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Sample records for artemia daphnia tenebrio

  1. Motion control of a population of Artemias

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    L. Fortuna

    2010-06-01

    Full Text Available In this work, the collective behavior of Artemia Salina is studied both experimentally and theoretically. Several experiments have been designed to investigate the Artemia motion under different environment conditions. From the results of such experiments, a strategy to control the direction of motion of an Artemia population, by exploiting their sensitivity to light, has been derived and then implemented.

  2. Artemia cyst production in Russia

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    Litvinenko, Liudmila I.; Litvinenko, Aleksandr I.; Boiko, Elena G.; Kutsanov, Kirill

    2015-11-01

    In Western Siberia (Russia) there are about 100 Artemia lakes with total area over 1 600 km2. Geographically these lakes are located between 51°-56°N and 61°-82°E. In general these lakes are shallow (depth less than 1.5 m), small or medium size (0.1 to 10 km2); they are chloride; their total salinity is from 40 to 250 g/L. The harvesting of cysts per year is only in 20-40 lakes. In Russia 550 tons of dry Artemia cysts (14%-18% of the world production) were harvested annually. This includes about 350 tons in the Altai region and 200 tons in other regions. During our regular 20-year study period the cyst harvest was: 95 tons in Kurgan; 65 tons in Omsk, 20 tons in Novosibirsk, 20 tons in Tyumen. Ways of increasing cyst harvest in Russia are considered in this article. During the last 30 years the harvest of cysts in Russia has increased from 7-20 to 500-600 tons. A significant influence of dryness of the year was found on productivity in selected lakes, but taken for all the lakes together, the relationship was not significant. The optimal salinity for productivity of cysts in the lakes was determined. Analysis of productivity of the lakes and the harvesting results showed that the stocks of cysts are underutilized by approximately 1.7 times.

  3. Comparison of the Artemia salina and Artemia fransiscana bioassays for toxicity of Indian medicinal plants

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    Thangapandi Veni

    2014-06-01

    Full Text Available Objective: To evaluate leaves extract of Azima tetracantha and Gmelina asiatica for lethality to brine shrimp larvae (Artemia salina and Artemia fransiscana. Methods: The plant materials were extracted based on polarity gradients of petroleum ether, benzene, chloroform, acetone, ethanol and methanol. The extracts were investigated for their cytotoxic potential. Results: In the brine shrimp lethality assay of all extracts, exception of acetone, ethanol and petroleum ether extracts Gmelina asiatica displayed 100% mortality at 1 000 μg/mL by Artemia salina and Artemia fransiscana. Chloroform extract was the most potent and presented the highest percentage of mortality with the lowest LC50 values by both assay too. Conclusions: The results of the present study suggest the presence of photochemical possessing cytotoxic agents.

  4. Comparison of the Artemia salina and Artemia fransiscana bioassays for toxicity of Indian medicinal plants

    Institute of Scientific and Technical Information of China (English)

    Thangapandi Veni; Thambusamy Pushpanathan

    2014-01-01

    Objective:To evaluate leaves extract of Azima tetracantha and Gmelina asiatica for lethality to brine shrimp larvae (Artemia salina and Artemia fransiscana). Methods: The plant materials were extracted based on polarity gradients of petroleum ether, benzene, chloroform, acetone, ethanol and methanol. The extracts were investigated for their cytotoxic potential. Results: In the brine shrimp lethality assay of all extracts, exception of acetone, ethanol and petroleum ether extracts Gmelina asiatica displayed 100%mortality at 1 000 μg/mL by Artemia salina and Artemia fransiscana. Chloroform extract was the most potent and presented the highest percentage of mortality with the lowest LC50 values by both assay too. Conclusions:The results of the present study suggest the presence of photochemical possessing cytotoxic agents.

  5. Nonhatching Decapsulated Artemia Cysts As a Replacement to Artemia Nauplii in Juvenile and Adult Zebrafish Culture.

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    Tye, Marc; Rider, Dana; Duffy, Elizabeth A; Seubert, Adam; Lothert, Brogen; Schimmenti, Lisa A

    2015-12-01

    Feeding Artemia nauplii as the main nutrition source for zebrafish is a common practice for many research facilities. Culturing live feed can be time-consuming and requires additional equipment to be purchased, maintained, and cleaned. Nonhatching decapsulated Artemia cysts (decaps) are a commercially available product that can be fed directly to fish. Several other ornamental fish species have been successfully cultured using decaps. Replacing Artemia nauplii with decaps could reduce the overall time and costs associated with the operation of a zebrafish facility. The objective of this study was to determine if decaps could be a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture. Wild-type zebrafish were fed one of three dietary treatments: decaps only, nauplii only, or a standard consisting of nauplii plus a commercially prepared pellet food. Survival, growth (length and weight), and embryo production were analyzed between the treatments. Fish receiving the decap diet demonstrated a significantly higher growth and embryo production when compared to the fish receiving the nauplii-only diet. When comparing the decap fish to the standard fish, no significant difference was found in mean survival, mean weight at 90 days postfertilization, or mean embryo production. It was determined that nonhatching decapsulated Artemia cysts can be used as a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture.

  6. Nonhatching Decapsulated Artemia Cysts As a Replacement to Artemia Nauplii in Juvenile and Adult Zebrafish Culture.

    Science.gov (United States)

    Tye, Marc; Rider, Dana; Duffy, Elizabeth A; Seubert, Adam; Lothert, Brogen; Schimmenti, Lisa A

    2015-12-01

    Feeding Artemia nauplii as the main nutrition source for zebrafish is a common practice for many research facilities. Culturing live feed can be time-consuming and requires additional equipment to be purchased, maintained, and cleaned. Nonhatching decapsulated Artemia cysts (decaps) are a commercially available product that can be fed directly to fish. Several other ornamental fish species have been successfully cultured using decaps. Replacing Artemia nauplii with decaps could reduce the overall time and costs associated with the operation of a zebrafish facility. The objective of this study was to determine if decaps could be a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture. Wild-type zebrafish were fed one of three dietary treatments: decaps only, nauplii only, or a standard consisting of nauplii plus a commercially prepared pellet food. Survival, growth (length and weight), and embryo production were analyzed between the treatments. Fish receiving the decap diet demonstrated a significantly higher growth and embryo production when compared to the fish receiving the nauplii-only diet. When comparing the decap fish to the standard fish, no significant difference was found in mean survival, mean weight at 90 days postfertilization, or mean embryo production. It was determined that nonhatching decapsulated Artemia cysts can be used as a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture. PMID:25495227

  7. Use of the genus Artemia in ecotoxicity testing

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    Nunes, Bruno S. [Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal) and Centro Interdisciplinar de Investigacao Marinha e Ambiental, Rua dos Bragas 289, 4150-123 Porto (Portugal)]. E-mail: bruno@ufp.pt; Carvalho, Felix D. [REQUIMTE, Departamento de Toxicologia da Faculdade de Farmacia da Universidade do Porto, Rua Anibal Cunha, 164, 4050-047 Porto (Portugal); Guilhermino, Lucia M. [Instituto de Ciencias Biomedicas de Abel Salazar, Departamento de Estudos de Populacoes, Laboratorio de Ecotoxicologia, Universidade do Porto, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Rua dos Bragas 289, 4150-123 Porto (Portugal); Van Stappen, Gilbert [Laboratory of Aquaculture and Artemia Reference Centre, Ghent University, Rozier 44, B-9000 Ghent (Belgium)

    2006-11-15

    Information related to varied uses of several species of the genus Artemia (commonly known as brine shrimp), is dispersed among literature from several scientific areas, such as Ecology, Physiology, Ecotoxicology, Aquaculture and Genetics. The present paper reviews information related to Artemia that may be considered relevant for ecotoxicity testing. Integration of different areas of scientific knowledge concerning biology, life cycle and environmental needs of Artemia is of crucial importance when considering the interpretation of results drawn from tests involving this genus. Furthermore, this paper provides suggestions to overcome problems related to toxicity assessment with the use of Artemia as test organism in bioassays, under the scope of estuarine, marine and hypersaline environments. Aspects related to variability in results, adoptable toxicity end-points, culture conditions, characteristics of species and strains, influence of geographical origins over physiological features and responses to exposure to chemical agents are considered. - The physiology, reproductive processes and general use of Artemia in modern ecotoxicological testing are reviewed.

  8. LC-MS/MS-based proteome profiling in Daphnia pulex and Daphnia longicephala: the Daphnia pulex genome database as a key for high throughput proteomics in Daphnia

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    Mayr Tobias

    2009-04-01

    Full Text Available Abstract Background Daphniids, commonly known as waterfleas, serve as important model systems for ecology, evolution and the environmental sciences. The sequencing and annotation of the Daphnia pulex genome both open future avenues of research on this model organism. As proteomics is not only essential to our understanding of cell function, and is also a powerful validation tool for predicted genes in genome annotation projects, a first proteomic dataset is presented in this article. Results A comprehensive set of 701,274 peptide tandem-mass-spectra, derived from Daphnia pulex, was generated, which lead to the identification of 531 proteins. To measure the impact of the Daphnia pulex filtered models database for mass spectrometry based Daphnia protein identification, this result was compared with results obtained with the Swiss-Prot and the Drosophila melanogaster database. To further validate the utility of the Daphnia pulex database for research on other Daphnia species, additional 407,778 peptide tandem-mass-spectra, obtained from Daphnia longicephala, were generated and evaluated, leading to the identification of 317 proteins. Conclusion Peptides identified in our approach provide the first experimental evidence for the translation of a broad variety of predicted coding regions within the Daphnia genome. Furthermore it could be demonstrated that identification of Daphnia longicephala proteins using the Daphnia pulex protein database is feasible but shows a slightly reduced identification rate. Data provided in this article clearly demonstrates that the Daphnia genome database is the key for mass spectrometry based high throughput proteomics in Daphnia.

  9. A note on the biogeographical origin of the brine shrimp Artemia urmiana Günther, 1899 from Urmia Lake, Iran.

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    Eimanifar, Amin; Asem, Alireza; Djamali, Morteza; Wink, Michael

    2016-01-01

    The brine shrimp Artemia urmiana, an abundant inhabitant of the hypersaline Urmia Lake in northwestern Iran, has recently been described from Lake Koyashskoe, also a shallow hypersaline lake that is located on the Black Sea coast of the Crimean Peninsula (Ukraine). This discovery has questioned the endemicity of A. urmiana in Urmia Lake and has also brought into question the biogeographical origin of this species. In the present study, we combined recent genetic divergence data (mtDNA-COI) with palaeoecological evidence to address the biogeographical origin of A. urmiana. Calibration of the molecular clock of the COI region was set by assigning the age of the micro-crustacean Daphnia pulex minimally at 145 Mya. The divergence age of A. urmiana in Urmia Lake dates back to 383,000 years, whereas Ukrainian Artemia reflects a very young populations that diverged about 196,000 years ago. Palaeoecological evidence suggests that the age of the major habitat of A. urmiana i.e. Urmia Lake goes back to the Tertiary Period while the Ukranian habitats of the species are very young, by virtue of geological features of the Holocene age. We conclude that the biogeographical origin of A. urmiana is outside of Europe and the current state of knowledge strongly suggests that Urmia Lake has been the major source of its expansion into its modern habitats in Europe. PMID:27394547

  10. The ecoresponsive genome of Daphnia pulex

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    Colbourne, John K.; Pfrender, Michael E.; Gilbert, Donald; Thomas, W. Kelley; Tucker, Abraham; Oakley, Todd H.; Tokishita, Shinichi; Aerts, Andrea; Arnold, Georg J.; Basu, Malay Kumar; Bauer, Darren J.; Caceres, Carla E.; Carmel, Liran; Casola, Claudio; Choi, Jeong-Hyeon; Detter, John C.; Dong, Qunfeng; Dusheyko, Serge; Eads, Brian D.; Frohlich, Thomas; Geiler-Samerotte, Kerry A.; Gerlach, Daniel; Hatcher, Phil; Jogdeo, Sanjuro; Krijgsveld, Jeroen; Kriventseva, Evgenia V; Kültz, Dietmar; Laforsch, Christian; Lindquist, Erika; Lopez, Jacqueline; Manak, Robert; Muller, Jean; Pangilinan, Jasmyn; Patwardhan, Rupali P.; Pitluck, Samuel; Pritham, Ellen J.; Rechtsteiner, Andreas; Rho, Mina; Rogozin, Igor B.; Sakarya, Onur; Salamov, Asaf; Schaack, Sarah; Shapiro, Harris; Shiga, Yasuhiro; Skalitzky, Courtney; Smith, Zachary; Souvorov, Alexander; Sung, Way; Tang, Zuojian; Tsuchiya, Dai; Tu, Hank; Vos, Harmjan; Wang, Mei; Wolf, Yuri I.; Yamagata, Hideo; Yamada, Takuji; Ye, Yuzhen; Shaw, Joseph R.; Andrews, Justen; Crease, Teresa J.; Tang, Haixu; Lucas, Susan M.; Robertson, Hugh M.; Bork, Peer; Koonin, Eugene V.; Zdobnov, Evgeny M.; Grigoriev, Igor V.; Lynch, Michael; Boore, Jeffrey L.

    2011-02-04

    This document provides supporting material related to the sequencing of the ecoresponsive genome of Daphnia pulex. This material includes information on materials and methods and supporting text, as well as supplemental figures, tables, and references. The coverage of materials and methods addresses genome sequence, assembly, and mapping to chromosomes, gene inventory, attributes of a compact genome, the origin and preservation of Daphnia pulex genes, implications of Daphnia's genome structure, evolutionary diversification of duplicated genes, functional significance of expanded gene families, and ecoresponsive genes. Supporting text covers chromosome studies, gene homology among Daphnia genomes, micro-RNA and transposable elements and the 46 Daphnia pulex opsins. 36 figures, 50 tables, 183 references.

  11. Larvicidal activity of some marine macrophytes against Artemia salina

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    PrabhaDevi; Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    and Microdictyon pseudohapteron, seagrasses (Halophila ovalis and Syringodium isoetifolium and lichens (Umbilicaria arpina) were tested for larvicidal activity using Artemia salina nauplii. The LC50 values for the PE-fraction of M. pseudohapteron and A. muscoides...

  12. Strong environmental tolerance of Artemia under very high pressure

    International Nuclear Information System (INIS)

    It was shown by the present authors group that a tardigrade in its tun-state can survive after exposed to 7.5 GPa for 13 hours. We have extended this experiment to other tiny animals searching for lives under extreme conditions of high hydrostatic pressure. Artemia, a kind of planktons, in its dried egg-state have strong environmental tolerance. Dozens of Artemia eggs were sealed in a small Teflon capsule together with a liquid pressure medium, and exposed to the high hydrostatic pressure of 7.5 GPa. After the pressure was released, they were soaked in seawater to observe hatching rate. It was proved that 80-90% of the Artemia eggs were alive and hatched into Nauplii after exposed to the maximum pressure of 7.5 GPa for up to 48 hours. Comparing with Tardigrades, Artemia are four-times stronger against high pressure.

