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Sample records for brachionus rotundiformis tschugunoff

  1. PENYIMPANAN ROTIFERA INSTAN (Brachionus rotundiformis PADA SUHU YANG BERBEDA DENGAN PEMBERIAN PAKAN MIKROALGA KONSENTRAT

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    Erlania Erlania

    2016-11-01

    Full Text Available Keberhasilan kegiatan budidaya perikanan harus ditunjang dengan ketersediaan benih yang berkesinambungan. Oleh karena itu, diperlukan juga ketersediaan pakan alami larva berupa rotifera (Brachionus rotundiformis. Desain percobaan berupa rancangan faktorial dengan dua faktor dan lima ulangan diaplikasikan dalam penelitian ini. Sebagai perlakuan berupa suhu ruang penyimpanan (suhu kamar, suhu ruang AC, dan suhu refrigerator/lemari es dan pakan mikroalga konsentrat (monospesies dan multispesies. Bakteri probiotik juga digunakan sebagai pengontrol kualitas air. Spesies mikroalga yang digunakan adalah Nannochloropsis sp., Dunaliella sp., Isochrysis sp., dan Pavlova sp. Parameter yang diukur adalah kelimpahan rotifera dan parameter kualitas air media kultur (pH, salinitas, DO, dan NH3. Analisis data terdiri atas analisis regresi, analisis ragam, dan uji keparalelan. Hasil pengukuran parameter kualitas air selama penyimpanan menunjukkan kondisi media yang relatif stabil dan merupakan kisaran optimum bagi pertumbuhan B. rotundiformis. Kelimpahan maksimum tertinggi dari B. rotundiformis baik pada perlakuan pakan monospesies maupun multispesies alga adalah pada suhu kamar. Dari interaksi kedua perlakuan, diperoleh kelimpahan akhir tertinggi pada suhu ruang AC–pakan multispesies. Hal ini menunjukkan bahwa rotifera dapat disimpan lebih lama pada suhu ruang AC dengan pemberian pakan multispesies alga. The success of any aquaculture practices should be supported by sustainable supply of fish fry. Therefore, the availability of rotifers (Brachionus rotundiformis as natural feed for fish larvae is required. The research was arranged in factorial design with two treatments and five replications. Treatments consisted of different room storage temperatures (refrigerator, room temperature, and room with air conditioner/AC and microalgae concentrate added as rotifer feed (monospecies and multispecies algae. Probiotic bacteria was used to control water quality

  2. Ingestion of Brachionus plicatilis under different microalgae conditions

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    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.

  3. Ingestion of Brachionus plicatilis under different microalgae conditions

    Science.gov (United States)

    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.

  4. 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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Population density, sexual reproduction and diapause in monogonont rotifers: new data for Brachionus and a review

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    John J. GILBERT

    2004-09-01

    Full Text Available Diapausing, fertilized eggs in monogonont rotifers typically are formed after an environmental signal induces amictic females to produce mictic daughters. Mictic females lay haploid eggs that may develop parthenogenetically into males, or that may be fertilized and develop into diapausing, female embryos called resting eggs. Laboratory experiments demonstrate that crowding is the signal for production of mictic females in strains of Brachionus calyciflorus from Texas, Spain and Germany, and in a strain of Brachionus variabilis from Spain. In these experiments, newborn amictic females were cultured singly in large and small volumes to give lowand high-density treatments. Therefore, the induction of mictic females is due exclusively to population density and cannot be attributed to a grouping effect involving some interaction among individuals. B. variabilis is very sensitive to population density; females had to be cultured in 30 ml to prevent appreciable production of mictic daughters. Crowding is now known to be the signal for initiation of sexuality and diapause in four species of Brachionus, two species of Epiphanes, and Rhinoglena frontalis. The chemical that mediates this response somehow influences oocytes in the maternal body cavity to differentiate into mictic females. Aggregation of individuals in natural systems may facilitate the production of mictic females. In some of these rotifers, the response to crowding is suppressed in early generations from the resting egg, assuring that clonal populations will attain higher population densities before committing to sexual reproduction. Fitness benefits of the mictic-female response to crowding, and to other environmental signals in other rotifers (dietary tocopherol, long photoperiod, are discussed.

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

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    Ignacio Alejandro Pérez-Legaspi

    2014-05-01

    Full Text Available 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.

  8. Influence of food-type on the population growth rate of the rotifier Brachionus calyciflorus in short-chronic assays

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Beekman, W.

    2006-01-01

    The type of food given during short chronic assays with the rotifer Brachionus calyciflorus might be one of the sources of variation in the reproductive rate of the rotifers. Ten green algal species were supplied as monospecific diets to examine variability in rotifer growth rate. In addition, rotif

  9. 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.

  10. Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions.

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    Kaneko, Gen; Yoshinaga, Tatsuki; Gribble, Kristin E; Welch, David M; Ushio, Hideki

    2016-07-22

    Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

  11. 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.

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

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    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.

  13. Comparative toxicant sensitivity of sexual and asexual reproduction in the rotifer Brachionus calyciflorus

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    Snell, T.W. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Biology; Carmona, M.J. [Univ. de Valencia (Spain). Area de Ecologia

    1995-03-01

    Cyclically parthenogenetic zooplankters like rotifers are important tools for assessing toxicity in aquatic environments. Sexual reproduction is an essential component of rotifer life cycles, but current toxicity tests utilize only asexual reproduction. The authors compared the effects of four toxicants on asexual and sexual reproduction of the rotifer Brachionus calyciflorus. Toxicants had a differential effect on sexual and asexual reproduction, with sexual reproduction consistently the most sensitive. Concentrations of 0.2 {mu}g/ml PCP (sodium pentachlorophenate) had no effect on the asexual reproductive rate, but significantly reduced sexual reproduction. Likewise, chlorpyrifos concentrations of 0.3 {mu}g/ml had no significant effect on asexual reproduction, but sexual reproduction was significantly reduced. There was no difference in NOECs, LOECs, and chronic values for asexual and sexual reproduction for cadmium and naphthol tests. However, comparison of toxicant effect levels revealed that sexual reproduction was more strongly reduced at each toxicant concentration. The four toxicants tested inhibited sexual reproduction 2 to 68 times more than asexual reproduction at the lowest observed effect concentrations. Toxicants inhibited sexual reproduction in its initial step: sexual female production. Because sexual reproduction is more sensitive, toxicity tests based exclusively on asexual reproduction may not be protective of rotifer life cycles.

  14. 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.

  15. 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...

  16. 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

  17. Population dynamics of Brachionus calyciflorus (Rotifera: Brachionidae) in waste water from food-processing industry in Mexico

    OpenAIRE

    Arévalo Stevenson, Raymundo Alfredo; Sarma, S SS; Nandini, S

    2015-01-01

    Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calycijlorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calycijlorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 106 células m¡-I. Concentraciones de nejayote por encima del 8% no pe...

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

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    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

  19. 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.

  20. Optofluidic technology for monitoring rotifer Brachionus calyciflorus responses to regular light pulses

    Science.gov (United States)

    Cartlidge, Rhys; Campana, Olivia; Nugegoda, Dayanthi; Wlodkowic, Donald

    2016-12-01

    Behavioural alterations can occur as a result of a toxicant exposure at concentrations significantly lower than lethal effects that are commonly measured in acute toxicity testing. The use of alternating light and dark photoperiods to test phototactic responses of aquatic invertebrates in the presence of environmental contaminants provides an attractive analytical avenue. Quantification of phototactic responses represents a sublethal endpoint that can be employed as an early warning signal. Despite the benefits associated with the assessment of these endpoints, there is currently a lack of automated and miniaturized bioanalytical technologies to implement the development of toxicity testing with small aquatic species. In this study we present a proof-of-concept microfluidic Lab-on-a-Chip (LOC) platform for the assessment of rotifer swimming behavior in the presence of the toxicant copper sulfate. The device was designed to assess impact of toxicants at sub-lethal concentrations on freshwater crustacean Brachionus calyciflorus, testing behavioral endpoints such as animal swimming distance, speed and acceleration. The LOC device presented in this work enabled straightforward caging of microscopic crustaceans as well as non-invasive analysis of rapidly swimming animals in a focal plane of a video-microscopy system. The chip-based technology was fabricated using a new photolithography method that enabled formation of thick photoresist layers with minimal distortion. Photoresist molds were then employed for replica molding of LOC devices with poly(dimethylsiloxane) (PDMS) elastomer. The complete bioanalytical system consisted of: (i) microfluidic PDMS chip-based device; (ii) peristaltic microperfusion pumping manifold; (iii) miniaturized CMOS camera for video data acquisition; and (iv) video analysis software algorithms for quantification of changes in swimming behaviour of B. calyciflorus in response to reference toxicants.

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

    Science.gov (United States)

    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

  2. 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

  3. The swimming speed alteration of two freshwater rotifers Brachionus calyciflorus and Asplanchna brightwelli under dimethoate stress.

    Science.gov (United States)

    Chen, Jianqiu; Wang, Zhiliang; Li, Guoping; Guo, Ruixin

    2014-01-01

    Two common freshwater rotifer species Brachionus calyciflorus and Asplanchna brightwelli were employed as test organisms to investigate the toxic effects of the widely used organophosphate pesticide, dimethoate. The swimming angular speed and linear speed alteration of two rotifers were evaluated under the toxic stress in four concentrations (0.4, 0.8, 1.2, and 1.6 mg L(-1)). For B. calyciflorus, the rotifer swimming angular speed and linear speed were both adversely affected as a function of the toxicant concentrations. After a 2h exposure, the angular speeds at four concentrations were 39.37, 30.74, 26.68 and 23.96° s(-1), 65.30%, 50.98%, 44.25% and 39.74% of that of the control, respectively, while the mean linear speed decreased from 194.80 to 91.85×10(-3) mm s(-1), which was 70.12%, 48.14%, 34.02% and 33.06% of that of the control (277.82×10(-3) mm s(-1)), respectively. The pesticide also significantly inhibited the swimming angular speed of A. brightwelli. After a 2h exposure, the angular speeds of this rotifer at four concentrations were 39.37, 30.74, 26.68 and 23.96° s(-1), only 22.99%, 17.16%, 16.21% and 13.63% of that of the control (170.80° s(-1)), respectively. Compared with the results of B. calyciflorus, A. brightwelli was more sensitive on the swimming angular speed when exposed to the toxicant. It implied that A. brightwelli should be an alternative candidate model species about the toxicities of aquatic pollutants. In addition, when the rotifer A. brightwelli was exposed to four pesticide concentrations, the swimming linear speed displayed symptoms of hormesis, characterized by the conversion of low-concentration stimulate to high-concentration inhibition. Our results show that dimethoate had a significant effect on swimming of freshwater rotifers.

  4. Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis

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    Kube Michael

    2009-03-01

    Full Text Available Abstract Background Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs for molecular characterisation of processes associated with the formation of resting eggs, their survival during dormancy and hatching. Results Four normalized and four subtractive libraries were constructed to provide a resource for rotifer transcriptomics associated with resting-egg formation, storage and hatching. A total of 47,926 sequences were assembled into 18,000 putative transcripts and analyzed using both Blast and GO annotation. About 28–55% (depending on the library of the clones produced significant matches against the Swissprot and Trembl databases. Genes known to be associated with desiccation tolerance during dormancy in other organisms were identified in the EST libraries. These included genes associated with antioxidant activity, low molecular weight heat shock proteins and Late Embryonic Abundant (LEA proteins. Real-time PCR confirmed that LEA transcripts, small heat-shock proteins and some antioxidant genes were upregulated in resting eggs, therefore suggesting that desiccation tolerance is a characteristic feature of resting eggs even though they do not necessarily fully desiccate during dormancy. The role of trehalose in resting-egg formation and survival remains unclear since there was no significant difference between resting-egg producing females and amictic females in the expression of the tps-1 gene. In view of the absence of vitellogenin transcripts, matches to lipoprotein lipase proteins suggest that, similar to the situation in dipterans, these

  5. Coal fly ash effluent affects the distributions of Brachionus calyciflorus sibling species.

    Science.gov (United States)

    Zhang, Gen; Xi, Yi-Long; Xue, Ying-Hao; Xiang, Xian-Ling; Wen, Xin-Li

    2015-02-01

    Fly ash, a coal combustion residue of thermal power plants and a source of multiple pollutants, has been recognized as an environmental hazard all over the world. Although it is known that fly ash effluent affects density, diversity and distribution of rotifers in drainage systems and receiving water bodies, the effect of fly ash effluent on the distributions of highly similar rotifer species remains unknown. In this study, the mtDNA COI genes of 90 individuals in Brachionus calyciflorus complex from Lake Hui (as a fly ash discharge water pond) and other two neighboring lakes (Lake Fengming and Lake Tingtang) were sequenced and analyzed, and the responses in selected life table demographic parameters (life expectancy at hatching, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring) of different rotifer populations to fly ash effluent were investigated. Overall, 72 mtDNA haplotypes were defined, and were split into two clades by the phylogenetic trees. The divergence of COI gene sequences between the two clades ranged from 11.8% to17.8%, indicating the occurrence of two sibling species (sibling species I and sibling species II). Sibling species I distributed in all the three lakes, showing strong capabilities for dispersal and colonization, which were supported by its higher level of gene flow (2.60-4.04) between the populations from Lake Hui and each of the other two lakes, longer life expectancy at hatching (101.6-148.2 h), and higher net reproductive rate (4.4-16.4 offspring/female) and intrinsic rate of population increase (0.60-0.98/d) when cultured in aerated tap water and fly ash effluent. Sibling species II distributed in both Lake Tingtang and Lake Fengming, showing that its dispersal existed between the two lakes. Considering that the distance between Lake Hui and Lake Fengming is shorter than that between Lake Tingtang and Lake Fengming, sibling species II is able to disperse at least from Lake Fengming to Lake

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

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    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Widespread secondary contact and new glacial refugia in the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula.

    Directory of Open Access Journals (Sweden)

    Sergi Campillo

    Full Text Available Small aquatic organisms harbour deep phylogeographic patterns and highly structured populations even at local scales. These patterns indicate restricted gene flow, despite these organisms' high dispersal abilities, and have been explained by a combination of (1 strong founder effects due to rapidly growing populations and very large population sizes, and (2 the development of diapausing egg banks and local adaptation, resulting in low effective gene flow, what is known as the Monopolization hypothesis. In this study, we build up on our understanding of the mitochondrial phylogeography of the halophilic rotifer Brachionus plicatilis in the Iberian Peninsula by both increasing the number of sampled ponds in areas where secondary contact is likely and doubling sample sizes. We analyzed partial mitochondrial sequences of 252 individuals. We found two deep mitochondrial DNA lineages differing in both their genetic diversity and the complexity of their phylogeographic structure. Our analyses suggest that several events of secondary contact between clades occurred after their expansion from glacial refugia. We found a pattern of isolation-by-distance, which we interpret as being the result of historical colonization events. We propose the existence of at least one glacial refugium in the SE of the Iberian Peninsula. Our findings challenge predictions of the Monopolization hypothesis, since coexistence (i.e., secondary contact of divergent lineages in some ponds in the Iberian Peninsula is common. Our results indicate that phylogeographic structures in small organisms can be very complex and that gene flow between diverse lineages after population establishment can indeed occur.

  12. 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.

  13. Successful Replacement of Artemia salina nauplii with Marine Rotifers (Brachionus plicatilis) in the Diet of Preadult Zebrafish (Danio rerio).

    Science.gov (United States)

    Lawrence, Christian; James, Althea; Mobley, Scottie

    2015-10-01

    Previously established rearing protocols for zebrafish begin feeding with marine rotifers (Brachionus plicatilis), followed by Artemia nauplii until the fish reach subadult stage, the developmental time point at which they can be most easily transitioned onto a processed diet. However, the inclusion of Artemia is less than ideal, given its fluctuating availability and high costs. We tested whether or not we could replace Artemia with rotifers during our normal rearing sequence and still meet published performance standards for (i) weaning fish onto a processed diet by 25 days postfertilization (dpf) and (ii) successful breeding by 60 dpf. Here, we present the results of trials where wild-type and casper zebrafish were fed exclusively with rotifers (R) or rotifers followed by Artemia (RA) for the first 25 dpf after which point all fish were transitioned to a processed diet (Gemma Micro 300). We measured growth and survival at days 25 and 60, and tested for reproductive capability at 60 dpf. While growth performance was significantly better in the RA groups, we were still able to meet goals for both weaning and generation time in the R groups without compromising survival or sex ratios.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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 (liquid fertilizer as compared to the other diets. The growth rates of M. macrocopa ranged from 0.1 to 0.38/d, and were highest with diets of C. vulgaris cultured in Bold medium and S. acutus cultured in fertilizer. Thus, regardless of the culture medium used, the growth rates of the evaluated zooplankton species were higher with Chlorella than with Scenedesmus. The peak population density was highest (2 800ind/mL) for A. fissa fed Chlorella that was cultured on liquid fertilizers, while B. rubens and M. macrocopa had peak abundances of 480 and 12ind/mL, respectively under similar conditions.

  16. 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.

  17. Effects of DDT and dicofol on population growth of Brachionus calyciflorus under different algal (Scenedesmus obliquus) densities.

