla ( Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Bacillariophyta, Pyrrophyta, Cryptophyta, Ciliophora, Stramenopiles, and Rotifera). Several of these groups are also found worldwide, indicating the cosmopolitan distribution of the phylotypes. The relationships between DGGE patterns and environmental factors were analyzed by redundancy analysis (RDA). The results suggested that, total nitrogen, nitrate, nitrite, ammonia, and CODMn concentrations, and water temperature were strongly correlated with the variation in plankton composition.

  12. Potential pest transfer mediated by international ornamental plant trade.

    Science.gov (United States)

    Patoka, Jiří; Bláha, Martin; Kalous, Lukáš; Vrabec, Vladimír; Buřič, Miloš; Kouba, Antonín

    2016-01-01

    In recent years, the keeping of ornamental freshwater animals and plants in garden ponds has been growing in popularity. Water hyacinth (Eichhornia crassipes) is one of the preferred macrophytes seasonally imported mainly from South-eastern Asia throughout the world. This constitutes a secondary introduction inasmuch as the species is native to South America. Although many assemblages of aquatic invertebrates have been described as associated with this plant in the wild, there has been no research focused on their potential introduction via the international plant trade. We examined 216 specimens of water hyacinths imported for ornamental purposes from Indonesia into the Czech Republic. Numerous meio- and macroinvertebrates belonging to at least 39 species were captured. On the total number of individuals, the highest prevalence was of Tubulinea and Rotifera. Most of these were still alive and vital, including a caterpillar of the Indo-Australian invasive moth Spodoptera litura. Water hyacinths are usually placed into outdoor ponds immediately after import, which facilitates the release of non-target alien species. The present paper aims to draw attention to "hitchhikers" associated with the ornamental trade. PMID:27221025

  13. Feeding of the hyperbenthic mysid Neomysis integer in the maximum turbidity zone of the Elbe, Westerschelde and Gironde estuaries

    Science.gov (United States)

    Fockedey, N.; Mees, J.

    1999-10-01

    The diet of the mysid Neomysis integer in the maximum turbidity zone (MTZ) of three European estuaries (Elbe, Westerschelde and Gironde) was investigated in spring 1993. The quality and quantity of the diet were assessed through measurement of the stomach fullness and microscopical analysis of the stomach content combined with image analyses. N. integer was found to be an omnivore which mainly utilizes mesozooplankton and detritus carbon pools. The quality of the diet did not differ between the sexes or between different developmental stages, although smaller individuals consumed fewer items. In all three estuaries the diet was dominated by Copepoda Calanoida (5-10 Eurytemora affinis ind -1 for adults; 2-5 ind -1 and 2-3 ind -1 for subadults and juveniles, respectively) and was supplemented with Rotifera and Cladocera. Phytoplankton and benthic organisms, though present in the stomachs, were negligible. Macrophytal detritus and amorphous material, the latter unidentifiable under the light microscope, were very abundant food items. The amorphous detritus was found to originate from the suspended sediment flocs which are characteristic for the MTZ and mainly consist of clay minerals. The energetic value of the flocs for N. integer remains unclear.

  14. Distribution and diet of larval and juvenile Arctic cod ( Boreogadus saida) in the shallow Canadian Beaufort Sea

    Science.gov (United States)

    Walkusz, Wojciech; Paulic, Joclyn E.; Williams, William J.; Kwasniewski, Slawomir; Papst, Michael H.

    2011-02-01

    The distribution and diet of larval and juvenile Arctic cod ( Boreogadus saida) were studied during summer 2005 in the coastal Canadian Beaufort Sea. A total of 275 individuals were captured and the highest abundance was observed at station depths of 20-30 m. This corresponds well with the location of the frontal zone where the Mackenzie River plume water and open sea water meet. Diet examinations were performed on 220 Arctic cod, which were found undamaged from sampling. We observed a gradual decrease in prey number per fish and increase in prey size as larvae grew which corresponded to a shift from Rotifera and nauplii towards larger copepodid stages. However, at all sizes, the larvae remain generalists and feed on a broad range of organisms. Environmental changes due to climate warming could have a two-fold impact on fish larvae feeding in the studied region. First, the potential for increased primary production may lead to increased zooplankton production that may impact the feeding and nutrition positively. On the other hand, greater discharge of turbid water from the Mackenzie River may reduce light penetration in the water column that may negatively influence the ability of visual predators to successively forage.

  15. Impact of environmental factors on maintaining water quality of Bakreswar reservoir, India

    Directory of Open Access Journals (Sweden)

    Moitreyee Banerjee

    2015-09-01

    Full Text Available Reservoirs and dams are engineered systems designed to serve purposes like supply of drinking water as well as other commercial and industrial use. A thorough assessment of water quality for these systems is thus necessary. The present study is carried out at Bakreswar reservoir, in Birbhum district, which was created by the dam, built on Bakreswar River. The major purpose of the reservoir is the supply of drinking water to the surrounding villages and Bakreswar Thermal Power Station. Water samples were collected fortnightly from three different stations of the reservoir. Physical and chemical factors like dissolved oxygen, atmospheric temperature, pH, conductivity, salinity, solar radiation, water temperature, alkalinity, hardness, chloride, productivity etc. were analysed using standard procedure. Abundance data is calculated for four major groups of zooplanktons (Cladocera, Copepoda, Ostracoda, and Rotifera with the software PAST 2.1. Multivariate statistical analysis like PCA, hierarchical cluster and CCA are performed in order to predict the temporal variation in the water quality factors using SPSS 20. Distinct seasonal variation was found for environmental factors and zooplankton groups. Bakreswar reservoir has good assemblage of zooplankton and distinct temporal variation of environmental factors and its association with zooplankton predicts water quality condition. These results could help in formulating proper strategies for advanced water quality management and conservation of reservoir ecosystem. Key elements for growth and sustenance of the system can then be evaluated and this knowledge can be further applied for management purposes.

  16. Gnathostomulida--an enigmatic metazoan phylum from both morphological and molecular perspectives.

    Science.gov (United States)

    Littlewood, D T; Telford, M J; Clough, K A; Rohde, K

    1998-02-01

    On the basis of few and contentious morphological characters Gnathostomulids have been thought to be the sister-group of either the Platyhelminthes or the Syndermata (Rotifera + Acanthocephala). We provide a full 18S rDNA sequence for a species of Gnathostomula and attempt to resolve its position among the Metazoa, on the basis of molecular evidence. Sixty sequences, representing 30 nominal phyla and including new entoproct and gastrotrich sequences, were used to reconstruct phylogenies using maximum-parsimony, neighbor-joining, and minimum evolution models. We were unable to support either of the morphological hypotheses outright and, moreover, our data supported more strongly a third possible relationship with the gnathostomulids as a member of the Nematoda + Chaetognatha clade. Superficially, as active benthic, vermiform creatures with sclerotized cuticular jaws, they fit a predicted ancestral form of the Nematoda + Chaetognatha clade and, as such, would arguably be members of the Ecdysozoa. The molecular data at least call for a reevaluation of the morphological data and a denser sampling of the lesser phyla. Data from morphology and molecules act synergistically in estimating phylogeny; morphology alone provided limited phylogenetic signal and alternative phylogenetic hypotheses, whereas the molecular solution suggested an alternative topology which, when interpreted in the light of comparative anatomy, may suggest previously unconsidered possibilities. PMID:9479696

  17. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    International Nuclear Information System (INIS)

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m-3), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  18. Abundance of plankton population densities in relation to bottom soil textural types in aquaculture ponds

    Directory of Open Access Journals (Sweden)

    F. Siddika

    2012-06-01

    Full Text Available Plankton is an important food item of fishes and indicator for the productivity of a water body. The present study was conducted to evaluate the effects of bottom soil textural conditions on abundance of plankton in aquaculture pond. The experiment was carried out using three treatments, i.e., ponds bottom with sandy loam (T1, with loam (T2 and with clay loam (T3. The ranges of water quality parameters analyzed were suitable for the growth of plankton during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed higher ranges in T2. A total 20 genera of phytoplankton were recorded belonged to Chlorophyceae (7, Cyanophyceae (5, Bacillariophyceae (5, Euglenophyceae (2 and Dinophyceae (1. On the other hand, total 13 genera of zooplankton were recorded belonged to Crustacea (7 and Rotifera (6. The highest ranges of phytoplankton and zooplankton densities were found in T2 where low to medium-type bloom was observed during the study period. Consequently, the mean abundance of plankton (phytoplankton and zooplankton density was significantly highest in T2. The highest abundance of plankton in the T2 indicated that pond bottom with loamy soil is suitable for the growth and production of plankton in aquaculture ponds.

  19. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    Science.gov (United States)

    Tang, L.; Li, H. X.; Yan, Y.

    2012-04-01

    Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, Pnematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, Pnematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by environmental variations.

  20. Water quality and zooplankton in tanks with larvae of Brycon Orbignyanus (Valenciennes, 1949).

    Science.gov (United States)

    Sipaúba-Tavares, L H; Alvarez, E J da S; Braga, F M de S

    2008-02-01

    Due to the importance of water variables conditions and available food in the development and survival of fish larvae, the current research evaluates the effects of two different food treatments (ration + zooplankton and only zooplankton) and water quality in tanks with Brycon orbignyanus larvae. Total water transparency (45 cm) has been mainly associated with short residence time, continuous water flow and shallowness. Dissolved oxygen ranged between 1.32 and 7.00 mg.L(-1) in tanks with ration + zooplankton and between 1.82 and 7.60 mg.L(-1) in tanks with only zooplankton treatments. Nutrients were directly affected by the addition of ration in water, with the exception of nitrite. Ten Rotifera species were found represented by high densities, ranging between 8.7 x 10(5) and 1.3 x 10(6) org.m(-3), throughout the experimental period (January to March/1996). Cladocera had the lowest density in the four tanks under analysis and ranged between 4.7 x 10(4) and 2.1 x 10(5) org.m(-3) for the six species. Diaphanosoma birgei has been classified as the most frequent species. Since ration + zooplankton produced better larvae yield, this treatment is recommended for Brycon orbignyanus larvae.

  1. A influência da larva de Chaoborus brasiliensis (Theobald, 1901 (Diptera, Chaoboridae na distribuição vertical da comunidade zooplanctônica da lagoa do Nado, Belo Horizonte, Estado de Minas Gerais The influence of the Chaoborus brasiliensis (Theobald, 1901 (Diptera, Chaoboridae larvae in the zooplankton vertical distribution at Nado Lagoon, Belo Horizonte, state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    José Fernandes Bezerra Neto

    2002-05-01

    Full Text Available Foi analisado o efeito do predador invertebrado, Chaoborus brasiliensis (Diptera, Chaoboridae, sobre a distribuição espacial dos táxons predominantes da comunidade zooplanctônica de um reservatório tropical raso, lagoa do Nado, explorando as mudanças na sobreposição espacial entre predador e presas durante a migração vertical diária. A comunidade zooplanctônica apresentou uma variada gama de respostas à pressão de predação exercida pelas larvas de Chaoborus. Diversos táxons exibiram MVD (Brachionus falcatus, B. caudatus, B. angularis, Moina micrura, Thermocyclops minutus e outros em que esse comportamento não foi tão nítido ou não foi detectado (K. cochlearis, K. tropica, K. bostoniensis e náuplios de T. minutus. A maioria dos táxons estudados tiveram a sua distribuição vertical associada à presença desse predador invertebrado, e a migração vertical diária dessas espécies foi importante na redução da sobreposição espacial com o predador. Além disso, o estudo demonstrou que esses padrões experimentam consideráveis mudanças ao longo do ciclo sazonal.The effects of Chaoborus brasiliensis (Diptera, Chaoboridae, an invertebrate predator, on the zooplankton spatial distribution in a shallow tropical reservoir, Nado Lagoon, were investigated in this work. The habitat overlap degree, i.e., the overlap in the vertical distribution of predator and potential preys was measured during diel vertical migration (DVM. The study focused the reservoir predominant taxa (defined as the most frequent and abundant species. Several organisms showed DVM (Brachionus falcatus, B. caudatus, B. angularis, Moina micrura and Thermocyclops minutus, while in others this behavior was not clear, or even not detected (Keratella cochlearis, K. tropica, K. bostoniensis and T minutus nauplii. The conclusion was that C. brasiliensis influenced directly most zooplankters spatial distribution in this reservoir, and DVM was important to reduce

  2. Vertical distribution of zooplankton in the water column of Lago Amapá, Rio Branco, Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Erlei Cassiano Keppeler

    2004-06-01

    Full Text Available The aim of investigation was to study the model of vertical distribution in Lago Amapá, taking into consideration the seasonality of its zooplanktonic composition. Lago Amapá (10º2'36"S and 67º50'24"W is located in the floodplain of the Rio Acre. Samplings were conducted at three different depths of the water column, to study the vertical distribution of zooplankton populations and determine some physico-chemical and biological parameters of Lago Amapá. Weekly samples were taken with a Van Dorn sampler. The species showed greater concentrations at the by means of water column. Thirty-eight zooplankton species were found in the samples represented by Rotifera (30, Cladocera (5 and Cyclopoida (3. The temperature of the water column showed a tendency toward relatively high values (about 30ºC with little variation, consequently resulting in low viscosity. Based of Jaccard's index, it was seen that during the low-water phase, S1 and S3 of the three sampling stations studied, had greater similarity (Cj = 0.7058 in the middle of the water column. Lago Amapá showed characteristics in line with the intermediate disturbance hypothesis model, favoring colonization by opportunistic species such as rotifers.O objetivo desta investigação foi observar a distribuição vertical da comunidade do zooplâncton no Lago Amapá (10º2'36"S e 67º50'24"W, localizado na planície de inundação do Rio Acre. Amostragens foram conduzidas em três diferentes profundidades da coluna da água, considerando aspectos sazonais do zooplâncton, parâmetros físicos, químicos e biológicos. Coletas foram realizadas semanalmente com Garrafa de Van Dorn. As espécies apresentaram maiores concentrações no meio da coluna da água. Foram encontradas 38 espécies, assim distribuídas: Rotifera (30, Cladocera (5 e Cyclopoida (3. A temperatura da coluna da água em geral apresentou-se alta, em torno de 30ºC, com pequena variação, resultando em baixa viscosidade. O

  3. EVALUACIÓN DE LA ROTIFEROFAUNA PRESENTE EN EL COMPLEJO DE PAJARALES DURANTE LA ÉPOCA LLUVIOSA, DEPARTAMENTO DE MAGDALENA, COLOMBIA Assessment Of The Pajarales Complex Rotiferofauna During The Rainy Season, Departamento De Magdalena, Colombia

    Directory of Open Access Journals (Sweden)

    SEBASTIÁN CELIS

    Full Text Available RESUMEN Con miras a evaluar posibles efectos de la recomunicación del río Magdalena con su antiguo delta, se determinó la abundancia y composición de la rotiferofauna del Complejo de Pajarales (CP, durante el período de mayor abundancia anual de zooplancton. El phylum Rotifera fue seleccionado por sus altas tasas reproductivas y eficiencia en procesos de transformación energética. Las muestras se colectaron con botella van Dorn durante la segunda temporada lluviosa de 2006. En cada una de las cuatro estaciones analizadas se registraron la salinidad, temperatura, pH y oxígeno disuelto. La diversidad se calculó empleando el índice de Shannon-Wiener H’ (log10 comparando estaciones y fechas de muestreo para establecer variaciones en el período de estudio. Gráficamente se relacionaron variables fisicoquímicas con valores de diversidad que emplearon un α de 0.05 y 95% de intervalo de confianza. En total, fueron encontrados 20 morfotipos pertenecientes a las familias Brachionidae, Lecanidae, Filiniidae, Synchaetidae, Hexarthriidae y Testudinellidae, siendo Brachionidae y Lecanidae las más abundantes. La relación entre diversidad y variables fisicoquímicas, indica que la salinidad es la principal responsable de la diversidad de rotíferos. En conclusión, la rotiferofauna actual en el CP es más abundante y diversa que hace 16 años, antes de la recomunicación con el río Magdalena. Así mismo, la concentración de oxigeno disuelto, pH y salinidad son diferentes. Teniendo en cuenta que la salinidad es el factor que más influyó en la diversidad de rotíferos, la reapertura de canales probablemente favoreció el incremento en la diversidad de rotíferos en el CP.ABSTRACT In order to assess the potential effects of the Magdalena River recommunication with its former delta, we studied the abundance and composition of the rotiferofauna of the Pajarales Complex (PC during its highest annual zooplankton abundance. We selected the Rotifera

  4. Short-term effects of drawing water for connectivity of rivers and lakes on zooplankton community structure

    Institute of Scientific and Technical Information of China (English)

    WU Zhenbin; LIU Aifen; ZHANG Shiyang; CHENG Shuiping; WU Xiaohui

    2008-01-01

    During 28-29,September 2005,water was drawn from Hanjiang River and Houguan Lake to the Yangzi River via Sanjiao Lake and Nantaizi Lake in Wuhan in order to provide favorable conditions for ecosystem restoration.To evaluate the feasibility and validity of drawing water as a means of ecosystem restoration,zooplankton populations were studied 3 times (before,immediately after finishing and a month after drawing water)at seven locations from 27 Sept.2005 to 2 Nov.2005.Water quality in the lakes was mostly improved and zooplankton species richness decreased as soon as drawing water had finished but increased a month after drawing water.Zooplankton density and biomass was reduced in the lakes by drawing water but was increased at the entrance to Sanjiao Lake because of landform geometry change.Before drawing water,most species in Sanjiao lake e.g.,Brachionus sp.and Keratella sp.were tolerant of contamination.After drawing water oligotrophic-prone species such as Lecane ludwigii and Gastropus stylifer emerged.We conclude that drawing water could be important for improving water quality and favour ecosystem restoration.Dilution of nutrient concentrations may be an important role in the effect.

  5. Passive zooplankton community in different environments of a neotropical floodplain - doi: 10.4025/actascibiolsci.v34i4.11161

    Directory of Open Access Journals (Sweden)

    Claudia Costa Bonecker

    2012-09-01

    Full Text Available Zooplankton is able to respond promptly to environmental changes, producing resting forms in order to maintain populations when the conditions become unfavorable. The hatchling of the resting eggs was assessed in environments from the upper Paraná river floodplain, during the limnophase of 2008. We predicted that a higher production of these eggs and individuals’ hatchling are observed at isolated lakes, during dried period. Sediment samples were obtained with a corer sampler. The resting eggs were sorted and kept in filtered water from the same environment, in the laboratory. We recorded the occurrence of 378 resting eggs, of which 122 individuals hatched (70 cladocerans and 52 rotifers. The highest number of hatchlings was verified for the isolated lakes (84 individuals, as well the shorter time for hatchling (2 days. The hatchlings occurred mainly in September, when we registered the lowest hydrologic level of Paraná river (2.40 m. Grimaldina brazzai presented the longest time for hatchling, 44 days; and Brachionus dolabratus and B. falcatus, the shortest time, 2 days. This result suggests that the longer residence time of the water, which did not allow a renewal of food resources and limnological conditions of the environment, caused a higher stress in the zooplankton.  

  6. The Effects of Petroleum Hydrocarbons on Algae Can Be Reversed in the Presence of a Primary Consumer.

    Science.gov (United States)

    Wang, Changyou; Zhang, Yong; Li, Hongli; Xing, Wenhui; Yu, Hua

    2015-09-01

    The ecotoxicological effects of a mixture of petroleum hydrocarbons were tested on densities of two algae, Platymonas helgolandica var. tsingtaoensis and Isochrysis galbana, and of a rotifer, Brachionus plicatilis, by single-species and customized community experiments. Test concentrations ranged from 0 to 100 mg L(-1), while five to seven treatments were assessed in triplicate within 1 month. A significant decrease in densities during single-species toxicity tests were found when concentrations of petroleum hydrocarbons were above 1.0 mg L(-1). However, equilibrium densities of algae in the customized community showed a different pattern, which increased with concentration and reached a peak at 20.0 mg L(-1). The community-based no observed effect concentration (NOEC; 1.0 mg L(-1)) was different from the NOEC derived by single-species toxic tests (0.25 mg L(-1)). This demonstrates that ecotoxicological effects on plankton as part of a community is significantly different from single-species toxicity tests owing to ecological interactions.

  7. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

    1995-12-31

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

  8. Use of commercial live feeds enrichment during first feeding period of the barber goby Elacatinus figaro

    Directory of Open Access Journals (Sweden)

    Marcelo R. P. Shei

    2012-03-01

    Full Text Available t. The first feeding period is the most critical phase for the production of marine fish larvae. The utilization of n-3 HUFA enrichment on live feed has improved the results for several species during the larviculture. To evaluate the effect of n-3 HUFA enrichment on survival and growth of the barber goby Elacatinus figaro Sazima, Moura & Rosa, 1997, newly hatched larvae were divided in two experimental groups (200 larvae per group, with two replicates each. One group was fed on non-enriched rotifers Brachionus plicatilis and the other group was fed with n-3 HUFA enriched rotifers. After 14 days of experiment, survival of larvae fed n-3 HUFA enriched rotifers was three times higher (35.7 ± 3.1% than those fed non-enriched rotifers (11.1 ± 5.2 %, however this difference was not significant. Growth was faster for larvae fed n-3 HUFA enriched rotifers after the first week of life, but at the end of 14 days, it was no longer significantly different between the two groups (6.09 ± 0.62 and 5.69 ± 0.66 mm. The results of this experiment suggest that barber goby should be fed n-3 HUFA enriched rotifer in order to maximize juvenile production.