  13. Specific anion effects in Artemia salina.

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    Lo Nostro, Pierandrea; Ninham, Barry W; Carretti, Emiliano; Dei, Luigi; Baglioni, Piero

    2015-09-01

    The specific anion effect on the vitality of Artemia salina was investigated by measuring the Lethal Time LT50 of the crustaceans in the presence of different sodium salts solutions at room temperature and at the same ionic strength as natural seawater. Fluoride, thiocyanate and perchlorate are the most toxic agents, while chloride, bromide and sulfate are well tolerated. The rates of oxygen consumption of brine shrimps were recorded in mixed NaCl+NaF or NaCl+NaSCN solutions as a function of time. The results are discussed in terms of the Hofmeister series, and suggest that, besides the biochemical processes that involve F(-), SCN(-) and ClO4(-), the different physico-chemical properties of the strong kosmotropic and chaotropic anions may contribute in determining their strong toxicity for A. salina. PMID:25978674

  14. Variant subunit specificity in the quaternary structure of Artemia hemoglobin.

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    Vandenberg, Cassandra J; Matthews, Charles M; Trotman, Clive N A

    2002-08-01

    The brine shrimp Artemia has three extracellular hemoglobins (Hbs) that are developmentally expressed and exhibit distinct oxygen-binding characteristics (Heip, Moens, and Kondo 1978; Heip et al. 1978 ). These Hbs are composed of two polymers, each of which comprises nine covalently linked globin domains. Although the cDNA sequences of two nine-domain globins from Artemia have been published, there is evidence for the existence of further expressed globin genes (Manning, Trotman, and Tate 1990 ). In the present study extensive analysis at the cDNA and genomic levels was performed in order to determine the globin gene copy number in Artemia. Sequence and Southern analysis suggest that four Hb polymers (T1, T2, C1, and C2) are expressed in Artemia. In addition, there is also at least one globin pseudogene. Protein sequencing of the native Hbs revealed that there are limitations on which two polymers can associate. The composition of the Hbs has been determined to be: Hb I, C1C2; Hb II, C1T2; and Hb III, T1T2. These pairings allow the levels of the three Artemia Hbs to be regulated independently by polymer expression alone, therefore explaining the previously inconsistent developmental and hypoxia-induced expression patterns. PMID:12140240

  15. Pesticide contamination of Tenebrio molitor (Coleoptera: Tenebrionidae) for human consumption.

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    Houbraken, Michael; Spranghers, Thomas; De Clercq, Patrick; Cooreman-Algoed, Margot; Couchement, Tasmien; De Clercq, Griet; Verbeke, Sarah; Spanoghe, Pieter

    2016-06-15

    The use of pesticides contributes to the productivity and the quality of the cultivated crop. A large portion of the agricultural produce is not consumed as it is not an edible part or the quality of the product is too low. This waste of agricultural produce can be valorised as a substrate for the production of certain insects for human consumption. However, pesticides applied on the plants might accumulate during the life cycle of the insects fed on the waste materials and may cause a health risk to humans consuming the insects. Pesticide residues in larvae of the yellow mealworm, Tenebrio molitor, were investigated. We monitored the accumulation of pesticides in the larvae upon consumption of contaminated fresh produce. An increased uptake rate by the insects was found for pesticides with higher Kow-values. Excretion of pesticides by the insect was inversely related to the log(Kow) values of the pesticides. PMID:26868575

  16. Physiological characteristics and stress resistance of great sturgeon (Huso huso) juveniles fed with vitamins C, E, and HUFA-enriched Artemia urmiana nauplii.

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    Jalali, Mohammad Ali; Hosseini, Seyed Abbas; Imanpour, Mohammad Reza

    2010-09-01

    This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and alpha-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 +/- 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33 degrees C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na(+) level in the C group on the 4th day at 6 ppt. Na(+) and Ca(2+) concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca(2+) level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and

  17. Effects of Artemia enriched with unsaturated fatty acids and vitamin C on growth, survival and resistance Salmo trutta caspius larvae

    OpenAIRE

    Javaheri baboli, Mehran

    2006-01-01

    This experiment was conducted to investigate the effect of using n-3 HUFA and Vitamin C enriched Artemia urmiana Nauplii Five difference treament were tested: for Caspian salmon (Salmo trutta caspius) larvae compare with artificial food in five treatment: (1) Artificial food, (2) Newly hatched Artemia (3) n-3 HUFA enriched Artemia (4) n-3 HUFA + 10% Ascorbyl Palmitate enriched Artemia (5) n-3 HUFA+20% Ascorbyl palmitate enriched Artemia during 15 days then all treatment were fe...

  18. Field culture of American strain of Artemia in India

    Digital Repository Service at National Institute of Oceanography (India)

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Pilot scale culture of Artemia was carried out in a 0.22 ha condenser unit of salt pans. Pond was fertilized with inorganic salts. The nauplii of San Francisco Bay, USA strain were inoculated. Within a period of 5 months a production of 20.6 kg dry...

  19. Origin and genetic diversity of diploid parthenogenetic Artemia in Eurasia.

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    Marta Maccari

    Full Text Available There is wide interest in understanding how genetic diversity is generated and maintained in parthenogenetic lineages, as it will help clarify the debate of the evolution and maintenance of sexual reproduction. There are three mechanisms that can be responsible for the generation of genetic diversity of parthenogenetic lineages: contagious parthenogenesis, repeated hybridization and microorganism infections (e.g. Wolbachia. Brine shrimps of the genus Artemia (Crustacea, Branchiopoda, Anostraca are a good model system to investigate evolutionary transitions between reproductive systems as they include sexual species and lineages of obligate parthenogenetic populations of different ploidy level, which often co-occur. Diploid parthenogenetic lineages produce occasional fully functional rare males, interspecific hybridization is known to occur, but the mechanisms of origin of asexual lineages are not completely understood. Here we sequenced and analysed fragments of one mitochondrial and two nuclear genes from an extensive set of populations of diploid parthenogenetic Artemia and sexual species from Central and East Asia to investigate the evolutionary origin of diploid parthenogenetic Artemia, and geographic origin of the parental taxa. Our results indicate that there are at least two, possibly three independent and recent maternal origins of parthenogenetic lineages, related to A. urmiana and Artemia sp. from Kazakhstan, but that the nuclear genes are very closely related in all the sexual species and parthenogegetic lineages except for A. sinica, who presumable took no part on the origin of diploid parthenogenetic strains. Our data cannot rule out either hybridization between any of the very closely related Asiatic sexual species or rare events of contagious parthenogenesis via rare males as the contributing mechanisms to the generation of genetic diversity in diploid parthenogenetic Artemia lineages.

  20. Competition in natural populations of Daphnia

    NARCIS (Netherlands)

    Boersma, M.

    1995-01-01

    I investigated the competitive relationships between two species of Daphnia, D. galeata and D. cucullata, and their interspecific hybrid. The term hemispecific competition was introduced to describe competition between parental species and hybrids. In eutrophic Tjeukemeer both parental species were

  1. Toxicity of cypermethrin to Daphnia magna HB

    Institute of Scientific and Technical Information of China (English)

    SHENG Xiu-mei; XIONG Li; WU Zhen-bin; TANG Hong-feng; LIU Tao; WANG Yuan

    2004-01-01

    The acute toxic effect of the pesticide cypermethrin to Daphnia magna HB was examined. D. magna HB was exposed to cypermethrin at concentrations of 0, 1, 3, 5, 7, and 9 mg/L for 24 h. Data showed that the 24 h-LC50 of cypermthrin on D. magna HB was 4.81 mg/L. In contrast, the 24 h-LC50 of K2Cr2O7(the national standard toxicant) to Daphnia magna was 0.38 mg/L in the current study. Results indicated that the Daphnia magna was very sensitive to pesticides. In addition, the effects of the culture condition(such as hardness, temperature and DO etc.) on Daphnia magna HB was also studied.

  2. Outlining eicosanoid biosynthesis in the crustacean Daphnia

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    Timmermans Martijn JTN

    2008-07-01

    Full Text Available Abstract Background Eicosanoids are biologically active, oxygenated metabolites of three C20 polyunsaturated fatty acids. They act as signalling molecules within the autocrine or paracrine system in both vertebrates and invertebrates mainly functioning as important mediators in reproduction, the immune system and ion transport. The biosynthesis of eicosanoids has been intensively studied in mammals and it is known that they are synthesised from the fatty acid, arachidonic acid, through either the cyclooxygenase (COX pathway; the lipoxygenase (LOX pathway; or the cytochrome P450 epoxygenase pathway. However, little is still known about the synthesis and structure of the pathway in invertebrates. Results Here, we show transcriptomic evidence from Daphnia magna (Crustacea: Branchiopoda together with a bioinformatic analysis of the D. pulex genome providing insight on the role of eicosanoids in these crustaceans as well as outlining a putative pathway of eicosanoid biosynthesis. Daphnia appear only to have one copy of the gene encoding the key enzyme COX, and phylogenetic analysis reveals that the predicted protein sequence of Daphnia COX clusters with other invertebrates. There is no current evidence of an epoxygenase pathway in Daphnia; however, LOX products are most certainly synthesised in daphnids. Conclusion We have outlined the structure of eicosanoid biosynthesis in Daphnia, a key genus in freshwater ecosystems. Improved knowledge of the function and synthesis of eicosanoids in Daphnia and other invertebrates could have important implications for several areas within ecology. This provisional overview of daphnid eicosanoid biosynthesis provides a guide on where to focus future research activities in this area.

  3. The brine shrimp Artemia: adapted to critical life conditions

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    Gonzalo M Gajardo

    2012-06-01

    Full Text Available The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to perceive forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity that are able to maintain the population under suitable conditions.At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism. The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress

  4. Functional analysis of C1 family cysteine peptidases in the larval gut of Tenebrio molitor and Tribolium castaneum

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    We studied protein digestion the tenebrionids Tenebrio molitor and Tribolium castaneum, pests of stored grains and grain products, to identify potential targets for biopesticide development. Tenebrionid larvae have highly compartmentalized guts, with primarily cysteine peptidases in the acidic anter...

  5. The influence of different rotifer and Artemia enrichment diets on growth, survival and pigmentation in turbot (Scophthalmus maximus L.) larvae

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Attramadal, Y.

    1992-01-01

    , approximately seven days after hatching, the larvae were fed newly-hatched Artemia salina nauplii (AT-1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tansk was further subdivided and the larvae fed Artemia nauplii enriched with one of four enrichment...

  6. Comparison live adult Artemia and squid meat on the growth of Penaeid shrimp Metapenaeus dobsoni (Miers)

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T.; Royan, J.P.

    An experiment lasting 14 weeks was conducted to compare the efficiency of live adult Artemia with fresh squid meat on growth of penaeid shrimp Metapenaeus dobsoni. The shrimps were found actively feeding on live Artemia and grew 84% more than those...

  7. [Composition of fat acids in three Mexican populations of Artemia franciscana from epicontinental waters].

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    Malpica Sánchez, Aída; Castro Barrera, Thalía; Sandoval Trujillo, Horacio; Castro Mejía, Jorge; De Lara Andrade, Ramón; Castro Mejía, Germán

    2004-03-01

    In this paper is presented the percentage of fatty acids composition of three Artemia franciscana Mexican populations of epicontinentals waters; two are from natural environments (Coahuila and San Luis Potosf) and one (Texcoco) is a culture fed with Spirulina. Determination of fatty acids composition in each population, was performed by extraction of total lipid by the soxhlet method and the fatty acids methyl esters were determined by gas chromatography. The results show that Artemia of Texcoco contains the six fatty acids recommended for the culture of fish and crustaceans (16:0; 16:1; 18:1; 18:2w6; 18:3w3 and 20:5w3); Artemia from San Luis Potosi showed the poorest content in these acids and Artemia from Coahuila, although it showed a wide profile, it lacks the linolenic acid. When comparing results among the three populations with ecological data that have been published, it can be pointed out that the environment is decisive for this crustacean; Artemia from Texcoco fed with Spirulina showed the largest variety of fatty acids; the other two populations are wild, and lives in different habitats, Artemia of Coahuila is found in waters that are rich in sulfates and Artemia of San Luis Potosf lives in evaporation saltern ponds, built with stone blocks and therefore with scarce phytoplankton growth. Both Artemia populations showed deficiencies in essential fatty acids, mainly the last one.

  8. Characterization of polymorphic microsatellite markers in the brine shrimp Artemia (Branchiopoda, Anostraca)

    DEFF Research Database (Denmark)

    Muñoz, Joaquin; Green, Andy J.; Figuerola, Jordi;

    2009-01-01

    The brine shrimp Artemia is a complex genus containing sexual species and parthenogenetic lineages. Artemia franciscana is native to America and its cysts (diapausing eggs) are used worldwide as a food source in aquaculture. As a consequence, this anostracan has become an invasive species in many...

  9. The Ecoresponsive Genome of Daphnia pulex

    Science.gov (United States)

    Colbourne, John K.; Pfrender, Michael E.; Gilbert, Donald; Thomas, W. Kelley; Tucker, Abraham; Oakley, Todd H.; Tokishita, Shinichi; Aerts, Andrea; Arnold, Georg J.; Basu, Malay Kumar; Bauer, Darren J.; Cáceres, Carla E.; Carmel, Liran; Casola, Claudio; Choi, Jeong-Hyeon; Detter, John C.; Dong, Qunfeng; Dusheyko, Serge; Eads, Brian D.; Fröhlich, Thomas; Geiler-Samerotte, Kerry A.; Gerlach, Daniel; Hatcher, Phil; Jogdeo, Sanjuro; Krijgsveld, Jeroen; Kriventseva, Evgenia V; Kültz, Dietmar; Laforsch, Christian; Lindquist, Erika; Lopez, Jacqueline; Manak, J. Robert; Muller, Jean; Pangilinan, Jasmyn; Patwardhan, Rupali P.; Pitluck, Samuel; Pritham, Ellen J.; Rechtsteiner, Andreas; Rho, Mina; Rogozin, Igor B.; Sakarya, Onur; Salamov, Asaf; Schaack, Sarah; Shapiro, Harris; Shiga, Yasuhiro; Skalitzky, Courtney; Smith, Zachary; Souvorov, Alexander; Sung, Way; Tang, Zuojian; Tsuchiya, Dai; Tu, Hank; Vos, Harmjan; Wang, Mei; Wolf, Yuri I.; Yamagata, Hideo; Yamada, Takuji; Ye, Yuzhen; Shaw, Joseph R.; Andrews, Justen; Crease, Teresa J.; Tang, Haixu; Lucas, Susan M.; Robertson, Hugh M.; Bork, Peer; Koonin, Eugene V.; Zdobnov, Evgeny M.; Grigoriev, Igor V.; Lynch, Michael; Boore, Jeffrey L.