    Science.gov (United States)

    Xu, Xiao-Ping; Xi, Yi-Long; Chu, Zhao-Xia; Xiang, Xian-Ling

    2014-09-01

    A number of organochlorine pesticides, including DDT and dicofol, used to be important in crop protection and management. Their residues may reach water bodies and eventually affect the non-target organisms such as rotifers. In the present study, we evaluated the effects of DDT (0.05, 0.1, 0.2 and 0.4 mg l(-1)) and dicofol (0.1, 0.2, 0.4 and 0.8 mg l(-1)) on the population growth of rotifer Brachionus calyciflorus under two levels of Scenedesmus obliquus (1.0 x 10(6) and 3.0 x 10(6) cell ml(-1)). Regardless of the food level, DDT was more toxic than dicofol to B. calyciflorus. Under low food level, DDT at 0.1 and 0.2 mg l(-1) decreased the population growth rate (r), and DDT at 0.05-0.4 mg l(-1) decreased the maximum population density (K). Dicofol at 0.4 and 0.8 mg l(-1) decreased r and K, but dicofol at 0.2 mg l(-1) increased K. Under high food level, DDT at 0.05-0.2 mg l(-1) increased K, whereas DDT at 0.4 mg l(-1) as well as dicofol at 0.4 and 0.8 mg l(-1) decreased r and K. Increase in food level increased r exposed to DDT at 0.05-0.2 mg l(-1) as well as dicofol at 0.8 mg l(-1), and Kexposed to DDTat 0.05-0.2 mg l(-1) as well as dicofol at 0.1 and 0.2 mg l(-1). DDT concentration, algal density and their interaction affected r and K of B. calyciflorus. Both dicofol concentration and algal density affected r. Dicofol concentration, algal density and their interaction affected K. Both r and K were suitable endpoints for assessing the effects of DDT and dicofol on the rotifers population dynamics under two algal densities, and the latter was more sensitive.

  18. 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

  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)

    OpenAIRE

    Luciana Almada Thomaz; Lídia Miyako Yoshii Oshiro; Andrea Cecchetto Bambozzi; José Teixeira de Seixas Filho; Leonardo Azevedo da Silva Rosadas

    2004-01-01

    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 Art...

  20. 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

    of swimming velocity for a 10 degrees C temperature reduction) that is found to be largest for the brine shrimp Artemia salina nauplius (37 %) and the rotifer Brachionus plicatilis (26%), but negligible for the copepod Acartia tonsa (4%). We suggest that experimental data on change in swimming velocity (V......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......) due to change in kinematic viscosity (v) be correlated in terms of a power law, V proportional to v(-m). The present data on swimming velocity of copepods, brine shrimps and rotifers show values of exponent m approximate to 1.5 to 3, with a trend of decreasing values for increasing size of species...

  1. Ultraviolet B retards growth, induces oxidative stress, and modulates DNA repair-related gene and heat shock protein gene expression in the monogonont rotifer, Brachionus sp

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ryeo-Ok [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Rhee, Jae-Sung [Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791 (Korea, Republic of); Won, Eun-Ji [Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Kyun-Woo [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Kang, Chang-Mo [Laboratory of Cytogenetics and Tissue Regeneration, Korea Institute of Radiological and Medical Science, Seoul 139-709 (Korea, Republic of); Lee, Young-Mi [Department of Green Life Science, College of Convergence, Sangmyung University, Seoul 110-743 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@hanyang.ac.kr [Department of Chemistry, and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2011-02-15

    Ultraviolet B (UV-B) radiation causes direct cellular damage by breakage of DNA strands and oxidative stress induction in aquatic organisms. To understand the effect of UV-B radiation on the rotifer, Brachionus sp., several parameters including 24-h survival rate, population growth rate, and ROS level were measured after exposure to a wide range of UV-B doses. To check the expression of other important inducible genes such as replication protein A (RPA), DNA-dependent protein kinase (DNA-PK), Ku70, Ku80, and heat shock proteins (hsps) after UV-B radiation, we observed dose- and time-dependency at 2 kJ/m{sup 2}. We also examined 13 hsp genes for their roles in the UV-B damaged rotifer. Results showed that UV-B remarkably inhibited the population growth of Brachionus sp. The level of intracellular reactive oxygen species (ROS) was high at 2 kJ/m{sup 2}, suggesting that 2 kJ/m{sup 2} would already be toxic. This result was supported by other enzymatic activities, such as GSH levels, glutathione peroxidase, glutathione S-transferase, and glutathione reductase. For dose dependency, low doses of UV-B radiation (2, 4, and 6 kJ/m{sup 2}) significantly up-regulated the examined genes (e.g. RPA, DNA-PK, Ku70, and Ku80). For the time course study, RPA genes showed immediate up-regulation but returned to basal or lower expression levels compared to the control 3 h after UV-B exposure. The DNA-PK and Ku70/80 genes significantly increased, indicating that they may be involved in repairing processes against a low dose of UV-B exposure (2 kJ/m{sup 2}). At the basal level, the hsp90{alpha}1 gene showed the highest expression, and followed by hsp10, hsp30, hsp60, and hsc70, and hsp90{beta} in adults (w/o egg). In eggs, the hsp10 gene was expressed the highest, and followed by hsp30, hsp27, hsp90{alpha}1, and hsp60 genes. In real-time RT-PCR array on rotifer hsp genes, low doses of UV-B radiation (2 and 4 kJ/m{sup 2}) showed up-regulation of several hsp genes but most of the hsp

  2. 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.

  3. 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.

  4. Life strategy and grazing intensity responses of Brachionus calyciflorus fed on different concentrations of microcystin-producing and microcystin-free Microcystis aeruginosa

    Science.gov (United States)

    Liang, Ye; Ouyang, Kai; Chen, Xinglan; Su, Yuqi; Yang, Jiaxin

    2017-01-01

    The occurrence of Microcystis blooms is a worldwide concern due to the numerous adverse effects on zooplankton. We therefore hypothesized that the cyanobacterium Microcystis aeruginosa is harmful to rotifer growth. Population and individual experiments were conducted with the same proportional volumes of Chlorella and Microcystis for given food densities. Life-table parameters, life-history traits, and the grazing intensity of Brachionus calyciflorus were evaluated after they had fed on microcystin-producing and microcystin-free Microcystis, both alone and combined with an edible alga (Chlorella pyrenoidosa), at concentrations of 1 × 105, 1 × 106, and 1 × 107 cells mL−1. The results showed that the interactive effects of food density and type appeared to be synergistic on generation time (T), net reproduction rate (R0), body length, swimming speed, and reproduction time. In contrast, these effects appeared to be antagonistic on intrinsic growth rate (r), finite rate of increase (λ), time to first brood, post-reproductive time and total offspring per female. The grazing rate of rotifers decreased with grazing time. Although the toxins released after grazing on M. aeruginosa had negative effects on rotifer growth and reproduction, B. calyciflorus changed its life strategy and grazing intensity in response to eutrophic conditions. PMID:28230067

  5. Substituição de Artemia sp. pelo rotífero Brachionus plicatilis na larvicultura do camarão-d'água-doce (Macrobrachium rosenbergii De Man, 1879)

    OpenAIRE

    Thomaz,Luciana Almada; Oshiro,Lídia Miyako Yoshii; Bambozzi,Andrea Cecchetto; Seixas Filho,José Teixeira de; Rosadas,Leonardo Azevedo da Silva

    2004-01-01

    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 Art...

  6. Use of Probiotic Bacillus spp. in Rotifer (Brachionus plicatilis) and Artemia (Artemia urmiana) Enrichment: Effects on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei, Larvae.

    Science.gov (United States)

    Jamali, Hadi; Imani, Ahmad; Abdollahi, Daruosh; Roozbehfar, Reza; Isari, Amin

    2015-06-01

    This study was to evaluate the effect of a preparation of Bacillus probiotic (Bacillus licheniformis and B. subtilis, 1:1) on growth and survival rate of Pacific white shrimp, Litopenaeus vannamei larvae. The larvae were fed on Artemia urmiana nauplii and Brachionus plicatilis enriched with the probiotic preparation at 1 × 10(6) CFU mL(-1) rate. The experimental setup was completely randomized design comprised of six treatments, namely solo Artemia nauplii (A) or rotifer (R), Artemia nauplii and rotifer without any enrichment (A + R), Artemia nauplii enrichment with probiotic bacilli (Bacillus licheniformis and B. subtilis) (A + B), rotifer enrichment with probiotic bacilli (R + B) and enriched Artemia nauplii and rotifer (A + R + B). All treatments were performed in triplicate. Chemical parameters of rearing water viz. pH, salinity and temperature were 7.5-8, 30-31 ppt and 31-32 °C, respectively. Photoperiod was 16L:8D. Shrimp larvae were fed Artemia nauplii and rotifers at 5-20 and 10-40 individuals per shrimp larvae four times a day, respectively. Growth and survival rate of larvae were determined at MII, MIII, PL1, PL4, PL7 and PL10 stages. Larvae in A + R + B treatment showed the highest total length (10.89 ± 0.51 mm), weight (674 ± 73 μg) and survival rate (65% ± 3.5). Lowest total length, weight and survival rate (7.96 ± 0.63 mm, 493 ± 52 μg and 24.5 ± 2.4%, respectively) were recorded in treatment B larvae. We concluded that Bacillus probiotic can improve growth and survival rate of Pacific white shrimp larvae without conceivably undesirable effects.

  7. 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®.

  8. Performances zootechniques comparées de Rotifères d'eau douce Brachionus calyciflorus et de nauplii d'Artemia salina chez les larves de la perche fluviatile Perca fluviatilis

    Directory of Open Access Journals (Sweden)

    Fiogbé, ED.

    2003-01-01

    Full Text Available Zootechnic Performences Compared between Freshwater Rotifer (Brachionus calyciflorus and Nauplii Artemia salina in River Perch Perca fluviatilis L. In able to improve survival rate and growth in perch Perca fluviatilis larvae which are very small at hatching stage, larvae are submitted two days after hatching to different live food: fresh water Rotifer Brachionus calyciflorus and nauplii of Artemia salina.Thus, to avoid the big mortality which occure because of manipulation of larvae, eggs in eye stage were shared in two duplicated groups and feeding of larvae started two days after hatching. Mortality was significant in the two groups from the day 7. However, at the end of the experiment, the group fed Rotifer at the begining of feeding, exhibited the best homogeneity, the best survival and the best food convertion ratio. So, this experiment has shown clearly that at hatching time, all perch larvae are not able to ingest nauplii Artemia. It is necessary to mix their starter food with Rotifer.

  9. 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.

  10. 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.

  11. 萼花臂尾轮虫多态性及形态型转化%Polymorphism and Morphotype Transformations in the Rotifer (Brachionus calyciflorus)

    Institute of Scientific and Technical Information of China (English)

    殷旭旺; 牛翠娟

    2007-01-01

    The relationship of three Brachionus calyciflorus morphotypes (two short-spined, single-spined and spineless ones) was studied in the laboratory. Newly hatched females of each morphotype were cultured individually in an inorganic or Asplanchna-conditioned mediums, and the morphotype of their offspring were checked at 200× magnification. Females of each morphotype, cultured in the inorganic medium, could produce offspring of these three morphotypes in a single generation. Females of all three morphotyes could respond to specific Asplanchna-substances when they were cultured in Asplanchna-conditioned medium. Moreover, we observed that these three morphotype females could coexist in the medium and had three types of egg-bearing females. Based on the above observations we suggest that B. calyciflorus was a morphotype complex and has three basic morphotypes.%在实验室条件下研究了萼花臂尾轮虫3种形态型(双短侧棘刺、单短侧棘刺和无侧棘刺)个体之间的关系. 从轮虫的培养水体中随机挑出若干3种形态型雌体的幼轮虫(龄长<24 h), 分别培养在正常培养液和晶囊轮虫培养液过滤液中. 将实验轮虫的后代(F1代)置于200倍显微镜下检查其个体的形态型. 实验结果表明, 在正常培养液中, 每种形态型轮虫个体都可以产生3种形态型的后代. 当培养在晶囊轮虫培养液过滤液中时, 这3种形态型轮虫的后代都具有2个显著增长的侧棘刺. 此外, 这3种形态型个体的轮虫能够共存于同一培养环境中, 而且每种形态型个体的轮虫都具有3种生殖类型的雌体. 由此推测萼花臂尾轮虫是一个由3种基础形态型个体组成的形态型轮虫复合体.

  12. 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

  13. Experimental evidence of the effect of nutrient enrichment on the zooplankton in a Brazilian coastal lagoon

    Directory of Open Access Journals (Sweden)

    B. KOZLOWSKY-SUZUKI

    Full Text Available Non-treated sewage disposal is one of the main impacts to which Imboassica Lagoon has been subjected. The aim of this study was to evaluate the effect of a potential increase in the artificial enrichment on the environmental conditions and zooplankton of this system. To this end, an experimental study was conducted in mesocosms where nutrients were added daily. Bacterial numbers, chlorophyll-a, and picoplanktonic cyanobacteria densities showed an increase with the availability of nutrients. Bacterio- and phytoplankton seemed to be regulated by the rotifers Brachionus rotundiformis and Hexarthra brandorffi.

  14. Application of the minute monogonont rotifer proales similis de Beauchamp in larval rearing of seven-band grouper epinephelus septemfasciatus

    OpenAIRE

    2011-01-01

    In comparison to the rotifer Brachionus rotundiformis, the euryhaline rotifer Proales similis has a much smaller body size (83μm in length and 40μm in width), and it may be applicable as live food for rearing marine fish larvae with a very small mouth size. A mass culture technique of P. similis was recently established, and it has already been confirmed that marine fish larvae could ingest P. similis. In the present study, we further investigated the use of P. similis as an initial food by o...

  15. 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

  16. Impact on spatial distribution of Brachionus calyciflorus species complex by coal ash pollution%粉煤灰污染影响萼花臂尾轮虫(Brachionus calyciflorus)种复合体空间分布的原因

    Institute of Scientific and Technical Information of China (English)

    薛颖昊; 席贻龙; 张根

    2012-01-01

    In order to analyze the ecological mechanism and the effect of coal ash pollution on distribution of Brachionus calyciflorus species complex in three lakes ( Lake Hui, Lake Tinglang and Lake Fengming) , the effects of aerated tap-water (control) , and 20% , 40% , 60% , 80% and 100% volume fractions of settled coal ash water diluted by aerated tap-water on population growth rates, ratios mictic females/amictic females, ovigerous females/non-ovigerous females, and resting egg productions of sibling species I have been collected from Lake Hui, Lake Tingtang and Lake Fengming and sibling species II have been collected from Lake Tingtang. Trie results showed that regardless of the volume fraction of settled coal ash water, sibling species I collected from all the three lakes had higher population growth rates (0.52-0.85 d-1 ) and resting egg productions (1.60-12.11 ind./(4d · 5 ml)) which made possible for population spread, population establishment and gene flow. Sibling species II collected from Lake Tingtang had much lower ratio mictic females/amictic females and resting egg production, and in the aerated lap-water, both of them were zero, which might be the main reason for that sibling species II living in Lake Tingtang and Lake Fengming could not spread into Lake Hui. The volume fraction of settled coal ash water significantly affects only the population growth rates of both two sibling species collected from Lake Tingtang. All the volume fractions of settled coal ash water made the population growth rate of sibling species I higher than that in the control, and 60% , 80% and 100% settled coal ash water made the population growth rate of sibling species II higher than that in the control, which indicated that the decreased rotifer density in natural water bodies polluted by coal ash did not attribute to the direct toxicity of elevated metal, salt concentrations, and pH level.%为探讨粉煤灰污染影响萼花臂尾轮虫(Brachionus calyciflorus)种复合体在

  17. 有机磷农药乐果对萼花臂尾轮虫游泳行为的影响%Behavioral Bioassay of Brachionus calyciflorus(rotifer)for Toxic Effect Assessment of Dimethoate

    Institute of Scientific and Technical Information of China (English)

    郭瑞昕; 王志良; 李国平; 陈建秋

    2013-01-01

    Toxic stress of dimethoate on freshwater rotifer Brachionus calyciflorus was evaluated,using swimming behaviors alteration as sub-lethal endpoint.Alteration of swimming behaviors was examined firstly when the rotifer was exposed under 5 dimethoate concentrations after 6h.The imbalance of swimming direction and inhibition on swimming speed of toxic stress was observed clearly.Alterations of swimming behavior under toxic stress were analyzed and classified into 3 aspects such as swimming direction change,swimming angle change and swimming speed change using principal component analysis.Toxicity test results indicated that the disruption of dimethoate on swimming behavior was high concentration dependent,which is the first study about the mode of dimethoate on different aspects of swimming behavior of rotifer.%以游泳行为变化情况为指标,考察了有机磷农药乐果对淡水种萼花臂尾轮虫(Brachionus calyciflorus)的毒性作用.测定了暴露在5个不同质量浓度乐果作用6小时后轮虫游泳行为的变化情况.可以观察到轮虫的游泳方向的平衡性被破坏,游泳角速度与线速度受到显著地抑制.采用主成分分析方法(PCA)分析了在乐果的作用下轮虫游泳行为的变化情况.结果显示游泳平衡性失衡,旋转角度变小,位移速率变慢.暴露6h后,0.2 mg/L质量浓度组轮虫游泳位移速率变慢最为明显,而在1.0,1.4和1.8 mg/L质量浓度组轮虫游泳平衡性失衡最为明显,结果表明轮虫游泳行为的变化情况与乐果的质量浓度高度相关.木研究方法与内容在国内外尚属首次报道.