  9. The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish.

    Science.gov (United States)

    Lawrence, Christian; Best, Jason; Cockington, Jason; Henry, Eric C; Hurley, Shane; James, Althea; Lapointe, Christopher; Maloney, Kara; Sanders, Erik

    2016-01-01

    The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding. PMID:26863035

  10. Seasonal variations of species composition and abundance of zooplankton in Ehoma Lake, a floodplain lake in Nigeria.

    Science.gov (United States)

    Okogwu, Okechukwu I

    2010-03-01

    Ehoma Lake is among the important breeding sites of the major fishes in the Mid-Cross River, Nigeria. The juveniles of these fishes are solely dependent on zooplankton, which has not been studied previously. I studied monthly the lake's physico-chemical variables and zooplankton composition in three stations (littoral, sub-littoral and pelagic) from March 2005 to August 2006. Sixty-seven zooplankton species (42 rotifers, 19 cladocerans and 6 copepods) were identified. Daphnia obtusa Kurz, Keratella valga Ehrenberg, Keratella ticinensis Callerrio, Keratella hiemalis Carlin, Brachionus dimidiatus Bryce and Lecane candida Hauer and Murray are new records for Nigeria The dominant zooplankters were Diaphanosoma excisum Kurz and Moina micrura Kurz. There was an inverse relationship between species richness and abundance. Richness was highest in the dry season while peak zooplankton abundance was recorded in the rainy season. Zooplankton abundance and species richness decreased progressively from the littoral to the pelagic station while the Shannon-Weaver diversity index varied from 0.68 to 1.28 without a clear seasonal trend. There is a succession pattern: rotifers that are dominant in the dry season are replaced by cladocerans in the rainy season. This succession was greatly influenced by seasonal flooding of the lake. As no previous information on the zooplankton of the lake is available, this study provides baseline data on the lake's zooplankton. PMID:20411715

  11. 海河干流浮游生物调查及富营养化状况%The Research of Plankton and Trophic State of Haihe River in Summer, 2012

    Institute of Scientific and Technical Information of China (English)

    武丹; 梅鹏蔚; 张震; 王斌

    2015-01-01

    为了解海河干流水体富营养化状况,于2012年8月对海河于流水质、浮游生物进行了调查.结果表明,海河干流综合营养状态指数(TLI(∑))为73.1,处于重富营养水平.浮游植物共计7门91种,丰度平均值为1051.6×104cells/L,以蓝、绿藻为主,优势种为微小色球藻(Chroococcus minutus)、水华微囊藻(Microcystis flos-aquae)和衣藻属(Chlamydomonas sp.).浮游动物共计18种,丰度平均值为63.18 ind/L,优势种包括萼花臂尾轮虫(Brachionus calyciflorus)、近邻剑水蚤(Cyclops vicinus)、小栉蚤(Daphnia cristata)、跨立小剑水蚤(Microcyclops varicans)、裸腹蚤属(Moina sp.)、低额蚤属(Simocephlaus sp.)和幼体(Nauplius spp.).依据多样性指数对海河干流浮游生物进行评价,表明海河干流处于中污染水平.

  12. Effects of predation by Hydra (Cnidaria on cladocerans (Crustacea: Cladocera

    Directory of Open Access Journals (Sweden)

    Ligia Rivera-De la Parra

    2016-03-01

    Full Text Available 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.

  13. 几种生物饵料对海蜇幼蜇生长的影响%Influence of Several Natural Foods on Growth of Juvenile Medusa, Rhopilema esculenta Kishinouye

    Institute of Scientific and Technical Information of China (English)

    李晓东; 刘铁钢; 张长新; 李颖; 王海兰

    2003-01-01

    试验结果表明:在海蜇(Rhopilema esculenta Kishinouye)养殖过程中,褶皱臂尾轮虫(Brachionus plicatilis)、细巧华哲水氵蚤(Sinocalnus tenellus)、近亲真宽水氵蚤(Eurytemora affinis)、蒙古裸腹水氵蚤(Moina mongolica)和卤虫(Artemia)无节幼体,均可作为幼蜇的饵料,在水温22~25 ℃,pH 8.4~8.8,溶氧4~8 mg/L,盐度30±0.5的条件下,培养22 d幼蜇日生长率为1.2%~3.2%,成活率为100%.其生长率与试验饵料的种类关系不大,而与投喂密度有关.轮虫的合适密度为0.5×104~1.0×104/L.笔者还根据试验结果,以等生物量法,提出了投喂其它几种生物饵料的参考密度指标.以期为海蜇的人工养殖寻找更加广阔的饵料资源.

  14. Captive propagation, reproductive biology, and early life history of the Diamond Darter (Crystallaria cincotta)

    Science.gov (United States)

    Ruble, Crystal L.; Rakes, Patrick L.; Shute, John R.; Welsh, Stuart

    2014-01-01

    Reproductive biology and early life history data are critical for the conservation and management of rare fishes. During 2008–2012 a captive propagation study was conducted on the Diamond Darter, Crystallaria cincotta, a rare species with a single extant population in the lower Elk River, West Virginia. Water temperatures during spawning ranged from 11.1–23.3 C. Females and males spawned with quick vibrations, burying eggs in fine sand in relatively swift clean depositional areas. Egg size was 1.8–1.9 mm, and embryos developed within 7 to 11 d. Diamond Darters were 6.7–7.2 mm total length (TL) at hatch. Larvae ranged from 9.0–11.0 mm TL following a 5–10 d period of yolk sac absorption. Larvae had relatively large mouth gapes and teeth and were provided brine shrimp Artemia sp., Ceriodaphnia dubia neonates, marine Brachionus rotifers, and powdered foods (50–400 µm) but did not appear to feed in captivity, except for one observation of larval cannibalization. Larvae survived for a maximum of 10 d. To increase larval survival and reduce the possibility of cannibalism, other alternative food sources are needed during captive propagation.

  15. The Selective Use of Hypochlorite to Prevent Pond Crashes for Algae-Biofuel Production.

    Science.gov (United States)

    Park, Sichoon; Van Ginkel, Steven W; Pradeep, Priya; Igou, Thomas; Yi, Christine; Snell, Terry; Chen, Yongsheng

    2016-01-01

    Although algae-biofuels have many advantages including high areal productivity, algae can be preyed upon by amoebas, protozoans, ciliates, and rotifers, particularly in open pond systems. Thus, these higher organisms need to be controlled. In this study, Chlorella kessleri was used as the algal culture and Brachionus calyciflorus as the source of predation. The effect of sodium hypochlorite (bleach) was tested with the goal of totally inhibiting the rotifer while causing minor inhibition to the alga. The 24-hr LC(50) for B. calyciflorus in spring water was 0.198 mg Cl/L while the 24-hr LC(50) for C. kessleri was 0.321 mg Cl/L. However, chlorine dissipates rapidly as the algae serves as reductant. Results showed a chlorine dosage between 0.45 to 0.6 mg Cl/L and a dosing interval of two hours created the necessary chlorine concentrations to inhibit predation while letting the algae grow; thus giving algae farmers a tool to prevent pond crashes.

  16. The Use of the Schizonticidal Agent Quinine Sulfate to Prevent Pond Crashes for Algal-Biofuel Production.

    Science.gov (United States)

    Xu, Chunyan; Wu, Kangyan; Van Ginkel, Steve W; Igou, Thomas; Lee, Hwa Jong; Bhargava, Aditya; Johnston, Rachel; Snell, Terry; Chen, Yongsheng

    2015-11-17

    Algal biofuels are investigated as a promising alternative to petroleum fuel sources to satisfy transportation demand. Despite the high growth rate of algae, predation by rotifers, ciliates, golden algae, and other predators will cause an algae in open ponds to crash. In this study, Chlorella kessleri was used as a model alga and the freshwater rotifer, Brachionus calyciflorus, as a model predator. The goal of this study was to test the selective toxicity of the chemical, quinine sulfate (QS), on both the alga and the rotifer in order to fully inhibit the rotifer while minimizing its impact on algal growth. The QS LC50 for B. calyciflorus was 17 µM while C. kessleri growth was not inhibited at concentrations <25 µM. In co-culture, complete inhibition of rotifers was observed when the QS concentration was 7.7 µM, while algal growth was not affected. QS applications to produce 1 million gallons of biodiesel in one year are estimated to be $0.04/gallon or ~1% of Bioenergy Technologies Office's (BETO) projected cost of $5/gge (gallon gasoline equivalent). This provides algae farmers an important tool to manage grazing predators in algae mass cultures and avoid pond crashes.

  17. The use of morphological and histological features as nutritional condition indices of Pagrus pagrus larvae

    Directory of Open Access Journals (Sweden)

    Marina Vera Diaz

    2013-09-01

    Full Text Available Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata and rotifers (Brachionus plicatilis were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.

  18. Seasonal baseline of nutrients and stable isotopes in a saline lake of Argentina: biogeochemical processes and river runoff effects.

    Science.gov (United States)

    Kopprio, Germán A; Kattner, Gerhard; Freije, R Hugo; de Paggi, Susana José; Lara, Rubén J

    2014-05-01

    The seasonal variability of inorganic and organic nutrients and stable isotopes and their relations with plankton and environmental conditions were monitored in Lake Chasicó. Principal component analysis evidenced the strong influence of the river runoff on several biogeochemical variables. Silicate concentrations were controlled by diatom biomass and river discharge. Higher values of nitrate and soluble reactive phosphorus (SRP) indicated agricultural uses in the river basin. Elevated pH values (∼ 9) inhibiting nitrification in the lake explained partially the dominance of ammonium: ∼ 83 % of dissolved inorganic nitrogen (DIN). The low DIN/SRP ratio inferred nitrogen limitation, although the hypotheses of iron and CO2 limitation are relevant in alkaline lakes. Particulate organic matter (POM) and dissolved organic matter (DOM) were mainly of autochthonous origin. The main allochthonous input was imported by the river as POM owning to the arid conditions. Dissolved organic carbon was likely top-down regulated by the bacterioplankton grazer Brachionus plicatilis. The δ(13)C signature was a good indicator of primary production and its values were influenced probably by CO2 limitation. The δ(15)N did not evidence nitrogen fixation and suggested the effects of anthropogenic activities. The preservation of a good water quality in the lake is crucial for resource management.

  19. A method linking the toxic effects at community-level with contaminant concentrations.

    Science.gov (United States)

    Wang, Changyou; Su, Rongguo; Zhang, Yong; Liu, Gang

    2016-11-01

    In this study, we developed a method to quantify and link the toxic effects in community-level ecosystems with concentrations of petroleum hydrocarbons. The densities of Platymonas helgolandica var. tsingtaoensis, Isochrysis galbana, and Brachionus plicatilis in single-species tests and customized ecosystems were examined in response to a concentration gradient of petroleum hydrocarbons ranging from 0 to 8.0mgL(-1). A three-population ecological model with interspecies competition-grazing relationships was used to characterize population sizes with concentrations of petroleum hydrocarbons. A threshold concentration of the simplified plankton ecosystem of 0.376mgL(-1) for petroleum hydrocarbons was calculated from the proposed model, which was higher than the no-effect concentration of 0.056mgL(-1) derived from the single-species toxicity tests and the predicted no-effect concentration of 0.076mgL(-1) calculated from the species sensitivity distribution. This finding indicates that interspecies competition and grazing reduced the toxic effect of petroleum hydrocarbons at the community level. The sensitivity analysis for model parameters demonstrates that plankton population biomasses are highly sensitive to filtration rates. Antagonism between interspecies interactions and petroleum hydrocarbon toxicity was attributed to the reduced filtration rate and zooplankton grazing pressure. The proposed method is a simple means to address the concern regarding the impacts of ecological interactions on ecological risk assessments of pollutants. PMID:27348700

  20. Fecundity, growth, and survival of the angelfish Pterophyllum scalare (Perciformes: Cichlidae) under laboratory conditions.

    Science.gov (United States)

    Ortega-Salas, Armando A; Cortés G, Isabel; Reyes-Bustamante, Hugo

    2009-09-01

    The freshwater angelfishes (Pterophyllum) are South American cichlids that have become very popular among aquarists, yet scarce information on their culture and aquarium husbandry exists. We studied Pterophyllum scalare to analyze dietary effects on fecundity, growth, and survival of eggs and larvae during 135 days. Three diets were used: A) decapsulated cysts of Artemia, B) commercial dry fish food, and C) a mix diet of the rotifer Brachionus plicatilis and the cladoceran Daphnia magna. The initial larval density was 100 organisms in each 40 L aquarium. With diet A, larvae reached a maximum weight of 3.80 g, a total length of 6.3 cm, and a height of 5.8 cm; with diet B: 2.80 g, 4.81 cm, and 4.79 cm, and with diet C: 3.00 g, 5.15 cm, and 5.10 cm, respectively. Significant differences were observed between diet A, and diet B and C, but no significantly differences were observed between diets B and C. Fecundity varied from 234 to 1,082 eggs in 20 and 50 g females, respectively. Egg survival ranged from 87.4% up to 100%, and larvae survival (80 larvae/40 L aquarium) from 50% to 66.3% using diet B and A, respectively. Live food was better for growing fish than the commercial balanced food diet. Fecundity and survival are important factors in planning a good production of angelfish. PMID:19928467

  1. Effect of addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange

    Directory of Open Access Journals (Sweden)

    Yllana Ferreira-Marinho

    2014-07-01

    Full Text Available The aim of this study was to evaluate the effect of the addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange systems. Four treatments were considered: zero water exchange (ZWE; ZWE with the addition of feed (ZWE-F; ZWE with the addition of Navicula sp. (ZWE-N and ZWE with the addition of feed and Navicula sp. (ZWE-FN, all in triplicate. Shrimp of 17.7 ± 0.02 mg were stocked at a density of 2500 shrimp m-3 and microalgae added on the 1st, 5th and 15th day at a density of 5x10(4 cell mL-1. The shrimp were fed a commercial feed composed by 42% crude protein four times a day except in the ZWE treatment. For data analysis we used Cochran, Shapiro-Wilk, ANOVA, Tukey and Student-t tests (P < 0.05. The most frequent genera were: Anabaena, Arcella, Asplanchma, Bosmina, Brachionus, Cylindrotheca, Daphnia, Fragilaria, Hemiaulus, Keratella, Orthoseira, Oscillatoria, Phymatodocis, Rhabdonema, Skeletonema, Sckizothrix and Ulothrix. Significant differences between treatments were observed for TAN, NO2-N, alkalinity, final weight, weight gain, final biomass, biomass gain, feed conversion ratio, specific growth rate and survival. The ZWE-FN treatment showed better production parameters, indicating the benefits of the addition of Navicula sp. as a natural food source for L. vannamei postlarvae in zero water exchange systems.

  2. Lanthanide ecotoxicity: First attempt to measure environmental risk for aquatic organisms

    International Nuclear Information System (INIS)

    The geochemical cycles of lanthanides are being disrupted by increasing global production and human use, but their ecotoxicity is not fully characterized. In this study, the sensitivity of Aliivibrio fischeri and Pseudokirchneriella subcapitata to lanthanides increased with atomic number, while Daphnia magna, Heterocypris incongruens, Brachionus calyciflorus and Hydra attenuata were equally sensitive to the tested elements. In some cases, a marked decrease in exposure concentrations was observed over test duration and duly considered in calculating effect concentrations and predicted no effect concentrations (PNEC) for hazard and risk assessment. Comparison of PNEC with measured environmental concentrations indicate that, for the present, environmental risks deriving from lanthanides should be limited to some hotspots (e.g., downstream of wastewater treatment plants). However, considering the increasing environmental concentrations of lanthanides, the associated risks could become higher in the future. Ecotoxicological and risk assessment studies, along with monitoring, are required for properly managing these emerging contaminants. - Highlights: • For alga and bacteria, ecotoxicity increases with increasing atomic number. • Interspecies differences and exposure condition strongly influenced ecotoxicity. • Current environmental risk for lanthanides appears limited to some hotspots. - Current environmental risk for lanthanides appears limited to some hotspots, but increasing human use could promote a more widespread risk in the future

  3. Evaluation of toxicity and removal of color in textile effluent treated with electron beam; Avaliacao da toxicidade e remocao da cor de um efluente textil tratado com feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Aline Viana de

    2015-07-01

    The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from Cl. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam. (author)

  4. Loss of sexual reproduction and dwarfing in a small metazoan.

    Directory of Open Access Journals (Sweden)

    Claus-Peter Stelzer

    Full Text Available Asexuality has major theoretical advantages over sexual reproduction, yet newly formed asexual lineages rarely endure. The success, or failure, of such lineages is affected by their mechanism of origin, because it determines their initial genetic makeup and variability. Most previously described mechanisms imply that asexual lineages are randomly frozen subsamples of a sexual population.We found that transitions to obligate parthenogenesis (OP in the rotifer Brachionus calyciflorus, a small freshwater invertebrate which normally reproduces by cyclical parthenogenesis, were controlled by a simple Mendelian inheritance. Pedigree analysis suggested that obligate parthenogens were homozygous for a recessive allele, which caused inability to respond to the chemical signals that normally induce sexual reproduction in this species. Alternative mechanisms, such as ploidy changes, could be ruled out on the basis of flow cytometric measurements and genetic marker analysis. Interestingly, obligate parthenogens were also dwarfs (approximately 50% smaller than cyclical parthenogens, indicating pleiotropy or linkage with genes that strongly affect body size. We found no adverse effects of OP on survival or fecundity.This mechanism of inheritance implies that genes causing OP may evolve within sexual populations and remain undetected in the heterozygous state long before they get frequent enough to actually cause a transition to asexual reproduction. In this process, genetic variation at other loci might become linked to OP genes, leading to non-random associations between asexuality and other phenotypic traits.

  5. Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo-Costa

    2015-09-01

    Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

  6. Remediation of mercury contaminated saltwater with functionalized silica coated magnetite nanoparticles.

    Science.gov (United States)

    Mohmood, Iram; Lopes, Cláudia B; Lopes, Isabel; Tavares, Daniela S; Soares, Amadeu M V M; Duarte, Armando C; Trindade, Tito; Ahmad, Iqbal; Pereira, Eduarda

    2016-07-01

    The study aimed to evaluate the efficiency of dithiocarbamate functionalized silica coated magnetite nanoparticles (NPs) for Hg decontamination of saltwater either contaminated with Hg alone or with As and Cd. For this, the residual levels of Hg in seawater were assessed and Hg-contaminated or Hg+As+Cd-contaminated seawater toxicity to aquatic biota, before and after the sorption process, was compared. The results showed that under highly competitive conditions (water salts, Cd and As), the removal of Hg from seawater, by using these magnetic NPs, for the lowest concentration (50μg/L) was superior to 98% and for the highest concentration (500μg/L) ranged between 61% to 67%. Despite the great affinity of the magnetic NPs for Hg, they were not effective at removing As and Cd from seawater. In relation to the ecotoxicity endpoints after remediation, the mixture with lower Hg concentration exhibited no toxicity to rotifer Brachionus plicatilis and bacteria Vibrio fischeri ; however, the mixture with higher concentration revealed toxicity. In addition, the toxicity of bacteria V. fischeri, rotifer B. plicatilis and algae Phaeodactylum tricornutum, whose responses where inhibited during its exposure to the non-remediate sample was considerably reduced after treatment with NPs. Furthermore, microalgae P. tricornutum appears to be most sensitive species while Artemia franciscana showed no toxic effects to the tested solutions. Both chemical and ecotoxicological approaches revealed a high efficiency for the remediation of Hg-contaminated saltwater.

  7. Sildenafil and tadalafil in simulated chlorination conditions: Ecotoxicity of drugs and their derivatives

    International Nuclear Information System (INIS)

    Chlorination experiments on two drugs (sildenafil and tadalafil) were performed mimicking the conditions of a typical wastewater treatment process. The main transformation products were isolated by chromatographic techniques (Thin Layer Chromatography (TLC), Column Chromatography (CC), High Performance Liquid Chromatography (HPLC)) and fully characterized employing Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) analyses. The environmental effects of the parent compounds and transformation products were evaluated using an overall toxicity approach that considered aquatic acute and chronic toxicity on Brachionus calyciflorus and Ceriodaphnia dubia as well as mutagenesis and genotoxicity on bacterial strains. The results revealed that both parent drugs did not show high acute and chronic toxicity for the organisms utilized in the bioassays while, chronic exposure to chlorine derivatives caused inhibition of growth population on rotifers and crustaceans. A mutagenic potential was found for all the compounds investigated. - Highlights: • Simulated disinfection process of pharmaceuticals was performed. • Toxicity and genotoxicity of sildenafil, tadalafil and their derivatives were evaluated. • Chlorine derivatives caused chronic toxicity on rotifers and crustaceans. • A mutagenic potential was found for all the compounds investigated

  8. Use of solar advanced oxidation processes for wastewater treatment: Follow-up on degradation products, acute toxicity, genotoxicity and estrogenicity.

    Science.gov (United States)

    Brienza, M; Mahdi Ahmed, M; Escande, A; Plantard, G; Scrano, L; Chiron, S; Bufo, S A; Goetz, V

    2016-04-01

    Wastewater tertiary treatment by advanced oxidation processes is thought to produce a treated effluent with lower toxicity than the initial influent. Here we performed tertiary treatment of a secondary effluent collected from a Waste Water Treatment Plant via homogeneous (solar/HSO5(-)/Fe(2+)) and heterogeneous (solar/TiO2) solar advanced oxidation aiming at the assessment of their effectiveness in terms of contaminants' and toxicity abatement in a plain solar reactor. A total of 53 organic contaminants were qualitatively identified by liquid chromatography coupled to high-resolution mass spectrometry after solid phase extraction. Solar advanced oxidation totally or partially removed the major part of contaminants detected within 4.5 h. Standard toxicity tests were performed using Vibrio fischeri, Daphnia magna, Pseudokirchneriella subcapitata and Brachionus calyciflorus organisms to evaluate acute and chronic toxicity in the secondary or tertiary effluents, and the EC50% was calculated. Estrogenic and genotoxic tests were carried out in an attempt to obtain an even sharper evaluation of potential hazardous effects due to micropollutants or their degradation by-products in wastewater. Genotoxic effects were not detected in effluent before or after treatment. However, we observed relevant estrogenic activity due to the high sensitivity of the HELN ERα cell line. PMID:26841289

  9. Evaluation of toxicity and removal of color in textile effluent treated with electron beam

    International Nuclear Information System (INIS)

    The textile industry is among the main activities Brazil, being relevant in number of jobs, quantity and diversity of products and mainly by the volume of water used in industrial processes and effluent generation. These effluents are complex mixtures which are characterized by the presence of dyes, surfactants, metal sequestering agents, salts and other potentially toxic chemicals for the aquatic biota. Considering the lack of adequate waste management to these treatments, new technologies are essential in highlighting the advanced oxidation processes such as ionizing radiation electron beam. This study includes the preparation of a standard textile effluent chemical laboratory and its treatment by electron beam from electron accelerator in order to reduce the toxicity and intense staining resulting from Cl. Blue 222 dye. The treatment caused a reduction in toxicity to exposed organisms with 34.55% efficiency for the Daphnia similis micro crustacean and 47.83% for Brachionus plicatilis rotifer at a dose of 2.5 kGy. The Vibrio fischeri bacteria obtained better results after treatment with a dose of 5 kGy showing 57.29% efficiency. Color reduction was greater than 90% at a dose of 2.5 kGy. This experiment has also carried out some preliminary tests on the sensitivity of the D. similis and V. fischeri organisms to exposure of some of the products used in this bleaching and dyeing and two water reuse simulations in new textile processing after the treating the effluent with electron beam. (author)

  10. Assessing the ecotoxicity of metal nano-oxides with potential for wastewater treatment.

    Science.gov (United States)

    Nogueira, V; Lopes, I; Rocha-Santos, T A P; Rasteiro, M G; Abrantes, N; Gonçalves, F; Soares, A M V M; Duarte, A C; Pereira, R

    2015-09-01

    The rapid development of nanotechnology and the increasing use of nanomaterials (NMs) raise concern about their fate and potential effects in the environment, especially for those that could be used for remediation purposes and that will be intentionally released to the environment. Despite the remarkable emerging literature addressing the biological effects of NMs to aquatic organisms, the existing information is still scarce and contradictory. Therefore, aimed at selecting NMs for the treatment of organic and inorganic effluents, we assessed the potential toxicity of NiO (100 and 10-20 nm), Fe2O3 (≈85 × 425 nm), and TiO2 (Lemna minor, Daphnia magna, Brachionus plicatilis, and Artemia salina. Also a mutagenic test was performed with two Salmonella typhimurium strains. Suspensions of each NM, prepared with the different test media, were characterized by dynamic light scattering (DLS) and eletrophoretic light scattering (ELS). For the assays with marine species, no toxicity was observed for all the compounds. In opposite, statistically significant effects were produced on all freshwater species, being D. magna the most sensitive organism. Based on the results of this study, the tested NMs can be classified in a decreasing order of toxicity NiO (100 nm) > NiO (10-20 nm) > TiO2 ( Fe2O3, allowing to infer that apparently Fe2O3 NMs seems to be the one with less risks for receiving aquatic systems. PMID:25940480

  11. Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus

    Science.gov (United States)

    Liu, Guangxing; Xu, Donghui

    2009-12-01

    Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods ( PDHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.