    2012-01-01

    We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 Mb and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than 1/3 of Daphnia’s genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The co-expansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes – including many additional loci within sequenced regions that are otherwise devoid of annotations – are the most responsive genes to ecological challenges. PMID:21292972

  10. Predation on Daphnia pulex by Lepidurus arcticus

    DEFF Research Database (Denmark)

    Christoffersen, Kirsten Seestern

    2001-01-01

    Abstract The tadpole shrimp Lepidurus arcticus frequently occurs in Greenland ponds and shallow lakes with a soft bottom. Literature describes it as mainly a scavenger, feeding on the sediment. Previous observations of its behaviour suggest, however, that large specimens can catch Daphnia pulex...... concentrations and the saturation levels were far above natural prey densities. Small-sized Daphnia (1.6 mm) were removed at significant faster rates (t-test, pLepidurus when offered in combination but not when offered separately. Although the recorded....... The calculated energetic advantages of plankton as supplement to a benthic diet seemed low (5% of body weight per day)....

  11. Radiation Damage to Artemia Cysts:Effects of Water Vapor.

    Science.gov (United States)

    Snipes, W C; Gordy, W

    1963-10-25

    Water vapor altered the form and greatly increased the rate of decay of the electron-spin resonance pattern of long-lived free radicals obtained upon gamma irradiation of Artemia salina cysts ( brine shrimp eggs). These results, combined with data on radiation survival, indicate that the water vapor protects the cysts from radiation damage, or heals the damage. They also indicate that water protects the cysts from the effect of oxygen by neutralizing the radiation-induced free radicals before they can interact with oxygen to produce irreversible damage. PMID:17748168

  12. Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

    Science.gov (United States)

    Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

    1994-08-01

    Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by intrduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spaceflight, and show that extensive degress of development can take place in this microgravity environment.

  13. Cadmium and zinc reversibly arrest development of Artemia larvae

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, J.C.; Rafiee, P.; Matthews, C.O.; MacRae, T.H.

    1986-08-01

    Despite the widespread distribution of heavy metals such as cadmium and zinc in the environment and their well-known cytotoxicity and embryotoxicity in mammals, comparatively little is known about their effect on aquatic organisms, particularly invertebrates. Post-gastrula and early larval development of the brine shrimp, Artemia, present some useful advantages for studies of developmental aspects of environmental toxicology. Dormant encysted gastrulae, erroneously called brine shrimp eggs, can be obtained commercially and raised in the laboratory under completely defined conditions. Following a period of post-gastrula development within the cyst, pre-nauplius larvae emerge through a crack in the cyst shell. A few hours later, free-swimming nauplius larvae hatch. Cadmium is acutely toxic to both adults and nauplius larvae of Artemia, but the reported LC50s are as high as 10 mM, depending on larval age. In this paper the authors show that pre-nauplius larvae prior to hatching are much more sensitive to cadmium than are hatched nauplius larvae. At 0.1 ..mu..m, cadmium retards development and hatching of larvae; higher concentrations block hatching almost completely and thus are lethal. However, the larvae arrested at the emergence stage survive for 24 hours or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect is reversible if the larvae are placed in cadmium-free medium. The effects of zinc parallel those of cadmium, although zinc is somewhat less toxic than cadmium at equal concentrations.

  14. Can Daphnia lumholtzi invade European lakes?

    Directory of Open Access Journals (Sweden)

    Meike Wittmann

    2013-03-01

    Full Text Available The cladoceran Daphnia lumholtzi is a subtropical and tropical zooplankter, and an invasive species in North America. Thus far, D. lumholtzi has not been detected in Europe. Here we investigated whether a hypothetical introduction to Europe could result in a successful invasion, either now or in the near future when facilitated by climate change. In laboratory experiments, we tested whether different clones of D. lumholtzi can invade a resident community consisting of native Daphnia from lake Klostersee, Germany, and how invasion success depends on temperature and the presence or absence of planktivorous fish. In some treatments, invasion success was consistently high, and D. lumholtzi reached densities similar to the native competitors by the end of the experiment. The presence of a planktivorous fish reduced the invasion success of D. lumholtzi, and a clone with an inducible defense against fish predation was a more successful invader than a permanently defended clone. Of the three temperatures tested in this study (15, 20, and 24 °C, invasion success was highest at 20 °C. To understand the competitive interaction between native and introduced Daphnia, we fit a Lotka-Volterra-type competition model to the population dynamics. Our experimental and modeling results suggest that D. lumholtzi can invade European lakes and can cause substantial declines in the population size of native Daphnia, with potential consequences for higher trophic levels.

  15. Diffusive properties of water in Artemia cysts as determined from quasi-elastic neutron scattering spectra. [Artemia shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Trantham, E.C.; Rorschach, H.E.; Clegg, J.S.; Hazlewood, C.F.; Nicklow, R.M.; Wakabayashi, N.

    1984-05-01

    Results have been obtained on the quasi-elastic spectra of neutrons scattered from pure water, 20% agarose gel (hydration four grams H/sub 2/O per gram of dry solid) and cysts of the brine shrimp Artemia for hydrations between 0.10 and 1.2 grams H/sub 2/O per gram of dry solids. The spectra were interpreted using a two-component model that included contributions from the covalently bonded protons and the hydration water, and a mobile water fraction. The mobile fraction was described by a jump-diffusion correlation function for the translation motion and a simple diffusive orientational correlation function. The results for the line widths ..gamma..(Q/sup 2/) for pure water were in good agreement with previous measurements. The agarose results were consistent with NMR measurements that show a slightly reduced translational diffusion for the mobile water fraction. The Artemia results show that the translational diffusion coefficient of the mobile water fraction was greatly reduced from that of pure water. The line width was determined mainly by the rotational motion, which was also substantially reduced from the pure water value as determined from dielectric relaxation studies. The translational and rotational diffusion parameters were consistent with the NMR measurements of diffusion and relaxation. Values for the hydration fraction and the mean square thermal displacement as determined from the Q-dependence of line areas were also obtained.

  16. Comparación biométrica del lóbulo frontal en poblaciones americanas de Artemia (Anostraca, Artemiidae Biometric comparision of the frontal knob in american populations of Artemia (Anostraca, Artemiidae

    Directory of Open Access Journals (Sweden)

    PATRICIO R DE LOS RIOS

    2000-03-01

    Full Text Available Se compararon el diámetro del lóbulo frontal y su relación con la longitud corporal, en poblaciones de Artemia franciscana (Chile y Estados Unidos, A. persimilis (Argentina y Artemia sp. (Chile, cultivadas en laboratorio bajo condiciones controladas. Se encontraron diferencias significativas en ambos parámetros entre las poblaciones de A. franciscana y Artemia sp., de Salina El Convento (Chile y entre A. persimilis y Artemia sp. de Torres del Paine (Chile. Se discuten en el presente trabajo los factores geográficos, ecológicos y genéticos que determinaron la especiación de Artemia en Chile y Argentina, y como ésta se manifiesta en distintos patrones morfométricosThe frontal knob diameter and its relationship with the total body lenght among populations of Artemia franciscana (Chile and U.S.A, A. persimilis (Argentina, and Artemia sp. (Chile, were asessed. All populations were cultured under laboratory conditions. Significant differences in both parameters between A. franciscana and Artemia sp. from Salina el Convento (Chile, and between A. persimilis and Artemia sp. from Amarga Lagoon (Chile were recorded.Geographical, ecological and genetic aspects which affected the speciation of Artemia populations in Chile and Argentina, and their expression in morphometric characters are discussed

  17. THE BRINE SHRIMP (ARTEMIA SALINA) LETHALITY OF Brassica oleracea var. capitata

    OpenAIRE

    O. T. TÜZÜN, E. GÜRKAN, S. DOĞANCA, F. HIRLAK,

    2015-01-01

    This work covers up the bio-activities of the five fractions obtained from the ethanolic extract of Brassica oleracea var. capitata (Cruciferae).Key Words: Brassica oleracea var. capitata, Brine shrimp (Artemia salina)

  18. Production dynamics of Brine Shrimp (Artemia franciscana) in the San Francisco Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Abundance, stage structure and population dynamics of brine shrimp Artemia franciscana in pond M4 of the San Francisco Bay National Wildlife Refuge were documented...

  19. Toxic Assessment of Triclosan and Triclocarban on Artemia salina.

    Science.gov (United States)

    Xu, Xiaolu; Lu, Yin; Zhang, Deyong; Wang, Yinyin; Zhou, Xianshan; Xu, Huiying; Mei, Yu

    2015-12-01

    In this study, we investigated the possible acute toxic and genotoxic effects of triclosan (TCS) and triclocarban (TCC) on Artemia salina. Genotoxicity was evaluated using single-cell gel electrophoresis and apoptotic frequency assays (Annexin V-FITC/PI assay). Acute toxicity test results showed that TCC (LC50-24 h = 17.8 µg/L) was more toxic than TCS (LC50-24 h = 171.1 µg/L). Significant increases in both genotoxic biomarkers were observed at 24 h after initial exposure, indicating that these two chemicals are potentially dangerous for this aquatic biological model. Although further studies are required, a comparison of data both in vitro and in vivo allowed us to suggest possible mechanisms of action for TCS and TCC in this sentinel organism. PMID:26310128

  20. Potentials of converting microalgae into brine shrimp Artemia

    OpenAIRE

    Sorgeloos, P

    1985-01-01

    High densities of brine shrimp Artemia can be cultured in flow-through systems using the effluent of microalgae cultures as a combined source of culture medium and food. It has been proven at the "St. Croix Artificial Upwelling Mariculture Project" that in comparison with the fast growing clam Tapes japonica, brine shrimp assure a much more efficient conversion of plant into animal biomass. It appears from the given examples that microalgae conversion into brine shrimp Artemia offers efficien...

  1. Evaluation of mono- and mixed diets as food for intensive Artemia culture

    OpenAIRE

    Lavens, P.; De Meulemeester, A.; Sorgeloos, P.

    1987-01-01

    In order to alleviate the problems encountered when using live algae or rice bran as Artemia food in intensive culturing, different alternative types of brine shrimp diets have been evaluated. Using a high-density flow-through recirculation culture system, a Single Cell Protein yeast and mixed diets, consisting of this yeast and micronized waste products from agricultural corps, were selected as suitable Artemia feeds.Production yields after 2 weeks culturing varied from 2 to 5 kg live weight...

  2. Telomerase activity and telomere length in Daphnia.

    Science.gov (United States)

    Schumpert, Charles; Nelson, Jacob; Kim, Eunsuk; Dudycha, Jeffry L; Patel, Rekha C

    2015-01-01

    Telomeres, comprised of short repetitive sequences, are essential for genome stability and have been studied in relation to cellular senescence and aging. Telomerase, the enzyme that adds telomeric repeats to chromosome ends, is essential for maintaining the overall telomere length. A lack of telomerase activity in mammalian somatic cells results in progressive shortening of telomeres with each cellular replication event. Mammals exhibit high rates of cell proliferation during embryonic and juvenile stages but very little somatic cell proliferation occurs during adult and senescent stages. The telomere hypothesis of cellular aging states that telomeres serve as an internal mitotic clock and telomere length erosion leads to cellular senescence and eventual cell death. In this report, we have examined telomerase activity, processivity, and telomere length in Daphnia, an organism that grows continuously throughout its life. Similar to insects, Daphnia telomeric repeat sequence was determined to be TTAGG and telomerase products with five-nucleotide periodicity were generated in the telomerase activity assay. We investigated telomerase function and telomere lengths in two closely related ecotypes of Daphnia with divergent lifespans, short-lived D. pulex and long-lived D. pulicaria. Our results indicate that there is no age-dependent decline in telomere length, telomerase activity, or processivity in short-lived D. pulex. On the contrary, a significant age dependent decline in telomere length, telomerase activity and processivity is observed during life span in long-lived D. pulicaria. While providing the first report on characterization of Daphnia telomeres and telomerase activity, our results also indicate that mechanisms other than telomere shortening may be responsible for the strikingly short life span of D. pulex.

  3. Swimming behaviour of Daphnia clones: differentiation through predator infochemicals

    NARCIS (Netherlands)

    Weber, A.; Van Noordwijk, A.J.

    2002-01-01

    We studied variation in small-scale swimming behavior (SSB) in four clones of Daphnia galeata (water flea) in response to predator infochemicals. The aim of this study was 3-fold. First, we tested for differences in SSB in Daphnia; second, we examined the potential of differences in SSB to explain s

  4. Effects of some sesquiterpenes on the stored-product insect Tenebrio molitor (Coleoptera: Tenebrionidae Efectos de algunos sesquiterpenos sobre el insecto de productos almacenados, Tenebrio molitor (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    Matías García

    2003-12-01

    Full Text Available In order to evaluate the allelochemical activity of some sesquiterpenes isolated from the native plant Tessaria absinthioides (Hook. et Arn. DC, and some semi synthetic derivatives against Tenebrio molitor L. larvae, we have developed bioassays directed to quantify repellency, larval mortality, and its effects on the development. Although costic aldehyde caused the maximum repellent effect, all the compounds showed a significant effect at some dose or time, indicating behavioral avoidance. The topical application of costic aldehyde produced the largest increase on the duration of the pupal stage. Tessaric acid exhibited the highest toxicity by topical application at the experiment closure. Both eremophilane-1(10,2,11(13-triene-12-oic, and -costic acids induced some morphological deformities.Con el objeto de evaluar sesquiterpenos aislados de la planta nativa Tessaria absinthioides (Hook et Arn y algunos derivados semisintéticos frente a larvas de Tenebrio molitor L., se desarrollaron bioensayos orientados a la cuantificación de la repelencia, mortalidad de larvas y efectos sobre el desarrollo. Aldehído cóstico produjo el mayor incremento en la duración del estado pupal por aplicación tópica. Acido tessárico exhibió el más alto porcentaje de mortalidad al finalizar el período de experimentación. Los productos eremophilan-1(10,2, 11(13-trien-12-oico y ácido -cóstico dieron lugar al mayor número de malformaciones. Si bien aldehído cóstico mostró la máxima actividad de repelencia, todos los compuestos evaluados produjeron efectos significativos en el ensayo de elección.