  18. 温度和食物密度对两种形态型裂足臂尾轮虫(Brachionus diversicornis)生活史特征和后代形态型的影响%Effects of temperature and algal density on life history characteristics and morphotype in offspring of two Brachionus diversicomis morphotypes

    Institute of Scientific and Technical Information of China (English)

    马杰; 席贻龙; 许丹丹; 葛雅丽

    2011-01-01

    运用单个体培养方法研究了温度(15℃、20℃、25℃和30℃)和斜生栅藻(Scenedesmus obliquus)密度(0.75×106、1.5×106、3.0×106和6.0 x 106 cells/ml)对等棘刺型和不等棘刺型裂足臂尾轮虫(Brachionus diversicornis)的净生殖率、种群内禀增长率、世代时间、生命期望和后代混交率等生活史参数和后代形态型的影响.结果表明:各温度下,两种形态型轮虫的存活率无显著差异;除20℃外,其余三个温度下,等棘刺型轮虫的繁殖率显著高于不等棘刺型;除30℃下等棘刺型轮虫的世代时间长于不等棘刺型轮虫外,各温度下两种形态型轮虫的各生活史参数均无显著差异.各食物密度下,两种形态型轮虫的存活率、繁殖率、各生活史参数也均无显著差异.两种形态型轮虫的种群内禀增长率、世代时间和生命期望对升高的温度反应不同,但食物密度仅对等棘刺型轮虫的净生殖率和内禀增长率有显著影响.等棘刺型轮虫的净生殖率在6.0×106cells/ml食物密度下显著低于0.75×106和3.0 x 106cells/ml食物密度下,1.5×106cells/ml食物密度下与上述三食物密度间均无显著差异;内禀增长率在6.0×106cells/ml食物密度下显著低于3.0×106cells/ml食物密度下,但两者均与0.75×106和1.5×106cells/ml食物密度下无显著差异.在各温度和食物密度下,两种形态型轮虫都能产生等棘刺型和不等棘刺型的后代.25℃下等棘刺型轮虫所产后代中等棘刺率明显高于不等棘刺型轮虫,但各食物密度下两种形态型轮虫所产后代中等棘刺率无显著的差异.温度对等棘刺型轮虫所产后代中等棘刺率有显著的影响,但食物密度对两种形态型轮虫所产后代中等棘刺率均无显著的影响.等棘刺型轮虫所产后代中等棘刺率在15℃和25℃、20℃和30℃间分别无显著差异,但前两者显著高于后两者.%Effects of temperature(15℃, 20℃, 25℃ and 30

  19. 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

  20. 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.

  1. 米氏凯伦藻对褶皱臂尾轮虫、卤虫和黑褐新糠虾存活的影响%Effect of Karenia mikimotoi on the survival of rotifer Brachionus plicatilis, brine shrimp Artemia salina, and Neomysis awatschensis

    Institute of Scientific and Technical Information of China (English)

    孙科; 颜天; 周名江; 何建宗

    2010-01-01

    初步研究了一株米氏凯伦藻对褶皱臂尾轮虫(Brachionus plicatilis)、卤虫(Artemia salina)幼体和黑褐新糠虾(Neomysis awatschensis)的毒性效应和机制.研究发现米氏凯伦藻(Karenia mikimotoi)在较低密度下就能明显减少轮虫的种群数量, 24 h EC50仅为20个/mL左右; 该藻的各组分毒性比较结果显示, 只有藻液和细胞重悬液有这种毒害作用, 而去藻过滤液和藻细胞破碎液的影响不明显, 表明这种毒害作用可能是由于活的藻细胞引起的; 在米氏凯伦藻中卤虫和黑褐新糠虾的存活数量也明显下降.结果表明, 米氏凯伦藻赤潮可能通过直接影响存活从而对浮游动物产生影响.

  2. TAXONOMICAL STATUS OF TWO BRACHIONUS CALYCIFLORUS MORPHOTYPES IN LAKE LIANTANG BASED ON ITS SEQUENCE%基于rDNA ITS序列分析莲塘湖萼花臂尾轮虫两种形态型的分类地位

    Institute of Scientific and Technical Information of China (English)

    张晋艳; 席贻龙; 马芹; 项贤领

    2010-01-01

    轮虫的周期变形是指种群内出现的轮虫形态随时间推移而发生的周期性变化,包括轮虫个体大小的变化、轮虫后棘刺或后侧棘刺的有无及长度的变化等.广泛存在的周期变形使轮虫的分类更加复杂.利用分子标记对不同形态型轮虫的遗传分化进行研究将有助于正确认识它们的分类地位.为此,研究对采自芜湖市莲塘湖水体中萼花臂尾轮虫(Brachionus calyciflorus)30个有棘刺型(Spined morohotype)的克隆(S1-S30)和18个无棘刺型(Unspined morphotype)的克隆(U1-U18)进行了rDNA ITS序列分析;以十指臂尾轮虫(B.patulus)为外群,构建了48个克隆的系统发生树(NJ、MP、ML和贝叶斯树).结果表明,所测48个克隆共包括16个单元型.在ITS序列中,T、C、A、G碱基的平均含量分别为28.6%、18.7%、35.9%、16.8%.其中A+T含量为64.5%,C+G含量为35.5%.单元型U12与其他单元型间的序列差异百分比为26.2%-26.6%,平均为26.47%;其中,发生在ITS1、5.8S和ITS2区间的序列差异百分比分别为26.9%-27.8%、2.9%-3.5%和44.4%-45.0%,平均依次为27.27%、3.09%和44.48%.而其他单元型间平均序列差异百分比为0.41%.4个系统树均支持将48个克隆分为2个支系:无棘刺型克隆U12独成一支,无棘刺型的其余克隆与所有有棘刺型克隆构成另一支系.单元型U12与其他单元型应分别属于两个不同的姐妹种;但两种形态型并非不同的亚种或互为姐妹种,它们间的形态差异主要南表型可塑性引起.

  3. Effects on the population dynamics of Brachionus rubens (Rotifera) caused by mercury and cadmium administered through medium and algal food Chlorella vulgaris%在培养基和食料中添加铅和镉对轮虫种群动态的影响

    Institute of Scientific and Technical Information of China (English)

    S.S.S.SARMA; Hilda Fabiola NUNEZ-CRUZ; S.NANDINI

    2005-01-01

    Due to industrial activities,heavy metal concentrations in aquatic systems of Mexico,are on the rise.Zooplankton,particularly rotifers,being sensitive and common components of freshwater,are widely used in ecotoxicological tests for establishing water quality criteria.Depending on the route of exposure (i.e.via medium or algal food),the toxicity of heavy metals varies.In the present study we evaluated the effect of cadmium and mercury exposed through medium and via algal food for the rotifer B.rubens.For both the heavy metals,we exposed rotifers via medium containing Chlorella at 0.5×106 cells/ml or fed daily on previously exposed (1,2 and 4 h) alga to the toxicants (using 5 times the value of LC50 for B.rubens).For cadmium toxicity through medium,we used 3 toxicant levels (0.1,0.2 and 0.4 mg/L) and for mercury,we used 0.005,0.010 and 0.015 mg/L.Based on the LC50,B.rubens was 24 times more sensitive to mercury (0.035±0.002 mg/L) than cadmium.At a concentration of 0.4 mg/L,cadmium through the medium caused increased lag phase of B.rubens.When grown on Chlorella exposed for different durations to cadmium,the rotifer density decreased with the increasing duration of algal exposure to the heavy metal.When mercury was used in the medium or via algal food,the trends in the population growth of B.rubens were similar to those for cadmium.An increase in heavy metal concentration in the medium resulted in a decrease of the rate of population increase per day (r).The r varied from 0.33 (in control) to 0.02 d-1 (in heavy metal treatment) depending on the mode of exposure though medium or via algal food[Acta Zoologica Sinica 51(1):46-52,2005].%由于工业活动的影响,墨西哥水体环境中的重金属浓度在上升.浮游动物,尤其是轮虫类,由于对环境变化十分敏感而且是淡水中的常见组成部分,因此被广泛用于生态毒理试验以确定水质标准.在不同的胁迫途径下(如通过培养基或食料),重金属的毒性是不同的.在本研究中,通过在轮虫Brachionus

  4. Comparative studies on life history characteristics of three sibling species in Brachionus calyciflorus species complex%萼花臂尾轮虫种复合体内三个姐妹种生活史特征的比较研究

    Institute of Scientific and Technical Information of China (English)

    李化炳; 席贻龙; 程新峰

    2008-01-01

    Life history characteristics of three sibling species including sibling HE1,HE3 and LE9 in Brachionus calyciflorus species complex collected from Lake Liantang and Pond Hehuatang in Wuhu City and cultured at 13℃,18℃,23℃ and 28℃ with 2.0×106 cells/mL of Scenedesmus obliquus was compared by means of life table demographic approach.The results showed that the differences in life table parameters among the three sibling species differed with temperatures.At 13"C,sibling species LE9 had longer life expectancy at hatching,average lifespan and generation time than sibling species HE3,and the highest net reproductive rate and intrinsic rate of population growth among the three sibling species.The percentage of mictie females in all produced offspring was similar among the three sibling species.At 18℃,sibling species LE9 had longer life expectancy at hatching and average lifespan than sibling species HE3,and longer generation time than sibling species HE1 and HE3.Sibling species HE3 had higher intrinsic rate of population growth than sibling species LE9,and produced the most mictic daughters among the three sibling species.However,the net reproductive rates were similar among the three sibling species.At 23℃,sibling species HE1 had the longest life expectancy at hatching,average lifespan and generation time among the three sibling species.Sibling species HEI produced less mietie daughters than sibling species HE3.Both net reproductive rate and intrinsic rate of population growth was similar among the three sibling species.At 28℃ and among the three sibling species,life expectancy at hatching,average lifcspan,generation time and intrinsic rote of population growth were all similar,sibling species HE1 had the lowest net reproductive rate,sibling species HE3 produced the most mietic daughters.The responses in life table parameters to increasing temperatures were different among the three sibling species.Temperature,sibling species and their interactions all

  5. 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.

  6. Investigation of a rotifer (Brachionus calyciflorus) - green alga (Scenedesmus pectinatus) interaction under non- and nutrient-limited conditions

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.

    2006-01-01

    Two-day life cycle tests with the rotifer Brachiomus calyciflorus were run to study the nutritional quality effects to rotifers of Scenedesmus pectinatus grown under non-limiting nitrogen limiting and phosphorus limiting conditions and the feedback of the rotifers oil the Food algae. Under nutrient-

  7. ENFRENTANDO AMENAZAS SIMULTANEAS: RESPUESTAS DEMOGRAFICAS DE BRACHIONUS CALYCIFLORUS FRENTE A RIESGO DE DEPRADACION Y EXPOSICION A PESTICIDA

    OpenAIRE

    HEINE FUSTER, INGER ANDREA

    2013-01-01

    El desarrollo de defensas en respuesta a señales químicas liberadas por depredadores es una estrategia plástica presente en muchas especies que habitan diferentes ambientes. Estas respuestas son expresadas como cambios reversibles en morfolgía, conducta o de atributos de historia de vida, lo que implica un costo de fitness en estos organismos y sus poblaciones. La exposición a químicos de fuentes antrópicas, como pesticidas, en bajas dosis pueden causar efectos subletales sobre los organismos...

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Inducible colony formation within the Scenedesmaceae: adaptive responses to infochemicals from two different herbivore taxa

    NARCIS (Netherlands)

    Verschoor, A.M.; Van der Stap, I.; Helmsing, N.R.; Lürling, M.; Van Donk, E.

    2004-01-01

    We studied the occurrence of colony formation within 40 different strains of Scenedesmaceae (Chlorococcales, Chlorophyta) in response to grazing-released infochemicals from the herbivorous zooplankters Brachionus calyciflorus Pallas (Rotifera) and Daphnia magna Strauss (Cladocera). With the exceptio

  13. Inducible colony formation within the Scenedesmaceae: Adaptive responses to infochemicals from two different herbivore taxa

    NARCIS (Netherlands)

    Verschoor, A.M.; Stap, I.; Helmsing, N.R.; Lürling, M.F.L.L.W.; Donk, van E.

    2004-01-01

    We studied the occurrence of colony formation within 40 different strains of Scenedesmaceae (Chlorococcales, Chlorophyta) in response to grazing-released infochemicals from the herbivorous zooplankters Brachionus calyciflorus Pallas (Rotifera) and Daphnia magna Strauss (Cladocera). With the exceptio

  14. 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.

  15. Dicty_cDB: Contig-U05205-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2079.fwd ABWZ Phakopsora pachyrhizi infec... 38 3e-04 3 ( EC368739 ) G840P313FD5.T0 Oscarella carmela pSport...04 3 ( FM901924 ) Brachionus plicatilis EST 5' end, clone sb101P001... 52 4e-04 2 ( EC369115 ) G840P313RD5.T0 Oscar

  16. Fo-spectra of chlorophyll fluorescence for the determination of zooplankton grazing

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Verschoor, A.M.

    2003-01-01

    In the PHYTO-PAM phytoplankton analyzer the minimal fluorescence of dark-adapted samples (F-0) was assessed, which gives direct information on the chlorophyll-a content. Clearance rates (CR) of Daphnia and Brachionus were calculated from a decrease in chlorophyll-a concentration using the PHYTO-PAM

  17. FO-spectra of chlorophyll fluorescence for the determination of zooplankton grazing

    NARCIS (Netherlands)

    Lürling, M.; Verschoor, A.M.

    2003-01-01

    In the PHYTO-PAM phytoplankton analyzer the minimal fluorescence of dark-adapted samples (F0) was assessed, which gives direct information on the chlorophyll- a content. Clearance rates (CR) of Daphnia and Brachionus were calculated from a decrease in chlorophyll-a concentration using the PHYTO-PAM

  18. 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...

  19. Phaeobacter gallaeciensis Reduces Vibrio anguillarum in Cultures of Microalgae and Rotifers, and Prevents Vibriosis in Cod Larvae

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Lillebø, Siril; Prol García, María Jesús

    2012-01-01

    -antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7) cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio...

  20. Environmental Analysis of Lake Pontchartrain, Louisiana, Its Surrounding Wetlands, and Selected Land Uses. Volume 1.

    Science.gov (United States)

    1980-02-01

    nauplil (2b) T. sphnctOaOma (41) Conochilus sp. (67) Polychsta (42) T. patina (68) (5) (3) 101 n 100 B. patulus (16) K. cochleris (13) Rare Lacane app...9 t Keratella smericana 11 207 *Keratella cochisaria 13 6 210 Kel Icott ia bostoniensia 14 Brachionus patulus 16 39 1 Lacane opp. 17 29 23 13 Iyichoc

  1. Revised Protocol for Zooplankton Automated Analysis

    Science.gov (United States)

    2011-11-01

    classify the viability of organisms in the ≥ 50 µm size class (Lemieux, et al. 2007). This work focused on standard test organisms, including brine shrimp ... Artemia franciscana) and rotifers (Brachionus plicatilis and B. calyciflorus). Initial work was conducted with homogeneous monocultures with

  2. Protocol for Automated Zooplankton Analysis

    Science.gov (United States)

    2010-01-01

    the viability of organisms in the > 50 urn size class (Nelson, et al. 2007). This work focused on standard test organisms, including brine shrimp ... Artemia franciscana) and rotifers {Brachionus plicatilis and B. calyciflorus). Initial work was conducted with homogeneous monocultures with little to

  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. Deepor Beel revisited: new records of rotifers (Rotifera: Eurotatoria with remarks on interesting species

    Directory of Open Access Journals (Sweden)

    B.K. Sharma

    2011-01-01

    Full Text Available Plankton samples collected (April 2009 - March 2010 from Deepor Beel, a Ramsar site, revealed 21 species of the Phylum Rotifera belonging to 12 genera and eight families as new records. Amongst these, Brachionus durgae is a new record for northeastern India. The recorded species included the Australasian Brachionus dichotomus reductus and Notommata spinata; two Oriental endemics, namely, Keratella edmondsoni and Lecane blachei while Lecane lateralis, L haliclysta, Lepadella benjamini, Platyias leloupi, Mytilina acanthophora, Macrochaetus longipes, Trichocerca bicristata and T. flagellata are examples of regional distribution interest. The present report increases the number of species recorded from this important wetland of northeastern India to 134 species which, in turn, is the richest rotifer diversity known till date from any aquatic ecosystem of South Asia.

  5. BMC Genomics

    OpenAIRE

    2009-01-01

    BACKGROUND Microscopic monogonont rotifers, including the euryhaline species Brachionus plicatilis, are typically found in water bodies where environmental factors restrict population growth to short periods lasting days or months. The survival of the population is ensured via the production of resting eggs that show a remarkable tolerance to unfavorable conditions and remain viable for decades. The aim of this study was to generate Expressed Sequence Tags (ESTs) for molecular characterisa...