  12. Decoloration and detoxification of effluents by ionizing radiation

    Science.gov (United States)

    Borrely, Sueli I.; Morais, Aline V.; Rosa, Jorge M.; Badaró-Pedroso, Cintia; da Conceição Pereira, Maria; Higa, Marcela C.

    2016-07-01

    Three distinct textile samples were investigated for color and toxicity (S1-chemical/textile industry; S2-final textile effluent; S3 - standard textile produced effluent-untreated blue). Radiation processing of these samples were carried out at Dynamitron Electron Beam Accelerator and color and toxicity removal were determined: color removal by radiation was 96% (40 kGy, S1); 55% (2.5 kGy, S2) and 90% (2.5 kGy, S3). Concerning toxicity assays, Vibrio fischeri luminescent bacteria demonstrated higher reduction after radiation than the other systems: removal efficiencies were 33% (20 kGy, S1); 55% (2.5 kGy, S2) and 33% (2.5 kGy, S3). Daphnia similis and Brachionus plicatilis fitted well for S3 effluents. Hard toxic volumes into biological treatment plant may be avoided if radiation would be previously applied in a real plant. Results reveled how indispensable is to run toxicity to more than one living-organism.

  13. Feeding Results on Red Drum Sciaenops ocellatus Larvae Rearing with Taurine-enriched Rotifers%牛磺酸强化轮虫对眼斑拟石首鱼仔鱼的投喂效果

    Institute of Scientific and Technical Information of China (English)

    王秋荣; 竹内俊郎; 陈振湘

    2006-01-01

    研究用3种不同质量浓度梯度(分别为T0组:0 mg/L;T4组:400 mg/L;T8组:800mg/L)牛磺酸强化的轮虫(Brachionus plicatilis)对3~20日龄的眼斑拟石首鱼(Sciaenops ocellatus)仔鱼的投喂效果.结果表明,T8组的仔鱼平均全长((8.5±0.8)mm)和成活率(70.5%)都明显高于T0组(平均全长:(6.3±1.0)mm;成活率:28.4%)和T4组(平均全长:(7.0±0.8)mm;成活率:27.4%),T0组和T4组之间生长和成活率并无显著差异;T8组仔鱼的耐干露及耐高盐度(65)能力明显比T0组和T4组强,即仔鱼的抗应激能力受轮虫强化剂牛磺酸的质量浓度影响显著(P<0.05).

  14. Remediation of mercury contaminated saltwater with functionalized silica coated magnetite nanoparticles.

    Science.gov (United States)

    Mohmood, Iram; Lopes, Cláudia B; Lopes, Isabel; Tavares, Daniela S; Soares, Amadeu M V M; Duarte, Armando C; Trindade, Tito; Ahmad, Iqbal; Pereira, Eduarda

    2016-07-01

    The study aimed to evaluate the efficiency of dithiocarbamate functionalized silica coated magnetite nanoparticles (NPs) for Hg decontamination of saltwater either contaminated with Hg alone or with As and Cd. For this, the residual levels of Hg in seawater were assessed and Hg-contaminated or Hg+As+Cd-contaminated seawater toxicity to aquatic biota, before and after the sorption process, was compared. The results showed that under highly competitive conditions (water salts, Cd and As), the removal of Hg from seawater, by using these magnetic NPs, for the lowest concentration (50μg/L) was superior to 98% and for the highest concentration (500μg/L) ranged between 61% to 67%. Despite the great affinity of the magnetic NPs for Hg, they were not effective at removing As and Cd from seawater. In relation to the ecotoxicity endpoints after remediation, the mixture with lower Hg concentration exhibited no toxicity to rotifer Brachionus plicatilis and bacteria Vibrio fischeri ; however, the mixture with higher concentration revealed toxicity. In addition, the toxicity of bacteria V. fischeri, rotifer B. plicatilis and algae Phaeodactylum tricornutum, whose responses where inhibited during its exposure to the non-remediate sample was considerably reduced after treatment with NPs. Furthermore, microalgae P. tricornutum appears to be most sensitive species while Artemia franciscana showed no toxic effects to the tested solutions. Both chemical and ecotoxicological approaches revealed a high efficiency for the remediation of Hg-contaminated saltwater. PMID:27039062

  15. Sildenafil and tadalafil in simulated chlorination conditions: Ecotoxicity of drugs and their derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Temussi, Fabio; DellaGreca, Marina; Pistillo, Paola; Previtera, Lucio; Zarrelli, Armando [UdR Napoli 4 INCA, Dipartimento di Scienze Chimiche, Complesso Universitario di Monte Sant' Angelo, Università Federico II, Via Cintia, I-80126 Napoli (Italy); Criscuolo, Emma; Lavorgna, Margherita; Russo, Chiara [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy); Isidori, Marina, E-mail: marina.isidori@unina2.it [Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta (Italy)

    2013-10-01

    Chlorination experiments on two drugs (sildenafil and tadalafil) were performed mimicking the conditions of a typical wastewater treatment process. The main transformation products were isolated by chromatographic techniques (Thin Layer Chromatography (TLC), Column Chromatography (CC), High Performance Liquid Chromatography (HPLC)) and fully characterized employing Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) analyses. The environmental effects of the parent compounds and transformation products were evaluated using an overall toxicity approach that considered aquatic acute and chronic toxicity on Brachionus calyciflorus and Ceriodaphnia dubia as well as mutagenesis and genotoxicity on bacterial strains. The results revealed that both parent drugs did not show high acute and chronic toxicity for the organisms utilized in the bioassays while, chronic exposure to chlorine derivatives caused inhibition of growth population on rotifers and crustaceans. A mutagenic potential was found for all the compounds investigated. - Highlights: • Simulated disinfection process of pharmaceuticals was performed. • Toxicity and genotoxicity of sildenafil, tadalafil and their derivatives were evaluated. • Chlorine derivatives caused chronic toxicity on rotifers and crustaceans. • A mutagenic potential was found for all the compounds investigated.

  16. 广州低盐河段轮虫群落结构特征及富营养化状况分析%Rotifer communities structure and eutrophication analysis in the low salinity river segment,Guangzhou,South China

    Institute of Scientific and Technical Information of China (English)

    袁丹妮; 王庆; 陈亮东; 杨宇峰; 刘胜

    2014-01-01

    Rotifers are an important part of the zooplankton community and key links to the microbial food web in river ecosystems.They can also be used as important indicators of water quality.Samples were collected monthly from April 201 0 to March 201 3 ,at the Zhongda (S1 )and Yuzhu (S2 )sites a-long the Guangzhou segment of the Pearl River in Guangzhou City.Rotifer species composition and abun-dance were analyzed and physico-chemical parameters of water samples were measured.A total of 48 spe-cies were identified,34 of which were pollution indicator species.The dominant species,including Anu-raeopsis fissa,Lififerotrocha subtilis,Brachionus angularis,Trichocerca pusilla,Filinia novaezealandia, and Brachionus caudatus,belong to pollution tolerant species.Rotifer abundance ranged from 2 to 4 063 ind./L,the annual mean densities were (1 359.46 ±1 89.54)ind./L (S1 )and (1 058.61 ±1 56.1 6) ind./L (S2 ),respectively.During the investigation period,salinity was less than 1.5 ,however,the contents of TN and TP were at high level at the two sampling stations.The annual mean TN contents were (6.22 ±0.39 )mg/L (S1 )and (6.32 ±0.35 )mg/L (S2 ),and the mean TP contents were (0.84 ± 0.53)mg/L (S1 )and (0.83 ±0.09)mg/L (S2),respectively.The contents of TN and TP were not significantly difference at the two sampling stations.The concentrations of chlorophyl-a range from 7.68 to 21 5.33 μg/L,the annual mean contents were (56.25 ±45.31 )μg/L (S1 )and (49.77 ±7.1 4 )μg/L (S2),respectively.Statistical analysis showed that there was a positive correlation between chloro-phyll-a concentrations (x)and rotifer abundance (y)(P<0.05;y=629.750 +1 0.71 7x).Based on ecological factors and water quality assessment system,the Guangzhou segment of the Pearl River is seri-ously eutrophic.%轮虫是浮游动物群落的重要组成部分,在河流生态系统微食物网的物质传递和能量流动过程中扮演着重要角色,同时也是水质评价的重要指标之一.为研究

  17. Meta-Zooplankton Investigation and Water Quality Assessment in Yelang Reservoir in Spring%夜郎湖水库春季后生浮游动物调查与水质评价

    Institute of Scientific and Technical Information of China (English)

    宁爱丽; 陈椽; 潘静; 徐兴华; 龙胜兴

    2012-01-01

    2011年3月对夜郎湖水库后生浮游动物及水质情况进行了调查.共鉴定出后生浮游动物17种,其中,桡足类2种,枝角类3种,轮虫类12种.优势种为针簇多肢轮虫(Polyarthra trigla Ehrenberg)、矩形龟甲轮虫(Keratella quadrata(Müller))、螺形龟甲轮虫(Keratella cochlearis Gosse)、曲腿龟甲轮虫(Keratella valga Ehrenberg)、透明溞(Daphnia hyalina Leydig)、长额象鼻溞(Bosmina longirostris (O.F.Müller))和近邻剑水蚤(Cyclops vicinus Uijanin).后生浮游动物数量为0.2~570.0 ind/L.利用后生浮游动物群落结构、理化指标及生物多样性指数进行综合评价,该水库水质为Ⅰ类.%Meta-zooplankton in Yelanghu reservoir was investigated; and the water quality was assessed in March 2011. The results indicated that 17 species of meta-zooplanktons were identified, consisting of 12 species of Rotifera, 2 Species of Clado-cera, and 3 species of Copepoda, The dominant species were Cyclops vicinns Uijanin, Daphnia hyalina Leydig, Bosmina lon-girostris (O.F.Müller), K. quadrata (Müller), K. cochlearis Gosse,Keratella valga Ehrenberg and Polyarthra trigla Ehrenberg. The abundance of meta-zooplankton ranged from 0.2 to 570.0 ind/L. The community structure of meta-zooplankton, physical and chemical indicators and diversity indexes were used to evaluate the water quality; and it was revealed that the water quality belonged to class I .

  18. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    Science.gov (United States)

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone. PMID:26970874

  19. Accumulation of atmospheric radionuclides and heavy metals in cryoconite holes on an Arctic glacier.

    Science.gov (United States)

    Łokas, Edyta; Zaborska, Agata; Kolicka, Małgorzata; Różycki, Michał; Zawierucha, Krzysztof

    2016-10-01

    Surface of glaciers is covered by mineral and organic dust, together with microorganisms forming cryoconite granules. Despite fact that glaciers and ice sheets constitute significance part of land surface, reservoir of freshwater, and sites of high biological production, the knowledge on the cryoconite granules still remain unsatisfactory. This study presents information on radionuclide and heavy metal contents in cryoconites. Cryoconites collected from the Hans Glacier in SW Spitsbergen reveal high activity concentrations of anthropogenic ((238,239,240)Pu, (137)Cs, (90)Sr) and natural ((210)Pb) radionuclides. The (238)Pu/(239+240)Pu activity ratios in these cryoconites significantly exceed the mean global fallout ratio (0.025). The (238)Pu/(239+240)Pu ranged from 0.064 to 0.118. The (239+240)Pu/(137)Cs varied from 0.011 ± 0.003 to 0.030 ± 0.007. Such activity ratios as observed in these cryoconites were significantly higher than the values characterizing global fallout, pointing to possible contributions of these radionuclides from other sources. Heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in cryoconites exceed both UCC concentrations and local rocks' concentrations, particularly for cadmium. The concentration ratios of stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(206)Pb) were determined to discriminate between the natural and anthropogenic sources of Pb in cryoconites and to confirm the strong anthropogenic contribution to heavy metal deposition in the Arctic. In investigated cryoconite holes, two groups of invertebrates, both extremophiles, Tardigrada and Rotifera were detected. Our study indicate that cryoconites are aggregates of mineral and organic substances on surfaces of glaciers are able to accumulate large amounts of airborne pollutants bound to extracellular polymeric substances secreted by microorganisms.

  20. Feeding activity and influence of intraspecific competition on zooplankton communities by jundiá (Rhamdia quelen Quoy and Gaimard, 1824) in laboratory.

    Science.gov (United States)

    Brandão-Gonçalves, L; Sebastien, N Y

    2013-11-01

    Experiments were designed to determine if the juvenile forms of jundia (Rhamdia quelen) exhibit selectivity feeding on zooplanktonic organisms and the influence of intraspecific competition on the diet. The fish were maintained in 5000-L containers, and after seven days from birth, they were acclimated in experimental units with different densities and supplied with water containing plankton (natural), where they remained for 24 h in the environment with food. In the first seven days at densities of 5 and 10 fish.L-1, the fish selected the Rotifera more intensely, and at densities of 20 and 40 fish.L-1, the Cladocera were more selected. At 14 days of age, the Cladocera were the most selected for all densities of fish. At 21 days of age, the juvenile forms of jundia maintained a preference for Cladocera, and there was an increase in the capture of Copepoda at a density of 40 fish.L-1. At 28 days of age, the Cladocera were the most captured at densities of 5 to 20 fish.L-1, and the consumption of copepods increased at a density of 40 fish.L-1. The juvenile forms of Rhamdia quelen showed a high feeding preference for Cladocera at all the ages tested (7, 14, 21 and 28 days), but the density of fish per litre influenced the capture of the preferential food. This study showed that the juvenile forms of jundia had a more rapid response to the presence of food at densities of more than 10 fish.L-1, and that at higher densities the fish decreased interactions of territorial defense and formed schools, which allowed the foraging of zooplanktonic organisms, larger in size, more agile and of greater energy gain, such as the Cladocera and copepods. PMID:24789392

  1. [Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure].

    Science.gov (United States)

    Quan, Guo-ming; Zhang, Jia-en; Xie, Jun-fang; Mao, Dan-juan; Xu, Hua-qin; Jiang, Wan-bing; Wen, Du-juan

    2011-07-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems. In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M. micrantha invasion on the soil meso- and micro-invertebrate community. Three sampling sites were installed, including M. micrantha-invaded site, ecotone, and native vegetation site. Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups. M. micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure. Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M. micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change. At M. micrantha-invaded site, the density-group index (DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index (D) and Simpson dominance index (C) tended to ascend, but Pielou evenness index (E) and Shannon index (H') tended to descend. The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M. micrantha-invaded site and native vegetation site. The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M. micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M. micrantha-invaded site. PMID:22007466

  2. Preliminary assessment of the zooplankton community composition in a region under the influence of a uranium mine (Caldas, Southeastern Brazil)

    International Nuclear Information System (INIS)

    The Ore Treatment Unit consists of an open cast mine (CM), its mining waste areas, facilities for the physical treatment of the ore, and a chemical treatment plant for uranium extraction. At CM, the processes of acid drainage create effluents, which are treated by chemical processes and, thereafter, disposed of in Antas dam. The objective of the present study was to make an inventory of zooplanktonic and describe the physicochemical characteristics of site CM and at the site of treated effluents disposal (site 41), located at Antas dam. Water samples were collected in October/08 and January/09, in order to describe the abiotic variables and the zooplankton community. The average values of conductivity at sites CM and 41 were 2415 and 422 μ/cm2, respectively. Values of pH at site CM remained acid, whereas, at site 41 we recorded values near neutrality. The concentrations of total nutrients at both sampling sites were higher in the rainy season. Zooplankton species richness present at site CM was lower than at site 41, and there were only two identified species Bosmina sp and Keratella americana. At site 41 we recorded more species, mainly of the Rotifera. Among Cladocera, we identified two species, regarding Copepoda, the orders Cyclopoida and Calanoida were present. At site CM the density values were lower compared to site 41. The preliminary assessment of the zooplankton community showed lower values of species richness and density at site CM, what may be probably explained by the adverse environmental conditions for zooplankton community. (author)

  3. Hydro biological Characteristics of Some Semi-intensive fish culture ponds of Lumding town of Nagaon district, Assam

    Directory of Open Access Journals (Sweden)

    Tapashi Gupta

    2013-04-01

    Full Text Available Hydrobiological assessment is useful for assessing the ecological quality of aquatic ecosystem since biological communities integrate the environmental effects of water chemistry. Ten fish ponds from Lumding town, which were under semi-intensive culture practice, were selected for hydrobiological investigations. Physico-chemical properties were studied for a period of two years from July 2009 to June 2011.Some selected parameters like pH, dissolve oxygen, free carbon dioxide, TDS , total alkalinity, total hardness, sp. Conductivity, transparency and BOD were studied on some fish pond water. P H ranges from 6.1 to8.5. Temperature ranges from 18 0 C-32 0 C. Color shows light green to dirty green. Transparency ranges 17-42cm, dissolve oxygen ranges from 3.2-8.0 ppm, total alkalinity ranges from 7.9-20.0ppm, Hardness ranges from 60-135 ppm, sp.conductance ranges from123-247µmhos/cm and BOD ranges from3.1-5.0ppm. The phytoplankton belonging to division Chlorophycae and Cyanophycae are predominant over the others and zooplanktons belonging to group Protozoa, Rotifers are predominant. . A total of 30 species of belonging to Chlorophycae. Cyanophycae were identified and a total of 20 species of Rotifera, 2 species of Cladocera and 1 genus of Copepods were found. The present study is expected to help achieve better and higher yield of fish by the fish farmer with increasing awareness regarding the hydrobiological feature of the pond and implement scientific management practices accordingly

  4. Accumulation of atmospheric radionuclides and heavy metals in cryoconite holes on an Arctic glacier.

    Science.gov (United States)

    Łokas, Edyta; Zaborska, Agata; Kolicka, Małgorzata; Różycki, Michał; Zawierucha, Krzysztof

    2016-10-01

    Surface of glaciers is covered by mineral and organic dust, together with microorganisms forming cryoconite granules. Despite fact that glaciers and ice sheets constitute significance part of land surface, reservoir of freshwater, and sites of high biological production, the knowledge on the cryoconite granules still remain unsatisfactory. This study presents information on radionuclide and heavy metal contents in cryoconites. Cryoconites collected from the Hans Glacier in SW Spitsbergen reveal high activity concentrations of anthropogenic ((238,239,240)Pu, (137)Cs, (90)Sr) and natural ((210)Pb) radionuclides. The (238)Pu/(239+240)Pu activity ratios in these cryoconites significantly exceed the mean global fallout ratio (0.025). The (238)Pu/(239+240)Pu ranged from 0.064 to 0.118. The (239+240)Pu/(137)Cs varied from 0.011 ± 0.003 to 0.030 ± 0.007. Such activity ratios as observed in these cryoconites were significantly higher than the values characterizing global fallout, pointing to possible contributions of these radionuclides from other sources. Heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in cryoconites exceed both UCC concentrations and local rocks' concentrations, particularly for cadmium. The concentration ratios of stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(206)Pb) were determined to discriminate between the natural and anthropogenic sources of Pb in cryoconites and to confirm the strong anthropogenic contribution to heavy metal deposition in the Arctic. In investigated cryoconite holes, two groups of invertebrates, both extremophiles, Tardigrada and Rotifera were detected. Our study indicate that cryoconites are aggregates of mineral and organic substances on surfaces of glaciers are able to accumulate large amounts of airborne pollutants bound to extracellular polymeric substances secreted by microorganisms. PMID:27372266

  5. Food web effects of titanium dioxide nanoparticles in an outdoor freshwater mesocosm experiment.

    Science.gov (United States)

    Jovanović, Boris; Bezirci, Gizem; Çağan, Ali Serhan; Coppens, Jan; Levi, Eti E; Oluz, Zehra; Tuncel, Eylül; Duran, Hatice; Beklioğlu, Meryem

    2016-09-01

    Over the course of 78 days, nine outdoor mesocosms, each with 1350 L capacity, were situated on a pontoon platform in the middle of a lake and exposed to 0 μg L(-1) TiO2, 25 μg L(-1) TiO2 or 250 μg L(-1) TiO2 nanoparticles in the form of E171 TiO2 human food additive five times a week. Mesocosms were inoculated with sediment, phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish before exposure, ensuring a complete food web. Physicochemical parameters of the water, nutrient concentrations, and biomass of the taxa were monitored. Concentrations of 25 μg L(-1) TiO2 and 250 μg L(-1) TiO2 caused a reduction in available soluble reactive phosphorus in the mesocosms by 15 and 23%, respectively, but not in the amount of total phosphorus. The biomass of Rotifera was significantly reduced by 32 and 57% in the TiO2 25 μg L(-1) and TiO2 250 μg L(-1) treatments, respectively, when compared to the control; however, the biomass of the other monitored groups-Cladocera, Copepoda, phytoplankton, macrophytes, chironomids and fish-remained unaffected. In conclusion, environmentally relevant concentrations of TiO2 nanoparticles may negatively affect certain parameters and taxa of the freshwater lentic aquatic ecosystem. However, these negative effects are not significant enough to affect the overall function of the ecosystem, as there were no cascade effects leading to a major change in its trophic state or primary production. PMID:26901391

  6. Indicadores de condición larvaria aplicados al camarón de río del norte Cryphiops caementarius (Molina, 1782, en condiciones de cultivo controlado Larval condition indicators applied to the northern river shrimp Cryphiops caementarius (Molina, 1782, under condition of controlled cultivation

    Directory of Open Access Journals (Sweden)