  5. The mysid Siriella armata as a model organism in marine ecotoxicology: comparative acute toxicity sensitivity with Daphnia magna.

    Science.gov (United States)

    Pérez, Sara; Beiras, Ricardo

    2010-01-01

    Siriella armata (Crustacea, Mysidacea) is a component of the coastal zooplankton that lives in swarms in the shallow waters of the European neritic zone, from the North Sea to the Mediterranean. Juveniles of this species were examined as standard test organisms for use in marine acute toxicity tests. The effects of reference toxicants, three trace metals (Copper, Cadmium and Zinc), and one surfactant, sodium dodecyl sulfate (SDS) were studied on S. armata neonates (\\24 h) reared in the laboratory. Acute toxicity tests were carried out with filtered sea water on individual chambers (microplate wells for metals or glass vials for SDS) incubated in an isothermal room at 20 degrees C, with 16 h light: 8 h dark photoperiod for 96 h. Each neonate was fed daily with 10-15 nauplii of Artemia salina. Acute (96 h) LC50 values, in increasing order, were 46.9 lg/L for Cu, 99.3 lg/L for Cd, 466.7 lg/L for Zn and 8.5 mg/L for SDS. The LC(10), NOEC and LOEC values were also calculated. Results were compared with Daphnia magna, a freshwater cladoceran widely used as a standard ecotoxicological test organism. Acute (48 h) LC(50) values were 56.2 lg/L for Cu, 571.5 lg/L for Cd, 1.3 mg/L for Zn and 27.3 mg/L for SDS. For all the reference toxicants studied, the marine mysid Siriella armata showed higher sensitivity than the freshwater model organism Daphnia magna, validating the use of Siriella mysids as model organisms in marine acute toxicity tests.

  6. Nutritional Content of Artemia sp. Fed with Chaetoceros calcitrans and Skeletonema costatum

    Directory of Open Access Journals (Sweden)

    VIVI ENDAR HERAWATI

    2014-12-01

    Full Text Available Artemia sp. is a natural food with high protein content, especially amino acid. Nowadays, Indonesia still relies on import for its supply. Hence, the utilization of local Artemia sp. as an alternative to the imported product is recommended as it contains more protein and less expensive. The advantages of local Artemia sp. is its better crystal quality as it is still fresh. It also provides better income for salt farmers because waste water from salt farm can be used to culture Artemia sp.. This research is aimed at determining the quality of locally-produced Artemia sp., by evaluation of its essential amino acid and fatty acid profiles after treatments. Our results indicated that Artemia sp. cysts with good quality were produced after 8 hours and Artemia sp. reaches a hatching rate of 1,320,000 cysts (95% after 27 hours. We also found an indication that the best feed concentration was a mix of 60% Chaetoceros calcitrans with 40% Skeletonema costatum. Fatty acid profile analyses showed that the highest SAFA (12.86% and PUFA (29.91% were gained after feeding with Chaetoceros calcitrans, whereas the highest HUFA (4.93% was gained after feeding with Skeletonemacostatum. Essential amino acid profile analyses revealed the highest content of amino acid (18912.62 ppm was after feeding with a combination of Chaetoceros calcitrans and Skeletonema costatum. Finally, the proper water quality during research was at 25-30 oC of temperature, 30-31 ppt of salinity, pH 7.8-8.9, and DO was at 3.0-4.4 mg/L.

  7. Purification and characterization of a carboxymethyl cellulase from Artemia salina.

    Science.gov (United States)

    Zin, Hyun Woo; Park, Kwang-Hyun; Choi, Tae Jin

    2014-01-01

    Brine shrimp (Artemia salina) belong to a group of crustaceans that feed on microalgae and require a cellulase enzyme that can be used in ethanol production from marine algae. Protein with potential cellulase activity was purified and the activity analyzed under different conditions. After initial identification of cellulase activity by CMC cellulase, surface sterilization and PCR using 16s rRNA primers was conducted to confirm that the cellulase activity was not produced from contaminating bacteria. The enzyme was purified by ammonium sulfate fractionation, gel filtration, and ion exchange chromatography. After the final purification, a 70-fold increase in specific enzyme activity was observed. SDS-PAGE results revealed that the cellulase enzyme had a molecular mass of 96 kDa. Temperature, pH, and salinity values were found to be optimal at 55 °C, pH 8.0, and 600 mM NaCl, respectively. Specifically, the enzyme showed a fivefold increase in enzyme activity in seawater compared to 600 mM NaCl in phosphate buffer. Further analysis of the purified enzyme by molecular spectrometry showed no match to known cellulases, indicating this enzyme could be a novel halophilic cellulase that can be used for the production of bioethanol from marine macroalgae. PMID:24291747

  8. Bacillus thuringiensis Cry3Aa protoxin intoxication of Tenebrio molitor induces widespread changes in the expression of serine peptidase transcripts

    Science.gov (United States)

    The yellow mealworm, Tenebrio molitor, is a pest of stored grain products and is sensitive to the coleopteran-specific Cry3Aa toxin from Bacillus thuringiensis (Bt). Larvae digest protein initially with cysteine peptidases in the anterior midgut and further with serine peptidases in middle and poste...

  9. TÓXICIDAD DE LA APITOXINA EN UN MODELO DE Artemia salina

    Directory of Open Access Journals (Sweden)

    Juan Manuel Pérez Agudelo

    2015-06-01

    Full Text Available Objetivo:Determinar la toxicidad del extracto acuoso de Apitoxina mediante bioprospección en el modelo de Artemia salina. Materiales y métodos: Previo montaje de Biorreactor, un grupo fue expuesto al extracto acuoso de Apitoxina (n=20 y el grupo control fue expuesto a agua destilada (n=20 la toxicidad se definió por la muerte de la Artemia salina a las 24 horas de administración del extracto. Se realizó análisis estadístico no paramétrico mediante la prueba de Chi cuadrado de homogeneidad (Pearson para determinar la diferencia en mortalidad de los grupos.Resultados:El Grupo Control no presentó mortalidad, en tanto el Grupo Apitoxina presentó una mortalidad del 95%. Se demostró una asociación estadísticamente significativa con un p<0,05(IC: 95% entre la mortalidad de la Artemia salina y la administración de apitoxina.Conclusión:El extracto acuoso de apitoxina presenta toxicidad a una concentración de 0.35 en el modelo de Artemia salina. Palabras Clave: Apitoxina, Artemia salina, Toxicidad

  10. Stress tolerance during diapause and quiescence of the brine shrimp, Artemia.

    Science.gov (United States)

    MacRae, Thomas H

    2016-01-01

    Oviparously developing embryos of the brine shrimp, Artemia, arrest at gastrulation and are released from females as cysts before entering diapause, a state of dormancy and stress tolerance. Diapause is terminated by an external signal, and growth resumes if conditions are permissible. However, if circumstances are unfavorable, cysts enter quiescence, a dormant stage that continues as long as adverse conditions persist. Artemia embryos in diapause and quiescence are remarkably resistant to environmental and physiological stressors, withstanding desiccation, cold, heat, oxidation, ultraviolet radiation, and years of anoxia at ambient temperature when fully hydrated. Cysts have adapted to stress in several ways; they are surrounded by a rigid cell wall impermeable to most chemical compounds and which functions as a shield against ultraviolet radiation. Artemia cysts contain large amounts of trehalose, a non-reducing sugar thought to preserve membranes and proteins during desiccation by replacing water molecules and/or contributing to vitrification. Late embryogenesis abundant proteins similar to those in seeds and other anhydrobiotic organisms are found in cysts, and they safeguard cell organelles and proteins during desiccation. Artemia cysts contain abundant amounts of p26, a small heat shock protein, and artemin, a ferritin homologue, both ATP-independent molecular chaperones important in stress tolerance. The evidence provided in this review supports the conclusion that it is the interplay of these protective elements that make Artemia one of the most stress tolerant of all metazoan organisms. PMID:26334984

  11. Artemia parthenogenetica (Branchiopoda: Anostraca) from the Large Aral Sea: Abundance, distribution, population structure and cyst production

    Science.gov (United States)

    Arashkevich, Elena G.; Sapozhnikov, P. V.; Soloviov, K. A.; Kudyshkin, T. V.; Zavialov, P. O.

    2009-03-01

    The brine shrimp Artemia parthenogenetica appeared in the Large Aral Sea (Central Asia) in 1998 when mineralization reached 63 ppt. Data on Artemia abundance and biomass, along with temperature and salinity measurements were collected in the western basin during 2002-2006, primarily in the autumn. During the study period, population density grew progressively, both in terms of number, from 250 to 1260 individuals per m 3, and in terms of biomass, from 0.3 to 1.3 g per m 3. In 2005, the population density and spatial distribution in the different parts of the sea (western and eastern basins and strait) was assessed. The horizontal distribution of the Artemia population was uniform in the deep central part of the western basin, although the distribution was quite patchy in the shallow coastal zone. Depth habitat of Artemia was restricted to the upper 20-25 m of depth, as the oxygen depletion and formation of anoxic layer prevented distribution of Artemia to the deeper waters. In autumn, all females reproduced oviparously, with an average clutch size of 30-35 eggs per female. The number of eggs in a clutch was positively correlated with female body length ( r2 = 0.36-0.44).

  12. Simulación de un Robot Hexápodo Bioinspirado en el Tenebrio

    Directory of Open Access Journals (Sweden)

    Juan Pablo Rodríguez-Calderón

    2015-06-01

    Full Text Available Los insectos son base fundamental en el estudio de la robótica reactiva ya que estos poseen características biológicas y motrices que son de interés para ser implementadas en robots bioinspirados, teniendo en cuenta el desempeño de éstos en diferentes áreas. Por otra parte los animales hexápodos poseen omnidireccionalidad y estabilidad, debido a la formación del trípode de apoyo, el cual se crea en sus patas al dar un paso, lo cual les permite sobrepasar diferentes obstáculos con facilidad y velocidad constante. En este proyecto se implementa el sistema locomotor del insecto Tenebrio debido a la facilidad con que se pueden apreciar sus movimientos. Se analiza el desplazamiento de las patas del insecto en diferentes trayectorias, vistas y terreno plano, posteriormente se encontraron los parámetros, ecuaciones y restricciones que limitan los diferentes eslabones de cada una de las patas del Tenebrio, esto se realizó por medio de un análisis de imágenes. Finalmente la información recogida se implementa en la plataforma MATLAB para determinar las características de movimiento, estabilidad y desplazamiento.

  13. Global biodiversity and geographical distribution of diapausing aquatic invertebrates: the case of the cosmopolitan brine shrimp, Artemia (Branchiopoda, Anostraca)

    DEFF Research Database (Denmark)

    Muñoz, Joaquin; Pacios, Fernando

    2010-01-01

    The genus Artemia comprises passively dispersed anostracan species with a distribution all around the world, except in Antarctica. We used both published and personal data to assess and update existing knowledge on the diversity and distribution of Artemia, in particular compiling also genetic an...

  14. Purification and characterization of phenoloxidase from brine shrimp Artemia sinica

    Institute of Scientific and Technical Information of China (English)

    Tingjun Fan; Zhao Jing; Xianyuan Fan; Miaomiao Yu; Guojian Jiang

    2011-01-01

    Phenoloxidase from Artemia sinica (AsPO) was purified by Superdex 200 gel-filtration and Q Sepharose fast flow ionexchange chromatography,and its properties were characterized biochemically and enzymatically by using L-dihydroxyphenylalanine (L-DOPA) as the specific substrate.Results showed that AsPO was isolated as a monomeric protein of 125.5 kDa in molecular mass.The optimal pH value and temperature are 7.0 and 50℃,respectively,for its PO activity.The AsPO had an apparent Km value of 4.2 mM on L-DOPA,and 10.9 mM on catechol,respectively.Oxidase inhibitor on PO activity showed that the AsPO was extremely sensitive to ascorbic acid,sodium sulfite,and citric acid; and was very sensitive to cysteine,benzoic acid,and l-phenyl-2-thiourea.Combined with its specific enzyme activity on L-DOPA and catechol,it can be concluded that AsPO is most probably a typical catechol-type O-diphenoloxidase.Its PO activity was also sensitive to metal ions and chelators,and 20 mM DETC-inhibited PO activity was obviously recovered by 15 mM Cu2+,indicating that AsPO is most probably a copper-containing metalloenzyme.All these data about specific substrate,sensitivity to oxidase inhibitor metal ions and chelators indicate that the AsPO has the properties of a catechol-type copper-containing Odiphenoloxidase that functions as a vital humoral factor in host defense via melaninization as in other Crustaceans.

  15. Ecotoxicity tests based on phototactic behaviour in Daphnia magna; Saggi di ecotossicita` con Daphnia magna basati sul comportamento fototattico

    Energy Technology Data Exchange (ETDEWEB)

    Dojmi di Delupis, Gianluigi [Istituto Superiore di Sanita`, Rome (Italy). Lab. di Tossicologia Comparata ed Ecotossicologia

    1997-03-01

    Zooplankton behaviour depending on light, such as phototaxis, is important, mainly in terms of its ecological significance, as, for example, in the role of phototaxis in the diurnal vertical migration of Daphnia magna, and its possible involvement in predator-prey relations. In Daphnia magna chemicals were found to induce roughly three types of phototaxis alteration: depression, enhancement and sign change. These phenomena are based on mechanisms that require further investigation. In spite of the complex photobehaviour of Daphnia magna and the scarce knowledge of toxic effects, it was possible to set up rapid and easy ecotoxicity tests by fixing certain experimental conditions.

  16. Biomass production of Artemia in air-water-lift raceway system

    Digital Repository Service at National Institute of Oceanography (India)

    Royan, J.P.; Vijayaraghavan, S.; Krishnakumari, L.

    to 6.3 kg/m 3 in the GSL strain; 3.78 and 4.35 kg/m in the Indian and Sri Lankan strains respectively. The advantages of biomass produc tion of Artcmia through AWL are discussed. Key-words: Artcmia, Biomass, AWL Raceway System Artemia biomass... system is fairly simple. Advantages ofculturing Artemia in raceways are many; different stages of Arternia such as nauplii, pre-adults and adults produced can be used for hatcheries and pet fishery market either in live fonn/frozen or freeze-dried fonn...

  17. TÓXICIDAD DE LA APITOXINA EN UN MODELO DE Artemia salina

    OpenAIRE

    Juan Manuel Pérez Agudelo; Juan Felipe Salazar Espinosa; Jorge Hernán Hernández Guevara

    2015-01-01

    Objetivo:Determinar la toxicidad del extracto acuoso de Apitoxina mediante bioprospección en el modelo de Artemia salina. Materiales y métodos: Previo montaje de Biorreactor, un grupo fue expuesto al extracto acuoso de Apitoxina (n=20) y el grupo control fue expuesto a agua destilada (n=20) la toxicidad se definió por la muerte de la Artemia salina a las 24 horas de administración del extracto. Se realizó análisis estadístico no paramétrico mediante la prueba de Chi cuadrado de homogeneidad (...