  6. Progress in live food production and use in fish and shellfish hatcheries

    OpenAIRE

    Sorgeloos, P

    1998-01-01

    Different species of microalgae, the rotifer, Brachionus spp., and the brine shrimp, Artemia spp., are essential live food in the farming of several species of molluscs (e.g. oyster, clam, scallop), crustaceans (e.g. marine shrimp, freshwater prawn, crabs) and fish (e.g. bass, bream, grouper, turbot, flounder, halibut, ayu). A brief overview is given of the latest developments in their production and use in industrial hatcheries.

  7. Investigation of Water Quality and Plankton in Selected Aquatic Habitats on the Lower Mississippi river.

    Science.gov (United States)

    1984-04-01

    At the relatively depauperate main channel stations, Keratella (principally K. cochlearis), followed by Vorticella , copepod nauplii, Brachionus...both of the Matthews Bend stations, but rare at main channel stations. Vorticella , plentiful at main channel stations, was relatively scarce at LEGEND -O...cochlearis. The second most numerous taxon was the stalked protozoan Vorticella . As 5 7 Vorticella normally attaches to substrates (Kudo 1966), their

  8. The effect of seasonality on the structure of rotifers in a black-water shallow lake in Central Amazonia

    Directory of Open Access Journals (Sweden)

    CLARICE C. NOVA

    2014-09-01

    Full Text Available Rotifers have often been used as indicators of sudden changes in physical and chemical features of the aquatic environment. Such features vary greatly during flood pulse events in small lakes connected to major floodplains. However, few are the studies that investigate the consequences of the flood pulse in rotifer species composition, abundance, richness and diversity, especially in Amazonian lakes. We analyzed samples from a small blackwater lake of an “igarapé” connected permanently to the Negro river, in Central Amazonia. Samples were taken twice a year for two years, comprising flooding and receding periods of the flood pulse. Rotifer abundance increased significantly after draught events, and electrical conductivity and turbidity were intrinsically related to such variation. Species composition also changed from flooding to receding periods. Some taxa, such as Brachionus zahniseri reductus and Lecane remanei were restricted to receding periods, while Brachionus zahniseri, Brachionus gillardi and Lecane proiecta were only present during flooding. A shift in the composition of rotifer families was observed from one period to another, showing the effect of renewing waters of the flood pulse. These results suggest that the flood pulse acts as a driving force and stressing condition, considerably altering rotifer community dynamics, either changing species composition or decreasing abundance.

  9. 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

  10. 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.

  11. An integrated fish-plankton aquaculture system in brackish water.

    Science.gov (United States)

    Gilles, S; Fargier, L; Lazzaro, X; Baras, E; De Wilde, N; Drakidès, C; Amiel, C; Rispal, B; Blancheton, J-P

    2013-02-01

    Integrated Multi-Trophic Aquaculture takes advantage of the mutualism between some detritivorous fish and phytoplankton. The fish recycle nutrients by consuming live (and dead) algae and provide the inorganic carbon to fuel the growth of live algae. In the meanwhile, algae purify the water and generate the oxygen required by fishes. Such mechanism stabilizes the functioning of an artificially recycling ecosystem, as exemplified by combining the euryhaline tilapia Sarotherodon melanotheron heudelotii and the unicellular alga Chlorella sp. Feed addition in this ecosystem results in faster fish growth but also in an increase in phytoplankton biomass, which must be limited. In the prototype described here, the algal population control is exerted by herbivorous zooplankton growing in a separate pond connected in parallel to the fish-algae ecosystem. The zooplankton production is then consumed by tilapia, particularly by the fry and juveniles, when water is returned to the main circuit. Chlorella sp. and Brachionus plicatilis are two planktonic species that have spontaneously colonized the brackish water of the prototype, which was set-up in Senegal along the Atlantic Ocean shoreline. In our system, water was entirely recycled and only evaporation was compensated (1.5% volume/day). Sediment, which accumulated in the zooplankton pond, was the only trophic cul-de-sac. The system was temporarily destabilized following an accidental rotifer invasion in the main circuit. This caused Chlorella disappearance and replacement by opportunist algae, not consumed by Brachionus. Following the entire consumption of the Brachionus population by tilapias, Chlorella predominated again. Our artificial ecosystem combining S. m. heudelotii, Chlorella and B. plicatilis thus appeared to be resilient. This farming system was operated over one year with a fish productivity of 1.85 kg/m2 per year during the cold season (January to April).

  12. Assessment the toxic effects of dimethoate to rotifer using swimming behavior.

    Science.gov (United States)

    Guo, Ruixin; Ren, Xinkun; Ren, Hongqiang

    2012-09-01

    The toxic effects of the common organophosphorus pesticide dimethoate on freshwater zooplankton Brachionus calyciflorus (rotifer) were tested. Because of the advantages of behavioral response in environmental monitoring, swimming behavior was used as the endpoint in this research. After exposure 6 h at five dimethoate concentrations (0.18, 0.53, 0.88, 1.23 and 1.59 mg·L(-1)), the pesticide disrupted the balance in rotifer swimming direction and caused an obvious direction preference. It also inhibited significantly the swimming angular and linear speed. Our results showed that dimethoate has a sublethal toxic effect on this aquatic invertebrate.

  13. 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.

  14. 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.

  15. Evolution of the AKH/corazonin/ACP/GnRH receptor superfamily and their ligands in the Protostomia

    DEFF Research Database (Denmark)

    Hauser, Frank; Grimmelikhuijzen, Cornelis

    2014-01-01

    In this review we trace the evolutionary connections between GnRH receptors from vertebrates and the receptors for adipokinetic hormone (AKH), AKH/corazonin-related peptide (ACP), and corazonin from arthropods. We conclude that these G protein-coupled receptors (GPCRs) are closely related and have...... limpet Lottia gigantea (pQIHFSPTWGSamide), the oyster Crassostrea gigas (pQVSFSTNWGSamide), and the freshwater pearl mussel Hyriopsis cumingii (pQISFSTNWGSamide). We also found AKHs in the tardigrade Hysibius dujardini (pQLSFTGWGHamide), the rotifer Brachionus calycifloros (p...

  16. Faunal diversity of rotifers (Rotifera: Eurotatoria of Nokrek Biosphere Reserve, Meghalaya, India

    Directory of Open Access Journals (Sweden)

    B.K. Sharma

    2011-02-01

    Full Text Available Plankton samples collected from the Nokrek Biosphere Reserve of Meghalaya (Northeast India revealed 70 species of Rotifera belonging to 24 genera and 15 families. Eight species are new records from the state of Meghalaya. The Oriental Lecane blachei and the palaeotropical L. unguitata are biogeographically interesting elements. The Rotifera taxocoenosis of Nokrek Biosphere Reserve is characterized by a distinct richness of the tropic-centered genus Lecane, paucity of Brachionus species, greater diversity of littoral-periphytonic elements and a general tropical character with cosmopolitan (71.4% > tropicopolitan (17.1 % species.

  17. Toxicity of two imidazolium ionic liquids, [bmim][BF4] and [omim][BF4], to standard aquatic test organisms: Role of acetone in the induced toxicity.

    Science.gov (United States)

    Tsarpali, Vasiliki; Dailianis, Stefanos

    2015-07-01

    The main goal of this study was to investigate the toxicity of the imidazolium-based ionic liquids (ILs), [bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate) and [omim][BF4] (1-octyl-3-methylimidazolium tetrafluoroborate), in battery of standard aquatic toxicity test organisms. Specifically, exposure of the algae Scenedesmus rubescens, crustaceans Thamnocephalus platyurus and Artemia franciscana, rotifers Brachionus calyciflorus and Brachionus plicatilis and bivalve Mytilus galloprovincialis to different concentrations of [bmim][BF4], [omim][BF4] and/or a binary mixture of [bmim][BF4]-[omim][BF4] (1:1) with or without acetone (carrier solvent), revealed that solvent can differentially mediate ILs' toxic profile. Acetone's ability to differentially affect ILs' cation's alkyl chain length, as well as the hydrolysis of [BF4(-)] anions was evident. Given that the toxic potency of the tested ILs seemed to be equal or even higher (in some cases) than those of conventional organic solvents, the present study revealed that the characterization of imidazolium-based ILs as "green solvents" should not be generalized, at least in case of their natural occurrence in mixtures with organic solvents, such as acetone.

  18. Seasonal variations of rotifers from a high altitude urban shallow water body, La Cantera Oriente (Mexico City, Mexico)

    Science.gov (United States)

    Gutiérrez, Sergio González; Sarma, S. S. S.; Nandini, S.

    2016-12-01

    La Cantera Oriente is a shallow freshwater volcanic water body located at an altitude of 2 270 m above sea level in the Ecological Reserve of San Angel Pedregal of Mexico City (Mexico). In order to ensure the conservation of its biological heritage including zooplankton, the present work was undertaken to quantify the seasonal changes in the diversity and density of rotifers and the selected physico-chemical variables during 2013-2014. Qualitative analysis of the zooplankton samples yielded 68 rotifer species which represented 24 genera in 15 families. B rachionus calyciflorus Pallas, 1766, B. quadridentatus Hermann, 1783, Polyarthra vulgaris Carlin, 1943, Lecane closterocerca (Schmarda, 1859) and Keratella cochlearis (Gosse, 1851) were the most common species. Preston plots of species frequency-density revealed that as many as 30% of the rotifer taxa were dominant throughout the year. The species with high population densities were Brachionus quadridentatus, Lecane closterocerca, Keratella cochlearis, and Lepadella patella; their peak densities were 2 000, 1 000, 180 and 90 ind./L, all occurring in summer. Canonical correspondence analysis showed that Platyias quadricornis was related to the concentration of phosphates available in the environment and the conductivity, while B. quadridentatus was positively correlated with chlorophyll-a. The trophic status of the lake was eutrophic based on Chl-a content but oligotrophic with relation to the Brachionus:Trichocerca ratio.

  19. 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).

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

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    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..

  2. 珠江广州河段轮虫群落结构的初步研究%PRIMARY STUDY ON ROTIFER COMMUNITY STRUCTURE IN THE GUANGZHOU SEGMENT OF THE RIVER PEARL

    Institute of Scientific and Technical Information of China (English)

    王庆; 杨宇峰

    2007-01-01

    2004年4月-2005年4月,对珠江广州河段轮虫群落结构特征进行了初步研究.经鉴定, 共发现轮虫65种(包括亚种),其中西氏三肢轮虫(Filinia novaezealandiae)、华美腔轮虫(Lecane elegans)为我国的新记录种.优势种为裂痕龟纹轮虫(Anuraeopsis fissa)、角突臂尾轮虫(Brachionus angularis)、尾突臂尾轮虫(Brachionus caudatus)、Filinia novaezealandiae、暗小异尾轮虫(Trichocerca pusilla)和微型多突轮虫(Liliferotrocha subtilis).调查发现径流量对轮虫密度有重要影响,轮虫的两次密度高峰分别出现在春末夏初和秋季.丰水期,轮虫密度较低;枯水期前期,轮虫密度较高;枯水期后期,轮虫密度较低.此外,轮虫种群还受到温度、盐度等因素的影响.研究结果表明轮虫在河流生态系统中具有重要作用.

  3. An ecotoxicological analysis of the sediment quality in a European Atlantic harbor emphasizes the current limitations of the Water Framework Directive.

    Science.gov (United States)

    Gonçalves, Sandra F; Calado, Ricardo; Gomes, Newton C M; Soares, Amadeu M V M; Loureiro, Susana

    2013-07-15

    The "PortoNovo" project was developed to standardize the methodologies for water quality management in the port areas of coastal Atlantic regions to improve the Water Frame Directive (WFD) for these specific water bodies. Under this scope, water and sediment samples were collected from five sites within the Port of Aveiro, Portugal. According to the physical and chemical parameters that were analyzed (i.e., metals, total organic carbon, polychlorinated biphenyls and polycyclic aromatic hydrocarbons), the sediments were not considered at risk based on European sediment quality laws. However, the bioassays that were performed on the sediment samples (Microtox®) and the standardized acute toxicity test using the marine rotifer, Brachionus plicatilis, on sediment elutriates revealed higher toxicity levels. The use of bioassays to assess sediment quality clearly complements more conservative approaches and highlights current gaps within the WFD. The approach presented here can be easily transferred to other port areas for more reliable water quality management.

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

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    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.

  5. Impact of arachidonic acid enrichment of live rotifer prey on bacterial communities in rotifer and larval fish cultures.

    Science.gov (United States)

    Seychelles, Laurent H; Doiron, Kim; Audet, Céline; Tremblay, Réjean; Pernet, Fabrice; Lemarchand, Karine

    2013-03-01

    Rotifers (Brachionus plicatilis), commonly used at first feeding in commercial fish hatcheries, carry a large bacteria load. Because they are relatively poor in essential fatty acids, it is common practice to enrich them with fatty acids, including arachidonic acid (AA). This study aims to determine whether prey enrichment with AA may act as a prebiotic and modify the microbial community composition either in AA-enriched rotifer cultures or in larval-rearing water using winter flounder (Pseudopleuronectes americanus) as a larval fish model. AA enrichment modified the bacterial community composition in both the rotifer culture tanks and the larval-rearing tanks. We observed an increase in the number of cultivable bacteria on TCBS (thiosulfate-citrate-bile salts-sucrose) agar, used as a proxy for the abundance of Vibrio sp. The results suggest that AA may also play an indirect role in larval health.

  6. 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

  7. Influence of dissolved organic matter character on mercury incorporation by planktonic organisms: an experimental study using oligotrophic water from Patagonian lakes

    Science.gov (United States)

    Diéguez, Maria C.; Queimaliños, Claudia P.; Guevara, Sergio Ribeiro; Marvin-DiPasquale, Mark C.; Cárdenas, Carolina Soto; Arribére, María A.

    2013-01-01

    Ligands present in dissolved organic matter (DOM) form complexes with inorganic divalent mercury (Hg2+) affecting its bioavailability in pelagic food webs. This investigation addresses the influence of a natural gradient of DOM present in Patagonian lakes on the bioaccumulation of Hg2+ (the prevailing mercury species in the water column of these lakes) by the algae Cryptomonas erosa and the zooplankters Brachionus calyciflorus and Boeckella antiqua. Hg2+ accumulation was studied through laboratory experiments using natural water of four oligotrophic Patagonian lakes amended with197Hg2+. The bioavailability of Hg2+ was affected by the concentration and character of DOM. The entrance of Hg2+ into pelagic food webs occurs mostly through passive and active accumulation. The incorporation of Hg2+ by Cryptomonas, up to 27% of the Hg2+ amended, was found to be rapid and dominated by passive adsorption, and was greatest when low molecular weight compounds with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds with a humic or fulvic signature kept Hg2+ in the dissolved phase, resulting in the lowest Hg2+ accumulation in this algae. In Brachionus and Boeckella the direct incorporation of Hg from the aqueous phase was up to 3% of the Hg2+ amended. The dietary incorporation of Hg2+ by Boeckella exceeded the direct absorption of this metal in natural water, and was remarkably similar to the Hg2+ adsorbed in their prey. Overall, DOM concentration and character affected the adsorption of Hg2+ by algae through competitive binding, while the incorporation of Hg2+ into the zooplankton was dominated by trophic or dietary transfer.

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

    Directory of Open Access Journals (Sweden)

    JDN. Paranhos

    Full Text Available 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.

  9. 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.

  10. Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

    2016-02-01

    Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

  11. Rotifer communities of Deepor Beel, Assam, India: richness, abundance and ecology

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    B.K. Sharma

    2010-07-01

    Full Text Available Plankton samples collected from two sampling stations of Deepor Beel (a Ramsar site in Assam, northeastern India between November 2002 and October 2003, reveal 110 and 100 species of Rotifera, exhibit monthly richness ranging between 43-65 (56 plus or minus 6 and 38-60 (52 plus or minus 7 species and record 48.9-88.1 and 53.1-89.7% community similarities respectively. Rotifera (231 plus or minus 60 and 198 plus or minus 70 n/l comprise between 48.7 plus or minus 6.1 and 42.6 plus or minus 4.1% of zooplankton abundance at station I and II respectively, and follow trimodal annual patterns with peaks during winter. Brachionidae (90 plus or minus 43, 79 plus or minus 39 n/l > Lecanidae (45 plus or minus 13, 29 plus or minus 9 n/l form important quantitative components of Rotifera while Asplanchnidae > Synchaetidae > Trochosphaeridae are other notable families. Lecane > Brachionus > Keratella > Asplanchna > Platyias contribute notably to temporal variations of the rotifers. Asplanchna priodonta, Keratella cochlearis, Platyias quadricornis, Lecane leontina, Polyarthra vulgaris, Keratella tropica and Brachionus falcatus are important species. Analysis of variance comparisons indicate significant temporal variations in richness and abundance of Rotifera between stations and months. The rotifer communities exhibit higher species diversity, higher evenness, lower dominance and lack of quantitative dominance of any individual species. The present results show no definite periodicity of richness and abundance of this group, families or species. Individual abiotic factors register limited influence on richness and abundance while multiple regression exhibits higher cumulative influence of ten abiotic factors on these parameters at both sampling stations.