    María C Morales

    2012-09-01

    Full Text Available Se estudia el desarrollo larvario del camarón de río del norte de Chile, Cryphiops caementarius, desde el estado de zoea 1 hasta el primer juvenil, caracterizando y analizando criterios que verificaron la aplicación de indicadores de tipo morfológico y de comportamiento para la evaluación de la condición larvaria de la especie, en condiciones de cultivo. Las larvas, se mantuvieron en cultivo, en un tanque de 250 L con agua a 20 psu y temperatura de 25 ± 1°C, controlada con termostato y con un recambio del 100% diariamente. La alimentación consistió en microalgas (Nannochloris sp. e Isochrysis sp., rotíferos (Brachionus plicatilis, nauplios de Artemia franciscana y alimento formulado. Se utilizaron cinco indicadores de carácter morfológico y de comportamiento aplicados a las larvas de C. caementarius: llenado intestinal, estado de la glándula digestiva, desarrollo branquial, comportamiento natatorio y respuesta fototáctica. Estos indicadores, permitieron determinar el estado de condición y calidad de las larvas de C. caementarius, logrando un efectivo seguimiento y asociación de cada uno de ellos, con cada estado de desarrollo larvario, estandarizando características deseables en las larvas y evidenciando resultados verificables, que permitan establecer un adecuado plan de seguimiento del cultivo, optimizar los protocolos de manejo y de alimentación de las larvas. Además de cada indicador, fue posible desglosar una amplia gama de potenciales estudios a realizar, basados en las relaciones que la morfología y el comportamiento larvario mantienen con las capacidades fisiológicas de las larvas en desarrollo.The larval development of the Chilean northern river shrimp Cryphiops caementarius was studied, from the condition of zoea 1 up to the condition of juvenile stage, analyzing and characterizing diverse criteria that allowed checking the application of morphological and behavioral indicators for the evaluation of the larval

  7. Microcrustáceos y Vibrio cholerae O1 viable no cultivable (VNC: resultados en la Cuenca del Río Salí, Tucumán, Argentina Microcrustaceans and viable but nonculturable (VNC Vibrio cholerae O1: results in the Salí River basin, Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Cecilia Locascio de Mitrovich

    2010-01-01

    Full Text Available Vibrio cholerae reside habitualmente en aguas marinas y continentales. Según las condiciones ambientales y los recursos le sean “favorables” o “desfavorables”, se generan estados viables cultivables (VC o viables no cultivables (VNC respectivamente y, bajo esta última forma sobrevive. Para abordar la problemática del cólera en la Cuenca del Río Salí (Tucumán, Argentina, se realizaron muestreos durante los años 2003-2005 donde se consideraron aspectos fisicos, químicos, biológicos y sanitarios. Para evaluar los probables reservorios del patógeno, se analizó el zooplancton del Río Salí (Canal Norte y Banda Río Salí y Río Lules. La mayor representatividad taxonómica la registraron los copépodos, especialmente Eucyclops neumani (Pesta, 1927, junto a Acanthocyclops robustus (Sars, 1863, Metacyclops sp., Paracyclops chiltoni y Notodiaptomus incompositus (Brian, 1925, además de algunos rotíferos y cladóceros como (Lecane sp., y (Brachionus sp., Moina sp. y Leydigia sp.. La frecuencia de ocurrencia fue baja y no superó el 25%. El Canal Norte fue ambiente más propicio por la riqueza específica, abundancia y constancia de la comunidad. Las variables fisicas y químicas asociadas al zooplancton coincidirían con los valores que por nuestros registros y los antecedentes, se conocen para el desarrollo del patógeno. En el período estival hubo coincidencia entre la presencia de la forma VNC de V. cholerae O1 (inmunofluorescencia con anticuerpos anti O1 y el desarrollo del zooplancton. Se observaron formas VNC sobre apéndices o estructuras de copépodos ciclopoideos y cladóceros quidóridos, reflejando probablemente afinidad con sustratos quitinosos.Vibrio cholerae habitually lives in marine and continental waters. According to "favourable" or "unfavourable" resources and environmental conditions, viable (VC or viable non-culturable (VNC states will be generated, surviving only the latter form. To address the problem of

  8. A successful microbound diet for the larval culture of Chinese shrimp Fenneropenaeus chinensis

    Science.gov (United States)

    Wang, Xinxia; Mai, Kangsen

    2005-07-01

    A 13-day feeding trial was carried out to evaluate the effectiveness of a microbound diet for rearing the larvae of Chinese shrimp Fenneropenaeus chinensis in comparison with the live foods that consist of Isochrysis galbana, Chlorella vulgaris, Tetraselmis chuii, rotifer (Brachionus plicatilis) and Artemia sp. Larvae of 0 to 13d post-hatch (dph) were reared in a temperature-controlled semi-open culture system and stocked at a density of 100 larvae L-1 in tanks, each containing 50 L sterilized seawater with salinity 30 32. Larvae were manually fed either the live foods or the microbound diet 6 times per day. At 13dph, the growth of the larvae fed on the microbound diet was approximately 84% of that fed on the live foods. The survival rate of the larvae fed on the microbound diet was 44.29% at 13 dph, which was not significantly different from that of larvae fed on live foods (63.55% ). The body length and development index (DI) of the larvae fed on the microbound diet were always lower than those of larvae fed on live foods. However, the differences reached significant levels only at 11 and 13dph (P<0.05). The mean dry weight loss of the microbound diet was 9.2% after 90min immersion in seawater, indicating that this diet has a good water stability. The microbound diet contains 5223% crude protein and 10.27% lipid and is easy to prepare. These characteristics of the diet suggest good potentials for its successful use in the larviculture of other penaeid and fish species.

  9. A Successful Microbound Diet for the Larval Culture of Chinese Shrimp Fenneropenaeus chinensis

    Institute of Scientific and Technical Information of China (English)

    WANG Xinxia; MAI Kangsen

    2005-01-01

    A 13-day feeding trial was carried out to evaluate the effectiveness of a microbound diet for rearing the larvae of Chinese shrimp Fenneropenaeus chinensis in comparison with the live foods that consist of Isochrysis galbana, Chlorella vulgaris, Tetraselmis chuii, rotifer (Brachionus plicatilis) and Artemia sp. Larvae of 0 to 13d post-hatch (dph) were reared in a temperature-controlled semi-open culture system and stocked at a density of 100 larvae L-1 in tanks, each containing 50 L sterilized seawater with salinity 30-32. Larvae were manually fed either the live foods or the microbound diet 6 times per day. At 13 dph, the growth of the larvae fed on the microbound diet was approximately 84% of that fed on the live foods.The survival rate of the larvae fed on the microbound diet was 44.29% at 13 dph, which was not significantly different from that of larvae fed on live foods (63.55%). The body length and development index (DI) of the larvae fed on the microbound diet were always lower than those of larvae fed on live foods. However, the differences reached significant levels only at 11and 13dph (P<0.05). The mean dry weight loss of the microbound diet was 9.2% after 90min immersion in seawater, indicating that this diet has a good water stability. The microbound diet contains 52.23% crude protein and 10.27% lipid and is easy to prepare. These characteristics of the diet suggest good potentials for its successful use in the larviculture of other penaeid and fish species.

  10. Influence of dispersants on petroleum bioavailability in a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

    1995-12-31

    When crude oil is accidentally released into the ocean it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, may alter the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface marine organisms. Further, the dispersing agent may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes, To date, little information exists on the sub-lethal effects of dispersants and factors modifying their role in the bioavailability and disposition of PH in marine food chains. The objective of the current research was to determine the impact of dispersing agents on PH bioavailability to primary levels of a marine food chain. Uptake, bioaccumulation, deputation, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for dispersed Prudhoe Bay Crude Oil (PBCO) vs. undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities (22 and 34 ppt) employing Isochrysis galbana, a primary producer, and Brachionus plicatilis, a primary consumer. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations. However, short term (eight hour) and long term (two week) static exposure studies indicate the uptake of{sup 14}C-naphthalene from WAF preparations is inhibited by up to 50% from dispersed oil preparations. Results of comparative static and flow-through chamber exposure studies will be presented.

  11. Does haplodiploidy purge inbreeding depression in rotifer populations?

    Directory of Open Access Journals (Sweden)

    Ana M Tortajada

    Full Text Available BACKGROUND: Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. METHODOLOGY/PRINCIPAL FINDINGS: We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed and interclonal (outcrossed crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured. CONCLUSIONS/SIGNIFICANCE: Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation.

  12. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    Science.gov (United States)

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms. PMID:25646807

  13. Grazing by meso- and microzooplankton on phytoplankton in the upper reaches of the Schelde estuary (Belgium/The Netherlands)

    Science.gov (United States)

    Lionard, M.; Azémar, F.; Boulêtreau, S.; Muylaert, K.; Tackx, M.; Vyverman, W.

    2005-09-01

    In contrast with the marine reaches of estuaries, few studies have dealt with zooplankton grazing on phytoplankton in the upper estuarine reaches, where freshwater zooplankton species tend to dominate the zooplankton community. In spring and early summer 2003, grazing by micro- and mesozooplankton on phytoplankton was investigated at three sites in the upper Schelde estuary. Grazing by mesozooplankton was evaluated by monitoring growth of phytoplankton in 200 μm filtered water in the presence or absence of mesozooplankton. In different experiments, the grazing impact was tested of the calanoïd copepod Eurytemora affinis, the cyclopoid copepods Acanthocyclops robustus and Cyclops vicinus and the cladocera Chydorus sphaericus, Moina affinis and Daphnia magna/ pulex. No significant grazing impact of mesozooplankton in any experiment was found despite the fact that mesozooplankton densities used in the experiments (20 or 40 ind. l -1) were higher than densities in the field (0.1-6.9 ind. l -1). Grazing by microzooplankton was evaluated by comparing growth of phytoplankton in 30 and 200 μm filtered water. Microzooplankton in the 30-200 μm size range included mainly rotifers of the genera Brachionus, Trichocerca and Synchaeta, which were present from 191 to 1777 ind. l -1. Microzooplankton had a significant grazing impact in five out of six experiments. They had a community grazing rate of 0.41-1.83 day -1 and grazed up to 84% of initial phytoplankton standing stock per day. Rotifer clearance rates estimated from microzooplankton community grazing rates and rotifer abundances varied from 8.3 to 41.7 μl ind. -1 h -1. CHEMTAX analysis of accessory pigment data revealed a similar phytoplankton community composition after incubation with and without microzooplankton, indicating non-selective feeding by rotifers on phytoplankton.

  14. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    Directory of Open Access Journals (Sweden)

    Qiuchan Yang

    Full Text Available Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v, respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms.

  15. The Lophotrochozoan TGF-β signalling cassette - diversification and conservation in a key signalling pathway.

    Science.gov (United States)

    Kenny, Nathan J; Namigai, Erica K O; Dearden, Peter K; Hui, Jerome H L; Grande, Cristina; Shimeld, Sebastian M

    2014-01-01

    TGF-β signalling plays a key role in the patterning of metazoan body plans and growth. It is widely regarded as a 'module' capable of co-option into novel functions. The TGF-β pathway arose in the Metazoan lineage, and while it is generally regarded as well conserved across evolutionary time, its components have been largely studied in the Ecdysozoa and Deuterostomia. The recent discovery of the Nodal molecule in molluscs has underlined the necessity of untangling this signalling network in lophotrochozoans in order to truly comprehend the evolution, conservation and diversification of this key pathway. Three novel genome resources, the mollusc Patella vulgata, annelid Pomatoceros lamarcki and rotifer Brachionus plicatilis, along with other publicly available data, were searched for the presence of TGF-β pathway genes. Bayesian and Maximum Likelihood analyses, along with some consideration of conserved domain structure, was used to confirm gene identity. Analysis revealed conservation of key components within the canonical pathway, allied with extensive diversification of TGF-β ligands and partial loss of genes encoding pathway inhibitors in some lophotrochozoan lineages. We fully describe the TGF-β signalling cassette of a range of lophotrochozoans, allowing firm inference to be drawn as to the ancestral state of this pathway in this Superphylum. The TGF-β signalling cascade's reputation as being highly conserved across the Metazoa is reinforced. Diversification within the activin-like complement, as well as potential wide loss of regulatory steps in some Phyla, hint at specific evolutionary implications for aspects of this cascade's functionality in this Superphylum. PMID:25690968

  16. Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota.

    Science.gov (United States)

    Miest, Joanna J; Arndt, Carmen; Adamek, Mikolaj; Steinhagen, Dieter; Reusch, Thorsten B H

    2016-01-01

    Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard(®)) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard(®) at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard(®) fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard(®) induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot. PMID:26564474

  17. Cultivation of Arthrospira (Spirulina platensis using confectionary wastes for aquaculture feeding

    Directory of Open Access Journals (Sweden)

    Hala Y. El-Kassas

    2015-12-01

    Full Text Available The microalga biomass production from confectionary effluent is a possible solution for the urgent need for a live food in aquaculture. Arthrospira (Spirulina platensis was the dominant alga in effluent of “Biscomisr a confectionary factory”, in Alexandria–Egypt. Therefore, it was isolated from the effluent samples and used throughout the study. The cyanobacterium, A. platensis was grown on the effluent using 22 Central Composite Design (22 CCD. This work addresses the best effluent dilution (WC, % as well as sodium bicarbonate concentration (SBC on the alga growth and biochemical composition. Total protein, carbohydrate, lipid contents and fatty acid profiles of the produced algal biomass were highly improved. The statistical analyses suggested that the main effect of (WC, % is significant negative influences on the algal contents of proteins, lipids and carbohydrates (p > 0.01. Although it had a significant positive influence on chlorophyll (p > 0.01, no significant effect on algal β carotenes (p > 0.05 had been reported. The inter action effect of SBC together with WC, % exerted a significant negative influence on the algal proteins (p > 0.01 and no significant effect on the other responses (p > 0.05. The produced alga biomass was used for feeding the rotifer, Brachionus plicatilis for further application in aquaculture. Growth rate, reproductive rate and fecundity attributes, fatty acid content of B. plicatilis were amended. The Pearson correlation test indicated that β carotenes displayed a highly positive significant correlation with the growth rate of B. plicatilis (r = 0.733, p < 0.01 and the carbohydrates showed significant positive correlations with Egg % (r = 0.657, p < 0.05.

  18. Effects of administration of probiotic strains on GALT of larval gilthead seabream: Immunohistochemical and ultrastructural studies.

    Science.gov (United States)

    Picchietti, Simona; Mazzini, Massimo; Taddei, Anna Rita; Renna, Raffaella; Fausto, Anna Maria; Mulero, Victoriano; Carnevali, Oliana; Cresci, Alberto; Abelli, Luigi

    2007-01-01

    Two bacterial strains Lactobacillus fructivorans (AS17B), isolated from adult seabream (Sparus aurata L.) gut, and Lactobacillus plantarum (906), isolated from human faeces, were administered contemporaneously during seabream development using Brachionus plicatilis and/or Artemia salina and dry feed as vectors. Experimental group A received the probiotic strains already via rotifers from day 5 post-hatch (ph), whereas treatment of group B began with Artemia feeding from day 27 ph. Fish were sampled at day 28 ph (group A and control) and day 99 ph (groups A, B and control) for electron microscopy, histology and immunohistochemistry with the polyclonal antiserum ORa against homologous serum Ig and the mAb G7 specific for seabream acidophilic granulocytes. In all groups, timing and pattern of differentiation of the digestive tract did not differ. Furthermore, neither tissue damage nor manifest inflammation was provoked by probiotic administration. At day 28 ph, the developing GALT already housed mucosal leucocytes, including Ig(+) cells but no acidophilic granulocytes. No differences were seen between experimental groups. At day 99 ph, the density of Ig(+) cells (+51%) and acidophilic granulocytes (+284%) was significantly higher (p<0.05) in group A than in controls. Also group B had a higher density of Ig(+) cells (+17%) and acidophilic granulocytes (+130%) compared with controls, although less pronounced. Light and electron microscopy observations detailed the occurrence of heterogeneous populations of lymphocytes and granulocytes in the developing intestinal mucosa, and highlighted the net expansion of G7(+) acidophilic granulocytes (A +536%, B +292% vs. control) due to probiotic administration. Evidence is provided that early feeding with probiotic-supplemented diet increased the number of Ig(+) cells and acidophilic granulocytes in seabream gut and that the effects were more pronounced when administration started during gut metamorphosis. These results point to a

  19. Dietary β-glucan (MacroGard®) enhances survival of first feeding turbot (Scophthalmus maximus) larvae by altering immunity, metabolism and microbiota.

    Science.gov (United States)

    Miest, Joanna J; Arndt, Carmen; Adamek, Mikolaj; Steinhagen, Dieter; Reusch, Thorsten B H

    2016-01-01

    Reflecting the natural biology of mass spawning fish aquaculture production of fish larvae is often hampered by high and unpredictable mortality rates. The present study aimed to enhance larval performance and immunity via the oral administration of an immunomodulator, β-glucan (MacroGard(®)) in turbot (Scophthalmus maximus). Rotifers (Brachionus plicatilis) were incubated with or without yeast β-1,3/1,6-glucan in form of MacroGard(®) at a concentration of 0.5 g/L. Rotifers were fed to first feeding turbot larvae once a day. From day 13 dph onwards all tanks were additionally fed untreated Artemia sp. nauplii (1 nauplius ml/L). Daily mortality was monitored and larvae were sampled at 11 and 24 dph for expression of 30 genes, microbiota analysis, trypsin activity and size measurements. Along with the feeding of β-glucan daily mortality was significantly reduced by ca. 15% and an alteration of the larval microbiota was observed. At 11 dph gene expression of trypsin and chymotrypsin was elevated in the MacroGard(®) fed fish, which resulted in heightened tryptic enzyme activity. No effect on genes encoding antioxidative proteins was observed, whilst the immune response was clearly modulated by β-glucan. At 11 dph complement component c3 was elevated whilst cytokines, antimicrobial peptides, toll like receptor 3 and heat shock protein 70 were not affected. At the later time point (24 dph) an anti-inflammatory effect in form of a down-regulation of hsp 70, tnf-α and il-1β was observed. We conclude that the administration of MacroGard(®) induced an immunomodulatory response and could be used as an effective measure to increase survival in rearing of turbot.

  20. Effect of dietary (n-3 highly unsaturated fatty acids on growth and survival of fat snook (Centropomus parallelus, Pisces: Centropomidae larvae during first feeding

    Directory of Open Access Journals (Sweden)

    M.E.B. Seiffert

    2001-05-01

    Full Text Available The effect of rotifers, Brachionus rotundiformis (S-type, fed three different diets: A (rotifer fed Nannochloropsis oculata, B (rotifer fed N. oculata and baker's yeast, 1:1, and C (rotifer fed N. oculata and baker's yeast, 1:1, and enriched with Selcoâ, was evaluated based on the survival, growth and swim bladder inflation rate of fat snook larvae. Rotifers of treatment A had higher levels (4.58 mg/g dry weight of eicosapentaenoic acid (EPA than B (1.81 mg/g dry weight, and similar levels (0.04 and 0.06 mg/g dry weight, respectively of docosahexaenoic acid (DHA. Rotifers of treatment C had the highest levels of EPA (13.2 mg/g dry weight and DHA (6.08 mg/g dry weight. Fat snook eggs were obtained by spawning induction with human chorionic gonadotropin. Thirty hours after hatching, 30 larvae/liter were stocked in black cylindric-conical tanks (36-liter capacity. After 14 days of culture, there were no significant differences among treatments. Mean standard length was 3.13 mm for treatment A, 3.17 mm for B, and 3.39 mm for C. Mean survival rates were very low (2.7% for treatment A, 2.3% for B, and 1.8% for C. Swim bladder inflation rates were 34.7% for treatment A, 27.1% for B, and 11.9% for C. The lack of differences in growth and survival among treatments showed that the improvement of the dietary value of rotifer may not have been sufficient to solve the problem of larval rearing. Some other factor, probably pertaining to the quality of the larvae, may have negatively influenced survival.

  1. The toxicity of carbofuran to the freshwater rotifer, Philodina roseola.

    Science.gov (United States)

    Moreira, Raquel Aparecida; da Silva Mansano, Adrislaine; Rocha, Odete

    2015-04-01

    In this study, the effects of exposing the rotifer Philodina roseola to the pesticide carbofuran were investigated. Its range of sensitivity to potassium dichromate, the acute toxicity of active ingredient carbofuran and of carbofuran dosed as its commercial form, Furadan(®) 350 SC were determined. Chronic toxicity of carbofuran dosed as Furadan(®) 350 SC on P. roseola survival and fecundity were also studied. The sensitivity of P. roseola to K2Cr2O7 ranged from 29.52 to 64.67 mg L(-1), averaging 47.10 mg L(-1). The 48-h EC50 were 13.36 ± 2.63 mg L(-1) for carbofuran and 89.32 ± 6.52 mg L(-1) for commercial form. Chronic toxicity tests showed that the survival of this rotifer was not affected by the carbofuran dosed as Furadan(®) 350 SC at the concentrations tested and that at 1.56 and 3.12 mg L(-1) their fecundity was higher than in the absence of this commercial product, characterizing the hormesis phenomenon. The sensitivity profile of several species to carbofuran indicated that P. roseola is more susceptible to this pesticide than the fish Clarias batrachus, the bacterium Vibrio fischeri, the protozoan Paramecium caudatum and the rotifer Brachionus calyciflorus, although the acute toxicity of carbofuran dosed as Furadan(®) 350 SC to P. roseola is much lower than that of active ingredient carbofuran. The results also imply that the exacerbated use of pesticides and the constant, accelerated expansion of agricultural activity will make aquatic non-target species even more vulnerable. Furthermore, the relevant role of benthic organisms in aquatic environments justifies the inclusion of P. roseola and other benthic species in toxicity screening for risk assessment, regarding this environmental compartment.

  2. The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

    Science.gov (United States)

    Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

    2016-02-01

    The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

  3. Zooplankton diversity and physico-chemical conditions in three perennial ponds of Virudhunagar district, Tamilnadu.

    Science.gov (United States)

    Rajagopal, T; Thangamani, A; Sevarkodiyone, S P; Sekar, M; Archunan, G

    2010-05-01

    Plankton diversity and physico-chemical parameters are an important criterion for evaluating the suitability of water for irrigation and drinking purposes. In this study we tried to assess the zooplankton species richness, diversity and evenness and to predict the state of three perennial ponds according to physico-chemical parameters. A total of 47 taxa were recorded: 24 rotifers, 9 copepods, 8 cladocerans, 4 ostracods and 2 protozoans. More number of zooplankton species were recorded in Chinnapperkovil pond (47 species) followed by Nallanchettipatti (39 species) and Kadabamkulam pond (24 species). Among the rotifers, Branchionus sp. is abundant. Diaphanosoma sp. predominant among the cladocerans. Among copepods, numerical superiority was found in the case of Mesocyclopes sp. Cypris sp. repeated abundance among ostracoda. Present study revealed that zooplankton species richness (R1 and R2) was comparatively higher (R1: 4.39; R2: 2.13) in Chinnapperkovil pond. The species diversity was higher in the Chinnapperkovil pond (H': 2.53; N1: 15.05; N2: 15.75) as compared to other ponds. The water samples were analyzed for temperature, pH, electrical conductivity alkalinity salinity, phosphate, hardness, dissolved oxygen and biological oxygen demand. Higher value of physico-chemical parameters and zooplankton diversity were recorded in Chinnapperkovil pond as compared to other ponds. The zooplankton population shows positive significant correlation with physico-chemical parameters like, temperature, alkalinity phosphate, hardness and biological oxygen demand, whereas negatively correlated with rainfall and salinity. The study revealed that the presence of certain species like, Monostyla sp., Keratella sp., Lapadella sp., Leydigia sp., Moinodaphnia sp., Diaptomus sp., Diaphanosoma sp., Mesocyclopes sp., Cypris sp. and Brachionus sp. is considered to be biological indicator for eutrophication.