  18. Intracellular water in Artemia cysts (brine shrimp): Investigations by deuterium and oxygen-17 nuclear magnetic resonance

    OpenAIRE

    Kasturi, S. R.; Seitz, P. K.; Chang, D. C.; Hazlewood, C. F.

    1990-01-01

    The dormant cysts of Artemia undergo cycles of hydration-dehydration without losing viability. Therefore, Artemia cysts serve as an excellent intact cellular system for studying the dynamics of water-protein interactions as a function of hydration. Deuterium spin-lattice (T1) and spin-spin (T2) relaxation times of water in cysts hydrated with D2O have been measured for hydrations between 1.5 and 0.1 g of D2O per gram of dry solids. When the relaxation rates (I/T1, I/T2) of 2H and 17O are plot...

  19. Bacteria contribute to Artemia nutrition in algae-limited conditions: A laboratory study

    OpenAIRE

    Toi, H.T.; P. Boeckx; Sorgeloos, P.; Bossier, P; Van Stappen, G.

    2013-01-01

    We investigated the effect of the stimulation of bacterial growth on Artemia performance in combination with a standard and with a low algal feeding regime. In both regimes, organic carbon (supplied as sucrose or soluble potato starch) and 15N labeled inorganic nitrogen (supplied as NaNO3) were used to stimulate bacterial growth in the Artemia cultures at C/N ratio 10 and 50. After a culture period of 15 days, significantly improved biomass production was obtained in all treatments with the l...

  20. Phylogeography and local endemism of the native Mediterranean brine shrimp Artemia salina (Branchiopoda: Anostraca)

    DEFF Research Database (Denmark)

    Muñoz, Joaquin; Gómez, Africa; Green, Andy J.;

    2008-01-01

    There has been a recent appreciation of the ecological impacts of zooplanktonic species invasions. The North American brine shrimp Artemia franciscana is one such alien invader in hyper-saline water ecosystems at a global scale. It has been shown to outcompete native Artemia species, leading...... to their local extinction. We used partial sequences of the mitochondrial Cytochrome c Oxidase Subunit 1 (COI or cox1) gene to investigate the genetic diversity and phylogeography of A. salina, an extreme halophilic sexual brine shrimp, over its known distribution range (Mediterranean Basin and South Africa...

  1. Acute and chronic toxicity of veterinary antibiotics to Daphnia magna

    DEFF Research Database (Denmark)

    Wollenberger, Leah; Halling-Sørensen, B.; Kusk, Kresten Ole

    2000-01-01

    The acute and chronic toxicity of nine antibiotics used both therapeutically and as growth promoters in intensive farming was investigated on the freshwater crustacean Daphnia magna. The effect of the antibiotics metronidazole (M), olaquindox (OL), oxolinic acid (OA), oxytetracycline (OTC...

  2. CRISPR/Cas-mediated targeted mutagenesis in Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Takashi Nakanishi

    Full Text Available The water flea Daphnia magna has been used as an animal model in ecology, evolution, and environmental sciences. Thanks to the recent progress in Daphnia genomics, genetic information such as the draft genome sequence and expressed sequence tags (ESTs is now available. To investigate the relationship between phenotypes and the available genetic information about Daphnia, some gene manipulation methods have been developed. However, a technique to induce targeted mutagenesis into Daphnia genome remains elusive. To overcome this problem, we focused on an emerging genome editing technique mediated by the clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas system to introduce genomic mutations. In this study, we targeted a functionally conserved regulator of eye development, the eyeless gene in D. magna. When we injected Cas9 mRNAs and eyeless-targeting guide RNAs into eggs, 18-47% of the survived juveniles exhibited abnormal eye morphology. After maturation, up to 8.2% of the adults produced progenies with deformed eyes, which carried mutations in the eyeless loci. These results showed that CRISPR/Cas system could introduce heritable mutations into the endogenous eyeless gene in D. magna. This is the first report of a targeted gene knockout technique in Daphnia and will be useful in uncovering Daphnia gene functions.

  3. Daphnia as an Emerging Epigenetic Model Organism

    Directory of Open Access Journals (Sweden)

    Kami D. M. Harris

    2012-01-01

    Full Text Available Daphnia offer a variety of benefits for the study of epigenetics. Daphnia’s parthenogenetic life cycle allows the study of epigenetic effects in the absence of confounding genetic differences. Sex determination and sexual reproduction are epigenetically determined as are several other well-studied alternate phenotypes that arise in response to environmental stressors. Additionally, there is a large body of ecological literature available, recently complemented by the genome sequence of one species and transgenic technology. DNA methylation has been shown to be altered in response to toxicants and heavy metals, although investigation of other epigenetic mechanisms is only beginning. More thorough studies on DNA methylation as well as investigation of histone modifications and RNAi in sex determination and predator-induced defenses using this ecologically and evolutionarily important organism will contribute to our understanding of epigenetics.

  4. Survival of the probiotic bacteria Lactobacillus rhamnosus in seawater and its bioencapsulation in the brine shrimp Artemia

    Directory of Open Access Journals (Sweden)

    Claudia Ofelio

    2014-06-01

    The results obtained in the first test showed that the L. rhamnosus was able to survive in seawater during the whole experiment (30h, maintaining densities of 10e7 CFU/ml during the first 6h although decreasing progressively afterwards (10e3 CFU/ml at 30h. This allows adequate levels at sufficient time for Artemia to incorporate the probiotic. In fact, bioencapsulation test demonstrated that Artemia metanauplii were able to bioencapsulate the probiotic, reaching the highest concentration in Artemia after 30 min of bioencapsulation (10e4 CFU/Artemia. A slight further decrease (10e3 CFU/Artemia was observed after 24h. Interestingly, L. rhamnosus reduced in 1Log total Vibrionaceae bacteria in Artemia during the 3 first hours. Therefore, 3 hours was the time established for the bioencapsulation protocol and further studies are in progress to determine the ability of Artemia metanauplii to maintain bioencapsulated L. rhamnosus once transferred to rearing tanks. Also, the capability of the probiotic to inhibit potential pathogenic or opportunistic bacteria will be assessed.

  5. Parasitismo por cestodos en Artemia spp. y su implicación en la invasión biológica de Artemia franciscana en la región Mediterránea

    OpenAIRE

    Redón Calvillo, Stella

    2015-01-01

    La presente Tesis Doctoral trata del fenómeno del parasitismo en el crustáceo Artemia y la implicación de los cestodos en el proceso de invasión biológica de la especie americana Artemia franciscana Kellogg, 1906 en la región Mediterránea. El crustáceo Artemia (Branchiopoda, Anostraca) es el invertebrado más conspicuo de los ecosistemas acuáticos hipersalinos de todo el mundo y un valioso recurso trófico para las poblaciones de aves acuáticas que residen en dichos ecosistemas. El uso generali...

  6. Isolation and identification of a cardioactive peptide from Tenebrio molitor and Spodoptera eridania.

    Science.gov (United States)

    Furuya, K; Liao, S; Reynolds, S E; Ota, R B; Hackett, M; Schooley, D A

    1993-12-01

    We isolated several cardioactive peptides from extracts of whole heads of the mealworm, Tenebrio molitor, and the southern armyworm, Spodoptera eridania, using a semi-isolated heart of Manduca sexta for bioassay. We have now isolated from each species the peptide with the strongest effect on rate of contraction of the heart. The peptides were identified using micro Edman sequencing and mass spectrometric methods. This cardioactive peptide has the same primary structure from both species: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, a cyclic nonapeptide which is identical to crustacean cardioactive peptide (CCAP) originally isolated from the shore crab, Carcinus maenas, and subsequently isolated from Locusta migratoria and Manduca sexta. This is additional evidence that CCAP has widespread occurrence in arthropoda. PMID:8129851

  7. Intracellular survival of Staphylococcus aureus during persistent infection in the insect Tenebrio molitor.

    Science.gov (United States)

    McGonigle, John E; Purves, Joanne; Rolff, Jens

    2016-06-01

    Survival of bacteria within host cells and tissues presents a challenge to the immune systems of higher organisms. Escape from phagocytic immune cells compounds this issue, as immune cells become potential vehicles for pathogen dissemination. However, the duration of persistence within phagocytes and its contribution to pathogen load has yet to be determined. We investigate the immunological significance of intracellular persistence within the insect model Tenebrio molitor, assessing the extent, duration and location of bacterial recovery during a persistent infection. Relative abundance of Staphylococcus aureus in both intracellular and extracellular fractions was determined over 21 days, and live S. aureus were successfully recovered from both the hemolymph and within phagocytic immune cells across the entire time course. The proportion of bacteria recovered from within phagocytes also increased over time. Our results show that to accurately estimate pathogen load it is vital to account for bacteria persisting within immune cells.

  8. Phylogenetic Analysis of Brine Shrimp (Artemia) in China Using DNA Barcoding

    Institute of Scientific and Technical Information of China (English)

    Weiwei Wang; Jun Yu; Qibin Luo; Haiyan Guo; Peter Bossier; Gilbert Van Stappen; Patrick Sorgeloos; Naihong Xin; Qishi Sun; Songnian Hu

    2008-01-01

    DNA barcoding is a powerful approach for characterizing species of organisms,especially those with almost identical morphological features, thereby helping to to establish phylogenetic relationships and reveal evolutionary histories. In this study, we chose a 648-bp segment of the mitochondrial gene, cytochrome c oxidase subunit 1 (COI), as a standard barcode region to establish phylogenetic relationships among brine shrimp (Artemia) species from major habitats around the world and further focused on the biodiversity of Artemia species in China, especially in the Tibetan Plateau. Samples from five major salt lakes of the Tibetan Plateau located at altitudes over 4,000 m showed clear differences from other Artemia populations in China. We also observed two consistent amino acid changes, 153A/V and 183L/F, in the COI gene between the high and low altitude species in China.Moreover, indels in the COI sequence were identified in cyst and adult samples unique to the Co Qen population from the Tibetan Plateau, demonstrating the need for additional investigations of the mitochondrial genome among Tibetan Artemia populations.

  9. Potential utilization of Artemia franciscana eggs as food for Coleomegilla maculata

    Science.gov (United States)

    We tested the hypothesis that Artemia franciscana Kellogg (brine shrimp, Anostraca: Artemiidae) eggs are suitable factitious, i.e., alternative, food to support the life history of a predatory ladybird beetle, Coleomegilla maculata DeGeer (Coleoptera: Coccinellidae). Using progeny from a stock colo...

  10. Assessment of cyst production potential of a natural population of brine shrimp Artemia

    Digital Repository Service at National Institute of Oceanography (India)

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Studies on a natural population of Artemia in the salterns of Jamnagar indicated that the population is parthenogenetic. These shrimps reach a maximum size of 9 mm. Number of cysts per brood varies from 10-32. Adults form about 68% of the total...

  11. Effect of artificial regulations of Artemia n-3 HUFA content on growth and survival of black seabream ( Sparus macrocephalus) larvae

    Science.gov (United States)

    Liu, Jing-Ke

    1998-06-01

    The requirement for dietary n-3 HUFA (highly unsaturated fatty acid) for growth and survival of black seabream ( Sparus macrocephalus) larvae was tested using Artemia with various levels of n-3 HUFA. Four treatments with Artemia differing in their n-3 HUFA were prepared by feeding them various oil emulsions. The results indicated that dietary n-3 HUFA significantly influences fish n-3 HUFA levels and are necessary for good growth and survival of black seabream larvae. The proper value of n-3 HUFA level and DHA, EPA level in Artemia should be 4.273% and 0.873% (wet weight) for good growth and survival in black seabream larvae respectively.

  12. Marine Lactobacillus pentosus H16 protects Artemia franciscana from Vibrio alginolyticus pathogenic effects.

    Science.gov (United States)

    Garcés, M E; Sequeiros, C; Olivera, N L

    2015-02-10

    Vibrio alginolyticus is an opportunistic pathogen which may affect different aquatic organisms. The aim of this study was to assess the probiotic properties and the protective mode of action of Lactobacillus pentosus H16 against V. alginolyticus 03/8525, through in vitro and in vivo studies using Artemia franciscana (hereafter Artemia). This strain showed antimicrobial activity against V. alginolyticus 03/8525 and Aeromonas salmonicida subsp. salmonicida ATCC33658 possibly related to lactobacilli organic acid production. It was able to survive at high rainbow trout bile concentrations and showed high selective adhesion to rainbow trout mucus (1.2×10(5)±8.0×10(3) cells cm(-2)). H16 outcompeted V. alginolyticus 03/8525 and A. salmonicida subsp. salmonicida ATCC33658, greatly reducing their adherence to rainbow trout mucus (64.8 and 74.1%, respectively). Moreover, H16 produced a cell-bound biosurfactant which caused an important decrease in the surface tension. H16 also protected Artemia nauplii against mortality when it was administered previous to V. alginolyticus 03/8525 inoculation. Furthermore, H16 bioencapsulated in Artemia, suggesting that it is possible to use live carriers in its administration. We conclude that the ability of L. pentosus H16 to selectively adhere to mucosal surfaces and produce cell-bound biosurfactants, displacing pathogenic strains, in addition to its antimicrobial activity, confer H16 competitive advantages against pathogens as demonstrated in in vivo challenge experiments. Thus, L. pentosus H16, a marine bacterium from the intestinal tract of hake, is an interesting probiotic for Artemia culture and also has the potential to prevent vibriosis in other aquaculture activities such as larvae culture and fish farming. PMID:25667335

  13. Effects of diel vertical migration on ephippia production in Daphnia

    Directory of Open Access Journals (Sweden)

    Victor ALEKSEEV

    2004-09-01

    Full Text Available Fish presence in experimentally simulated temperature conditions (limno-towers led to diel vertical migration and resulted in a decrease of ephippia production in Daphnia pulicaria. Diel fluctuation of food, temperature and day length similar to those experienced by migrating Daphnia were tested in laboratory experiments with flow-through-systems. Daphnids were kept under these conditions for 15 days and the proportions of females producing an ephippium were determined. In addition, maturation time, survival to maturation, size of the first clutch and female dry weight (without eggs on day 15 were traced. The most important factor affecting ephippia production in migrating Daphnia was photoperiod change, and when mother and embryo are exposed to alternating light conditions, these are thought to have the effect on the mother of acting as a signal to stop ephippia production. Such effects might be explained by the different sensitiveness to light intensity in females carrying an embryo and an embryo itself in broods. Fish presence forced Daphnia to stay in low-light conditions during daytime hours, to avoid attacks by fish. The Daphnia were able to check light intensity constantly by short vertical jumps above a light-threshold that was confirmed experimentally in limno-towers. The dim conditions were possibly light enough for adults to check day length, but were too dark for embryos shaded by the mother's body. Food conditions played a relatively small role in the process, and no effects of temperature on ephippia production were found. As expected, food affected the size of the first clutch, and temperature controlled the time to maturation. Photoperiod had a marginally significant influence on the time to maturation in Daphnia. A hypothesis on the role of photoperiod as the key factor for Daphnia life cyclic recurrence and other seasonal adaptations is proposed.