  12. 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.

  13. 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

  14. The Composition and Community Structure of Zooplankton of Nenjiang River Downstream in Spring and Autumn%嫩江下游春、秋两季浮游动物数量特征与群落结构分析

    Institute of Scientific and Technical Information of China (English)

    张昊; 于洪贤; 马成学; 霍堂斌

    2013-01-01

    为了解和监测嫩江下游水域生态系统的结构与功能,维持整个水域生态系统的平衡,于2011年5月(春季)和9月(秋季),对嫩江下游10个采样点的浮游动物群落结构进行了分析,并利用多维尺度分析法对各采样点浮游动物群落组成的相似性进行了研究,共鉴定出浮游动物3门21属36种.其中:轮虫种类最多,11属21种,占61.8%;原生动物7属9种,占26.5%;桡足类2属4种,占11.7%;未发现枝角类.两季浮游动物的丰度波动于900~3 900 ind./L之间,浮游动物的生物量为0.09~4.67 mg/L.在优势种种类组成上,原生动物有两种:小口钟虫(Vorticella microstoma)和绿急游虫(Strombidium viride).轮虫有5种:浦达臂尾轮虫(Brachionus budapestiensis)、萼花臂尾轮虫(Brachionus quadridentatus)、螺形龟甲轮虫(Keratella cochlearis)、长刺盖氏轮虫(Kellicottica longispina)、长三肢轮虫(Filinia longiseta).桡足类有一种,为无节幼体(Nauplius larva).用多维尺度分析各采样点数据可以看出:春季(5月)分为4个不同的群落;秋季(9月),分为3个不同的群落.多维尺度分析图可以清楚地显示各采样点之间浮游动物群落的距离(即相似性),同时也表明各点位浮游动物群落的组成存在明显的差异.

  15. Avaliação dos grupos zooplanctônicos em tanques experimentais submetidos à adubação com diferentes substratos orgânicos Evaluation of zooplankton groups in experimental ponds with the use of different organic substrates

    Directory of Open Access Journals (Sweden)

    Giovani Sampaio Gonçalves

    2000-05-01

    Full Text Available Objetivando avaliar a influência de diferentes substratos orgânicos sobre a comunidade de organismos zooplanctônicos, foram utilizados 20 tanques com capacidade para 1.000 L, distribuídos em quatro tratamentos, com cinco repetições em um delineamento inteiramente casualizado, constituídos por esterco de aves, bovinos, coelhos e suínos. Foram feitas coletas do plâncton a cada três dias, monitoradas as variáveis físicas e químicas e procedida a análise qualitativo-quantitativa. Constatou-se que a adubação com esterco de aves levou a maiores densidades de organismos, seguida de suínos, e por fim, bovinos e coelhos, com predominância dos gêneros Brachionus, Keratella, Vorticella e náuplios de copépodes. Entretanto, o esterco de aves levou a menores diversidades de espécies. Concluiu-se, portanto, que os diferentes tratamentos exerceram influência na composição em espécies da comunidade zooplanctônica com os estercos de aves e suínos proporcionando maiores densidades.Aiming to determine the influence of organic fertilizer on zooplankton organism community twenty 1,000 liter ponds were used distributed in four treatments with poultry, cattle, rabbit or pig manure with five replicates in a complete randomized design. Planktons were collected every three days whose physical and chemical parameters were monitored and qualitatively and quantitatively analyzed. Poultry manure showed to be the best fertilizer followed by pig, cattle, and rabbit fertilizer respectively for plankton density in which Brachionus sp, Keratella sp, Vorticella sp and Copepoda's nauplius predominated. Therefore cattle and rabbit manure led to lower species diversity. The results led to the conclusion that the manure used exerted a greater influence on zooplankton structure and biomass and that poultry and pig manure provided the greatest organism densities.

  16. 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.

  17. The ghost of herbivory past: slow defence relaxation in the chlorophyte Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    Jacobus VIJVERBERG

    2009-08-01

    Full Text Available The freshwater chlorophyte Scenedesmus obliquus (Turpin Kützing produces colonies as an inducible defence against herbivores. We investigated the dynamics of Scenedesmus colony formation and disintegration in response to the density of the herbivorous rotifer Brachionus calyciflorus in large-scale mesocosms. Additional bioassays were performed to investigate Scenedesmus colony disintegration under different light regimes. In the mesocosm experiment, colony formation took place rapidly, but relaxation towards the initial size took relatively long (>10 d after cessation of herbivory. In the bioassays, in the absence of infochemicals, colonies disintegrated almost immediately in the dark (1-1.5 d, within 4 d under a photoperiod of 16:8 (L:D and between 8 and 12 days under full light. Colony disintegration times in the mesocosm experiment were substantially longer as compared to treatments with the same photoperiod (L:D 16:8 in the bioassays. So after a peak of herbivory, the 'ghost of herbivory past', i.e. the remaining infochemicals, may continue to induce colony formation, causing an additional lengthening of colony disintegration times and associated fitness costs (higher sedimentation loss rates. This indicates that costs of colony formation are not only important during the induction phase, but may be even more important during the relaxation phase. We compared these sedimentation costs to the costs of herbivory for differently sized Scenedesmus, and found a clear trade-off pattern for these costs.

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

    Directory of Open Access Journals (Sweden)

    Marina Vera Diaz

    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.

  19. Goplers relative trofiske niveau bestemt ved δ15N

    DEFF Research Database (Denmark)

    Christensen, Jens Tang; Sode, Sidsel; Krawack, Marie-Louise

    , hvor den indbyrdes afstand mellem to arter er bestemt på samme tid og i samme vandmasse. I laboratorieforsøg har Aurelia vist lave værdier for trofisk berigelse (forskel på fødens og Aurelias 15N) på 0,74 ‰ for Artemia, 0,99 ‰ for Brachionus og 0,58 ‰ for skrubbelarver. Dette bør undersøges i flere...... forsøg, men giver dog et sammenligningsgrundlag for prøver taget i havet. I seks hav-prøvetagninger lå Cyanea capillata 0,21-2,28 ‰ over Aurelia i 15N, mens Aurelia i en syvende prøvetagning lå 0,86 ‰ over Cyanea (forskel dog ikke signifikant). I tre prøvetagninger lå Mnemiopsis leidyi 0,01-1,61 ‰ over...... Aurelia i 15N mens Mnemiopsis lå 0,29 ‰ over Cyanea capillata i én sammenligning, mens den lå 1,72 ‰ over Cyanea lamarcki i en anden prøvetagning. I tre prøvetagninger lå Pleurobrachia pileus 1,74-4,18 ‰ over Aurelia i 15N og 1,06-2,51 ‰ over Cyanea capillata. Generelt synes ribbegoplerne at ligge på et...

  20. Diversity and distribution of Brachionidae (Rotifera in Thailand, with a key to the species

    Directory of Open Access Journals (Sweden)

    Sujeephon Athibai

    2013-08-01

    Full Text Available We investigated the diversity of brachionid rotifers in Thailand. Rotifers were collected from a wide range of habitat types (294 sites, 508 samples including canals, lakes, peat swamps, ponds, reservoirs, rice fields, rivers, swamps and temporary ponds from April 1998 to January 2004. Twenty-eight species including 11 infrasubspecific forms belonging to five genera were identified. The most frequently encountered species was Brachionus falcatus (50.7% of the sampling sites, followed by Keratella cochlearis (50%, B. angularis (49.7%, K. tropica (46.3% and B. forficula (45.9%. Less frequently encountered species were B. caudatus, B. durgae and B. urceolaris. These species were found in low abundances and only in a single site. Two sites in the Northeast – Nong Changpeuak and Bueng Srithat – recorded the greatest richness with 15 taxa, whereas no brachionid rotifers were found in 31 sites. On average, the species richness was five taxa per sampling site. A key to the genera and species of Thai brachionid rotifers is provided.

  1. Use of rotifers for the maintenance of monoalgal mass cultures of Spirulina

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, S.A.; Richmond, A.

    1987-01-01

    Zooplankton was successfully used for the biological control of unicellular algal contaminants in Spirulina mass cultures even under conditions adverse to the growth of Spirulina (maximal winter daily temperature of approximately 10 degrees C and very low bicarbonate concentration). Brachionus plicatilis (Rotifera) was the most successful species of zooplankton used. The interrelationships between Spirulina, green unicellular contaminant, and B. plicatilis were studied under various conditions. Two species of unicellular contaminant were used; Monoraphidium minutum was isolated from local cultures and Chlorella vulgaris, obtained from contaminated Spirulina cultures in Israel. The rotifer B. plicatilis successfully controlled the population size of both contaminants whether they were introduced in a single addition or as a daily dose. The biological control of the unicellular contaminants allows Spirulina to be cultured in a medium low in bicarbonate, thereby reducing the cost of the medium and increasing the quantity of CO2 that may be freely absorbed from the atmosphere at the optimal pH for Spirulina cultivation. (Refs. 9).

  2. 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.

  3. 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.

  4. Zooplankton-based assessment of the trophic state of a tropical forest river in Nigeria

    Directory of Open Access Journals (Sweden)

    Imoobe T.O.T.

    2009-01-01

    Full Text Available In this study, we explore the usefulness of zooplankton as a tool for assessing the trophic status of a Nigerian forest river. The river was sampled monthly and investigated for water physico-chemistry and zooplankton community structure using basic statistical measurement of diversity indices to characterize the zooplankton fauna. The trophic sta­tus of the river evaluated from its physico-chemical parameters indicates that the river is oligotrophic. The zooplankton composition was typical of a tropical freshwater river, with a total of 40 species, made up of 16 rotifers, 12 cladocerans, and 12 copepods and their developing stages in the following order of dominance: Rotifera > Cladocera > Cyclopoida > Calanoida. There were strong correlations between the lake's trophic status and its zooplankton communities. The zoo­plankton community was dominated by numerous species of rotifers and crustaceans, which are typical of oligotrophic to mesotrophic systems, such species including Conochilus dossuarius and Synchaeta longipes. However, the most dominant zooplankton species in West African freshwater ecosystems, viz., Keratella tropica, Keratella quadrata, Brachionus angularis, Trichocerca pusilla, Filinia longiseta, Pompholyx sulcata, and Proales sp., and others that are indicator species of high trophic levels, were not recorded in the river. The river is very clear and can be used for all manner of recreational activities.

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

    Directory of Open Access Journals (Sweden)

    Chunyan Xu

    2015-11-01

    Full Text Available 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.

  6. 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.

  7. A priori assessment of ecotoxicological risks linked to building a hospital.

    Science.gov (United States)

    Perrodin, Yves; Christine, Bazin; Sylvie, Bony; Alain, Devaux; Jean-Luc, Bertrand-Krajewski; Cécile, Cren-Olivé; Audrey, Roch; Elodie, Brelot

    2013-01-01

    Hospital wastewaters contain a large number of chemical pollutants such as disinfectants, detergents, and drug residues. A part of these pollutants is not eliminated by traditional urban waste water treatment plants, leading to a major risk for the aquatic ecosystems receiving these effluents. After having formulated a specific methodology in order to assessment ecotoxicological risk for such a situation, we applied it to the project to build a new hospital shared by several towns in the French Alps. This methodology is based on the ecotoxicological characterisation of the hospital wastewater using a battery of three chronic bioassays (Pseudokirchneriella subcapitata, Heterocypris incongruens and Brachionus calyciflorus) and of genotoxicity tests (Ames fluctuation assay on Salmonella typhimurium, and a Fpg-modified comet assay on the trout liver cell line RTL-W1). The formulated methodology highlights a moderate risk of the hospital wastewater for the organisms of the water column of the river concerned. Nevertheless, this discharge contributes significantly to the global ecotoxicological risk when taking into account all the releases of the watershed into the river. This leads to recommending the implementation of a specific treatment system in the urban WWTP, or upstream to it, in view to protecting the aquatic organisms.

  8. A posteriori assessment of ecotoxicological risks linked to building a hospital.

    Science.gov (United States)

    Perrodin, Yves; Bazin, Christine; Orias, Frédéric; Wigh, Adriana; Bastide, Thérèse; Berlioz-Barbier, Alexandra; Vulliet, Emmanuelle; Wiest, Laure

    2016-02-01

    Hospital wastewater (HWW) contain a large number of chemical pollutants such as disinfectants, surfactants, and pharmaceutical residues. A part of these pollutants is not eliminated by traditional urban wastewater treatment plants (WWTP), leading to a risk for the aquatic ecosystems receiving these effluents. In order to assess this risk, we formulated a specific methodology based on the ecotoxicological characterisation of the hospital wastewater using a battery of three chronic bioassays (Pseudokirchneriella subcapitata, Heterocypris incongruens and Brachionus calyciflorus). We used it for the posteriori risk assessment of a hospital recently built in south-east France, and we studied the evolution of this risk during two years. We also used it to assess the decrease of the ecotoxicological risk after treatment of the effluent in a specific line of the local WWTP. Lastly, we compared these results with the risk assessment made before the building of the hospital in the context of a priori risk assessment. The results obtained showed an important evolution of the risk overtime, according to the hospital activities and the river flows, and a real decrease of the risk after treatment in the dedicated line. They also showed that the a priori assessment of ecotoxicological risks, made previously, was overstated, mainly because of the application of the precautionary principle.

  9. Evidence Supporting the Uptake and Genomic Incorporation of Environmental DNA in the “Ancient Asexual” Bdelloid Rotifer Philodina roseola

    Directory of Open Access Journals (Sweden)

    Olaf R. P. Bininda-Emonds

    2016-09-01

    Full Text Available Increasing evidence suggests that bdelloid rotifers regularly undergo horizontal gene transfer, apparently as a surrogate mechanism of genetic exchange in the absence of true sexual reproduction, in part because of their ability to withstand desiccation. We provide empirical support for this latter hypothesis using the bdelloid Philodina roseola, which we demonstrate to readily internalize environmental DNA in contrast to a representative monogonont rotifer (Brachionus rubens, which, like other monogononts, is facultative sexual and cannot withstand desiccation. In addition, environmental DNA that was more similar to the host DNA was retained more often and for a longer period of time. Indirect evidence (increased variance in the reproductive output of the untreated F1 generation suggests that environmental DNA can be incorporated into the genome during desiccation and is thus heritable. Our observed fitness effects agree with sexual theory and also occurred when the animals were desiccated in groups (thereby acting as DNA donors, but not individually, indicating the mechanism could occur in nature. Thus, although DNA uptake and its genomic incorporation appears proximally related to anhydrobiosis in bdelloids, it might also facilitate accidental genetic exchange with closely related taxa, thereby maintaining higher levels of genetic diversity than is otherwise expected for this group of “ancient asexuals”.

  10. 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.

  11. 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.

  12. 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).

  13. A new method for analysis of the toxicity of organophosphorus pesticide, dimethoate on rotifer based on response surface methodology.

    Science.gov (United States)

    Guo, Ruixin; Ren, Xinkun; Ren, Hongqiang

    2012-10-30

    This study analyzed the toxicity of organophosphorus pesticide, dimethoate on freshwater rotifer Brachionus calyciflorus, using swimming angular and linear speed alteration as the sub-lethal endpoints. Response surface methodology (RSM) was applied in experimental design and data analysis to consider two related factors: toxic concentration, exposure time and their interaction. In general, inhibition effect of the pesticide on rotifer swimming was observed clearly at any given toxicant concentration. The highest inhibition rates in angular and linear speed were obtained in the shortest exposure time (11.36 min) and the highest dimethoate concentration (1.85 mg L(-1)). The RSM used for the analysis of treatment combinations showed that a cubic polynomial regression model was in good agreement with experimental results, with R(2)=0.992 and 0.9997, for swimming angular speed inhibition rate and linear speed inhibition rate (p<0.01, F-test, respectively). 3D reference surface plots and contour plots showed that the toxic effect was influenced not only by dimethoate concentration, but also by the exposure time. A time-step effect was observed clearly. Thus, the pesticide dimethoate had toxic stress on the swimming behavior of rotifers.

  14. The process-dependent impacts of dimethoate on the feeding behavior of rotifer.

    Science.gov (United States)

    Chen, Jianqiu; Guo, Ruixin

    2015-01-01

    Traditional toxicological studies usually depict the dose-effect relationship at the given exposure time while ignore how toxic effects vary during and after the exposure. In the present study, feeding depression of the rotifer Brachionus calyciflorus under the impact of dimethoate was evaluated not only in the exposure time but also in the post-exposure time. Both the filtration rates (F) and the ingestion rates (I) of the rotifers varied during the exposure period under any concentration of dimethoate. A three-stepwise stress was observed when the rotifers were exposed to 0.2 and 1.0 mg L(-1) of the pesticide respectively, whereas 1.8 mg L(-1) dimethoate caused only one-step stress on the rotifers during the whole period. In addition, although the feeding behaviors of the rotifers recovered after the exposure, two feeding rates both got even more depressed at 8h in the post-exposure time. The latent inhibition after exposure was related to the exposure concentrations and the exposure time. Our works indicated that the impact of dimethoate on the feeding behavior of the rotifers was highly process-dependent that caused the stepwise stress during the exposure period and the latent stress after the exposure.