  4. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

  5. Aeolian transport of biota with dust: A wind tunnel experiment

    Science.gov (United States)

    Rivas, J. A., Jr.; Gill, T. E.; Van Pelt, R. S.; Walsh, E.

    2015-12-01

    Ephemeral wetlands are ideal sources for dust emission, as well as repositories for dormant stages of aquatic invertebrates. An important component of invertebrate dispersal and colonization to new areas is the ability to be entrained into the atmosphere. Aquatic invertebrate eggs fall within the size of dust and sand grains (30-600μm), are less dense and aerodynamically shaped. We have shown previously that aquatic invertebrates can be dispersed long distances in dust storms but the extent of transport of taxa based on diapausing egg size/morphology has not been investigated. Here, we control the wind erosion process in a wind tunnel to test entrainment of diapausing stages of brine shrimp, clam shrimp, tadpole shrimp, fairy shrimp, Daphnia, and the rotifers Brachionus plicatilis and B. calyciflorus into the air by saltation. Diapausing eggs were mixed with sterilized wind-erodible soil. The soil/egg mixture was moistened with distilled water and air dried to form a crust. Dust was generated in a wind tunnel by releasing sand grains that act as saltator material similar to wind-entrained natural sands. Maximum wind velocity was 10m/s and entrained particles were sampled through an isokinetic horizontal intake opening. Aeolian sediment was collected from three points in the system; transfer section for coarse sediment, the pan subtending a settling chamber for finer saltation-sized sediment, and two paper filters for suspension-sized sediment. Samples were then passed through 250 and 350 μm sieves to remove abrader sand and rehydrated with various sterile media depending on the type of organism. We retrieved viable brine, fairy, and tadpole shrimp, ostracods, Daphnia, and diapausing eggs of the rotifers after hydration. This experiment demonstrates that resting stages of many invertebrates can be wind-eroded due to size and egg morphology and remain viable under controlled conditions mimicking dust emission.

  6. First feed affects the expressions of microRNA and their targets in Atlantic cod.

    Science.gov (United States)

    Bizuayehu, Teshome Tilahun; Furmanek, Tomasz; Karlsen, Ørjan; van der Meeren, Terje; Edvardsen, Rolf Brudvik; Rønnestad, Ivar; Hamre, Kristin; Johansen, Steinar D; Babiak, Igor

    2016-04-14

    To our knowledge, there is no report on microRNA (miRNA) expression and their target analysis in relation to the type of the first feed and its effect on the further growth of fish. Atlantic cod (Gadus morhua) larvae have better growth and development performance when fed natural zooplankton as a start-feed, as compared with those fed typical aquaculture start-feeds. In our experiment, two groups of Atlantic cod larvae were fed reference feed (zooplankton, mostly copepods, filtered from a seawater pond) v. aquaculture feeds: enriched rotifers (Brachionus sp.) and later brine shrimp (Artemia salina). We examined the miRNA expressions of six defined developmental stages as determined and standardised by body length from first feeding for both diet groups. We found eight miRNA (miR-9, miR-19a, miR-130b, miR-146, miR-181a, miR-192, miR-206 and miR-11240) differentially expressed between the two feeding groups in at least one developmental stage. We verified the next-generation sequencing data using real-time RT-PCR. We found 397 putative targets (mRNA) to the differentially expressed miRNA; eighteen of these mRNA showed differential expression in at least one stage. The patterns of differentially expressed miRNA and their putative target mRNA were mostly inverse, but sometimes also concurrent. The predicted miRNA targets were involved in different pathways, including metabolic, phototransduction and signalling pathways. The results of this study provide new nutrigenomic information on the potential role of miRNA in mediating nutritional effects on growth during the start-feeding period in fish larvae. PMID:26857476

  7. Warming-induced changes in predation, extinction and invasion in an ectotherm food web.

    Science.gov (United States)

    Seifert, Linda I; Weithoff, Guntram; Gaedke, Ursula; Vos, Matthijs

    2015-06-01

    Climate change will alter the forces of predation and competition in temperate ectotherm food webs. This may increase local extinction rates, change the fate of invasions and impede species reintroductions into communities. Invasion success could be modulated by traits (e.g., defenses) and adaptations to climate. We studied how different temperatures affect the time until extinction of species, using bitrophic and tritrophic planktonic food webs to evaluate the relative importance of predatory overexploitation and competitive exclusion, at 15 and 25 °C. In addition, we tested how inclusion of a subtropical as opposed to a temperate strain in this model food web affects times until extinction. Further, we studied the invasion success of the temperate rotifer Brachionus calyciflorus into the planktonic food web at 15 and 25 °C on five consecutive introduction dates, during which the relative forces of predation and competition differed. A higher temperature dramatically shortened times until extinction of all herbivore species due to carnivorous overexploitation in tritrophic systems. Surprisingly, warming did not increase rates of competitive exclusion among the tested herbivore species in bitrophic communities. Including a subtropical herbivore strain reduced top-down control by the carnivore at high temperature. Invasion attempts of temperate B. calyciflorus into the food web always succeeded at 15 °C, but consistently failed at 25 °C due to voracious overexploitation by the carnivore. Pre-induction of defenses (spines) in B. calyciflorus before the invasion attempt did not change its invasion success at the high temperature. We conclude that high temperatures may promote local extinctions in temperate ectotherms and reduce their chances of successful recovery. PMID:25564019

  8. Unexpected increases in rotifer resting egg abundances during the period of contamination of Lake Orta

    Directory of Open Access Journals (Sweden)

    Roberta Piscia

    2016-04-01

    Full Text Available Despite their ecological importance and rapid response to environmental changes, rotifers are rarely included in palaeolimnological studies. Here, we describe changes in abundance (ABD and morphotype (MTs diversity of rotifer resting eggs in the sediments of deep subalpine Lake Orta, Italy, covering a period prior to (pre- 1926, during long-term ammonia and metal pollution from a rayon factory, and subsequent recovery of water quality. Following the pollution and bacterial oxidation of the ammonia, Lake Orta became the largest and deepest acid lake in Europe. Recovery of water quality followed both a ban on the discharge of industrial wastes, and a liming intervention in 1989 and 1990. We sectioned a sediment core collected from the deepest part of the lake (ORTA 07/2A to provide a high  time resolution, given the ca. 3-4 y cm-1 of sediment accumulation. Rotifer resting egg (RRE abundance and morphotypes were examined from the sediments and compared to limnological variables indicating the pollution. Rotifer resting egg abundance significantly increased with lake contamination (r=0.609 and -0.624 for copper and pH, respectively; P<0.001; n=27. A lake-water copper concentration threshold of ca. 40 µg L-1discriminated among pre-, during-, and post- pollution compositions of the rotifer morphotype assemblages. Diversity and morphotype richness increased during the recovery from copper pollution and with complete restoration from acidity, while abundance increased during pollution. The persistence of presumably viable Brachionus resting eggs and of hatched egg cases during the heavy pollution phase suggests that, unlike most other organisms, which were extirpated by the pollution of the lake, rotifers survived producing resting eggs, which secured future generations.

  9. Supplementation of Indigenous Lactobacillus Bacteria in Live Prey and as Water Additive to Larviculture of Portunus pelagicus (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    A.D. Talpur

    2011-10-01

    Full Text Available Experimental trials were conducted to demarcate the effects of indigenous Lactobacillus probiotics as bioencapsulated in live prey (rotifers Brachionus plicatilis and Artemia franciscana and water additives together on the survival of blue swimming crab, Portunus pelagicus larvae. Three LAB probiotics L. plantarum, L. salivarius and L. rhamnosus at final concentration 1x107 cfu/mL were bioencapsulated in live prey added daily and same allowance was added to culture water on day 1, 3, 5, 7, 9, 11, 13 as a single isolates to treatments A, B, C and multi isolates to D with no probiotic added to control tanks. Bacteria were successfully accumulated in both rotifers and Artemia within two hours of incubation. Total viable count of bacteria in Artemia observed lower at sampling days in inoculated tanks compared to those at time of incubation, contrary it increased in controls and no Vibrio was determined in Artemia in LAB mixture isolate inoculated samples on the day 13. Highest LAB bacteria 4.10×103 was determined in Artemia on day 11 in those inoculated with mixture of LAB isolates. At the end of the trials, larvae treated with a mixture of LAB probiotics did produce significantly highest survival 13.83±0.76% over other LAB treatments. As a single isolates L. plantarum did produce survival 13.50±1.32% compared with those treated with L. salivarius and L. rhamnosus and those without probiotics (control. There was no statistical significance (p>0.05 in the survival of larvae in any treatment. Results indicate that LAB probiotics could be used to enhance survival of P. pelagicus larvae.

  10. The toxicity of carbofuran to the freshwater rotifer, Philodina roseola.

    Science.gov (United States)

    Moreira, Raquel Aparecida; da Silva Mansano, Adrislaine; Rocha, Odete

    2015-04-01

    In this study, the effects of exposing the rotifer Philodina roseola to the pesticide carbofuran were investigated. Its range of sensitivity to potassium dichromate, the acute toxicity of active ingredient carbofuran and of carbofuran dosed as its commercial form, Furadan(®) 350 SC were determined. Chronic toxicity of carbofuran dosed as Furadan(®) 350 SC on P. roseola survival and fecundity were also studied. The sensitivity of P. roseola to K2Cr2O7 ranged from 29.52 to 64.67 mg L(-1), averaging 47.10 mg L(-1). The 48-h EC50 were 13.36 ± 2.63 mg L(-1) for carbofuran and 89.32 ± 6.52 mg L(-1) for commercial form. Chronic toxicity tests showed that the survival of this rotifer was not affected by the carbofuran dosed as Furadan(®) 350 SC at the concentrations tested and that at 1.56 and 3.12 mg L(-1) their fecundity was higher than in the absence of this commercial product, characterizing the hormesis phenomenon. The sensitivity profile of several species to carbofuran indicated that P. roseola is more susceptible to this pesticide than the fish Clarias batrachus, the bacterium Vibrio fischeri, the protozoan Paramecium caudatum and the rotifer Brachionus calyciflorus, although the acute toxicity of carbofuran dosed as Furadan(®) 350 SC to P. roseola is much lower than that of active ingredient carbofuran. The results also imply that the exacerbated use of pesticides and the constant, accelerated expansion of agricultural activity will make aquatic non-target species even more vulnerable. Furthermore, the relevant role of benthic organisms in aquatic environments justifies the inclusion of P. roseola and other benthic species in toxicity screening for risk assessment, regarding this environmental compartment. PMID:25588673

  11. Adverse effects and bioconcentration of chromium in two freshwater rotifer species.

    Science.gov (United States)

    Hernández-Ruiz, Esmeralda; Alvarado-Flores, Jesús; Rubio-Franchini, Isidoro; Ventura-Juárez, Javier; Rico-Martínez, Roberto

    2016-09-01

    Bioaccumulation of trivalent (CrIII) and hexavalent chromium (CrVI), and its adverse effects were studied in two rotifer species: Brachionus calyciflorus (two different strains), and Lecane quadridentata. Median Lethal Concentration (LC50) at 24 h of both species showed that CrVI is highly toxic: LC50 ranges from 4.7 × 10(-5) to 4 × 10(-6) mg L(-1)), compared with CrIII: LC50 ranges from 0.64 to 1.279 mg L(-1). Using the LC50 as an exposure concentration, and using atomic absorption, the bioconcentration factor (BCF) was obtained and BCFs of rotifers exposed to CrIII are four orders of magnitude lower than BCFs of rotifers exposed to CrVI. The effect of Cr on the elemental composition of the two species of rotifers in their structures by X-ray microanalysis by energy dispersion showed that Cr is found in intoxicated rotifers, but not in control rotifers. The basal immunoreactivity to metallothioneins is greater in B. calyciflorus than L. quadridentata. The immunoreactivity to metallothioneins decreases in B. calyciflorus when is exposed to CrIII, in contrast in L. quadridentata the immunoreactivity to metallothioneins increase when is exposed to CrIII, and the immunoreactivity to CrVI in L. quadridentata decrease. A mechanism is proposed in which the harder lorica of L. quadridentata acts as a barrier and accumulator of CrVI, and allows for attenuating responses like metallothionein production in L. quadridentata. Instead, in B. calyciflorus the lack of a harder lorica allows for deeper penetration of CrVI, and no time to produce attenuating measures. PMID:27258901

  12. Zooplankton of an urban coastal lagoon: composition and association with environmental factors and summer fish kill

    Directory of Open Access Journals (Sweden)

    Leonardo C. e Souza

    2011-06-01

    Full Text Available Zooplankton may be regarded as a sensitive tool for monitoring environmental variations in coastal lagoons due to their ability to immediately react to changes in the water column trophic features and salinity levels. As a coastal lagoon with a broad history of anthropic influence, Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil is widely used for water sports and artisanal fishing. The present study aimed to expand the knowledge base about zooplankton in the Rodrigo de Freitas Lagoon by assessing the composition and time-spatial distribution of the major zooplankton groups. Samples were collected fortnightly from at four distinct sampling points August 2001 to July 2002. At each point, salinity, temperature, dissolved oxygen and water transparency were measured. During the study period, the lagoon behaved as an spatially homogeneous environment in what regards the abiotic variables. However, all these variables showed significant differences along the time, mainly related to seasonality (air temperature and rainy and dry periods. The zooplankton community showed low taxonomic richness, with the predominance of species commonly found in coastal lagoons, especially with mesohaline conditions, as well as those found in estuaries. An interesting fact was the rise in zooplankton abundance at all sampling points right after a fish kill event. Such increase was caused mainly by the Brachionus plicatilis O.F. Müller 1786 species. Thus, the zooplankton community was affected by physical and chemical factors, mainly by the dissolved oxygen decline event and variations in the influx of seawater into the lagoon. In addition, phytoplankton availability and fish predation pressure were suggested as important regulating factors of the zooplankton community.

  13. Diapause and maintenance of facultative sexual reproductive strategies.

    Science.gov (United States)

    Stelzer, Claus-Peter; Lehtonen, Jussi

    2016-10-19

    Facultative sex combines sexual and asexual reproduction in the same individual (or clone) and allows for a large diversity of life-history patterns regarding the timing, frequency and intensity of sexual episodes. In addition, other life-history traits such as a diapause stage may become linked to sex. Here, we develop a matrix modelling framework for addressing the cost of sex in facultative sexuals, in constant, periodic and stochastically fluctuating environments. The model is parametrized using life-history data from Brachionus calyciflorus, a facultative sexual rotifer in which sex and diapause are linked. Sexual propensity was an important driver of costs in constant environments, in which high costs (always > onefold, and sometimes > twofold) indicated that asexuals should outcompete facultative sexuals. By contrast, stochastic environments with high temporal autocorrelation favoured facultative sex over obligate asex, in particular, if the penalty to fecundity in 'bad' environments was large. In such environments, obligate asexuals were constrained by their life cycle length (i.e. time from birth to last reproductive adult age class), which determined an upper limit to the number of consecutive bad periods they could tolerate. Nevertheless, when facultative asexuals with different sexual propensities competed simultaneously against each other and asex, the lowest sex propensity was the most successful in stochastic environments with positive autocorrelation. Our results suggest that a highly specific mechanism (i.e. diapause linked to sex) can alone stabilize facultative sex in these animals, and protect it from invasion of both asexual and pure sexual strategies.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. PMID:27619700

  14. Effect of food type and concentration on growth and fatty acid composition of early larvae of the anchovy (Engraulis encrasicolus) reared under laboratory conditions

    KAUST Repository

    Garrido, Susana

    2012-12-01

    Experiments were conducted during the summer of 2008 and 2009 to study the growth of early post yolk-sac European anchovy (Engraulis encrasicolus, Linnaeus, 1758) larvae reared under different food regimes. The fatty acid composition was used to assess nutritional condition of the larvae. Prey items used in the experiments were Gymnodinium sanguineum, Brachionus plicatilis and nauplii of the copepods Acartia grani and Euterpina acutifrons. Food type and concentration affected the growth of the larvae. Mixed diets composed of rotifers and copepod nauplii at high concentration resulted in higher anchovy larvae growth rates in comparison with single-prey diets using either rotifers or copepod nauplii. The addition of the dinoflagellate G. sanguineum (25-50cellsml -1) to the prey offered did not enhance significantly larval growth. Highest growth rates of anchovy larvae (0.28mmd -1) were obtained using high concentrations of a mixed diet, particularly the combination of rotifers and A. grani nauplii. Fatty acid composition at hatch was similar to the composition observed in the field, but during larvae ontogeny there was a marked decrease in the contribution of polyunsaturated fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Such difference reflects the high requirements of these PUFA for larvae development, and suggests that the food offered failed to fulfill the larvae nutritional requirements. The growth rates obtained in our experiments were, overall, in the lower range of those observed in natural conditions. Taking into considerations the fact that larvae in the field are expected to encounter lower prey concentrations, we discuss the reasons for such disagreement. © 2012 Elsevier B.V.

  15. Filming of zooplankton: a case study of rotifer males and Daphnia magna

    Directory of Open Access Journals (Sweden)

    Pierluigi Colangeli

    2015-11-01

    Full Text Available Filming live organisms can give new insights into the hidden life of plankton. Accessibly priced digital cameras are now available for a large range of users. Here, we demonstrate the technical setup and workflow of using a single-lens reflex (DSLR camera to film the behaviour of males of two rotifer species, Brachionus angularis Gosse (1851 and Keratella cochlearis Gosse (1851, and of the cladoceran Daphnia magna Straus (1820. Rotifers are cyclical parthenogens that produce males only under certain environmental conditions. Thus, knowledge on rotifer males is still limited because of their ephemeral nature and because they are often smaller than females. We filmed males of B. angularis and K. cochlearis with a DSLR camera connected to a compound microscope to better understand their morphology and behaviour in comparison to conspecific females. While written descriptions have their scientific value, seeing is complementary because everyone can verify what has been described. We made our videos publicly accessible through links connected to the paper. Our videos are, to our best knowledge, the first on males of B. angularis and K. cochlearis. Furthermore, we filmed the behavioural response of D. magna to ultraviolet (UV radiation with a macro lens attached to the DSLR camera. Approaches like this are valuable tools in environmental teaching. To see live organisms with one’s own eyes may contribute to raising public awareness about the value of water resources and their hidden communities. In summary, filming can be a valuable tool to ignite scientific discussion, but the videos need an open-access platform where they can be referenced in a topic-related order.

  16. 哈素海浮游动物群落结构季节变化规律研究%Zooplankton and Zoobenthos Investigation in Lake Hasuhai and the Estimation of Nutrition Status

    Institute of Scientific and Technical Information of China (English)

    王俊; 赵林

    2012-01-01

    2008年7月、8月和10月及2009年1月和4月,对哈素海浮游动物群落结构进行了调查,共检测出浮游动物4大类,2科28属62种.其中原生动物10属,31种;枝角类2属,6种;桡足类6属,8种.全年优势的浮游动物有无节幼体、象鼻溞、剑水蚤、龟甲轮虫、疣毛轮虫、多肢轮虫、晶囊轮虫、哲水蚤等.大型浮游动物的年均丰度为228.5个/L,年均生物量为1.934 mg/L;原生动物的年均丰度和生物量分别为1.68×104个/L和0.0499 mg/L.在各季节中夏季浮游动物量最多,春秋季次之,冬季最少.对哈素海浮游动物优势种类及丰度和生物量指标的分析结果显示,哈素海的水质状况为中富营养水体,并且受到一定程度的污染.%A monitoring of zooplankton and zoobenthos was conducted in Lake Hasuhai in July, August,2008 and January,April,2009. A total of 28 genera and 62 species of zooplankton were detected in Lake Hasuhai. These include 10 genera and 17 species of Protozoa, 10 genera and 31 species of Rotifera, 2 genera and 6 species of Cladocera,and 6 genera and 8 species of Copepods. Zooplankton of the full-year advantage include Nauplii, Bosmina, Cyclopoida, Keratella, Synchaetidae, Polyarthra, Asplanchnidae and Calanidae. The annual large zooplankton adundance was 228. 5/L and biomass was 1. 934 mg/L. The average annual abundance and biomass of the protozoan were 1. 68 × 104/L,0. 049 9 mg/L in each of seasons the quantity of Zooplankton in summer than spring and autumn,and winter at least. According to zooplankton, abundance and biomass indicators in Lake Hasuhai, the status of water quality is middle nutritional water and a certain degree of pollution.