  14. The genus Artemia Leach, 1819 (Crustacea: Branchiopoda: I. True and false taxonomical descriptions El género Artemia Leach, 1819 (Crustacea: Branchiopoda: I. Descripciones taxonómicas verdaderas y falsas

    Directory of Open Access Journals (Sweden)

    Alireza Asem

    2010-01-01

    Full Text Available The brine shrimp Artemia is important for aquaculture since it is bighly nutritious. It is also used widely in biological studies because it is easy to culture. The aim of the present study is to review the literature on the taxonomical nomenclature of Artemia. The present study indicates the existence of seven species: three living in the Americas, one in Europe, and three in Asia.El camarón de salmuera Artemia es importante para la acuicultura por su alta calidad nutricional y es muy utilizado para estudios biológicos por ser de fácil cultivo. El objetivo del presente estudio es revisar la literatura sobre la nomenclatura taxonómica de Artemia. Se determina la existencia de siete especies; tres de ellas viven en América, una en Europa y tres en Asia.

  15. Reducing Vibrio load in Artemia nauplii using antimicrobial photodynamic therapy: a promising strategy to reduce antibiotic application in shrimp larviculture

    Digital Repository Service at National Institute of Oceanography (India)

    Aparna, A.; Arshad, E.; Jasmin, C.; Pai, S.S.; BrightSingh, I.S.; Mohandas, A.; Anas, A.

    be attributed to the destruction of outer membrane protein of V. harveyi by reactive oxygen intermediates produced during the photosensitization. Further, mesocosm experiments with V. harveyi and Artemia nauplii demonstrated that in 30 min, the aPDT could kill...

  16. [Acute Toxicity of Coptis chinensis Rhizome Extracts to Daphnia carinata].

    Science.gov (United States)

    Chen, Ya-nan; Yuan, Ling

    2015-10-01

    Coptis chinensis rhizome and preparations were widely used for the treatment of fish diseases in aquaculture. the acute toxicological effect of CRE on lethal, movement and phototaxis was studied on Daphnia carinata monoclone as a test animal in the present experiment. The results showed that CRE was acute toxic to this animal and alkaloids berberine concentrations in CRE changed in the following sequence: half lethal > half inhibitory > limitable, which led to a significant change in phototaxis index of Daphnia carinata. The concentration of CRE for the significant change in phototaxis index was 4.27 mg x L(-1), which was lower than the concentration in water to cure the fish diseases and this conclusion indicated an ecological risk of this antibiotic to Daphnia carinata in aquaculture. In addition, the concentration of CRE in phototaxis index was changed from 30.62 times at 48th hour to 36.51 times at 24th hour that were lower than half lethal concentration. Detecting phototaxis index was easy and only 3 hours was required, so utilizing the quickly change of Daphnia carinata phototaxis can be an effective method to monitor the toxicity effect of CRE on Daphnia carinata. The abuse of rhizome or preparations in aquaculture might destroy the aquatic food chain, resulting in an imbalance of aquatic ecosystems.

  17. Using Daphnia bio-sensor for random number generation

    Directory of Open Access Journals (Sweden)

    Đorđević Đorđe

    2013-01-01

    Full Text Available One of the most used bioassays for toxicity screening of chemicals and for toxicity monitoring of effluents and contaminated waters is the acute toxicity test performed with Daphnia Magna. Standard methods have been developed and gradually improved by national and international organizations dealing with toxicity testing procedure, in view of its application within a regulatory framework. As for all toxicity tests, the organisms used for the acute Daphnia magna assay have to be obtained from live stocks which are cultured in the laboratory on live food (micro-algae. The technical and biological problems inherent in year-round culturing and the culturing/maintenance costs of live stocks restricts its application to a limited number of highly specialized laboratories. This bottleneck in toxicity testing triggered investigations forward the concept of "microbiotests" or "small-scale" toxicity tests. This paper deals with the measurement of changes in the behavior of Daphniae using device BIOTOXINOMER, awarded by Ministry for Science and Technological Development of Republic Serbia with Diploma for best Innovation idea in year 2010 in category Medicine, Health, and Ecology. Actually, the main topic is digitalization of bio-monitoring results and random number generating on the base of Daphniae movement (distance. The on-line monitoring is available on site www.dundjer.co.rs/Daphniae and open-source software support is available on the same site. [Projekat Ministarstva nauke Republike Srbije, br. III44006 i br. TR37003

  18. USE OF BRINE SHRIMP (ARTEMIA IN THE FEEDING OF STURGEON JUVENILES (ACIPENSERIDAE (REVIEW

    Directory of Open Access Journals (Sweden)

    M. Simon

    2016-06-01

    Full Text Available Purpose. To review scientific sources on the technological and biological characteristics of the use of brine shrimp (Artemia in the feeding of sturgeon juvenilse (Acipenseridae. To highlight the common biotechnological bases of the enrichment of brine shrimp with biologically active substances necessary for the full development of sturgeon juveniles. Findings. The review of scientific papers showed that the technology is the use of brine shrimp in the feeding of sturgeon speices not only had not lost its relevance in aquaculture, but also continued to evolve in response to new challenges. The review contains a description of the peculiarities of the biological structure of brine shrimp eggs and methods of their quality assessment in the field. It describes the nutritional characteristics of Artemia. It is shown that brine shrimp is the best food organism for the use in the feeding of sturgeon fingerlings. The calculation scheme for Artemia decapsulation and incubation is provided. The main technological stages of of the preparation of shrimps before their use in feeding – activation, hydration, decapsulation, incubation, dehydration were described. The effect of brine shrimp nauplia enriched with biologically active substances enriched brine shrimp on sturgeon juveniles was highlighted. Practical value. Fish farm owners search for cost-effective, easy to use, and available food that is preferred by sturgeon juveniles (Acipenseridae. Brine shrimp nauplii obtained from cysts can be readil used to feed fish just after one-day incubation. Instar I (the nauplii that just hatched and contain large yolk reserves in their body and instar II nauplii (the nauplii after first moult and with functional digestive tracts are more widely used in aquaculture, because they are easy for operation, rich in nutrients, and small, which makes them suitable for feeding fish larvae as live feed or after drying. The generalized information will be important for

  19. Comparative Developmental Staging of Female and Male Water Fleas Daphnia pulex and Daphnia magna During Embryogenesis.

    Science.gov (United States)

    Toyota, Kenji; Hiruta, Chizue; Ogino, Yukiko; Miyagawa, Shinichi; Okamura, Tetsuro; Onishi, Yuta; Tatarazako, Norihisa; Iguchi, Taisen

    2016-02-01

    The freshwater crustacean genus Daphnia has been used extensively in ecological, developmental and ecotoxicological studies. Daphnids produce only female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable conditions and external stimuli, they produce male offspring. Although we reported that exogenous exposure to juvenile hormones and their analogs can induce male offspring even under female-producing conditions, we recently established a male induction system in the Daphnia pulex WTN6 strain simply by changing day-length. This male and female induction system is suitable for understanding the innate mechanisms of sexual dimorphic development in daphnids. Embryogenesis has been described as a normal plate (developmental staging) in various daphnid species; however, all studies have mainly focused on female development. Here, we describe the developmental staging of both sexes during embryogenesis in two representative daphnids, D. pulex and D. magna, based on microscopic time-course observations. Our findings provide the first detailed insights into male embryogenesis in both species, and contribute to the elucidation of the mechanisms underlying sexual differentiation in daphnids.

  20. The response of European Daphnia magna Straus and Australian Daphnia carinata King to changes in geomagnetic field.

    Science.gov (United States)

    Krylov, Viacheslav V; Bolotovskaya, Irina V; Osipova, Elena A

    2013-03-01

    This study investigates the effects of lifelong exposure to reversed geomagnetic and zero geomagnetic fields (the latter means absence of geomagnetic field) on the life history of Daphnia carinata King from Australia and Daphnia magna Straus from Europe. Considerable deviation in the geomagnetic field from the usual strength, leads to a decrease in daphnia size and life span. Reduced brood sizes and increased body length of neonates are observed in D. magna exposed to unusual magnetic background. The most apparent effects are induced by zero geomagnetic field in both species of Daphnia. A delay in the first reproduction in zero geomagnetic field is observed only in D. magna. No adaptive maternal effects to reversed geomagnetic field are found in a line of D. magna maintained in these magnetic conditions for eight generations. Integrally, the responses of D. magna to unusual geomagnetic conditions are more extensive than that in D. carinata. We suggest that the mechanism of the effects of geomagnetic field reversal on Daphnia may be related to differences in the pattern of distribution of the particles that have a magnetic moment, or to moving charged organic molecules owing to a change in combined outcome and orientation of the geomagnetic field and Earth's gravitational field. The possibility of modulation of self-oscillating processes with changes in geomagnetic field is also discussed. PMID:23320498

  1. Experimental assessment of environmental influences on the stable isotopic composition of Daphnia pulicaria and their ephippia

    Directory of Open Access Journals (Sweden)

    J. Schilder

    2015-02-01

    δ15N values of ephippia and Daphnia between the 12 °C and 20 °C treatments, but the δ18O values of Daphnia and ephippia were on average 1.2‰ lower at 20 °C compared with 12 °C. We conclude that the stable isotopic composition of Daphnia ephippia provides information on that of the parent Daphnia and of the food and water they were exposed to, with small offsets between Daphnia and ephippia relative to variations in Daphnia stable isotopic composition reported from downcore studies. However, our experiments also indicate that temperature may have a minor influence on the δ13C, δ15N and δ18O values of Daphnia body tissue and ephippia. This aspect deserves attention in further controlled experiments.

  2. Evolutionary Origin and Phylogeography of the Diploid Obligate Parthenogen Artemia parthenogenetica (Branchiopoda: Anostraca)

    DEFF Research Database (Denmark)

    Muñoz, Joaquin; Gómez, Africa; Green, Andy J.;

    2010-01-01

    Background: Understanding the evolutionary origin and the phylogeographic patterns of asexual taxa can shed light on the origin and maintenance of sexual reproduction. We assessed the geographic origin, genetic diversity, and phylogeographic history of obligate parthenogen diploid Artemia...... and recent evolutionary origin of diploid A. parthenogenetica, and strongly suggested that the geographic origin of parthenogenesis in Artemia was in Central Asia. Our results indicate that the maternal sexual ancestors of diploid A. parthenogenetica were an undescribed species from Kazakhstan and A. urmiana....... Conclusions/Significance: We found evidence for multiple origin of parthenogenesis in Central Asia. Our results indicated that, shortly after its origin, diploid A. parthenogenetica populations underwent a rapid range expansion from Central Asia towards the Mediterranean region, and probably to the rest...

  3. Participation of metanauplii and juvenile individuals of Artemia parthenogenetica (Branchiopoda) in the circulation of avian cestodes.

    Science.gov (United States)

    Redón, Stella; Amat, Francisco; Hontoria, Francisco; Vasileva, Gergana P; Nikolov, Pavel N; Georgiev, Boyko B

    2011-04-01

    Adult crustaceans of the genus Artemia (brine shrimps) are intermediate hosts in the life cycle of cestode species parasitic in aquatic birds as their definitive hosts. However, there are no data on the role of larval and juvenile brine shrimps in the transmission of avian helminth parasites. In order to examine the possible role of early developmental stages (nauplii, metanauplii and juveniles) of Artemia for the circulation of avian cestodes, the natural cestode infection in the population of Artemia parthenogenetica from La Mata Lagoon, Mediterranean coast of Spain, was studied. Metacestodes (cysticercoids) of four cestode species were recorded in adult brine shrimps: Flamingolepis liguloides and Flamingolepis flamingo (hymenolepidids parasitic in flamingos), Confluaria podicipina (a hymenolepidid species parasitic in grebes) and Eurycestus avoceti (a dilepidid species parasitic in avocets, stilts, plovers and, to a lesser extent, in flamingos). No cysticercoids were found in nauplii. Two species, F. liguloides and F. flamingo, were found in metanauplii and juvenile brine shrimps. Only 36.3% of the cysticercoids of F. liguloides occurred in adult brine shrimps; the remaining 63.7% were parasitic in metanauplii (39.6%) and juveniles (24.1%). Similarly, the metacestodes of F. flamingo were also distributed among various age groups: in adults (44.4% of cysticercoids), juveniles (27.8%) and metanauplii (27.8%). These results indicate that the early developmental stages of Artemia have an important role for the circulation of certain parasite species. No cysticercoids of C. podicipina and E. avoceti were recorded in larval and juvenile brine shrimps. The selective infestation of larval brine shrimps with flamingo parasites is probably associated with the feeding behaviour of definitive hosts, which are filtering predators; in contrast, grebes and waders pick brine shrimps individually one by one. The possible underlying mechanism for selective infestation of

  4. Morphological changes about Artemia Salina by the effect of gamma radiation

    International Nuclear Information System (INIS)

    Direction Council of Europe require restriction of laboratory vertebrae in biological experiments. Once by possibilities is using biological test II. generation among which belongs to and test for Artemia salina. Still this time published test however value only lethality in dependence on dose, exposition and time survival. This work document possibility watch of expressive morphological changes, which consist in retardation development brine shrimps stage in dependence on dose gamma radiation 60Co. (authors)

  5. Vaccination of European sea bass fry through bioencapsulation of Artemia nauplii

    OpenAIRE

    Chair, M.; Gapasin, R.S.J.; Dehasque, M.; Sorgeloos, P.

    1994-01-01

    European sea bass (Dicentrarchus labrax) fry vaccinated orally by bioencapsulation in Artemia nauplii or by bath method exhibited better performance than control fish in terms of growth, food conversion and resistance to stress. The comparable survival between vaccinated and non-vaccinated animals suggests that vaccination methods are stressful. The present study shows that oral vaccination can be used to enhance growth in fish fry.

  6. Biological screening of selected Pacific Northwest forest plants using the brine shrimp (Artemia salina) toxicity bioassay.