  15. Use of neutralized industrial residue to stabilize trace elements (Cu, Cd, Zn, As, Mo, and Cr) in marine dredged sediment from South-East of France.

    Science.gov (United States)

    Taneez, Mehwish; Marmier, Nicolas; Hurel, Charlotte

    2016-05-01

    Management of marine dredged sediments polluted with trace elements is prime issue in the French Mediterranean coast. The polluted sediments possess ecological threats to surrounding environment on land disposal. Therefore, stabilization of contaminants in multi-contaminated marine dredged sediment is a promising technique. Present study aimed to assess the effect of gypsum neutralized bauxaline(®) (bauxite residue) to decrease the availability of pollutants and inherent toxicity of marine dredged sediment. Bauxaline(®), (alumia industry waste) contains high content of iron oxide but its high alkalinity makes it not suitable for the stabilization of all trace elements from multi-contaminated dredged sediments. In this study, neutralized bauxaline(®) was prepared by mixing bauxaline(®) with 5% of plaster. Experiments were carried out for 3 months to study the effect of 5% and 20% amendment rate on the availability of Cu, Cd, Zn, As, Mo, and Cr. Trace elements concentration, pH, EC and dissolved organic carbon were measured in all leachates. Toxicity of leachates was assessed against marine rotifers Brachionus plicatilis. The Results showed that both treatments have immobilization capacity against different pollutants. Significant stabilization of contaminants (Cu, Cd, Zn) was achieved with 20% application rate whereas As, Mo, and Cr were slightly stabilized. Toxicity results revealed that leachates collected from treated sediment were less toxic than the control sediment. These results suggest that application of neutralized bauxaline(®) to dredged sediment is an effective approach to manage large quantities of dredged sediments as well as bauxite residue itself.

  16. 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.

  17. 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.  

  18. 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.

  19. Higher rates of sex evolve in spatially heterogeneous environments.

    Science.gov (United States)

    Becks, Lutz; Agrawal, Aneil F

    2010-11-04

    The evolution and maintenance of sexual reproduction has puzzled biologists for decades. Although this field is rich in hypotheses, experimental evidence is scarce. Some important experiments have demonstrated differences in evolutionary rates between sexual and asexual populations; other experiments have documented evolutionary changes in phenomena related to genetic mixing, such as recombination and selfing. However, direct experiments of the evolution of sex within populations are extremely rare (but see ref. 12). Here we use the rotifer, Brachionus calyciflorus, which is capable of both sexual and asexual reproduction, to test recent theory predicting that there is more opportunity for sex to evolve in spatially heterogeneous environments. Replicated experimental populations of rotifers were maintained in homogeneous environments, composed of either high- or low-quality food habitats, or in heterogeneous environments that consisted of a mix of the two habitats. For populations maintained in either type of homogeneous environment, the rate of sex evolves rapidly towards zero. In contrast, higher rates of sex evolve in populations experiencing spatially heterogeneous environments. The data indicate that the higher level of sex observed under heterogeneity is not due to sex being less costly or selection against sex being less efficient; rather sex is sufficiently advantageous in heterogeneous environments to overwhelm its inherent costs. Counter to some alternative theories for the evolution of sex, there is no evidence that genetic drift plays any part in the evolution of sex in these populations.

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

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    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.

  1. Ecotoxicological effects of sediments from Mar Piccolo, South Italy: toxicity testing with organisms from different trophic levels.

    Science.gov (United States)

    Costa, Elisa; Piazza, Veronica; Gambardella, Chiara; Moresco, Roberto; Prato, Ermelinda; Biandolino, Francesca; Cassin, Daniele; Botter, Margherita; Maurizio, Daniela; D'Adamo, Raffaele; Fabbrocini, Adele; Faimali, Marco; Garaventa, Francesca

    2016-07-01

    The Mar Piccolo of Taranto (Ionian Sea, Southern Italy) is a semi-enclosed and strongly polluted basin. For decades, it has been subjected to different anthropogenic impacts. These stressors caused severe sediments contamination with high concentration of different pollutants (PAHs, PCB, heavy metals). In order to assess the current status of sediments contamination, an ecotoxicological investigation combined with chemical analysis (heavy metals, PAH, and PCB) has been performed. In order to derive ecologically relevant conclusions, a multiorganisms and multiend-points approach has been applied, exposing organisms from different trophic levels to elutriate and whole sediment. The battery of bioassays consists of a microalgal growth inhibition test (Dunaliella tertiolecta), acute and sublethal assays (end-points: mortality, immobilization and swimming speed alteration) on crustaceans larvae and juveniles, and rotifers (Amphibalanus amphitrite, Artemia salina, Corophium insidiosum and Brachionus plicatilis), and embryotoxicity test on echinoderms (Paracentrotus lividus). Considering the high levels of sediment contamination highlighted from chemical analysis, an unexpected very low toxic effect was observed, even considering the sublethal end-point (larval swimming speed alteration). The results of this study suggest a very complex contaminants dynamic in the Mar Piccolo sediments that, despite a strong level of contamination, seems to not affect in a proportional manner the biological compartment.

  2. 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.

  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. 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.

  5. 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.

  6. Réflexions sur les rotifères en tant qu'indicateurs biologiques

    Directory of Open Access Journals (Sweden)

    POURRIOT R.

    1976-01-01

    Full Text Available Quelques espèces de Rotifères fournissent un bon exemple d'indicateurs écologiques pour un facteur limitant : Synchaeta lakowitziana, Conochitoides natans, Notholca spp (température, Brachionus plicatilis (salinité. Le système d'indexation des espèces à la qualité des eaux est discuté. Les espèces strictement édaphiques (non aquatiques, les espèces rares appartenant à des genres où la variabilité est grande et les espèces euryoecques, peu caractéristiques, devraient être exclues des listes d'indicateurs établies par SLADECEK (1973, car elles ne facilitent pas l'application de ce système. Il s'avère nécessaire d'améliorer le poids indicatif et la valeur de saprobité des espèces, de ne conserver que les plus caractéristiques par leur constance et leur fidélité. Il serait, de plus, intéressant de se référer à des index plus dynamiques que statiques.

  7. 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.

  8. Effect of Different Diet Combinations on WSSV Load and Survival Rate of Fenneropenaeus chinensis Larvae

    Institute of Scientific and Technical Information of China (English)

    Xiao Guangxia; Meng Xianhong; Kong Jie; Cao Baoxiang; Liu Ning; Zhang Qingwen; Luo Kun; Li Zhanjun

    2015-01-01

    Using microalgae( SA),artificial feed( AF),Brachionus plicatilis( BP) and brine shrimp larvae( BS),four diets including SA + AF,SA + AF + BP,SA + AF + BS and SA + AF + BP + BS were formulated and used to rear Fenneropenaeus chinensis larvae. The fertilized eggs fed with SA + AF were divided into disinfection group with iodophor and untreated group,and the fertilized eggs fed with other diets were all disinfected with iodophor. The survival rates,body weight and WSSV load of post larvae at each stage were compared. The results showed that there was no significant difference in the survival rate of prawns at the N-Z stage by feeding with different diets( P > 0. 05),but the survival rate of prawns fed with BP was higher than others( P 0. 05); prawns fed with CF + AF and AF had significant difference with the other two groups( P 0. 05). WSSV artificial infection test showed that the accumulated mortality of prawns fed with four diets were higher than 90%,and the difference was not significant( P > 0. 05).

  9. A checklist of the freshwater rotifer fauna of Thailand (Rotifera, Monogononta, Bdelloidea

    Directory of Open Access Journals (Sweden)

    Phannee Sa-Ardrit

    2013-08-01

    Full Text Available We provide a checklist of the freshwater Rotifera recorded from Thailand, based on a review of available literature. Approximately 398 species of rotifers are recorded. The rotifer fauna of Thailand has been investigated quite comprehensively and these studies focus on four main parts of the country: the northern, north-eastern, central and southern. The number of rotifers on record is the highest in the north-eastern part (275, followed by the southern part (261, the central part (182 and the northern part (115. The majority of Thai Rotifera belongs to family Lecanidae (24.4%, Lepadellidae (11.3%, Brachionidae (11.1%, Trichocercidae (9.0% and Flosculariidae (9.0%. The most diverse genus is Lecane followed by Trichocerca, Lepadella and Brachionus. Although most Thai rotifers are cosmopolitan, there are a number of Oriental endemics, including some strict Thai or regional endemics. Illoricate rotifers and bdelloids are understudied, while experimental and molecular approaches promise to add most to our knowledge and understanding of the role of rotifers in ecosystem functioning.

  10. Biodiversity of freshwater rotifers (Rotifera: Eurotatoria of Mizoram, Northeast India: composition, new records and interesting features

    Directory of Open Access Journals (Sweden)

    Bhushan Kumar Sharma

    2015-10-01

    Full Text Available The plankton and semi-plankton samples examined from Mizoram state of northeast India (NEI revealed speciose and diverse Rotifera assemblage including a total richness (S of 162 species belonging to 19 families and 35 genera. The reports of six species new to India, four species new to NEI and 76 new records to Mizoram merit biodiversity interest. The occurrence of one Australasian, one Oriental, seven Paleotropical, one Holarctic, one cosmo (sub tropical and five other interesting species imparts biogeographical value while several species indicate regional distribution importance. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 69.7% of total richness (S. Lecane > Lepadella > Trichocerca are diverse genera (~52.0% of S while Brachionus spp. (~8.0% deserve cautious mention. The rotifer diversity pattern is predominantly ‘tropical’ with a large component of cosmopolitans (~71.0% of S while tropicopolitan and pantropical species contributed ~16.0%. This study indicated high richness of the littoral-periphytonic and relative paucity of planktonic taxa. Analysis of periphytic, sessile, colonial and benthic taxa, and of cryptic diversity in certain species-groups merit attention for further biodiversity update and we estimate occurrence of 250+ rotifer species in Mizoram.

  11. Two-dimensional micro-beam imaging of trace elements in a single plankton measured by a synchrotron radiation X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ezoe, Masako; Sasaki, Miho; Hokura, Akiko; Nakai, Izumi [Tokyo Univ. of Science, Faculty of Science, Tokyo (Japan); Terada, Yasuko [Japan Synchrotron Radiation Research Inst., Mikazuki, Hyogo (Japan); Yoshinaga, Tatsuki; Tukamoto, Katsumi [Tokyo Univ., Ocean Research Inst., Tokyo (Japan); Hagiwara, Atsushi [Nagasaki Univ., Graduate School of Science and Technology, Bunkyou, Nagasaki (Japan)

    2002-10-01

    Two-dimensional imaging and a quantitative analysis of trace elements in rotifer, Brachionus plicatilis, belonging to zooplankton, were carried out by a synchrotron radiation X-ray fluorescence analysis (SR-XRF). The XRF imaging revealed that female rotifers accumulated Fe and Zn in the digestive organ and Fe, Zn, Cu, and Ca in the sexual organs, while the Mn level was high in the head. From a quantitative analysis by inductively coupled plasma mass spectrometry (ICP-MS), we found that rotifers eat the chlorella and accumulate the above elements in the body. The result of quantitative analyses of Mn, Cu, and Zn by SR-XRF in a single sample is in fair agreement with the average values determined by ICP-MS analyses, which were obtained by measuring a large number of rotifers, digested by nitric acid. The present study has demonstrated that SR-XRF is an effective tool for the trace element analysis of a single individual of rotifer. (author)

  12. 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.

  13. 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.

  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. 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

  16. 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

  17. 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

  18. Screening of Native Rotifers, Hydra, Planaria for Deriving Aquatic Life Criteria%水生生物水质基准研究中轮虫、水螅、涡虫类受试生物的筛选

    Institute of Scientific and Technical Information of China (English)

    郑欣; 闫振广; 刘征涛; 刘婷婷; 王晓南; 武江越; 王伟莉

    2015-01-01

    轮虫、水螅、涡虫是水生生态系统的重要生物类群.因其对水体污染较敏感,所以对水生生物基准研究有重要意义.依据我国生物区系资料及毒性数据丰度,筛选出8种代表性本土轮虫、水螅、涡虫类生物.参照美国水生生物基准技术指南,搜集、筛选了这8种代表性生物的急性毒性数据,通过数据分析,筛选出对各物种毒性最大的污染物,主要包括重金属、农药、有机锡化物、表面活性剂、吡啶胺类杀菌剂.分析污染物的物种敏感度分布,依据累积概率对代表性生物的物种敏感性进行分类,结果为:萼花臂尾轮虫(Brachionus calyciflorus)、绿水螅(Hydrav iridissima)、普通水螅(Hydra vulgaris)对重金属铜的累积概率为6.5%、85%和10.4%,普通水螅(Hydra vulgaris)对重金属汞的累积概率为6.3%;龟甲轮虫(Keratella cochlearis)和四齿腔轮虫(Lecane quadridentata)对五氯酚钠的累积概率为5.1%和7.6%;褐水螅(Hydrao ligactis)和绿水螅(Hydra viridissima)对三丁基氧化锡的累积概率为6.9%和13.8%,萼花臂尾轮虫(Brachionus calyciflorus)对氟啶胺的累积概率为6.7%,日本三角涡虫(Dugesia japonica)对四氯化碳、十二烷基苯磺酸钠的累积概率分别为6.7%和7.1%.上述结果表明:萼花臂尾轮虫、绿水螅对重金属铜敏感;普通水螅对重金属铜和汞敏感;龟甲轮虫和四齿腔轮虫对农药敏感;褐水螅和绿水螅对有机锡化物敏感;萼花臂尾轮虫对吡啶胺类杀菌剂敏感;日本三角涡虫对四氯化碳、表面活性剂敏感.这7种代表性生物可作为相关污染物的水生生物基准受试物种.

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

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    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.

  20. 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

  1. 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

    Institute of Scientific and Technical Information of China (English)

    LIU Guangxing; XU Donghui

    2009-01-01

    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 (P<0.01). Three live organisms were used for raising larvae and juveniles ofParalichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods (S. poplesia) had significantly higher growth rate than thosc fed with the other two organisms (P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others (P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia (P<0.05). The contents of three types of HUFAs (DHA, 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.

  2. Does haplodiploidy purge inbreeding depression in rotifer populations?

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    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.

  3. 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.

  4. 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.

  5. 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.

  6. The stabilizing effects of genetic diversity on predator-prey dynamics.

    Science.gov (United States)

    Steiner, Christopher F; Masse, Jordan

    2013-01-01

    Heterogeneity among prey in their susceptibility to predation is a potentially important stabilizer of predator-prey interactions, reducing the magnitude of population oscillations and enhancing total prey population abundance. When microevolutionary responses of prey populations occur at time scales comparable to population dynamics, adaptive responses in prey defense can, in theory, stabilize predator-prey dynamics and reduce top-down effects on prey abundance. While experiments have tested these predictions, less explored are the consequences of the evolution of prey phenotypes that can persist in both vulnerable and invulnerable classes. We tested this experimentally using a laboratory aquatic system composed of the rotifer Brachionus calyciflorus as a predator and the prey Synura petersenii, a colony-forming alga that exhibits genetic variation in its propensity to form colonies and colony size (larger colonies are a defense against predators). Prey populations of either low initial genetic diversity and low adaptive capacity or high initial genetic diversity and high adaptive capacity were crossed with predator presence and absence. Dynamics measured over the last 127 days of the 167-day experiment revealed no effects of initial prey genetic diversity on the average abundance or temporal variability of predator populations. However, genetic diversity and predator presence/absence interactively affected prey population abundance and stability; diversity of prey had no effects in the absence of predators but stabilized dynamics and increased total prey abundance in the presence of predators. The size structure of the genetically diverse prey populations diverged from single strain populations in the presence of predators, showing increases in colony size and in the relative abundance of cells found in colonies. Our work sheds light on the adaptive value of colony formation and supports the general view that genetic diversity and intraspecific trait variation of

  7. The stabilizing effects of genetic diversity on predator-prey dynamics [v1; ref status: indexed, http://f1000r.es/9u

    Directory of Open Access Journals (Sweden)

    Christopher F Steiner

    2013-02-01

    Full Text Available Heterogeneity among prey in their susceptibility to predation is a potentially important stabilizer of predator-prey interactions, reducing the magnitude of population oscillations and enhancing total prey population abundance. When microevolutionary responses of prey populations occur at time scales comparable to population dynamics, adaptive responses in prey defense can, in theory, stabilize predator-prey dynamics and reduce top-down effects on prey abundance. While experiments have tested these predictions, less explored are the consequences of the evolution of prey phenotypes that can persist in both vulnerable and invulnerable classes. We tested this experimentally using a laboratory aquatic system composed of the rotifer Brachionus calyciflorus as a predator and the prey Synura petersenii, a colony-forming alga that exhibits genetic variation in its propensity to form colonies and colony size (larger colonies are a defense against predators. Prey populations of either low initial genetic diversity and low adaptive capacity or high initial genetic diversity and high adaptive capacity were crossed with predator presence and absence. Dynamics measured over the last 127 days of the 167-day experiment revealed no effects of initial prey genetic diversity on the average abundance or temporal variability of predator populations. However, genetic diversity and predator presence/absence interactively affected prey population abundance and stability; diversity of prey had no effects in the absence of predators but stabilized dynamics and increased total prey abundance in the presence of predators. The size structure of the genetically diverse prey populations diverged from single strain populations in the presence of predators, showing increases in colony size and in the relative abundance of cells found in colonies. Our work sheds light on the adaptive value of colony formation and supports the general view that genetic diversity and intraspecific

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

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    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.