  17. Zooplankton Community Structure and Its Seasonal Variation in the Surface Water of Lugu Lake%泸沽湖表层水体浮游动物种群结构及季节变化

    Institute of Scientific and Technical Information of China (English)

    董云仙; 王忠泽

    2014-01-01

    is the deep plateau lake on the Yunnan-Guizhou Plateau with the highest latitude and alti-tude.Study of the zooplankton community in Lugu Lake was first reported in 1983 and focused on Rotifera, Copep-oda and Cladocera, but no published research has been found on the zooplankton of Lugu Lake.To characterize zo-oplankton community structure, a seasonal investigation of the zooplankton in Lugu Lake was carried out in January, April, August and November of 2010 at nine sample sites.Characteristics of the zooplankton community including structure, species composition, distribution and seasonal variation were described and the relationship of zooplankton with water quality and macrophytes were analyzed to reveal the primary factors affecting zooplankton bi-omass.Zooplankton samples for qualitative analysis were collected with a No.25 plankton net and fixed with Lugol′s solution after filtration.For quantitative analysis of protozoa and rotifers, 1 L water samples were collected 0.5 m below surface.For quantitative analysis of copepods and cladocerans, 10 L water sample were filtered with a No.25 plankton net.Counting and species identification in all samples were carried out under a microscope.A total of 80 species of zooplankton, belong to 33 families and 58 genera were observed in Lugu Lake, including Protozoa (10 families, 13 genera and 19 species), Rotifera (10 families, 22 genera and 32 species), Cladocera (4 families, 9 genera and 13 species), Copepoda (3 families, 8 genera and 10 species), and other taxa (6 families, 6 genera and 6 species) .The range of plankton densities with average number and percent contribution to total zooplankton density in parentheses were as follows:total zooplankton, 219.4-2 200.3 ind/L (813.2 ind/L, 100%);Proto-zoan, 30.0 -2 400.0 ind/L ( 660.7 ind/L, 81.25%,); Rotifera; 3.0 -780.0 ind/L, ( 145.4 ind/L, 17.88%), Cladocera, 0 -12.0 ind/L (4.1 ind/L, 0.50%); Copepoda, 0 -13.0 ind/L (2.7 ind/L, 0.33%);other taxa, 0-4.0 ind/L, (0.3 ind

  18. 北京翠湖湿地浮游动物调查及水质评价%A Survey of Zooplankton and Assessment Water Quality in Cuihu Wetland of Beijing

    Institute of Scientific and Technical Information of China (English)

    张强

    2013-01-01

      2012年4月至10月,在翠湖湿地选6个具有代表性的采样点,分别对湿地水体内浮游动物的种类及数量进行的调查显示,在翠湖湿地共有浮游动物4大类45种,其中以轮虫和原生动物种类最多,占浮游动物总数的82.2%。翠湖湿地浮游动物数量以6月最多,4月次之,8月和10月的种类数量相差不大。E/O指数等多种评价方法结果均显示翠湖湿地水体呈富营养化状态,6月翠湖湿地水体为超富营养类型。翠湖湿地外围取水渠的水质最差,其次为荷花塘和雁鸭湖,边境湖和天鹅湖的水质相对较好。%From April to October in 2012, 6 representative samples were collected from Cuihu Wetland to analyze the species and population size of zooplankton in water body. 45 species of zooplankton belonging to 4 major categories were identified in the wetland. Among them, Rotifera and Protozoa had the highest number of species, accounting for 82.2%of the total number of zooplankton. The number of zooplankton peaked in June, and followed by April. The difference of species number between August and October was not evident. Assessment by E/O index and some other methods showed that the water body of Cuihu Wetland is in eutrophication and at a state of super eutrophication in June. Results also showed that the worst water quality was in the surrounding canals, followed by Hehua Pond and Yanya Lake, the water quality of Bianjing Lake and Tian’e Lake was relatively good.

  19. [Selectivity of zooplankton and trophic overlap between size Menidia humboldtiana fish (Atheriniformes: Atherinopsidae) in the reservoir Danxhó, Mexico].

    Science.gov (United States)

    Merino, Regina Sánchez; Benítez, Miriam Y Fermín; Estrada, Angélica Mendoza

    2009-01-01

    The Menidia humboldtiana silverside is considered one of the most important species in fisheries in some states of Mexico. Knowing the choice that this species exercises over its food gives us an understanding of the behavior of zooplankton in presence of zooplanktonic fish, and tells us if the silverside choose amongst bigger prey fish, and if there is competition for food between the native and introduced fish in the reservoir. The purpose of this study was to determine if M. humboldtiana selects its food, and in which genera, and to establish whether there was an overlap in the diet of the different sizes of silverside. The fish were catched with a 88 mm mesh net, in six sampling points during one year, from Danxh6 (19 degrees 5'17" - 53'46" N, 99 degrees 32'42" - 35'40" W) reservoir. Samples of filtered zooplankton were also taken with a 125 micron net. The analysis of stomach contents was carried out in fish grouped by regular size intervals during each season of the year, using the volumetric method and Chesson's selectivity coefficient. To evaluate the trophic overlap between the different size groups, the Morisita index, modified by Horn, was used. The zooplankton community was represented by twelve genera: Mastigodiaptomus and Cyclops (Copepoda); Bosmina, Diaphanosoma, Daphnia, Ceriodaphnia, Moina, Alonopsis and Camptocercus, (Cladocera); Asplanchna, Conochillus and Filinia (Rotifera). Mastigodiaptomus was the most abundant throughout the year. The silverside consumed only four genera: Bosmina, Mastigodiaptomus, Daphnia and Ceriodaphnia; the group measuring 5 to 8.9 cm consumed a high percentage of Bosmina, Mastigodiaptomus and Daphnia, and a lesser percentage of Ceriodaphnia. The larger fish (9 to 10.9 cm) consumed only Mastigodiaptomus and Daphnia. In accordance with the selectivity values, the small and medium size silverside selected their prey, with more intensity on the genera Bosmina and Daphnia, while the bigger fish concentrated on Daphnia and

  20. EVALUACIÓN DE LA ROTIFEROFAUNA PRESENTE EN EL COMPLEJO DE PAJARALES DURANTE LA ÉPOCA LLUVIOSA, DEPARTAMENTO DE MAGDALENA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    LEÓN JENNY A.

    2008-08-01

    Full Text Available Con miras a evaluar posibles efectos de la recomunicación del río Magdalena con su antiguo delta, se determinó la abundancia y composición de la rotiferofauna del Complejo de Pajarales (CP, durante el período de mayor abundancia anual de zooplancton. El phylum Rotifera fue seleccionado por sus altas tasas reproductivas y eficiencia en procesos de transformación energética. Las muestras se colectaron con botella van Dorn durante la segunda temporada lluviosa de 2006. En cada una de las cuatro estaciones analizadas se registraron la salinidad, temperatura, pH y oxígeno disuelto. La diversidad se calculó empleando el índice de Shannon-Wiener H’ (log10 comparando estaciones y fechas de muestreo para establecer variaciones en el período de estudio. Gráficamente se relacionaron variables fisicoquímicas con valores de diversidad que emplearon un α de 0.05 y 95% de intervalo de confianza. En total, fueron encontrados 20 morfotipos pertenecientes a las familias Brachionidae, Lecanidae, Filiniidae, Synchaetidae, Hexarthriidae y Testudinellidae, siendo Brachionidae y Lecanidae las más abundantes. La relación entre diversidad y variables fisicoquímicas, indica que la salinidad es la principal responsable de la diversidad de rotíferos. En conclusión, la rotiferofauna actual en el CP es más abundante y diversa que hace 16 años, antes de la recomunicación con el río Magdalena. Así mismo, la concentración de oxigeno disuelto, pH y salinidad son diferentes. Teniendo en cuenta que la salinidad es el factor que más influyó en la diversidad de rotíferos, la reapertura de canales probablemente favoreció el incremento en la diversidad de rotíferos en el CP.

  1. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    Directory of Open Access Journals (Sweden)

    L. Tang

    2012-04-01

    Full Text Available Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm−2 and 690.51 ± 210.64 μg 10 cm−2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 % and polychaetes (1.39 %. Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=−0.747, P<0.05 and significantly negatively correlated with silt-clay content (r=−0.516, P<0.01 and medium diameter (r=−0.499, P<0.01 of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01. Meiobenthos abundance differed significantly among seasons (P<0.05, although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of

  2. Modern and fossilized biological communities from sediments of Bolshoy Harbei lake (Bolshezemelskaya tundra, Russia) and their response to climate change

    Science.gov (United States)

    Tumanov, Oleg; Nazarova, Larisa; Fefilova, Elena; Baturina, Maria; Loskutova, Olga; Frolova, Larisa; Palagushkina, Olga

    2013-04-01

    High-altitude regions are subjected to the threats of global warming. During the last decade the depth of seasonal melting of permafrost in Northern Russia, significantly increased. Investigation of lake sediments from polar regions has an extreme importance for understanding of the modern environmental processes and their influence on northern ecosystems and biological diversity of these regions. Invertebrate communities are used for diagnostic of lake ecosystems because they have a great sensitivity to climatic changes (Andronnikova, 1996; Lazareva, 2008; O'Brien et al., 2005). The data can be used as well as a basis for inference models for reconstruction of the paleoclimatic conditions. Chironomid-based, Cladocera-based and diatom models have successfully been developed (Nazarova et al., 2008, 2011; Self et al., 2011) and can be used for precise paleotemperature reconstructions (Kienast et al., 2011). In summer 2012, we investigated complex of Kharbei lakes, located in the interfluve of Korotaiha and Bolshaya Rogovaya rivers in the east side of Bolshezemelskaya tundra, Russia (67°33'22″ N, 62°53'23″ E). Six different lakes were investigated using modern hydrobiological and palaeoecological methods. In total 9 cores were obtained, cut, dated and further investigated using sedimenthological, geochemical, and paleobiological methods. The standard hydrobiological methods have shown that the modern zooplankton communities did not change significantly during the last 40 years. Taxonomic composition and structure of planktonic communities didn't change, except for appearance of crustaceans Polyarthra euryptera and Daphnia cucullata. In planktonic communities of Bolshoy Harbei lake we revealed 39 species and forms of Rotifera, 19 - Cladocera and 11 - Copepoda. In zoobenthic communities we registered 24 taxonomical groups characteristic for large tundra lakes of the North East of Russia. Chironomids and Oligochaeta are dominant groups of invertebrates. 103 taxa of

  3. 唐山“三岛”海域小型底栖动物丰度的研究%Abundance of meiobenthos in the sea area of three islands in Tangshan

    Institute of Scientific and Technical Information of China (English)

    曹英昆; 王小瑞; 夏辉; 王东昕; 申亮; 曾昭春; 郭冉

    2015-01-01

    于2013年5月,8月和10月份对唐山“三岛”海域12个不同站位小型底栖动物进行调查采样。共鉴定出自由生活海洋线虫、桡足类、多毛类、枝角类、端足类、介形类、涡虫类、轮虫类、双壳类及等足类10个类群。最优势类群是线虫,每个站位所占比例基本大于95%,平均丰度大约735.2 ind/10 cm2。其他类群各站位所占比例不同,且都较小。结果表明,小型底栖动物各类群所占比例随月份的变化并没明显变化;不同月份,各类群的丰度有所变化,其中5月份丰度较高,10月次之,8月份丰度最低。%A three-cruise investigation on the meiobenthos in the sea of Tangshan three islands was conducted in May ,August and October 2013 .A total of ten meiobenthic groups were identified . Free-living marine nematodes ,copepoda ,polychaeta ,cladocera ,amphipoda ,ostracoda ,turbel‐laria ,rotifera ,bivalvia and isopoda .Nematodes was the most dominant group in abundance ,about 735 .2 ind/10 cm2 ,with a relative dominance of 95% .Other groups of stations with different pro‐portion ,and the smaller .The results showed that ,meiobenthos in each group had no obvious change in the proportion .The abundance of different months ,each group had the change ,which in May higher abundance ,followed in October ,August the lowest abundance .

  4. Limnological Study of River Soan (Punjab, Pakistan

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    Furhan Iqbal

    2006-06-01

    Full Text Available River Soan is one of the important aquatic systems of the Punjab province in Pakistan and flows into Indus River near Kalla Bagh (District Mianwali. In order to measure the quality of water and to evaluate planktonic community, an integrated monitoring system was applied from May to December 2001. During the study period total of 202 genera were observed of which 134 were of phytoplankton present in various phylums including Cyanophyta (22, Cyarophyta (7, Xanthophyta (5, Bacillariophyta (22, Euglenophyta (5, Chlorophyta (62, Chrysophyta (8, Pyrrophyta (1 and Cphryrotophyta (2. 53 genera of zooplankton were observed including Protozoa (33, Rotifera (8, Cladocera (7, Copepoda (4 and Aquatic insecta (1. In addition to phyto and zooplankton 3 genera of Charophyta and 11 genera of Macrophyta were observed. Diversity index of phytoplankton ranged from 4.6 to 13.5 and of zooplankton from 1.94 to 5.90. Water samples were collected on monthly basis for estimation of various physical and chemical water quality parameters i.e., water temperature (9-31 0C, light penetration (1.2-22.3 cm, viscosity (0.8570-1.0572 mNS m-2, conductivity (7-19 mv, surface tension (69.28-72.63 dynes cm-1, density (0.980-1.022 mg l-1, specifi c gravity (0.796-1.025, boiling point (95-98 0C, turbidity (0.02-0.48 mg l-1, pH (8-9, dissolved oxygen (4.6- 9.3 mg l-1, alkalinity (19-36 mg l-1, acidity 1.0-1.8 mg l-1, carbonates (0, bicarbonates (19-36 mg l-1, total solids (0.56-4.24 mg l-1, total dissolved solids (0.53-4.83 and total dissolved volatile solids (0.05-0.29. Among elements, sodium (22.50-168.75 ppm, potassium (3.94-12.31 ppm, calcium (2.75-34.25 ppm, strontium (0.00-0.47 ppm, magnesium (0.00 ppm and zinc (0.00 ppm were detected through atomic absorption while seasonal variation in planktonic diversity was analyzed by calculating the frequency of occurrence, relative abundance and diversity index of planktonic life. The overall water quality of the study site remained

  5. Limnological Study of River Soan (Punjab, Pakistan

    Directory of Open Access Journals (Sweden)

    Furhan Iqbal

    2006-10-01

    Full Text Available River Soan is one of the important aquatic systems of the Punjab province in Pakistan and flows into Indus River near Kalla Bagh (District Mianwali. In order to measure the quality of water and to evaluate planktonic community, an integrated monitoring system was applied from May to December 2001. During the study period total of 202 genera were observed of which 134 were of phytoplankton present in various phylums including Cyanophyta (22, Cyarophyta (7, Xanthophyta (5, Bacillariophyta (22, Euglenophyta (5, Chlorophyta (62, Chrysophyta (8, Pyrrophyta (1 and Cphryrotophyta (2. 53 genera of zooplankton were observed including Protozoa (33, Rotifera (8, Cladocera (7, Copepoda (4 and Aquatic insecta (1. In addition to phyto and zooplankton 3 genera of Charophyta and 11 genera of Macrophyta were observed. Diversity index of phytoplankton ranged from 4.6 to 13.5 and of zooplankton from 1.94 to 5.90. Water samples were collected on monthly basis for estimation of various physical and chemical water quality parameters i.e., water temperature (9-31 0C, light penetration (1.2-22.3 cm, viscosity (0.8570-1.0572 mNS m-2, conductivity (7-19 mv, surface tension (69.28-72.63 dynes cm-1, density (0.980-1.022 mg l-1, specifi c gravity (0.796-1.025, boiling point (95-98 0C, turbidity (0.02-0.48 mg l-1, pH (8-9, dissolved oxygen (4.6- 9.3 mg l-1, alkalinity (19-36 mg l-1, acidity 1.0-1.8 mg l-1, carbonates (0, bicarbonates (19-36 mg l-1, total solids (0.56-4.24 mg l-1, total dissolved solids (0.53-4.83 and total dissolved volatile solids (0.05-0.29. Among elements, sodium (22.50-168.75 ppm, potassium (3.94-12.31 ppm, calcium (2.75-34.25 ppm, strontium (0.00-0.47 ppm, magnesium (0.00 ppm and zinc (0.00 ppm were detected through atomic absorption while seasonal variation in planktonic diversity was analyzed by calculating the frequency of occurrence, relative abundance and diversity index of planktonic life. The overall water quality of the study site remained

  6. 生态强化法原位净化村镇污水微生物特性∗%Microbial characteristics of in-situ strengthening bioremediation of rural domestic sewage

    Institute of Scientific and Technical Information of China (English)

    尹勇; 冯国勇; 周静; 刘明元; 胡林潮; 张文艺

    2015-01-01

    To investigate the microbial characteristic of in⁃situ strengthening bioremediation of rural domestic sewage, sediment microorganisms of Qianqiao demonstration project for rural domestic sewage treatment in Wujin,changzhou as the object of investigation were examined by phospholipid fatty acid method(PLFA).Microscopic examination showed that there were protozoa,rotifera,bacteria and algae in the sediment. PLFA analysis showed that total PLFAs were composed as follows, 76�97% saturated fatty acid,19.07% monounsaturated fatty acid,3.96% polyunsaturated fatty acid. Index of PLFA biomarkers volume showed pseudomonas and aerobic bacteria were predominant in the sediment microorganisms. It was proposed showed that the pollutants were mostly removed by microbial decomposition and plant uptaking, as well as synergistic effect of algae⁃aquatic animals/plants⁃bacteria.%为揭示生态强化法原位净化村镇污水机制与微生物特性,以常州市武进区前黄镇前桥污水治理示范工程底泥中微生物为研究考察对象,通过倒置显微镜镜检、磷脂脂肪酸( PLFA)分析手段对其进行了系统研究.镜检显示底泥中含有原生动物、轮虫以及菌藻. PLFA 分析表明,底泥中饱和脂肪酸含量最为丰富,占76�97%;其次为单不饱和脂肪酸,占19.07%;最少是多不饱和脂肪酸,占3.96%.以脂肪酸生物标记量为指标,表明底泥的生态群落中是以假单胞杆菌、好氧细菌为主导.生态强化法原位净化村镇污水可能主要通过微生物的分解、水生植物的吸收以及藻类⁃水生动植物⁃细菌的协同作用实现对污染物的去除.

  7. 淀山湖浮游动物群落结构特征及其影响因子%Community Structure of Zooplankton and Influencing Factors in Dianshan Lake of Shanghai

    Institute of Scientific and Technical Information of China (English)

    李强; 田华; 姜民; 蔡文婕; 曹玥

    2015-01-01

    for species identification,counting and weighing.Phytoplankton sampling and measurement of physi-cochemical parameters (water temperature,pH,dissolved oxygen,chemical oxygen demand,nitrate nitrogen,ni-trite nitrogen)were carried out simultaneously.A total of 60 zooplankton species were identified:31 species of roti-fer (51.7%),19 species of cladocera (31.7%),and 10 species of copepod (16.7%).The dominant species were Brachionus calyciflorus,B.schizocerca,Keratella quadrala,Asplanchna priodonta,Mesocyclops leuckarti, Schmackeria forbesi,Bosmina coregoni,B.longirostris,and Diaphanosoma brachyurum.From March to June,and from September and December,the dominant species varied significantly.The mean density and biomass of zoo-plankton were 78.10 ind /L and 2.06 mg/L,with the highest density occurring in September.Total zooplankton density was determined by rotifers in March and December and by cladocera in June and September.Generally,the values of Shannon-Wiener indices (H′),species richness indices (d)and Pielou evenness indices (J′)were high-er in September and December than in March and June,and higher upstream than downstream.Correlation analysis indicates a significant association between the zooplankton community and environmental factors such as phytoplank-ton species,density of pyrrophyta,density of euglenophyta,density of cryptophyta,water temperature,nitrite ni-trogen,nitrate nitrogen,permanganate index and chemical oxygen demand.Based on analysis of the biological di-versity index and indicator organisms,the water quality of Dianshan Lake can be regarded as βmesosaprobity (moderately polluted)with an improving trend.%为进一步了解生态修复后淀山湖水域浮游动物的群落特征,于2013年3-12月对淀山湖浮游动物包括轮虫及浮游甲壳动物的种类组成、数量、优势种和生物多样性进行研究,并初步探讨了浮游动物群落结构与浮游植物和水体理化因子的关系。结果表明,4次淀山湖水

  8. Spatial-temporal Dynamics of Rotifer Community Structure in the Jinan Region%济南地区河流轮虫群落结构的时空动态研究

    Institute of Scientific and Technical Information of China (English)

    王博涵; 李晨; 姜力文; 陈鹏; 殷旭旺; 徐宗学

    2016-01-01

    control in the Jinan region.A total of 19 sam-pling sites were selected,representing each county and the Jinan urban area.Qualitative rotifer samples were ob-tained by trawling with a No.25 plankton net both horizontally and vertically at sampling sites.For quantitative roti-fer analysis,a water sampler was used to collect samples at different depths and 50 L samples were mixed and fil-tered.Sediments were concentrated to 30 mL after samples had settled 48 h.Rotifer species identification and den-sity determination were completed under a microscope.Physicochemical parameters of water at each site were deter-mined including water temperature (Temp),pH,dissolved oxygen (DO),conductivity (Cond),Ca2 +,Cl -, TD,ALK,NH3-N,CODMn ,TP and TN.A total of 38 rotifer species from 17 genera were identified with dominant species from genera Keratella and Brachionus.In spring,summer and autumn,30,17 and 9 rotifer species were recorded,respectively,with average densities of 114.4 ind /L,10 ind /L and 8.3 ind /L.Rotifer pollution indica-tors included 20 species:3 associated with oligosaprobic water,5 with oligosaprobic to β-medium-polluted water,8 with β-medium-polluted water,2 with α-medium-polluted water and 2 with β-α-medium-polluted water.Fifteen pollution indicator species were observed in spring,11 species in summer and 8 species in autumn.The number and density of pollution indicators accounted for 52.63% and 77.99% of the total number and density of the rotifer community.Chromogaster ovalis,Brachionus calyciflorus,Brachionus calyciflorus,Asplanchna brightwellii and As-planchna priodonala were the dominant rotifer species.The average Shannon-Wiener indices of the rotifer communi-ty in spring,summer and autumn were 2.67,1.38 and 1.20 respectively,and the average Pielou evenness indices were 0.66,0.41 and 0.35.Canonical correspondence analysis (CCA)showed that TN,NH3-N and Ca2 + were the main environmental factors affecting rotifer community structure in spring,CODMn in summer

  9. Plancto e hidrobiologia sanitária de tanques tropicais com dáfnias e rotíferos

    Directory of Open Access Journals (Sweden)

    Lejeune P. H. de Oliveira

    1967-01-01

    NH[4 subscripted]. b Species of the genus Chlamydomonas; it is even possible that all the species of theses genus inhabit strong-mesosaprobic to polysaprobic waters when in massive blooms. c Several species of Euglenaceae in fast growing number, at the same time of the protozoa Amoebidae, Vorticellidae and simultaneous with deposition of the decaying cells of the blue algae Anacystis cyanea (= Microcystis when the consumed oxygen by organic matter resulted in 40 mg. L. But, we found, among various Euglenacea the cosmopolite species (Euglena viridis, a well known polysaprobic indicatior of which presence occur in septic zone. d Analcystis cyanea (= M. aeruginosa as we observed was in blooms increasing to the order of billions of cells per litter, its maximum in the summer. Temperatures 73ºF to 82ºF but even 90ºF, the pH higher than 8. When these blue algae was joined to the rotifer Brachionus calyflorus the waters gets a milky appearance, but greenished one. In fact, that cosmopolite algae is used as a mesosaprobic indicator. Into the water of the ponds its predominance finished when the septic polysaprobic conditions began. e Ankistrodesmus falcatus was present in the 5th pond from 26the. April untill the 26th July, and when N.NH[4 subscripted] gets 1.28 mg. L. and when chlorinity stayed from 0.034 to 0.061 mg. L. It never was found at N.NH[4 subscripted] higher than 1 mg. L. The green algae A. falcatus, an indicatior of pollution, lives in moderate mesosaprobic waters. f As everyone knows, the rotifer eggs may be widely dispersed by wind. The rotifer Asplanchna brightwelli in our observation seemed like a green colored bag, overcharged by green cells and detritus, specially into its spacious stomach, which ends blindly (the intestine, cloaca, being absent. The stock of Asplanchna in the ponds, during the construction of the bridge "PONTE OSWALDO CRUZ" inhabits alkaline waters, pH 8,0 a 8,3, and when we observed we noted its dissolved oxygen from 3.5 to 4 mg. L

  10. The Feeding Habits of Misgurnus Anguilicaudatus During the Early Developmental Stage%泥鳅早期发育阶段的食性研究

    Institute of Scientific and Technical Information of China (English)

    彭聪; 樊启学; 刘汝鹏; 胡培培; 姚昌林; 王昆鹏

    2013-01-01

    对池养泥鳅(Misgurnus anguillicaudatus)早期发育阶段的食物组成和食物选择性进行了研究.结果表明,泥鳅早期发育阶段主要摄食浮游动物.7日龄和9日龄泥鳅主要摄食轮虫,其数量比例和重量比例分别达到98.73%、79.59%和97.59%、66.67%.13日龄枝角类的数量和重量比例高达41.15%和98.04%,17日龄桡足类的数量比例和重量比例为30.00%和62.03%.24日龄和31日龄,枝角类和桡足类的数量比例虽然都小于20.00%,但是其重量比例共占到95.00%;13 ~31日龄,枝角类和桡足类为泥鳅的主要食物.7日龄和9日龄,泥鳅对臂尾轮虫属(Brachionus)、龟甲轮虫属(Keratella)和异尾轮虫属(Trichocerca)表现出较强的摄食喜好性,对微型裸腹溞(Moina micrura)也表现出一定的摄食喜好性,对桡足类回避.13日龄和17日龄泥鳅对臂尾轮虫属和龟甲轮虫属仍有较强的摄食偏好性,同时对裸腹溞属(Moina)、秀体溞属(Diaphanosoma)、剑水蚤属(Cyclops)和华哲水蚤属(Sinocalanus)也表现出了较强的摄食喜好性.24日龄和31日龄泥鳅不再主动选食轮虫,喜好摄食裸腹潘属、低额溞属(Simocephalus)、剑水蚤属和华哲水蚤属.