    Science.gov (United States)

    Karchesy, Yvette M; Kelsey, Rick G; Constantine, George; Karchesy, Joseph J

    2016-01-01

    The brine shrimp (Artemia salina) bioassay was used to screen 211 methanol extracts from 128 species of Pacific Northwest plants in search of general cytotoxic activity. Strong toxicity (LC50  1000 µg/ml). Our subsequent studies of conifer heartwoods with strong activity confirm the assay's value for identifying new investigational leads for materials with insecticidal and fungicidal activity. PMID:27186474

  7. Oxygen bioavailability and haemoglobins in the brine shrimp Artemia franciscana

    OpenAIRE

    Wachter, B; Blust, R.; Decleir, W.

    1992-01-01

    Bioavailability of oxygen for the saline-water invertebrate Artemia franciscana was studied, since both oxygen concentration and oxygen diffusion rate change with salinity. Total haemoglobin concentration and the relative contribution of each of three haemoglobins was measured in specimens acclimated to different salinities and oxygen concentrations. Both haemoglobin concentration and contribution were influenced by salinity and the group observed (males, females with and females without eggs...

  8. Genetic characterization of Artemia tibetiana (Crustacea: Anostraca)

    OpenAIRE

    Abatzopoulos, T.J.; Kappas, I.; Bossier, P.; Sorgeloos, P.; Beardmore, J. A.

    2002-01-01

    The brine shrimp Artemia consists of a number of bisexual species and a large number of parthenogenetic forms, which collectively, inhabit a wide range of hypersaline habitats. A recently described species (A. tibetiana) from a carbonate lake (Lagkor Co) in Tibet at an altitude of 4490 m has been tested with New World (A. franciscana USA, and A. franciscana feral population Vietnam) and Old World species (A. salina, A. urmiana, A. sinica) for cross fertility. These tests show complete inferti...

  9. Neuroanatomical clues to peripheral locomotor control in small crustaceans (Artemia salina).

    Science.gov (United States)

    Kane, E S

    1975-08-01

    Brine shrimp (Artemia salina) were prepared for light and electron microscopy at several stages. Immersion-fixed, rapid Golgi impregnations demonstrated two distinct neuronal types in thoracic appendages of mature, freely swimming Artemia. Isolated motor neurons had large cell somas and thick, radiating dendrites at the body wall-limb junction. A long, elaborate axon extended into the limb. Groups of a second type of neuron with smaller somas and very thin, radiating processes occurred in the distal limb near presumably tactile bristles. Thick axons from motor neurons were traced to terminals associated with limb muscle. Both muscle and axon were best seen with Nomarski optics. Motor axons possessed elongate, irregularly shaped boutons en passant and morphologically variable boutons terminaux; the latter included huge endings with knobbed projectiles arising from thick collaterals, or smaller, round boutons from thin collaterals. In addition, a thick unidentified axon coursed longitudinally within the central body wall, sending short collaterals peripherally. The elaborate peripheral neurons described in this Golgi study may be anatomical correlates for the extraordinary coordination of mature brine shrimp. Because Artemia movements resemble those of leech and decapods, which have been studied extensively electrophysiologically, the possibility of similarly elaborate peripheral structures supplementing central control of locomotion in those invertebrates should be considered.

  10. Laboratory generation of new parthenogenetic lineages supports contagious parthenogenesis in Artemia

    Directory of Open Access Journals (Sweden)

    Marta Maccari

    2014-06-01

    Full Text Available Contagious parthenogenesis—a process involving rare functional males produced by a parthenogenetic lineage which mate with coexisting sexual females resulting in fertile parthenogenetic offspring—is one of the most striking mechanisms responsible for the generation of new parthenogenetic lineages. Populations of the parthenogenetic diploid brine shrimp Artemia produce fully functional males in low proportions. The evolutionary role of these so-called Artemia rare males is, however, unknown. Here we investigate whether new parthenogenetic clones could be obtained in the laboratory by mating these rare males with sexual females. We assessed the survival and sex ratio of the hybrid ovoviviparous offspring from previous crosses between rare males and females from all Asiatic sexual species, carried out cross-mating experiments between F1 hybrid individuals to assess their fertility, and estimated the viability and the reproductive mode of the resulting F2 offspring. Molecular analysis confirmed the parentage of hybrid parthenogenetic F2. Our study documents the first laboratory synthesis of new parthenogenetic lineages in Artemia and supports a model for the contagious spread of parthenogenesis. Our results suggest recessive inheritance but further experiments are required to confirm the likelihood of the contagious parthenogenesis model.

  11. Assessment of toxic potential of Cerrado fruit seeds using Artemia salina bioassay

    Directory of Open Access Journals (Sweden)

    Raíza Cavalcante Fonseca

    2013-06-01

    Full Text Available Artemia salina bioassay was used to assess toxicity of seeds and kernels of Brazilian fruits from cerrado (central high plains region and other inner regions of the country. Water extracts of the kernels were filtered and added to Artemia cultures containing ten individuals per mL. Dose - response curves were constructed, and LD50 values were calculated. Pure potassium cyanide standard was used to draw a calibration curve for comparison to detect the presence of cyanide in the samples tested. Extracts of the seeds of araticum, mangaba, cagaita, jatobá, and tucumã were found toxic to Artemia salina, and some of the dose - response curves were very similar in shape to those obtained with pure potassium cyanide standards, while the samples of baru, cajá-manga, siriguela, trauma, and veludo showed no toxicity at all. The Guignard test, specific for cyanide detection, showed negative results in all toxic samples, suggesting the presence of other toxic compounds rather than cyanide. The comparison of araticum dose - response curve with those of other annonaceous fruits suggests the presence acetogenins as the main toxic compounds in the seeds. These results could be useful to prevent poisoning by industrial derivatives of the fruits studied.

  12. Linear solvation energy relationships for toxicity of selected organic chemicals to Daphnia pulex and Daphnia magna

    Science.gov (United States)

    Passino, Dora R.M.; Hickey, James P.; Frank, Anthony M.

    1988-01-01

    In the Laurentian Great Lakes, more than 300 contaminants have been identified in fish, other biota, water, and sediment. Current hazard assessment of these chemicals by the National Fisheries Research Center-Great Lakes is based on their toxicity, occurrence in the environment, and source. Although scientists at the Center have tested over 70 chemicals with the crustacean Daphnia pulex, the number of experimental data needed to screen the huge array of chemicals in the Great Lakes exceeds the practical capabilities of conducting bioassays. This limitation can be partly circumvented, however, by using mathematical models based on quantitative structure-activity relationships (QSAR) to provide rapid, inexpensive estimates of toxicity. Many properties of chemicals, including toxicity, bioaccumulation and water solubility are well correlated and can be predicted by equations of the generalized linear solvation energy relationships (LSER). The equation we used to model solute toxicity is Toxicity = constant + mVI/100 + s (π* + dδ) + bβm + aαm where VI = intrinsic (Van der Waals) molar volume; π* = molecular dipolarity/polarizability; δ = polarizability 'correction term'; βm = solute hydrogen bond acceptor basicity; and αm = solute hydrogen bond donor acidity. The subscript m designates solute monomer values for α and β. We applied the LSER model to 48-h acute toxicity data (measured as immobilization) for six classes of chemicals detected in Great Lakes fish. The following regression was obtained for Daphnia pulex (concentration = μM): log EC50 = 4.86 - 4.35 VI/100; N = 38, r2 = 0.867, sd = 0.403 We also used the LSER modeling approach to analyze to a large published data set of 24-h acute toxicity for Daphnia magna; the following regression resulted, for eight classes of compounds (concentration = mM): log EC50 = 3.88 - 4.52 VI/100 - 1.62 π* + 1.66 βm - 0.916 αm; N = 62, r2 = 0.859, sd = 0.375 In addition we developed computer software that identifies

  13. Interaction of Tenebrio Molitor Antifreeze Protein with Ice Crystal: Insights from Molecular Dynamics Simulations.

    Science.gov (United States)

    Ramya, L; Ramakrishnan, Vigneshwar

    2016-07-01

    Antifreeze proteins (AFP) observed in cold-adapting organisms bind to ice crystals and prevent further ice growth. However, the molecular mechanism of AFP-ice binding and AFP-inhibited ice growth remains unclear. Here we report the interaction of the insect antifreeze protein (Tenebrio molitor, TmAFP) with ice crystal by molecular dynamics simulation studies. Two sets of simulations were carried out at 263 K by placing the protein near the primary prism plane (PP) and basal plane (BL) of the ice crystal. To delineate the effect of temperatures, both the PP and BL simulations were carried out at 253 K as well. The analyses revealed that the protein interacts strongly with the ice crystal in BL simulation than in PP simulation both at 263 K and 253 K. Further, it was observed that the interactions are primarily mediated through the interface waters. We also observed that as the temperature decreases, the interaction between the protein and the ice increases which can be attributed to the decreased flexibility and the increased structuring of the protein at low temperature. In essence, our study has shed light on the interaction mechanism between the TmAFP antifreeze protein and the ice crystal. PMID:27492241

  14. Rearing Tenebrio molitor in BLSS: Dietary fiber affects larval growth, development, and respiration characteristics

    Science.gov (United States)

    Li, Leyuan; Stasiak, Michael; Li, Liang; Xie, Beizhen; Fu, Yuming; Gidzinski, Danuta; Dixon, Mike; Liu, Hong

    2016-01-01

    Rearing of yellow mealworm (Tenebrio molitor L.) will provide good animal nutrition for astronauts in a bioregenerative life support system. In this study, growth and biomass conversion data of T. molitor larvae were tested for calculating the stoichiometric equation of its growth. Result of a respiratory quotient test proved the validity of the equation. Fiber had the most reduction in mass during T. molitor‧s consumption, and thus it is speculated that fiber is an important factor affecting larval growth of T. molitor. In order to further confirm this hypothesis and find out a proper feed fiber content, T. molitor larvae were fed on diets with 4 levels of fiber. Larval growth, development and respiration in each group were compared and analyzed. Results showed that crude-fiber content of 5% had a significant promoting effect on larvae in early instars, and is beneficial for pupa eclosion. When fed on feed of 5-10% crude-fiber, larvae in later instars reached optimal levels in growth, development and respiration. Therefore, we suggest that crude fiber content in feed can be controlled within 5-10%, and with the consideration of food palatability, a crude fiber of 5% is advisable.

  15. Quantity estimation based on numerical cues in the mealworm beetle (Tenebrio molitor

    Directory of Open Access Journals (Sweden)

    Pau eCarazo

    2012-11-01

    Full Text Available In this study, we used a biologically relevant experimental procedure to ask whether mealworm beetles (Tenebrio molitor are spontaneously capable of assessing quantities based on numerical cues. Like other insect species, mealworm beetles adjust their reproductive behaviour (i.e. investment in mate guarding according to the perceived risk of sperm competition (i.e. probability that a female will mate with another male. To test whether males have the ability to estimate numerosity based on numerical cues, we staged matings between virgin females and virgin males in which we varied the number of rival males the experimental male had access to immediately preceding mating as a cue to sperm competition risk (from 1 to 4. Rival males were presented sequentially, and we controlled for continuous cues by ensuring that males in all treatments were exposed to the same amount of male-male contact. Males exhibited a marked increase in the time they devoted to mate guarding in response to an increase in the number of different rival males they were exposed to. Since males could not rely on continuous cues we conclude that they kept a running tally of the number of individuals they encountered serially, which meets the requirements of the basic ordinality and cardinality principles of proto-counting. Our results thus offer good evidence of ‘true’ numerosity estimation or quantity estimation and, along with recent studies in honey-bees, suggest that vertebrates and invertebrates share similar core systems of non-verbal numerical representation.

  16. Trade-off between cellular immunity and life span in mealworm beetles Tenebrio molitor

    Institute of Scientific and Technical Information of China (English)

    Indrikis KRAMS; Jan(i)na DAUK(S)TE; Inese KIVLENIECE; Ants KAASIK; Tatjana KRAMA; Todd M.FREEBERG; Markus J.RANTALA

    2013-01-01

    Encapsulation is a nonspecific,cellular response through which insects defend themselves against multicellular pathogens.During this immune reaction,haemocytes recognize an object as foreign and cause other haemocytes to aggregate and form a capsule around the object,often consisting of melanized cells.The process of melanisation is accompanied by the formation of potentially toxic reactive oxygen species,which can kill not only pathogens but also host cells.In this study we tested whether the encapsulation response is costly in mealworm beetles Tenebrio molitor.We found a negative relationship between the duration of implantation via a nylon monofilament and remaining life span.We also found a negative relationship between the strength of immune response and remaining life span,suggesting that cellular immunity is costly in T.molitor,and that there is a trade-off between immune response and remaining life span.However,this relationship disappeared at 31-32 hours of implantation at 25 ± 2℃.As the disappearance of a relationship between duration of implantation and lifespan coincided with the highest values of encapsulation response,we concluded that the beetles stopped investment in the production of melanotic cells,as the implant,a synthetic parasite,was fully isolated from the host's tissues.

  17. Evaluation of MWNT toxic effects on daphnia and zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Olasagasti, Maider; Rainieri, Sandra [AZTI-TECNALIA, Parque Tecnologico de Bizkaia 609, 48160 Derio (Spain)], E-mail: srainieri@azti.es; Alvarez, Noelia; Vera, Carolina [INASMET-TECNALIA, Mikeletegi pasealekua, 2, Parque Tecnologico, 20009 San Sebastian (Spain)

    2009-05-01

    Organisms of daphnia (Daphnia magna) and zebrafish (Danio rerio) embryos were exposed to a range of different concentrations of COOH-functionalized MWCNT suspended in an aqueous solution of Tween 20. Immobilization of daphnia and growth retardation, inhibition and malformation of zebrafish embryos were the endpoints tested after 24 and 48 hours. Immobilization of daphnia could be observed from 3 to 16 ppm and an increasing mortality of zebrafish embryo was detected at all the concentration tested. To identify more subtle toxic effects, we took advantage of the extensive information available on the zebrafish genome and monitored by RT-PCR the expression patterns of different zebrafish genes that could act as toxicity bio-markers. At some of the concentrations tested, changes in the expression profiles of the genes examined were detected. Our results suggest that MWCNT could potentially represent a risk to human health and environment, therefore a wider range of concentrations and further testing of this molecules should be carried out to define possible limitations in their use.

  18. Seston composition and the potential for Daphnia growth

    NARCIS (Netherlands)

    Lange, de H.J.; Arts, M.T.

    1999-01-01

    A field survey was conducted to study the relationships amongst the composition of the seston, the nutritional value of the seston for herbivorous zooplankton (Daphnia), and selected water clarity parameters. Sixteen ponds in a wetland area and seven larger lakes, all located in south central Saskat

  19. Effect of lindane on the clearance rate of Daphnia magna

    NARCIS (Netherlands)

    Hartgers, E.M.; Heugens, E.W.; Deneer, J.W.