  9. Assessing the impacts of dimethoate on rotifers' reproduction through the pre-exposure history.

    Science.gov (United States)

    Guo, Ruixin; Chen, Jianqiu

    2015-01-01

    Organism usually undergoes an exposure of environmental pollution after a maternal exposure before birth. Traditional toxicological studies often initiated with rotifer neonates derived from the unexposed mothers while ignoring the pre-exposure (maternal exposure). The present study assessed the effect of dimethoate on the reproduction of the rotifer Brachionus calyciflorus, considering how the pre-exposure occurred in the parental generation influenced the subsequent impact. The F0 generation rotifers were exposed to the pesticide at five concentrations until the first F1 generation rotifers were reproduced. The neonates (F1 generation) were then exposed to the pesticide at the corresponding concentrations. The offspring reproduction, the time begins to reproduce, the duration of the reproductive period and the lifespan of the F1 generation rotifers were evaluated. Our results indicated that dimethoate influenced the maturation and reproduction of the rotifers. The highest concentration (1.8 mg L(-1)) of dimethoate caused an inhibition in the offspring reproduction, shortened the life span and reduced the duration of the reproductive period. In addition, of particular interest in our study was that reproduction is also accelerated by the lowest concentration (0.2 mg L(-1)). However, the pre-exposure had a significant effect on the subsequent impact. The dimethoate pre-exposure increased the impacts when the F1 generation rotifers were exposed to the substance, even at the same concentrations as in pre-exposure. It suggests that the maternal exposure history before birth is also important and has the long-lasting consequence from one generation to another.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. The evolution of sex is favoured during adaptation to new environments.

    Science.gov (United States)

    Becks, Lutz; Agrawal, Aneil F

    2012-01-01

    Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., "short-" or "long-term" effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This "long-term advantage" builds over multiple generations, eventually resulting in higher fitness of sexual types.

  12. 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.

  13. 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.

  14. 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.

  15. Phaeobacter gallaeciensis reduces Vibrio anguillarum in cultures of microalgae and rotifers, and prevents vibriosis in cod larvae.

    Directory of Open Access Journals (Sweden)

    Paul W D'Alvise

    Full Text Available Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7 cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.

  16. Evolution of the AKH/corazonin/ACP/GnRH receptor superfamily and their ligands in the Protostomia.

    Science.gov (United States)

    Hauser, Frank; Grimmelikhuijzen, Cornelis J P

    2014-12-01

    In this review we trace the evolutionary connections between GnRH receptors from vertebrates and the receptors for adipokinetic hormone (AKH), AKH/corazonin-related peptide (ACP), and corazonin from arthropods. We conclude that these G protein-coupled receptors (GPCRs) are closely related and have a common evolutionary origin, which dates back to the split of Proto- and Deuterostomia, about 700 million years ago. We propose that in the protostomian lineage, the ancestral GnRH-like receptor gene duplicated as did its GnRH-like ligand gene, followed by diversification, leading to (i) a corazonin receptor gene and a corazonin-like ligand gene, and (ii) an AKH receptor gene and an AKH-like ligand gene in the Mollusca and Annelida. Subsequently, the AKH receptor and ligand genes duplicated once more, yielding the situation that we know from arthropods today, where three independent hormonal systems exist, signalling with AKH, ACP, and corazonin. Our model for the evolution of GnRH signaling in the Protostomia is a striking example of receptor-ligand co-evolution. This model has been developed using several bioinformatics tools (TBLASTN searches, phylogenetic tree analyses), which also helped us to annotate six novel AKH preprohormones and their corresponding AKH sequences from the following molluscs: the sea hare Aplysia californica (AKH sequence: pQIHFSPDWGTamide), the sea slug Tritonia diomedea (pQIHFSPGWEPamide), the fresh water snail Bithynia siamensis goniomphalos (pQIHFTPGWGSamide), the owl limpet Lottia gigantea (pQIHFSPTWGSamide), the oyster Crassostrea gigas (pQVSFSTNWGSamide), and the freshwater pearl mussel Hyriopsis cumingii (pQISFSTNWGSamide). We also found AKHs in the tardigrade Hysibius dujardini (pQLSFTGWGHamide), the rotifer Brachionus calycifloros (pQLTFSSDWSGamide), and the penis worm Priapulus caudatus (pQIFFSKGWRGamide). This is the first report, showing that AKH signaling is widespread in molluscs.

  17. 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.

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

    Science.gov (United States)

    Taylor, Rebecca L; Caldwell, Gary S; Bentley, Matthew G

    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 24h LD(50) values of 7 and 20 microM 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 microM of copper sulphate in solutions of decadienal resulted in the reduction of the 24h LD(50) of decadienal by approximately a third for both species. 1 microM of copper chloride in solutions of decadienal reduced the 24h LD(50) of decadienal to A. salina nauplii by approximately 11% and 1 microM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 microM 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Ecotoxicological properties of wastewater treated using tertiary methods.

    Science.gov (United States)

    Petala, M; Samaras, P; Zouboulis, A; Kungolos, A; Sakellaropoulos, G

    2006-08-01

    The objective of this work was the examination of the efficiency of coagulation and ozonation processes for the production of reclaimed wastewater with low toxicity. Municipal secondary effluents were treated by FeCl3, Al2(SO4)3 (alum), and a commercial substance at metal ion concentrations of 0.5 and 1 mmol/L. Alternatively, the effluents were treated by ozonation in a semibatch ozone reactor. The feed gas was introduced at a flowrate of 3 L/min containing ozone at various concentrations, ranging between 2.5 and 8 mg/L; ozone residence times were 2, 5, 15, and 30 min. The toxic effects of the advanced treated effluents were examined by a battery of tests using the marine bacteria Vibrio fischeri, the freshwater crustaceans Daphnia magna, Daphnia pulex, and Thamnocephalus platyurus, and the rotifers Brachionus calyciflorus. The addition of alum decreased the toxic effect of reclaimed wastewater on immobilization of D. pulex, from 90 to 60%. Ozonation was also effective for toxicity removal, which decreased to 25% effect on D. pulex after treatment by 2.5 mg O3/L for 2 min. However, acute toxic effects after ozonation, were observed on V. fischeri and were related to ozone gas concentration and contact time. At the highest ozone dosage, the toxicity reached almost 100% inhibition of bioluminescence after 15 min. The toxicity of the ozonated effluents to bacteria decreased with sample storage time and was almost negligible after 48 h, indicating that the potential adverse effect of reclaimed wastewaters on receiving waters might be reduced by storage for a certain time.

  5. Does copepods influence dusky grouper (Epinephelus marginatus early development?

    Directory of Open Access Journals (Sweden)

    Monica Mateus

    2014-06-01

    Full Text Available Good knowledge on the development of early life stages is essential for successful conservation programs of threatened fish species. Diet and rearing system affects early life survival and juvenile quality. Copepods are the natural food of fish larvae in the wild possessing high nutritional value, when compared with live feeds used in aquaculture (rotifers and artemia, and a wide range of size classes. Rearing systems with low water column disturbance and low larval densities enhanced the survival of fragile fish larvae. The aim of this work is to evaluate the effect of the introduction of copepods in the diet of early dusky grouper larvae reared in controlled mesocosm systems using larval development and juvenile quality as indicators. Two feeding protocols were tested, one composed only by rotifers (Brachionus plicatilis, brine shrimp (Artemia spp. and dry feed and the other supplemented with copepods (Paracartia grani from mouth opening (2 day after hatching - DAH to 8 DAH. Feeding behavior, growth, survival, skeletal malformations and digestive enzymes activity was assessed at different developmental stages. The addition of copepods to the early larvae diet of dusky grouper resulted in faster development and higher survival rates. Larvae fed with copepods improved their development. At 20 DAH all larvae reared at the mesocosm with copedods were already at the stage of post-flexion while in the system without copepods this stage was attained later. At 25 DAH only 64% of the larvae were in post flexion in the mesoscosm without copepods. At 30 DAH larvae supplemented with copepods attained an acidic digestion (high specific activity of pepsin earlier than at the system without copepods. In this last system alkaline digestion (trypsin specific activity, characteristic of early larval stages, was significantly higher reinforcing the faster development of larvae fed with copepods. In both systems the incidence of skeletal malformations was low.

  6. 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

  7. 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

  8. 饵料浮游动物种类和密度对海月水母摄食和生长的影响%Effect of zooplanktonter species and density on feeding and growth in jellyfish Aurelia aurita

    Institute of Scientific and Technical Information of China (English)

    杨为东; 赵文; 李多慧; 滕力平; 杨担光; 袁霞; 韩婷婷

    2010-01-01

    研究了5种浮游动物(卤虫Artemia无节幼体、大尾猛水蚤Harpacticus uniremis 、短角异剑水蚤Apocyclops royi、蒙古裸腹溞Moina mongolica 和褶皱臂尾轮虫Brachionus plicatilis)饵料对海月水母Aurelia aurita摄食和碟状体生长的影响.结果表明:海月水母摄食卤虫无节幼体没有明显的节律性,对蒙古裸腹溞、大尾猛水蚤、短角异剑水蚤和褶皱臂尾轮虫都是在上午8:00摄食量最大;海月水母对卤虫无节幼体和轮虫的个体摄食率最大,分别为42.8、42.0 个/(个·h).摄食卤虫无节幼体的海月水母碟状体的生长率最大,达到8.8%~11.2%;摄食蒙古裸腹溞和大尾猛水蚤的次之,生长率分别为4.4%~6.1%和3.1%~5.2%;摄食褶皱臂尾轮虫的碟状体生长率极低,仅为0.3%~0.4%.研究表明,卤虫无节幼体、蒙古裸腹溞和大尾猛水蚤均可作为海月水母碟状体的饵料,合适投喂密度分别为550~700、150~300个/L和250~450个/L.

  9. 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.

  10. 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

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

    Directory of Open Access Journals (Sweden)

    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

  12. 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

  13. 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

    species like Thermocyclops hyalinus, Mesocyclops sp., Moina micrura, Brachionus caudatus, B. falcatus and Filina longiseta were recorded at all sites investigated allover the study period. The scarcity of zooplankton species from Al-Khadoud spring and its irrigation canal could be due to the nature of these reservoirs as both receiving reuse-drainage and treated sewage water. Conclusion: These results indicated that after receiving water from the outlets either treated sewage water or of re-use drainage water, the spring water had an obvious increase in electrical conductivity, COD, total alkalinity, nitrates, phosphorus, chloride and potassium. These features indicated pollution with organic wastes, increased salinity and deteriorated oxygenated state. Based on this we can say that all these factors can be affected both soil and plants cultivated in the area of Al-Hassa.

  14. G. J. Billberg's (1833) 'On the ichthyology, and description of some new fish species of the pipefish genus Syngnathus'.

    Science.gov (United States)

    Kullander, Sven O

    2016-01-14

    Gustaf Johan Billberg's review of ichthyology, published in Swedish in 1833 in the Linnéska samfundets handlingar, mentions 92 fish taxa at genus and species level, 41 of which represent new taxa, unnecessary replacement names, or unjustified emendations. Billberg presents his own classification of fishes, in which five new family names are introduced: Ballistidae, Diodontidae, Ooididae, Chironectidae, and Macrorhyncidae. Diodontidae has priority over Diodontidae Bonaparte, 1835. Macrorhyncidae was published earlier than Gempylidae Gill, 1862, but the latter has priority by prevailing usage.        Billberg mentions 61 genera of fishes, 41 of them listed only by name. Six generic names proposed by Billberg are available as unjustified emendations: Myxinus, Petromyzus, Scylia, Mustellus, Zyganna, and Ballistes. Brachionus is an unnecessary replacement name. Aphrus, Capriscus, Exormizus, Enneophthalmus, and Oedaus are nomina nuda. Eight new genera of fishes are proposed: Anodon, Posthias, Orbis, Sphaeroides, and Ooides are junior synonyms; Cotilla is a nomen oblitum in relation to Sufflamen Jordan, 1916; Tropigaster a nomen oblitum in relation to Aracana Gray, 1835; and Tetragonizus a nomen oblitum in relation to Lactoria Jordan & Fowler, 1902.        Billberg lists 31 species of fishes. Three represent new combinations; two are nomina nuda. The following 14 new species are described based on literature: Raja forskohlii, Cephaloptera dumerillii, Myliobatis lacepedei, Scylia russelii, Anodon macropterus, Cotilla frenata, Monacanthus blochii, M. sebae, M. cuvieri, M. marcgravii, Tetraodon striatus, Orbis psittacinus, Orbis punctulatus, and Orbis guttatus. All of those are invalid, except Scylia russelii, which is a species inquirenda. The following nine species group names are unnecessary replacement names and consequently invalid: Raja arabica, Myliobatis rissoi, Scylia isabellina, Anodon cirrhosus, Anodon cornutus, Zyganna voracissima, Centrina

  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. 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.

  17. DESCRIPTION DE LA ZOOÉPIBIOSE DE L’ÉCREVISSE SIGNAL (PACIFASTACUS LENIUSCULUS, DANA EN ASTACICULTURE

    Directory of Open Access Journals (Sweden)

    CUELLAR M. C.

    2002-07-01

    Full Text Available Des recherches ont été effectuées concernant la zooépibiose de l’écrevisse signal (Pacifastacus leniusculus, D., provenant d’un centre d’astaciculture espagnol, au cours de la période 1997-1998. Les organismes épibiotiques dominants trouvés sur l’exosquelette appartiennent aux groupes zoologiques d’Invertébrés suivants : Mastigophora (Bodo, Cilliophora (Stentor, Epistylis, Zoothamnium, Acineta, Turbelaria (Temnocephala, Rotifera (Brachionus, Annelida (Branchiobdella, Acarina (Hygrobates et Ostracode (Eucypris ou Enthocytera, on souligne le nombre élevé de Branchiobdellides de l’espèce Branchiobdella instabilia M., dont les quantités minimum et maximum, en mâles et femelles, oscillent de 12 à 139 et de 7 à 130, respectivement. Les hyperbranchiobdelloses provoquent des automutilations, des décollements des pinces et autres appendices, des mues anormales, des lésions cuticulaires, de l’hémocytopénie et des changements éthologiques. Les colonisations maximales d’Ostracodes de l’espèce Eucypris virens, J.O., Enthocytera heterodonta, R., dans les poches d’incubation des femelles donnent lieu à une coloration rougeâtre des oeufs et à leur perte postérieure. Compte tenu de leur nombre limité et de la période d’épibiose, les genres des sous-types Mastigophora, Ciliophora, Turbelaria, Rotifera et Arachnida ne représentent aucun danger pour les écrevisses. En ce qui concerne la zooépibiose associée aux appendices et aux régions du corps des écrevisses du Pacifique, les chélipèdes ou pinces constituent le substrat où se place de préférence le genre Branchiobdella ; le céphalothorax sert de support à tous les groupes taxonomiques d’épibiontes identifiés.