  11. Analysis and appraisement of nutrient compositions for Daphniopsis tibetana Sars%西藏拟溞营养成分的分析与评价

    Institute of Scientific and Technical Information of China (English)

    赵文; 霍元子; 高敬

    2006-01-01

    对采自西藏纳木卡错并驯养于稀释海水(盐度20)中的西藏拟溞(Daphniopsis tibetana Sars)一般生化组成、氨基酸和脂肪酸组成进行测定,与蒙古裸腹溞(Moina mongolica)、淡水裸腹溞(Moina spp.)、日本虎斑猛水蚤(Tigiopus japonica)、褶皱臂尾轮虫(Brachionus plicatilis)和卤虫(Artemia)进行比较.结果表明,西藏拟溞的氨基酸和组成与上述饵料生物基本相似,18种氨基酸占蛋白质含量的69.68%,其中异亮氨酸、苏氨酸、蛋氨酸和组氨酸的含量均明显高于上述饵料生物,蛋氨酸的含量最高,达3.64%,完全能满足鱼虾生长对必需氨基酸的需要.西藏拟溞的主要脂肪酸为C16:0、C16:3、C18:1ω9、C18:2ω6和C18:ω3,不饱和脂肪酸含量高达71.58%,C18:2ω6和C18:3ω3含量分别达到9.97%和26.52%.EPA(C20:5ω3)和AA(C20:4ω6)的含量分别为1.41%和0.63%.从营养成分的角度进行评价,西藏拟溞经一定的营养强化后将成为一种很有前途的海淡水仔稚鱼虾的活饵料.[中国水产科学,2006,13(3):446-451

  12. Caracterización limnológica de la laguna de Cashibococha (UcayaliPerú durante el año 2001

    Directory of Open Access Journals (Sweden)

    José Riofrío

    2013-06-01

    Full Text Available Durante el año 2001 se realizaron muestreos bimensuales en tres estaciones fijas en la laguna de Cashibococha (Ucayali, Perú. Cashibococha presenta aguas de color verdoso a café oscuro, con pH entre 6 a 6,8, Conductividad entre 10 y 30µS.cm −1 , Transparencia de 21 a 59 cm y Alcalinidad Total entre 14 y 22 mg CaCO3 / L . La temperatura superficial del agua osciló entre 24,4 y 37 ºC y el Oxígeno Disuelto entre 1,3 y 7,4 mg/ L. Los análisis bacteriológicos registraron recuentos de aerobios mesófilos entre 350 y 3600 UFC/ mL. Los coliformes totales oscilaron entre 3 y 43 NMP/ 100 mL. Se diferenciaron 47 especies pertenecientes a 20 familias de macrófitas acuáticas; el mayor número de especies se reportó durante la época de Transición − Creciente (octubre − noviembre, debido a la inundación del bosque. Fueron identificadas 52 especies de fitoplancton, la División Chlorophyta fue la mas dominante. La comunidad fitoplanctónica está dominada por las especies Actinastrum hantzschi, Spirogyra sp., Eudorina elegans, Pandorina morum y Closterium kuetzingui. Se diferenciaron 54 especies de Zooplancton. Los rotíferos fue el taxa dominante. La densidad de zooplancton está dominada por Brachionus patulus macracanthus y Polyarthra vulgaris. Fueron identificadas 66 especies de peces, pertenecientes a 55 géneros, 11 familias y 4 órdenes. El orden dominante en diversidad y abundancia fue el de Characiformes, Curimata vittata fue la especie dominante en la comunidad de peces en éstas áreas litorales. Los índices de diversidad fueron superiores a 3,0 bits. ind –1 , en todas las estaciones y lugares de muestreo. De igual manera los valores de equitabilidad fueron superiores a 0,8 en todas las estaciones y lugares de muestreo.

  13. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

    Energy Technology Data Exchange (ETDEWEB)

    De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@Ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Rodriguez, P. [Centro de Investigacion Minera y Metalurgica (CIMM), Santiago (Chile); Vleminckx, K. [Department for Molecular Biomedical Research, Ghent University (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium)

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO{sub 4}{sup 2-}). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}.2H{sub 2}O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data

  14. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data.

    Science.gov (United States)

    De Schamphelaere, K A C; Stubblefield, W; Rodriguez, P; Vleminckx, K; Janssen, C R

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO(4)(2-)). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na(2)MoO(4)·2H(2)O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this study can

  15. L'élevage larvaire des poissons marins : chaînes alimentaires et aliments composés

    Directory of Open Access Journals (Sweden)

    GIRIN M.

    1977-01-01

    Full Text Available L'approvisionnement quotidien en nourriture est, en règle générale, le principal facteur limitant de productions à grande échelle de jeunes poissons marins.La pêche de plancton dans la nature a été, et reste, le moyen d'expérimentation le plus immédiat, et le plus satisfaisant sur le plan qualitatif. Mais la récolte des quantités nécessaires, au moment voulu, devient très délicate dès que l'on dépasse l'échelle de l'aquarium. Le développement, ces dernières décennies, de techniques de production en masse d'animaux-proies a permis le lancement d'élevages à grande échelle. Parmi ces proies, le Branchiopode Artemia salina et le Rotifère Brachionus plicatilis dominent incontestablement ; tandis que l'élevage des Copépodes, part la plus intéressante du plancton naturel, reste encore mal maîtrisé. Cependant , l'élevage et l'emploi de proies vivantes, quelles qu'elles soient, imposent la réalisation d'installations coûteuses et l'emploi d'un abondant personnel qualifié. Il en est résulté récemment un important effort de recherche en direction de nourritures inertes, broyats , poudres et aliments composés, généralement abandonnés après les échecs enregistrés pendant les premières années du siècle. Quelques résultats encourageants ont été obtenus, mais ils restent limités et soulèvent de délicats problèmes d'hygiène des bacs d'élevage. L'emploi de proies vivantes , au moins pendant le premier mois des élevages , reste donc encore une obligation. Dans ce contexte, l'essentiel de l'effort actuel tend , d'une part à réduire leur durée d'emploi au minimum possible et, d'autre part, à rendre leur production plus rationnelle , en recherchant des méthodes qui évitent, pour leur alimentation , de faire appel à des algues planctoniques vivantes.

  16. Effects of population outcrossing on rotifer fitness

    Directory of Open Access Journals (Sweden)

    Serra Manuel

    2010-10-01

    Full Text Available Abstract Background Outcrossing between populations can exert either positive or negative effects on offspring fitness. Cyclically parthenogenetic rotifers, like other continental zooplankters, show high genetic differentiation despite their high potential for passive dispersal. Within this context, the effects of outcrossing may be relevant in modulating gene flow between populations through selection for or against interpopulation hybrids. Nevertheless, these effects remain practically unexplored in rotifers. Here, the consequences of outcrossing on the rotifer Brachionus plicatilis were investigated. Cross-mating experiments were performed between a reference population and three alternative populations that differed in their genetic distance with regard to the former. Two offspring generations were obtained: F1 and BC ('backcross'. Fitness of the outcrossed offspring was compared with fitness of the offspring of the reference population for both generations and for three different between-population combinations. Four fitness components were measured throughout the rotifer life cycle: the diapausing egg-hatching proportion, clone viability (for the clones originating from diapausing eggs, initial net growth rate R for each viable clone, and the proportion of male-producing clones. Additionally, both the parental fertilisation proportion and a compound fitness measure, integrating the complete life cycle, were estimated. Results In the F1 generation, hybrid vigour was detected for the diapausing egg-hatching proportion, while R was lower in the outcrossed offspring than in the offspring of the reference population. Despite these contrasting results, hybrid vigour was globally observed for the compound measure of fitness. Moreover, there was evidence that this vigour could increase with the genetic differentiation of the outcrossed populations. In the BC generation, the hybrid vigour detected for the egg-hatching proportion in the F1

  17. Development of fingerlings of Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae in tanks fertilized with organic manures/ Desenvolvimento de juvenis de Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae em tanques experimentais fertilizados com adubação orgânica

    Directory of Open Access Journals (Sweden)

    Carmino Hayashi

    2005-06-01

    Full Text Available The objective of this paper was to study the development of Piracanjuba (Brycon orbignyanus in tanks under differents organic fertilizers. The experiment, entirely randomized, was accomplished in 16 tanks of 1000 liters, fertilized with manures of bovine (BOV, pigs (SUI, chickens (FRG and others without fertilizer (SAO, using 15 fish/m3 with an initial average weight and length of 10,87+0,31 g e 9,78+0,07 cm. After 30 days, the experiment showed a uniform development of the fish and high survival rate in thestudied density. The treatments presented significant statistical differences (PO objetivo deste trabalho foi estudar o desenvolvimento de juvenis de Piracanjuba (Brycon orbignyanus, em tanques com adubações orgânicas. O experimento, inteiramente casualizado, foi realizado em 16 tanques de 1000 litros, adubados com estercos de bovinos (BOV, suínos (SUI, frangos de corte (FRG e outros sem adubação (SAO, utilizando 15 peixes/m3 com peso e comprimento médios iniciais de 10,87+0,31 g e 9,78+0,07 cm. Após 30 dias, o experimento mostrou um desenvolvimento uniforme dos peixes e alta taxa de sobrevivência na densidade estudada. Os tratamentos apresentaram diferenças estatisticamente significativas (p < 0,05 para ganho de peso e crescimento diário, com exceção dos tratamentos BOV e SUI quando comparados entre si. A temperatura e o oxigênio dissolvido foram os fatores abióticos que exerceram maior influência sobre a biota aquática, afetando o desenvolvimento dos peixes. Entre o fitoplâncton houve maior abundância de organismos nanoplanctônicos favorecendo o desenvolvimento do zooplâncton, destacando-se as clorófitas, com o gênero Scenedesmus, e as cianofíceas, com o gênero Microcystis, e entre o zooplâncton, a maior abundância foi de rotíferos dos gêneros Brachionus e Keratella, seguido por copépodas. O tratamento adubado com esterco de frangos possibilitou um maior desenvolvimento da comunidade planctônica, e melhores

  18. The effect of pH on chronic aquatic nickel toxicity is dependent on the pH itself: Extending the chronic nickel bioavailability models.

    Science.gov (United States)

    Nys, Charlotte; Janssen, Colin R; Van Sprang, Patrick; De Schamphelaere, Karel A C

    2016-05-01

    The environmental quality standard for Ni in the European Commission's Water Framework Directive is bioavailability based. Although some of the available chronic Ni bioavailability models are validated only for pH ≤ 8.2, a considerable fraction of European surface waters has a pH > 8.2. Therefore, the authors investigated the effect of a change in pH from 8.2 to 8.7 on chronic Ni toxicity in 3 invertebrate (Daphnia magna, Lymnaea stagnalis, and Brachionus calyciflorus) and 2 plant species (Pseudokirchneriella subcapitata and Lemna minor). Nickel toxicity was almost always significantly higher at pH 8.7 than at pH 8.2. To test whether the existing chronic Ni bioavailability models developed for pH ≤ 8.2 can be used at higher pH levels, Ni toxicity at pH 8.7 was predicted based on Ni toxicity observed at pH 8.2. This resulted in a consistent underestimation of toxicity. The results suggest that the effect of pH on Ni(2+) toxicity is dependent on the pH itself: the slope of the pH effect is steeper above than below pH 8.2 for species for which a species-specific bioavailability model exists. Therefore, the existing chronic Ni bioavailability models were modified to allow predictions of chronic Ni toxicity to invertebrates and plants in the pH range of 8.2 to 8.7 by applying a pH slope (SpH ) dependent on the pH of the target water. These modified Ni bioavailability models resulted in more accurate predictions of Ni toxicity to all 5 species (within 2-fold error), without the bias observed using the bioavailability models developed for pH ≤ 8.2. The results of the present study can decrease the uncertainty in implementing the bioavailability-based environmental quality standard under the Water Framework Directive for high-pH regions in Europe. PMID:26335781

  19. Plankton and Macrobiota Composition and Diversity of Three Tropical Freshwaters Rivers in Ogun and Ondo States, Southwest Nigeria

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    Taofikat Abosede ADESALU

    2016-06-01

    Full Text Available Three different rivers in Ogun and Ondo states were investigated for both micro and macro-biota of the water bodies. Several physical and chemical properties of these rivers were determined. The pH value of the studied water bodies was essentially neutral with salinity values between 0.02 - 4.0‰. Microalgae communities were represented by three divisions: Cyanophyta, Bacillariophyta and Chlorophyta at Oluwa and Ifara Rivers (Ondo state, while at Ibefun River (Ogun state, five divisions: Cyanophyta, Bacillariophyta, Chlorophyta, Euglenophyta and Pyrrhophyta were identified. Diatoms dominated these water bodies, with Navicula radiosa Kutz. at Ifara River, Fragilaria sp. in Oluwa River, while out of 90 algal taxa identified in Ibefun river, 64 were diatoms species belonging to 26 genera, with Melosira sp. and Synedra sp. recording the highest numbers of cell count. Dinoflagellates recorded only Peridinium sp. while Phacus orbicularis Hubner and Trachelomonas sp. dominated the euglenoids. For the zooplankton composition at Ibefun, rotifers (75.95% were represented by Brachionus sp., which recorded 62.03%, and Gastropus sp. with 13.92% of the total zooplankton, thus dominated the spectrum, while the copepod recorded 22.78% of the total organisms, with Copilia sp. and Euchirella sp. having 8.86% each. The macrobenthic invertebrates were represented by 3 taxa, belonging to 3 groups, with the dominant group Insecta accounted for 57% of the total individuals (7 individuals/m2, while Oligochaeta and Hirudinea accounted for 29% and 14% respectively of the total individuals at Oluwa and Ifara Rivers. At Ibefun River, the macrobenthic invertebrates were represented by 5 taxa, belonging to 3 groups, Bivalves, Oligochaeta and Insecta, with bivalves being the dominant group (51.7% of the total individuals, as 64 individuals/m2, while Oligochaeta and Insecta accounted for 26.6% and 21.9% respectively of the total individuals. The dominant taxon, Macoma cumana

  20. Investigation of Zooplankton in Chengdu City%成都市区淡水浮游动物多样性初步调查

    Institute of Scientific and Technical Information of China (English)

    何先进; 吴鹏飞

    2012-01-01

    为了研究成都市区浮游动物群落多样性,对成都市区内主要河流及公园湖泊的浮游动物进行了调查.共鉴定到浮游动物18属25种,群落组成以轮生为主,群落密度变动范围在70 -260 ind · L-1,生物量在0.036~ 1.016 mg· L-1之间,表明成都市区水体处于贫营养状态.Shannon多样性指数(H)变化范围为2.61 >H >0.84,Mugalef丰富度指数(D)为2.88 >D>0.44,表明成都市区河流木体为中度污染到重度污染.不同采样点比较显示,随着河流进入人口密集的市中心区域,浮游动物群落受影响程度增大,流出城市后,所受的影响降低至入城之前的水平.因此,城市湖泊的人为管理会对湖泊中浮游动物群落产生影响;城市建筑施工向河流倾倒建筑垃圾,会对水中浮游动物群落产生严重影响.%In November 2010, investigations were made on the zooplankton in mainstream of river and lakes in Chengdu City. A tofal of 25 species were identified, including 15 Rotifera (60 % ) , 4 Cladocera ( 16 % ) , 3 Copepoda and 3 Protozoa (12 % respectively). The dominant species were Branchonus calyciflorus, Asplanchna girodi, Asplanchna priodonta and Euchlanis pellucid. In the seven sampling sites, the zooplankton's average abundance ranged from 70 to 260 ind. · L-1, and the biomass ranged from 0.036 to 1.016 mg·L-1. In addition, Shannon index( H) ranged from 0. 84 to 2.61, Margalef index from 0.44 to 2. 88, which showed that river in Chengdu city was Moderately or heavily polluted. One-way ANOVA indicated that zooplankton community density,the biomass and community diversities were significantly different among sampling sites. Further comparing results revealed the zooplankton community was influenced more when the river went through civic centre, but it recovered when the river passed downtown ,labor management could change the zooplankton community of a Lake in the public garden, and that building site would be a grave threat to

  1. Effects of liming and development of Curimbatá (Prochilodus lineatus larvae on the abundance of zooplankton in fish ponds Efeitos da calagem e desenvolvimento do Curimbatá (Prochilodus lineatus na abundância do zooplâncton em viveiros de piscicultura

    Directory of Open Access Journals (Sweden)

    Thécia Alfenas Silva Valente Paes

    2011-12-01

    Full Text Available AIM: We aimed to evaluate the influence of the correction of the water alkalinity in the fish ponds on the density of zooplankton under a period they were stocked with larvae of Prochilodus lineatus, a neotropical fish called "Curimbatá". METHODS: We used a factorial design completely randomized. In one plot (2 ponds there was no correction of the alkalinity of the water (20 mg CaCO3.L-1 and in two others, this variable was adjusted weekly to values around 30 and 60 mg CaCO3.L-1 ¹, with two replicates each. Zooplankton was sampled weekly and the experiment lasted 63 days. RESULTS: Significant differences in the density of the zooplankton over time (F = 6.78, p OBJETIVO: Nosso objetivo foi avaliar a influencia da correção da alcalinidade da água em viveiros de piscicultura na densidade do zooplâncton em período em que foram estocados com larvas de Prochilodus lineatus, um peixe neotropical denominado "Curimbatá". MÉTODOS: Foi utilizado um delineamento experimental fatorial, inteiramente causualizado. Em um tratamento (2 viveiros, não houve correção da alcalinidade da água, e em outros dois viveiros, a alcalinidade foi ajustada semanalmente para valores em torno de 30 e 60 mg CaCO3.L-1, com duas réplicas cada. Os organismos zooplanctônicos foram coletados semanalmente durante 63 dias. RESULTADOS: Diferenças significativas foram observadas na densidade do zooplâncton ao longo do tempo (F = 6,78, p < 0,05 e um decréscimo acentuado na densidade do zooplâncton foi observado da primeira para a segunda semana, e pequenos aumentos sucessivos na densidade da quarta semana até o final do experimento. Ao considerar todo o período experimental, a alcalinidade corrigida para 60 mg CaCO3.L-1 resultou em maiores densidades de zooplâncton. Ocorreram grandes mudanças na composição zooplanctônica. Rotifera foram dominantes no início do experimento e Cladocera e Copepoda nas últimas semanas, possivelmente devido a uma interação da

  2. The use of multivariate analysis to link sediment contamination and toxicity data to establish sediment quality guidelines: an example in the Gulf of Cadiz (Spain); El uso del analisis multivariante en la union de datos de toxicidad y contaminacion para establecer guias de calidad de sedimento: Un ejemplo en la Bahia de Cadiz (Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Del Valls, T. Angel; Forja, Jesus M [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz, (Spain); Gomez-Parra, Abelardo [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz, (Spain)

    1998-03-01

    To evaluate marine sediment quality in the Gulf of Cadiz, chemical concentration and toxicity test endpoints from sediments were linked using multivariate analysis. Sediment samples were collected synoptically at seven stations in two littoral ecosystems of the Gulf of Cadiz (five in the Bay of Cadiz and two in the salt marsh of the Barbate River), and subjected to six separate, replicated sediment toxicity tests and comprehensive sediment chemistry analyses. The toxic effects of sediments were tested using three operational sediment phases: whole sediment, using the estuarine amphipod Microdeutopus gryllotalpa (10 d static: survival) and the estuarine clam Ruditapes philippinaru (48 h static: survival) and of the marine fish Sparus aurata (48 h static. Survival); and interstitial water, using populations of the estuarine rotifer Brachionus Plicatilis (7 d static: Population decline) and of the marine bacteria Photobacterium phosphoreum (Microtox ). To evaluate the levels of contamination, the concentrations in the sediments of organic carbon, 14 trace metals (Fe, Mn, Cu, Zn, Pb, Cd, Ag, Hg, As, Sn, V, Ni, Co and Cr) and the surfactant linear alkylbenzenesulphonate (LAS) were measured. The results of the toxicity tests were compared in a dose-response relationship between sites, demonstrating a general agreement between the toxicity values determined by all the tests, except in the case of interstitial water toxicity (principally due to toxic mixtures of trace metals). Data derived from sediment chemistry and bioassays were assembled by multivariate statistical techniques (PCA and factor analysis), showing that the two data types could be represented by only five factors corresponding to five overlapping chemical-biological effect relations. Positive prevalence of these factors in the cases studied was used to establish those ranges in chemical concentrations associated with adverse effects. The sediment quality guidelines, in terms of concentrations at or below

  3. Efeitos de fertilização na biomassa e qualidade nutricional do zooplâncton utilizado para alimentação de alevinos na estação de hidrobiologia e piscicultura de Furnas, MG Fertilization effects on biomass and nutritional quality of zooplancton in feeding of fry in the Furnas (MG, Brazil hydrobiology and pisciculture station

    Directory of Open Access Journals (Sweden)

    Raquel Magalhães Santeiro

    2000-05-01

    Full Text Available O estudo objetivou avaliar os efeitos da adição intensiva de dejetos orgânicos e de nutrientes na qualidade do zooplâncton obtido em tanques de plâncton, empregado na alimentação de alevinos de “trairão” (Hoplias lacerdae. Os teores de lipídeos totais do zooplâncton bem como sua abundância e biomassa foram acompanhados, através de duas coletas semanais, em dois tanques de produção de plâncton durante dois meses seguidos. Foram medidos ainda a temperatura, pH, oxigênio dissolvido, condutividade elétrica na coluna de água. As concentrações de clorofila-a, fósforo total, amônia e nitrogênio total (TKN foram acompanhadas semanalmente. Nos primeiros trinta dias, foi feita a adubação a cada cinco dias e, nos últimos trinta dias, não houve qualquer adubação em ambos os tanques. A interrupção da fertilização causou uma notável e rápida mudança na qualidade físico-química da água bem como na estrutura da comunidade zooplanctônica. Houve um decréscimo nos teores de condutividade, amônia, nitrogênio total, fósforo total e clorofila-a. Em contraste, houve um aumento nos níveis de oxigênio dissolvido e pH. Logo após a parada da fertilização, houve um pico na biomassa total do zooplâncton que perdurou por cerca de 20 dias, em ambos os tanques. Nesse período, o cladócero Moina reticulata e o rotífero Brachionus calyciflorus foram os mais abundantes. No entanto, ao final do período de estudos, os ciclopóides voltaram a ser os organismos dominantes, embora com predominância de formas imaturas. Os teores de lipídeos totais do zooplâncton permaneceram baixos durante todo o período de estudos (6-10%, sugerindo a má qualidade do seu alimento dentro dos tanques. O estudo demonstra que a fertilização é necessária para que seja obtido um zooplâncton com maiores valores nutricionais mas a baixa qualidade da água causada pela hipereutrofização e os baixos níveis de lipídeos encontrados no zoopl

  4. Characterization of biocenosis in the storage-reservoirs of liquid radioactive wastes of 'Mayak' PA

    Energy Technology Data Exchange (ETDEWEB)

    Pryakhin, E.; Tryapitsina, G.; Andreyev, S.; Akleyev, A. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Mokrov, Y.; Ivanov, I. [Mayak PA (Russian Federation)

    2014-07-01

    cycle. In reservoir R-3 there was no small pelophylic mollusks either, 90% of zooplankton community was represented by rotifers, in zoo-benthos community there was no small pelophylic mollusks, in species composition of ichthyofauna there was no carnivorous species of fish. In reservoir R-17 ichthyofauna was completely absent, species diversity of phytoplankton was significantly reduced, zooplankton was represented only by rotifers, and zoo-benthos was represented only by gnat larvae. In reservoir R-9 there was no ichthyofauna; phytoplankton was almost a mono-culture of cyanobacteria Geitlerinema amphibium, zooplankton was almost a mono-culture of rotifers Brachionus calyciflorus or Hexartra fennic in different years. In all of the above mentioned reservoirs, the development of bacterial plankton was at the levels characteristic of the standing water bodies of this geographical zone. Document available in abstract form only. (authors)

  5. Community structure of rotifers and ecological assessment of water quality in the tidal Guangzhou segment of the Pearl River%珠江广州河段轮虫群落结构特征与水质生态学评价

    Institute of Scientific and Technical Information of China (English)

    侯磊; 王庆; 杨宇峰

    2011-01-01

    2008年4月至2010年3月,对珠江广州河段2个站点(中大码头和鱼珠码头)轮虫群落结构进行每月一次的调查,同时测定了透明度、叶绿素、总氮、总磷等理化指标,利用非生物环境因子对水体的营养状况进行了评价,并通过轮虫种类组成、富营养型指示种数/贫营养型指示种数(E/O)指数对水质进行评价.调查期间,共记录轮虫66种,其中污染指示轮虫46种.优势种为微型多突轮虫、裂痕龟纹轮虫、西氏三肢轮虫、角突臂尾轮虫.轮虫丰度范围为69~5 200 ind./L,中大码头采样点丰度最高;高峰期均出现在枯水期.轮虫丰度与pH、氮磷比显著正相关(P<0.05),与温度显著负相关(P<0.05).根据水质生态学评价指标,珠江广州河段水体已达重度富营养水平,与非生物环境因子营养状态综合评价结果一致.%Community structure of rotifers was investigated at two different sites in the tidal Guangzhou segment of the Pearl River with monthly sampling from April 2008 to March 2010. Transparency, Chlorophyll a (Chl a), Total Nitrogen (TN), Total Phosphorus (TP) and other physicochemical parameters were also measured simultaneously. Trophic state of waters was evaluated through non-biologic environmental factors. Ecological assessment of water quality was also carried out through the analysis of species composition of rotifers and E/O index. During the survey period, 66 species of rotifer were recorded and 46 species belong to pollution indicator. Lififerotrocha subtilis, Anuraeopsis fissa, Filinia novaezealandiae and Brachionus angularis were the dominant species. The abundance of rotffers ranged from 69 to 5 200 ind./L with the highest value at Zhongda pier site, The peak value of abundance was observed in the dry season. There was significantly positive correlations between pH, nitrogen-phosphorus ratios and rotifers abundance (P < 0. 05 ). A significantly negative correlation was detected between

  6. Fatty acid composition analysis and their nutrient effect evaluation of some pelagic food organisms%几种饵料浮游动物脂肪酸组成分析及营养效果评价

    Institute of Scientific and Technical Information of China (English)

    林元烧; 曹文清; 郑爱榕; 李文权; 陈清花

    2001-01-01

    本文采用气相色谱分析法对海水鱼类育苗常用的4种饵料浮游动物的脂肪酸组成和含量进行了测定分析.结果表明:卤虫无节幼虫、皱褶臂尾轮虫、蒙古裸腹溞和太平洋纺锤水蚤的粗脂肪含量分别占其体重的21.54%、9.70%、6.67%和4.66%.单不饱和脂肪酸的含量排序分别为蒙古裸腹溞>纺锤水蚤>轮虫>卤虫;多不饱和脂肪酸含量则为卤虫>裸腹溞>轮虫>纺锤水蚤.此外,太平洋纺锤水蚤尚含有C22:6(DHA)高不饱和脂肪酸,这在其它饵料生物中并未检出.卤虫无节幼虫和褶皱臂尾轮虫的脂肪酸组成中,油酸(C18:1)、亚油酸(C18:2)和亚麻酸(C18:3)占有较大比例,而二十碳以上的不饱和脂肪酸含量很低.文中讨论了脂肪酸组成和含量与营养效果的关系.%Fatty acid composition and contents in 4 kinds of planktonic food animals were measured quantitatively by means of gas chromatographic technique. The coarse fat occupied their body weight (wet weight) in nauplii of Artemia salina (cysts from Great Salt Lake, USA),Brachionus plicatilis (Rotifer), Moina mongonica (Cladocera) and Acartia paci fica (Copepod)were 21.54, 9.7, 6.67 and 4.66%, respectively. The total mono-unsatisfied fatty acid (TMUFA) ranks in descent sequence of M. mongonica, A. pacifica , B. plicatilis, Ar. salina, and total poly-unsatified fatty acid (TPUFA) Ar. salina, M. mongonica, B. plicatilis and A.pacifica. DHA (C22:6) was detected only in A. pacifica samples. There were greater propotion of C18: 1, C18:2 and C18:3 in Ar. salina and B. plicatilis samples comparative to A. pacifica and M. mongonica, but the contents of unsatisfied fatty acid which carbon number is more than 20 were scarce. The relationship between contents of fatty acid and nutrient effect on the health and survivorship of marine fry culture was discussed in this paper.

  7. Characterization of biocenosis in the storage-reservoirs of liquid radioactive wastes of 'Mayak' PA

    International Nuclear Information System (INIS)

    small pelophylic mollusks either, 90% of zooplankton community was represented by rotifers, in zoo-benthos community there was no small pelophylic mollusks, in species composition of ichthyofauna there was no carnivorous species of fish. In reservoir R-17 ichthyofauna was completely absent, species diversity of phytoplankton was significantly reduced, zooplankton was represented only by rotifers, and zoo-benthos was represented only by gnat larvae. In reservoir R-9 there was no ichthyofauna; phytoplankton was almost a mono-culture of cyanobacteria Geitlerinema amphibium, zooplankton was almost a mono-culture of rotifers Brachionus calyciflorus or Hexartra fennic in different years. In all of the above mentioned reservoirs, the development of bacterial plankton was at the levels characteristic of the standing water bodies of this geographical zone. Document available in abstract form only. (authors)

  8. 单巢类轮虫有性生殖的研究进展与展望%Sexual reproduction in monogonont rotifers: A review

    Institute of Scientific and Technical Information of China (English)

    孙栋; 牛翠娟

    2013-01-01

    This paper focuses on the recent findings of sexual reproduction in monogonont rotifers, which account for the main bulk of phylum Rotifera. Generally, they act as one of the major groups of primary consumers in freshwater ecosystem. Thus, studies on population dynamics and their mechanisms of monogonont rotifers may provide important data to both theoretical and applied research on freshwater ecosystems. As a group with parthenogenetic life history, sexual reproductive strategy in monogonont rotifers may profoundly affect their population dynamics and evolution. This review summarized several aspects of sexual reproduction in the monogonont rotifers, such as the mechanism, pheromones, models, influence factors, and particularly, empirical evidences. More specifically, we emphasized three models about their sexual reproduction patterns: " bang-bang" model, intermediate mictic ratios model and no-delaying mixis model. Then we summarized the exogenous and endogenous factors that affect sexual reproduction. The major exogenous factors include the concentration and type of food, temperature, salinity and special bacteria, while the major endogenous factors include the maternal age, a transgenerational maternal effect induced by food concentration, mixis delay and some potential maternal effects. We especially highlighted the model, mechanism and empirical evidences of mixis delay, since this phenomenon existed widely and was deem to be a potential explanation for species or clones coexistence. We also gave some personal views on the relationship between sex allocation theory and sexual reproduction in the monogonont rotifers. Finally, several potential hotspots in the future study were highlighted.%作为轮虫动物门的主体,单巢类轮虫是淡水浮游动物的重要组成部分.它们通常作为一类主要的初级消费者在淡水生态系统中起着重要作用,因而深入了解它们在自然水体中的种群动态及其决定机制对淡水生态系

  9. Estudio de la composición y abundancia del zooplancton durante la fase de llenado del embalse Amaní, Norcasia (Caldas

    Directory of Open Access Journals (Sweden)

    Reyes Blandon Carmen

    2003-06-01

    Full Text Available La variación de la composición, abundancia y diversidad del zooplancton fue analizada durante la fase de llenado del embalse Amaní en un gradiente horizontal y vertical, a partir de trece muestreos semanales realizados entre junio y agosto de 2002. La composición del zooplancton es similar a otros ecosistemas lénticos tropicales de baja altitud y fue registrado un total 32 taxa, de los cuales se destaca el rotífero Keratella por su elevada abundancia durante junio y julio. Rotifera fue el grupo que presentó la mayor riqueza de especies (16 así como una sobresaliente dominancia numérica sobre copépodos y cladóceros, con una abundancia relativa superior al 60%. La densidades promedio del zooplancton fluctuaron de manera significativa (6 a 1525 org l-1, y de forma diferencial entre los brazos del embalse

  10. 薇甘菊入侵对中小型土壤动物群落结构特征的影响%Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure

    Institute of Scientific and Technical Information of China (English)

    全国明; 章家恩; 谢俊芳; 毛丹鹃; 徐华勤; 姜万兵; 文杜娟

    2011-01-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems.In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M.micrantha invasion on the soil meso- and micro-invertebrate community.Three sampling sites were installed, including M.micrantha-invaded site, ecotone, and native vegetation site.Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups.M.micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure.Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M.micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change.At M.micrantha-invaded site, the density-group index ( DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index ( D) and Simpson dominance index ( C) tended to ascend, but Pielou evenness index ( E) and Shannon index (H') tended to descend.The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M.micrantha-invaded site and native vegetation site.The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M.micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M.micrantha-invaded site.%薇甘菊是菊科假泽兰属的恶性杂草,在我国华南地区已成功入侵并造成严重危害.为了解薇甘菊入侵对土壤动物的影响效应,采用

  11. Influence of net-cage fish farming on zooplankton biomass in the Itá reservoir, SC, Brazil Influência da piscicultura em tanque-rede sobre a biomassa do zooplâncton no reservatório de Itá, SC, Brasil

    Directory of Open Access Journals (Sweden)

    Bruna Roque Loureiro

    2011-12-01

    Full Text Available OBJECTIVES: This study aimed to verify the influence of net-cage fish farming on zooplankton biomass in the Itá reservoir (Uruguay River, Brazil. METHODS: Samples were collected monthly from October/2009 to May/2010 at the surface and at the bottom in two sampling stations, the net-cage area and in a control area using a Van Dorn bottle and a plankton net (68 µm. RESULTS: The Cladocera and Copepoda biomass was estimated by dry weight using a micro-analytical balance, and the Rotifera biomass by Biovolume. Total zooplankton biomass varied between 6.47 and 131.56 mgDW.m-3 Calanoida copepod presented the highest value of biomass (127.56 mgDW.m-3 and rotifers, despite having an important contribution to total density, showed a maximum biomass of 2.01 mgDW.m-3. Zooplankton biomass at the net-cage area surface was higher when compared with the control area during the months of October to January. However, the zooplankton biomass was similar at the bottom of the two areas throughout the studied period. From February until May, zooplankton biomass decreased in both sampling stations, a fact probably associated with the flushing of the reservoir, followed by an increase in water transparency and a decrease in chlorophyll-a concentration in the following months (February to May. CONCLUSIONS: The influence of fish farming on zooplankton biomass was detected at the surface of the net-cage area only from October to January. From February to May this influence was not found, probably by the influence of the flushing of the reservoir.OBJETIVO: Este estudo teve o objetivo de verificar a influencia da piscicultura em tanque-rede sobre a biomassa da comunidade zooplanctônica no reservatório de Itá (Rio Uruguai, Brasil. METODOLOGIA: Foram realizadas coletas mensais de outubro/2009 a maio/2010 na superfície e no fundo em dois pontos amostrais, ponto tanque-rede e em uma área controle, com o auxílio da garrafa Van Dorn e rede de plâncton (68 µm. RESULTADOS

  12. A Preliminary Study on the Diversity of Micro-and Meso-fauna Communities in the Campus of Xinjiang Normal University%新疆师范大学校园中小型土壤动物群落多样性初步研究

    Institute of Scientific and Technical Information of China (English)

    古丽布斯坦·努尔买买提; 吾玛尔·阿布力孜; 努尔夏提·努尔买买提

    2013-01-01

    The communities diversity of micro-and meso-fauna in relation to5 different habitats in campus of Xinjiang Normal University were investigated by Tullgren dry funnel method with emphasis on the composition and diversity from September to November in 2010 . The results showed that a total of 1630 soil animals was extracted and classified into 4 phyla,10 classes,and 18 orders, respectively. Collembola (25. 77%),Acariformes (17. 36%),Coleoptera (11. 53%),Dipterra(11. 17%)were the dominant groups, and they were accounting for 65. 83%, and Lumbricida ( 3 . 8%) , Gastropoda ( 7 . 67%) , Araneae ( 3 . 25%) , Isopoda ( 1 . 16%) , Chilopoda ( 4 . 66%), Orthoptera (1. 47%), Dermaptera (2. 02%), Hemiptera (3. 93%),Hymenoptera(2. 15%),Homoptera (2. 33%) and so on were common groups and they were accounting for 33. 62%., and the Thysanoptera ( 0. 06%),Rotifera(0. 18%),Symphyla(0. 31%) were rare groups, and they were accounting for 0. 55 % of total numbers. The results also suggested that the types of different habitats were affected on the individual density and group number of soil fauna community,and the in order of individual number is Bio-geography building greenland>Dormitory building greenland >Main building greenland >Library greenland >Playground greenland. The order of group number is Bio-geography building greenland >Dormitory building greenland >Main building greenland >Li-brary greenland >Playground greenland. We also analysed the community diversity indices such as diversity index ( H) , evenness index ( E) , and dominant index ( C) , and found that there were significant differences among the different greenlands. The Shannon-Wiener diversity index of Bio-geography building greenland>Dormitory building greenland >Main building greenland >Library greenland >Playground greenland. The order of evenness index ( E) of Playground Greenland >Library greenland >Main building greenland>Dormitory building greenland>Bio-geogra-phy building greenland. The dominance index of

  13. 太湖新银鱼移植对(鳖)早期摄食和生长的影响%THE INFLUENCES TO TRANSPLANTATION OF ICEFISH (NEOSALANX TAIHUENSIS CHEN) ON EARLY-LIFE FEEDING AND GROWTH OF HEMICULTER LEUCISCULUS BASILEWSKY

    Institute of Scientific and Technical Information of China (English)

    王星璐; 向建国; 刘家寿; 柳明; 吴朗; 谢松光

    2012-01-01

    Neosalanx taihuensis Chen is an important zooplanktivorous commercial fish, which was widely introduced into Chinese freshwaters. Transplantation of this species has induced decline and even extinction of native fish species in some waters. In this study, impacts of N. Taihuensis transplantation on early growth and feeding of an indigenous zooplanktivorous fish Hemiculter leucisculus Basilewsky were investigated by comparing the juveniles of the latter in two reservoirs in the middle reach of the Yangtze River. Huangshi Reservoir (HSR) and Mengquan Reservoir (MQR) are geographically proximate and display similar nutrient regimes and native fish faunas. The major difference between the two water is that N. Taihuensis has been transplanted in HSR but not in MQR. A total of 157 juvenile H. Leucisculus was collected in late July and middle August in both reservoirs. The juveniles collected in late July aged from 14 to 23 days, and were similar in growth rate between the two waters. The juveniles collected in middle August aged from 20 to 49 days. Growth rate of juveniles in HSR was significantly smaller than those in MQR. Otolith growth trajectories showed that incremental width was not significantly different between the two reservoirs until the age of 25 days but narrower for juveniles in HSR than those in MQR after that. Diet analysis showed that food compositions of the juveniles younger than 25 days were similar between the two waters, composing mainly Rotifera, small-sized Cladocera and Cyclopoida. For juveniles older than 25 days, food compositions in HSR were similar to the younger juveniles, while the food com positions in MQR changed to large-sized Cladocera, insects, eggs and fish larvae. Spawning season of N. Taihuensis is earlier than H. Leucisculus in the middle reach of Yangtze River, and diet competition between the two species may oc cur after the later shifts from feeding on small-sized to large-sized zooplanktons. In HSR, N. Taihuensis may induce the

  14. 长江口南北支浮游动物群落生态学研究%Zooplankton community ecology in north and south branches at Yangtze River estuary

    Institute of Scientific and Technical Information of China (English)

    郑金秀; 胡菊香; 彭建华; 汪红军

    2011-01-01

    虫(Keratella)、刺簇多肢轮虫(Polyarthra trigla)、萼花臂尾轮虫(Brachionus calyciflorus)、砂壳虫(Difflugia)、表壳虫(Arcella)、砂壳纤毛虫(Tintirmid)、中华哲水蚤(Calanus sinicus)、汤匙华哲水蚤(Sinocalanusdorrii)、广布中剑水蚤(Mesocyclops leuckarti)、象鼻溞(Bosmina)等.文章对南北两支浮游动物的种类组成和结构进行了比较,南支浮游动物的种类、数量及生物多样都高于北支,南北两支的浮游动物群落相似度很低.南北两支水域环境的不同造成其浮游动物群落结构的较大差异,文章分析了环境因子与浮游动物群落结构的相关性,其中水温是重要的影响因素,水温的季节性决定了浮游动物在时间分布上的变化.盐度对浮游动物群落结构的影响主要决定了其物种生态类型及空间分布.从整体上看,南北支主要受长江径流控制,浮游动物的种类组成以淡水种为主,咸水种在断面3出现较多.

  15. Feeding habits and growth characteristics of larval, juvenile, and young F1 of Epinephelus fuscoguttatus (♀) × E. lanceolatus (♂)%棕点石斑鱼(♀)×鞍带石斑鱼(♂)杂交F1仔、稚、幼鱼的摄食与生长特性分析

    Institute of Scientific and Technical Information of China (English)

    于欢欢; 李炎璐; 陈超; 孔祥迪; 张廷廷; 刘莉; 徐万土; 庞尊方; 李文升

    2015-01-01

    采用生态学方法,观察分析了人工育苗条件下棕点石斑鱼(Epinephelus fuscoguttatus,♀)×鞍带石斑鱼(Epinephelus lanceolatus,♂)杂交F1仔、稚、幼鱼的摄食习性和生长特性。结果表明,在水温29~30℃,盐度为29~30时,其杂交F1仔鱼3天开口摄食,开口饵料为ss型褶皱臂尾轮虫(Brachionus plicatilis),随后饵料系列为L型褶皱臂尾轮虫、卤虫无节幼体(Artemia salina)、卤虫(Artemia)和配合饵料;6日龄仔鱼的摄食率为92.31%,7~9日龄以后仔鱼的饱食率大都达到90%~100%;随着仔稚幼鱼的生长发育,其饱食时间逐渐缩短,消化时间逐渐增加。杂交F1仔稚鱼的摄食高峰都出现在白天,仔稚鱼夜间几乎不摄食,属白天摄食型。此外,仔、稚、幼鱼纯体重(W)与摄食量(Y)的关系为 Y=0.2078W–3.3738,全长(L)与日龄(X)的关系为 L=2.3159e0.0595X,纯体重(W)与日龄(X)的关系为W=0.0748e0.2021X,全长(L)与纯体重(W)的关系为W=0.0045L3.3775,口裂宽(Y)与日龄(X)的关系为Y=1.9687e0.0605X。由此可知杂交F1仔、稚、幼鱼的生长属于均匀生长型。%Nutrition is an important factor that restricts the normal growth of fish fry. In the nutrition transition period or feeding conversion process, it is crucial that the larval, juvenile, and young fish have access to adequate nutrition. Groupers are ferocious, carnivorous marine fish;if food supply is not sufficient, they feed on their own larvae and juveniles, and breeding efforts undergo substantial loss. In this research, we studied the feeding habits and growth characteristics of larval, juvenile, and young fish of the F1 generation of Epinephelus fuscoguttatus(♀) × E. lanceolatus (♂) cross using artificial ecological methods. The larvae were fed when their mouths opened, and samples selected from the breeding pool every afternoon after the larvae were fed. We sampled every day before the larvae were 10 days old;then, we sampled every 2 days. Each sample