  18. 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

  19. 有机磷农药乐果对萼花臂尾轮虫生殖的影响%The effect of Dimethoate on the reproduction of freshwater rotifer

    Institute of Scientific and Technical Information of China (English)

    陈建秋; 王志良; 李国平; 郭瑞昕

    2012-01-01

      乐果是一种农业生产上广泛使用的有机磷农药,在对病虫害防治的同时也会对非靶生物带来一定的生态环境效应,轮虫是淡水生态系统中连接食物链的初级生产者与高级消费者的重要环节,考察乐果对轮虫的作用对于研究有机磷农药对水生生态系统的影响有着十分重要的意义.以常见淡水种萼花臂尾轮虫(Brachionus calyciflorus)为受试生物,考察了亚致死剂量乐果对淡水种萼花臂尾轮虫(Brachionus calyciflorus)生殖的影响,主要考察的实验指标有:轮虫总产卵量、总产后代量以及生活史各时期历时.结果表明乐果对轮虫的性成熟和生殖都有显著的影响.一方面,在任意的虫龄段1.0、1.4和1.8 mg·L-13个质量浓度乐果都显著地抑制了轮虫的生殖输出,总产卵量和总后代量有了明显地下降,3个质量浓度组轮虫总产卵量依次为(10.33±0.14)、(9.48±0.27)和(8.71±0.31)个,仅为对照组的78.69%、72.23%和66.34%,而总后代量依次为(7.64±0.12)、(6.85±0.25)和(5.69±0.13)个,仅为对照组的75.61%,67.83%和56.31%;另一方面乐果扰乱了轮虫正常的生活史周期,性成熟时间被推迟,1.0、1.4和1.8 mg·L-13个质量浓度组轮虫的幼年期依次为(24.28±1.17)、(30.31±0.32)和(28.50±0.40) h,占整个生活史的时间分配比例由16.99%(对照值)延长至21.23%、26.44%和27.16%,分别比对照组增加了13.78%、42.03%和33.55%.但轮虫的生殖期历时被缩短,3个质量浓度组轮虫的生殖期历时依次为(69.77±3.78)、(63.98±2.99)和(58.22±0.83) h,分别为对照组值的89.71%、82.27%和74.86%,占整个生活史的时间分配比例依次下降了1.02%、6.14%和6.45%.但低质量浓度的乐果(0.2和0.6 mg·L-1)对轮虫却有一定的刺激作用.0.2和0.6 mg·L-12个质量浓度组轮虫总产卵量分别比对照组提高了38.90%和22.99%,所产的后代总数分别比对照组提高了36.62%和34.22%,2个质量浓度

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

    Institute of Scientific and Technical Information of China (English)

    陈骞; 何伟添; 刘阳; 黄建荣

    2014-01-01

    于2012年12月(冬季)、2013年3月(春季)、6月(夏季)和9月(秋季)对澳门4个典型湿地的浮游动物进行了调查,包括其种类组成、密度、优势种以及生物多样性等。结果表明,浮游动物有110种,各采样点浮游动物种类组成均以原生动物和轮虫为主;种类数总体呈现出夏季>秋季>春季>冬季;在空间分布上,筷子基湾>望德圣母湾>莲花大桥滩涂>南湾湖。浮游动物密度在时间分布上,冬季>春季>秋季>夏季,在空间分布上,筷子基湾>莲花大桥滩涂>望德圣母湾>南湾湖。球形急游虫( Strombidium globosaneum)、银灰膜袋虫( Cyclidium glaucoma)、针棘匣壳虫( Centropyxis aculeate)、淡水筒壳虫( Tintinnidium fluviatile)、角突臂尾轮虫( Brachionus an-gularis)、疣毛轮虫(Synchaeta sp.)、右突新镖水蚤(Neodiaptomus schmackeri)和桡足类无节幼体是最主要的优势种;浮游动物组成具有明显的热带水体区系特征。%The wetlands of Macao are important stopover sites for international migratory birds and also the winte-ring habitat for the black-faced spoonbill, a rare and endangered bird species.Research on wetland water quality and phytoplankton community structure in reclaimed wetlands, as well as the characteristics of the coastal zone eco-system, has been reported, but a study on the zooplankton community structure of the wetlands has not been repor-ted.We examined zooplankton species composition, density, dominant species and species diversity in four typical wetlands in Macao.The investigation was carried out in December 2012 (winter), March 2013 (spring), June 2013 ( summer) and September 2013 ( autumn) and the community structure of the zooplankton was analyzed.Pro-tozoan samples were collected from the water column 0.5 m below the surface water using a water sampler.2 L of water were taken from each sample site, fixed with

  1. 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

  2. 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

  3. Repurposing FDA-approved drugs for anti-aging therapies.

    Science.gov (United States)

    Snell, Terry W; Johnston, Rachel K; Srinivasan, Bharath; Zhou, Hongyi; Gao, Mu; Skolnick, Jeffrey

    2016-11-01

    There is great interest in drugs that are capable of modulating multiple aging pathways, thereby delaying the onset and progression of aging. Effective strategies for drug development include the repurposing of existing drugs already approved by the FDA for human therapy. FDA approved drugs have known mechanisms of action and have been thoroughly screened for safety. Although there has been extensive scientific activity in repurposing drugs for disease therapy, there has been little testing of these drugs for their effects on aging. The pool of FDA approved drugs therefore represents a large reservoir of drug candidates with substantial potential for anti-aging therapy. In this paper we employ FINDSITE(comb), a powerful ligand homology modeling program, to identify binding partners for proteins produced by temperature sensing genes that have been implicated in aging. This list of drugs with potential to modulate aging rates was then tested experimentally for lifespan and healthspan extension using a small invertebrate model. Three protein targets of the rotifer Brachionus manjavacas corresponding to products of the transient receptor potential gene 7, ribosomal protein S6 polypeptide 2 gene, or forkhead box C gene, were screened against a compound library consisting of DrugBank drugs including 1347 FDA approved, non-nutraceutical molecules. Twenty nine drugs ranked in the top 1 % for binding to each target were subsequently included in our experimental analysis. Continuous exposure of rotifers to 1 µM naproxen significantly extended rotifer mean lifespan by 14 %. We used three endpoints to estimate rotifer health: swimming speed (mobility proxy), reproduction (overall vitality), and mitochondria activity (cellular senescence proxy). The natural decline in swimming speed with aging was more gradual when rotifers were exposed to three drugs, so that on day 6, mean swimming speed of females was 1.19 mm/s for naproxen (P = 0.038), 1.20 for fludarabine (P = 0

  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. 程海浮游动物种群特征与数量的周年变化%Annual Changes of Population Characteristics and Quantities of Zooplankton in Chenghai Lake

    Institute of Scientific and Technical Information of China (English)

    董云仙; 王忠泽

    2013-01-01

    为深入了解程海湖泊生态系统的状况,2009年10月至2010年7月对程海浮游动物进行了季节性调查.结果表明,程海有浮游动物34科、59属、86种;其中,原生动物13科、18属、28种,轮虫10科、23属、34种,枝角类5科、7属、11种,桡足类2科、7属、9种,其他浮游动物4科、4属、4种.原生动物纤毛虫类(Ciliophora)四季均为优势类群,溞钟虫(Vorticella kahli)春季数量较多,而急游虫(Strombidium sp.)和湖累枝虫(Epistylis lacustris)在秋季数量达到高峰.轮虫优势种为暗小异尾轮虫(Trichocerca pusilla)、奇异巨腕轮虫(Pedalia mira)、裂痕龟纹轮虫(Anuraeopsis flasa)和萼花臂尾轮虫(Brachionus calyciflorus).枝角类种类少、数量多,主要是棘爪网纹溞(Ceriodaphnia reticulata)、短尾秀体潘(Diaphanosoma brachyurum)、透明溞(Daphnia hyaline)、园形盘肠溞(Chydorus sphaericus)和长肢秀体溞(D.leuchtenbergianum);桡足类种类少、数量低,近剑水蚤(Tropocyclops sp.)、锯齿真剑水蚤(Eucyclops macruroides deticulatus)、透明温剑水蚤(Thermocyclops hyalinus)常见并有一定优势.浮游动物数量为3 316.9个/L;其中,春季2 635.6个/L,夏季3 010.7个/L,秋季3 998.0个/L,冬季3 623.5个/L;水平分布南部明显偏高,东部数量高于西部,湖心明显偏少.相关分析表明,影响浮游动物数量变动的主要因子是温度、食物和鱼类摄食.在水体富营养化和太湖新银鱼(Neosalanx taihuensis)的强大摄食压力下,程海浮游动物小型化趋势明显.

  6. Diversity characteristics of rotifer community at the Yangtze River estuary%长江口轮虫生物多样性特征分析

    Institute of Scientific and Technical Information of China (English)

    郭章伟; 孙薇; 袁林; 薛俊增; 周淑辉; 吴惠仙

    2014-01-01

    The distribution of runoff at the Yangtze River estuary is uneven , the runoff in the south branch is more than in the north , and the north salinity is greater than the south , so there is some difference in biological community between the south and north branches .We collected rotifers from five cross-sections in the south and north branches and investigated the rotifer biology. A total of9 species were i-dentified at the Taihaiqidu cross-section, belonging to 8 genera, 6 families, and the dominant species were Ascomorpha ecaudis, Tricho-cerca pusilla, Brachionus calyciflorus, et al.20 rotifer species were identified in the south branch , belonging to 12 genera, 6 families, and the dominant species of the south branch T.pusilla, L.patella, Lecane ungulata;11 rotifer species were identified in the south branch, belonging to 10 genera, 7 families, and the dominant species of the north branches were A.saltans, A.ecaudis, L.patella.We compared the component and structure of rotifer in the south and the north branches , and found that the species , density, diversity of the south was higher than those of the north , similarity of rotifers in the south and north branches was low .The different water environment of the two branches caused the difference of rotifer community structure , correlation between rotifers and water environment factors was ana-lyzed by relativity analysis among which salinity was the important factor , and difference of salinity determined the difference in species , density, and spatial-distribution of rotifer.%长江口径流在南北支分布不均导致北支盐度高于南支,因此南北支之间生物群落存在一定差异。2010年在长江口分支前的江段和南北支设置5个断面,开展轮虫生态研究。分支前的太海汽渡断面处共采集到轮虫9种,隶属6科8属,其中优势种为没尾无柄轮虫、暗小异尾轮虫、萼花臂尾轮虫等;长江口南支2个断面共采集轮虫20种,隶属于6

  7. 广东省水库轮虫分布特征%Rotifer distribution in tropical reservoirs, Guangdong Province, China

    Institute of Scientific and Technical Information of China (English)

    林秋奇; 赵帅营; 韩博平

    2005-01-01

    在2000年调查了广东省18座水库的轮虫种类分布特征.在此基础上,于2001~2003年研究了滞留时间对飞来峡水库、流溪河水库和新丰江水库三座典型水库(平均滞留时间分别为14d、172d和644d)轮虫分布的影响.共检到轮虫101种,其中大多数种类来自臂尾轮科(Brachionidae)、腔轮科(Lecanidae)、异尾轮科(Trichcercidae)和疣毛轮科(Synchaetidae).常见属为龟甲轮属(Keratella)、臂尾轮属(Brachionus)、腔轮属(Lecane)、多肢轮属(Polyarthra)、异尾轮属(Trichocerca)、晶囊轮属(Asplanchna)、聚花轮属(Conochilus)和无柄轮属(Ascomorpha).从不同生活习性种类组成看,每次采样均以浮游种类为主.在直流型的飞来峡水库中,底栖和着生种类占种类数的41%;而在长滞留时间的新丰江水库中只占18%;中等滞留时间的流溪河水库则介于它们之间.从不同食性种类的丰度看,在新丰江水库和流溪河水库中,轮虫以滤食细小悬浮颗粒物的种类(螺形龟轮虫、独角聚花轮虫和广生多肢轮虫)为优势种;而在直流型的飞来峡水库中,以劫掠粒径较大食物的种类(疣毛轮虫等)为优势种.聚类分析表明,不同营养水平水库轮虫的组成并不是绝然不同的,而是随着营养水平的上升逐渐发生变化的.在营养水平较低水库中以广栖性的螺形龟甲轮虫为优势种,随着营养水平的上升,螺形龟甲轮虫优势度逐渐降低,而异尾轮虫或臂尾轮虫优势度逐渐上升,并在中富营养和富营养水库中成为优势种.

  8. Seasonal dynamics of rotifer in a seasonal fishing moratorium lake - Lake Erhai, Yunnan Province, China%一座季节性休渔湖泊——洱海轮虫的季节动态特征

    Institute of Scientific and Technical Information of China (English)

    吴秋婷; 卫志宏; 朱江; 孟良; 吕兴菊; 赵萍萍; 韩博平; 林秋奇

    2012-01-01

    于2009年2-11月对洱海轮虫进行月际采样,分析洱海轮虫的多样性及其群落结构季节动态特征.洱海作为一个高原湖泊,其轮虫种类组成仍然呈现出热带-亚热带的主要特征.本研究共鉴定轮虫68种,多数种类为广布性或暖水性种类,隶属17科25属,异尾轮属、腔轮属和臂尾轮属是种类最多的三个属,占鉴定轮虫种类的37%.Lecane arcuata和Trichocera inermis为我国新记录种.轮虫生物量的季节分布呈“双峰型”,并分别出现在休渔期的中期和捕鱼期前期.在休渔期中期,轮虫主要以前节晶囊轮虫为优势种;在捕鱼期前期,轮虫先以螺形龟甲轮虫和广生多肢轮虫为优势,后以前节晶囊轮虫为优势.季节性休渔不仅使鱼类对轮虫的捕食压力出现季节性变化,而且还通过影响枝角类的群落结构改变枝角类对轮虫的竞争压力.在捕食和竞争的双重作用下,轮虫主要以大型杂食性种类——前节晶囊轮虫为优势种类,并呈现“双峰型”的季节分布模式.%Rotifers were sampled monthly from February to November in 2009 in Lake Erhai, Yunnan Province, China, in order to study their diversity and seasonal dynamics. Lake Erhai has a rotifer composition with tropical-subtropical characteristics: 68 species belonging to 25 genera of 17 families were identified, the majority of which were eurythermal or mesophilic. The genera of Tri-chocerca, Lecane and Brachionus were more abundant than others, accounting for 37% of the total community. Lecane arcuata and Trichocera inermis are new records in China. Biomass of the rotifer communities in Lake Erhai exhibited a bimodal seasonal cycle. An increase occurred during spring from low winter levels to an annual maximum in the mid fishing moratorium and a second increase in the early fishing season. In the mid fishing moratorium, the rotifer biomass was dominated by Asplanchna priodonla; while in the early fishing season, it was

  9. 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

  10. 鄱阳湖国家级自然保护区浮游生物群落结构及空间分布%COMMUNITY STRUCTURE AND SPATIAL DISTRIBUTION OF PLANKTON IN THE POYANG LAKE NATIONAL NATURE RESERVE, CHINA

    Institute of Scientific and Technical Information of China (English)

    张婷; 马行厚; 王桂苹; 李德亮; 金斌松; 秦海明

    2014-01-01

    To evaluate the plankton characteristics of the Poyang Lake National Nature Reserve after the drought oc-curred in spring 2011, the community structure and spatial distribution of plankton in the Poyang Lake National Nature Reserve were investigated and analyzed in August, 2011. A total of 97 phytoplankton and 42 zooplankton species were identified, which belonged to 49 and 23 genera, respectively. The zooplankton were consisted of 13 species of protozoa, 23 species of rotifera, 3 species of cladocera and 3 species of copepoda. The numbers of plankton species in Lake Da-huchi and Zhushihu were more than that of the other lakes and rivers. The abundances of plankton among each lake and river were significantly different, and varied from 260 to8.18×106 cells/L for phytoplankton and 3630 to 73173 ind./L for zooplankton, respectively. The results showed that the abundances of plankton in Xiu River and the lakes that lo-cated at the west of Gan River, were significantly higher than that of Gan River and the other lakes. Statistical analysis indicated that the dominant species of phytoplankton in the Poyang Lake National Nature Reserve wereAnabaena flos-aquae, Scenedesmus quadricauda,S.bijuga,Melosira granulatavar. angustissima,M. granulate,M. graunlatavar. angustissima f. spiralis,Synedra acus andFragilaria capucina,while the dominant species of zooplankton wereStentor amethysinus,Difflugia lobostoma,Centropyxis discoides,Strombidim viride,Brachionus diversicornis,B. bennini, Trichocerca rousseleleti,T. longiseta andAsplanchna girodide. The maximum values of diversity indices (H′) and evenness (J) of both phytoplankton and zooplankton were 2.41 and 0.96, respectively. The values of abundance (Dm) of plankton were both less than 3. Evaluated with the diversity indices (H′), evenness (J) and abundance (Dm) of plankton, the water qualities of lakes and rivers in the Poyang Lake National Nature Reserve wereβ-type of pollution, except Lake Banghu and Meixihu.%为评

  11. 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.

  12. Morphological development and growth pattern of Verasper variegatus,Temminck et Schlegel in early life stages%圆斑星鲽的早期生长发育特征

    Institute of Scientific and Technical Information of China (English)

    宁鑫; 柳学周; 孙中之; 徐永江; 王妍妍

    2011-01-01

    Morphological and quantitative characteristics of Verasper variegatus in early life stages including embryonic development, yolk sac larva, pre-flexion larva, post-flexion larva, and juveniles were recorded. The eggs are 1.75mm 0. 08mm in diameter, without oil globule and spherical in shape when they are suspended in sea water. There is negative a relationship between the temperature and the hatching time, and the calculated lower threshold temperature for hatching of embryos is 5.14 ℃. The larvae hatched out 159h post fertilization at temperatures of 11±0.5 C, salinity of 31-32, and DO≥Smg/L. The newly hatched larvae is transparent and 4.95±0. 15mm in total length. Larval development and growth completely depended on the energy from the yolk sac and oil globe till 7 DAH (days after hatching). Meantime, mouth and anus opened, larvae entered the mixed feeding stage. Larvae entered the complete exogenous feeding stage after the yolk was completely absorbed at 11DAH. The first feeding food was L type rotifers Brachionus plicatilis. Larvae began to feed rotifers at 7 DAH. At 11 DAH, larvae were fed nauplii of brine shrimp Artemia salina at densities of 0.5 1.5 ind./mi till 46 DAH. Weaning to commercial diet started at 31 DAH and larvae fed mainly commercial diet after 40 DAH. There is no swim bladder present all through the early life history. The flexion of notochord started at 17 DAH at a total length of 7.32 0.23 mm (n=30), and finished at 33DAH when the total length reached 11.2 0.33 mm (n=30). Meanwhile, metamorphosis began at 33 DAH and completed at 50 DAH with the left eye moved completely to the right side, and the juveniles entered the bottom life stage. At 70 DAH, lateral line formed and the juveniles entered the young stage with the total length up to 25.3 3.23 mm (n=30), with similar appearance as the adults. The dorsal fin, pectoral fin, pelvic fin, caudal fin, and anal fin reached their full numbers at 70DAH. There were 4-5 black spots on the dorsal

  13. 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