    1999-01-01

    The impact of the insecticide lindane (%-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 7g Lm1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 7g Lm1). The onset of the effect

  20. Observation of two-dimensional yttrium oxide nanoparticles in mealworm beetles (Tenebrio molitor).

    Science.gov (United States)

    Chen, Yunyun; Sanchez, Carlos; Yue, Yuan; González, Jorge M; Parkinson, Dilworth Y; Liang, Hong

    2016-09-01

    Nanomaterials are being used in medicine, manufacturing and consumer products, but their effects on organisms and the environment are not well understood because of the difficulty in detecting them. Here dual-energy X-ray K-edge subtraction was used to track two-dimensional yttrium oxide nanoparticles (which can be found in such household objects as color televisions) in adult mealworms (Tenebrio molitor). The insects ingested nanoparticle-infused feed for different time periods, up to 24 h, and the nanoparticles could then be identified at several locations in the insects' head, thorax and abdomen, mostly within the digestive tract. In time, all particles were excreted. PMID:27577775

  1. Effects of food type on the life history of Daphnia clones from lakes differing in trophic state. I. Daphnia galeata feeding on Scenedesmus and Oscillatoria

    NARCIS (Netherlands)

    Repka, S.

    1997-01-01

    1. Effects of the green alga Scenedesmus obliquus and the filamentous cyanobacterium Oscillatoria limnetica as food sources on the growth and reproduction of nine Daphnia galeata clones were studied. A high concentration of these two algae species was fed to Daphnia clones collected from four lakes

  2. The effects of dietary administration with chemical treated Saccharomyces cerevisiae strain YG3-1 on the growth of aquatic invertebrates in Artemia

    Directory of Open Access Journals (Sweden)

    Behnam Shekarchi

    2016-02-01

    Full Text Available Objective: To investigate the biological effects of β-glucans in cell wall of new identified strain Saccharomyces cerevisiae strain YG3-1 on the growth of aquatic invertebrates, in Artemia as model organism. Methods: All yeasts used in the present study were isolated from Rainbow trout intestine and then cultured in yeast extract-peptone-glycerol medium. Activation of β-glucan in yeasts was performed by chemical treatment with 2-mercaptoethanol (2ME (3.5% v/v. Then nauplii and larvae individuals of Artemia urmiana and Artemia franciscana (two different species of Artemia as test organisms were fed with 2ME-treated yeasts during the culture. At the end of experiment, after feeding individual length (total length and growth rate in adult individuals of Artemia was measured. Results: Following this administration, growth in both species of Artemia was improved (P < 0.05. So, the results showed that Artemia urmiana adults individuals that fed with 2MEtreated yeasts had the highest growth and total length. These results were confirmed with growth measurement in adult individuals of Artemia. Conclusions: This study suggested that 2ME-treated Saccharomyces cerevisiae strain YG3-1 yeasts can be used for enhancing the growth of other aquatic invertebrates like shrimps as probiotic supplement and growth promoter.

  3. Toxic effect of selenium on the zooplankton, Daphnia magna and Daphnia pulicaria, in water and the food source (Chlamydomonas reinhardtii)

    Energy Technology Data Exchange (ETDEWEB)

    Boyum, K.W.

    1984-01-01

    Acute and chronic toxicity experiments were performed on the zooplankton, Daphnia magna and Daphnia pulicaria, to investigate the toxicity of selenium on these aquatic invertebrates. The acute 48 h LC/sub 50/ of sodium selenate for Daphnia magna and Daphnia pulicaria were 1.01 and 0.25 mg Se/1, respectively. The 48 h LC/sub 50/ of sodium selenite for D. magna and D. pulicaria were 0.45 and 0.006 mg Se/1, respectively. Chronic 28-day toxicity tests were performed on D. magna at 0.05, 0.10, 0.50, and 1.00 mg Se/1 as sodium selenate in the water and with two food types. One food type was algae raised in clean Lake Michigan water and the second treatment was algae raised in media with selenium concentrations corresponding to those in the water cited above. When compared to Daphnia fed selenium-free algae, D. magna fed selenium-laden algae had greater survival, a greater number of offspring produced, and a greater intrinsic growth rate, r, at the toxicant concentration in the water of 0.05, 0.10, and 0.50 mg Se/1. These parameters were, however, lower than those observed in the controls. Uptake of /sup 75/Se as sodium selenate in D. magna was reduced in the presence of selenium-laden algae and DL-selenomethionine, while L-methionine increased the uptake of /sup 75/Se. Selenium bound to an amino acid such as Dl-selenomethionine or organically bound within an algal food source appears to be preferentially incorporated thereby reducing the uptake of inorganic forms from the water.

  4. Toxic effect of selenium on the zooplankton, Daphnia magna and Daphnia pulicaria, in water and the food source (Chlamydomonas reinhardtii)

    International Nuclear Information System (INIS)

    Acute and chronic toxicity experiments were performed on the zooplankton, Daphnia magna and Daphnia pulicaria, to investigate the toxicity of selenium on these aquatic invertebrates. The acute 48 h LC50 of sodium selenate for Daphnia magna and Daphnia pulicaria were 1.01 and 0.25 mg Se/1, respectively. The 48 h LC50 of sodium selenite for D. magna and D. pulicaria were 0.45 and 0.006 mg Se/1, respectively. Chronic 28-day toxicity tests were performed on D. magna at 0.05, 0.10, 0.50, and 1.00 mg Se/1 as sodium selenate in the water and with two food types. One food type was algae raised in clean Lake Michigan water and the second treatment was algae raised in media with selenium concentrations corresponding to those in the water cited above. When compared to Daphnia fed selenium-free algae, D. magna fed selenium-laden algae had greater survival, a greater number of offspring produced, and a greater intrinsic growth rate, r, at the toxicant concentration in the water of 0.05, 0.10, and 0.50 mg Se/1. These parameters were, however, lower than those observed in the controls. Uptake of 75Se as sodium selenate in D. magna was reduced in the presence of selenium-laden algae and DL-selenomethionine, while L-methionine increased the uptake of 75Se. Selenium bound to an amino acid such as Dl-selenomethionine or organically bound within an algal food source appears to be preferentially incorporated thereby reducing the uptake of inorganic forms from the water

  5. Aging in sexual and obligately asexual clones of Daphnia from temporary ponds

    OpenAIRE

    DUDYCHA, JEFFRY L.; Hassel, Christiane

    2013-01-01

    The freshwater crustacean Daphnia is an emerging model system in the biology of aging. Diversity in aging patterns is thought to be caused by ecological variation in selection on age-specific performance. Previous work in Daphnia has shown a strong correspondence between selective differences and genetic variation in aging in the Daphnia pulex species complex. However, recent evidence suggests obligate asexuality could account for the more rapid aging found in pond genotypes compared with lak...

  6. Effects of cell-bound microcystins on survival and feeding of Daphnia spp

    DEFF Research Database (Denmark)

    Rohrlack, T; Dittmann, E; Börner, T;

    2001-01-01

    microcystin synthesis, were compared. Additionally, the relationship between microcystin ingestion rate by the Daphnia clones and Daphnia survival time was analyzed. Microcystins ingested with Microcystis cells were poisonous to all Daphnia clones tested. The median survival time of the animals was closely......-producing and -lacking cells, and (iv) the strength of the toxic effect can be predicted from the microcystin ingestion rate of the animals....

  7. The components of the Daphnia pulex immune system as revealed by complete genome sequencing

    OpenAIRE

    Blaxter Mark L; Colbourne John K; Conlon Claire; McTaggart Seanna J; Little Tom J

    2009-01-01

    Abstract Background Branchiopod crustaceans in the genus Daphnia are key model organisms for investigating interactions between genes and the environment. One major theme of research on Daphnia species has been the evolution of resistance to pathogens and parasites, but lack of knowledge of the Daphnia immune system has limited the study of immune responses. Here we provide a survey of the immune-related genome of D. pulex, derived from the newly completed genome sequence. Genes likely to be ...

  8. Supplementation with Sterols Improves Food Quality of a Ciliate for Daphnia magna

    OpenAIRE

    Martin-Creuzburg, Dominik; Bec, Alexandre; Elert, Eric von

    2006-01-01

    Experimental results provide evidence that trophic interactions between ciliates and Daphnia are constrained by the comparatively low food quality of ciliates. The dietary sterol content is a crucial factor in determining food quality for Daphnia. Ciliates, however, presumably do not synthesize sterols de novo. We hypothesized that ciliates are nutritionally inadequate because of their lack of sterols and tested this hypothesis in growth experiments with Daphnia magna and the ciliate Colpidiu...

  9. 用卤虫(Artemia salina L.)评价杀虫活性%Evaluate Insecticidal Activity Using Artemia salina L.

    Institute of Scientific and Technical Information of China (English)

    王再强; 周红; 韩俊; 何月秋; 录丽平

    2011-01-01

    [Aims]Artemia salina L.is general used for preliminary assessment of pharmacological activity.However,it is necessary to evaluate the suitability of A.salina L.before it is used as a model material for screening insecticidal activity.Here, 14 insecticides with 10 different action mechanisms were selected to evaluate insecticidal activity against A.salina L.used as a model material.[Results]13 Insecticides significantly killed A.salina L., Moulting hormone agonist and compound stimulating GABA release were the most active.[Conclusions]A.salina L.is a suitable organism to evaluate insecticidal activity and the method is simple having good sensitivity to many insecticides with different action mechanisms.%[目的]以卤虫(Artemia salina L.)为模式生物对化合物的药理活性进行初步评价.对10种不同作用机制的14种杀虫剂进行了生物筛选试验.[结果]14种供试杀虫剂中有13种对卤虫有显著的毒杀效果,作用于以γ-氨基丁酸为神经递质传导系统的化合物及蜕皮激素类似物效果最为显著.[结论]用卤虫筛选杀虫剂活性的方法简便,对多种作用机制的杀虫剂灵敏.

  10. Evolutionary origin and phylogeography of the diploid obligate parthenogen Artemia parthenogenetica (Branchiopoda: Anostraca.

    Directory of Open Access Journals (Sweden)

    Joaquín Muñoz

    Full Text Available BACKGROUND: Understanding the evolutionary origin and the phylogeographic patterns of asexual taxa can shed light on the origin and maintenance of sexual reproduction. We assessed the geographic origin, genetic diversity, and phylogeographic history of obligate parthenogen diploid Artemia parthenogenetica populations, a widespread halophilic crustacean. METHODOLOGY/PRINCIPAL FINDINGS: We analysed a partial sequence of the Cytochrome c Oxidase Subunit I mitochondrial gene from an extensive set of localities (including Eurasia, Africa, and Australia, and examined their phylogeographic patterns and the phylogenetic relationships of diploid A. parthenogenetica and its closest sexual relatives. Populations displayed an extremely low level of mitochondrial genetic diversity, with one widespread haplotype shared by over 79% of individuals analysed. Phylogenetic and phylogeographic analyses indicated a multiple and recent evolutionary origin of diploid A. parthenogenetica, and strongly suggested that the geographic origin of parthenogenesis in Artemia was in Central Asia. Our results indicate that the maternal sexual ancestors of diploid A. parthenogenetica were an undescribed species from Kazakhstan and A. urmiana. CONCLUSIONS/SIGNIFICANCE: We found evidence for multiple origin of parthenogenesis in Central Asia. Our results indicated that, shortly after its origin, diploid A. parthenogenetica populations underwent a rapid range expansion from Central Asia towards the Mediterranean region, and probably to the rest of its current geographic distribution. This contrasts with the restricted geographic distribution, strong genetic structure, and regional endemism of sexual Artemia lineages and other passively dispersed sexual continental aquatic invertebrates. We hypothesize that diploid parthenogens might have reached their current distribution in historical times, with a range expansion possibly facilitated by an increased availability of suitable

  11. Toxicity of Five Phenolic Compounds to Brine Shrimp Artemia sinica(Crustacea:Artemiidae)

    Institute of Scientific and Technical Information of China (English)

    Ali Shaukat; LIU Guangxing; LI Zhengyan; XU Donghui; HUANG Yousong; CHEN Hongju

    2014-01-01

    The acute toxicity of five phenolic compounds each to 15 d old Artemia sinica was determined in this study. The brine shrimp A. sinica was hatched from the encysted dry eggs (Bohai Bay Brand) produced by Dongying Ocean Artemia Co., Ltd., China at 27℃± 1℃in pre-filtered (through pores of 0.45 µm in diameter) and autoclaved seawater (salinity 31, pH 7.5-8.0) in a cilindroconical glass beaker (2000 mL in volume) under continuous illumination (provided by a side set 20 W fluorescent lamp) with slight aeration. Ten Artemia individuals from the same batch of the hatched were cultured in 10 mL toxicant solution prepared with seawater (salinity 31, pH 7.5-8.0) at room temperature (about 20℃) to determine 24 h, 48 h and 72 h medium lethal concentration (LC50) of 5 phenolic compounds each. It was found that the toxicity of n-heptylphenol was the highest followed by nonylphenol, t-butylphenol, 2,4-dichlorophenol and bisphenol A in order. The LC50 values of the 5 compounds were calculated with regression analysis. The real concentration (in µg L-1) of 5 phenolic compounds each in toxicant solutions was measured with GC/MS analysis. Significant loss of phenolic compounds caused by either adsorption or desorption was not found. The significant difference of LC50 values was found among the five compounds 3 exposure times each. The range between the highest no-observed-effect concentration (NOEC) and 100%death causing concentration of five phenolic compounds each was determined. The toxicity in term of 24 h LC50 value of n-HP was 9.10 times higher than that of BPA, 1.71 times higher than t-BP, 1.53 times higher than 2,4-DCP and 1.36 times higher than NP, respectively.

  12. May arsenic pollution contribute to limiting Artemia franciscana invasion in southern Spain?

    Science.gov (United States)

    Sánchez, Marta I; Petit, Cathleen; Martínez-Haro, Mónica; Taggart, Mark A; Green, Andy J

    2016-01-01

    Limited information exists regarding the complex interactions between biological invasions, pollution, and climate change. Most studies indicate that pollution tends to favor invasive species. Here, we provide evidence that arsenic (As) pollution may have a role in limiting the invasion of the exotic brine shrimp Artemia franciscana. We tested As toxicity in natural populations of Artemia parthenogenetica (a native taxon) and A. franciscana from localities in southern Spain with differing degrees of As contamination. Tests were conducted both under current mean temperature conditions (25 °C), and as per a future climate scenario (i.e., an increase in mean temperature of 4 °C). Acute toxicity was estimated on the basis of the median lethal concentration (at 24 h), and chronic toxicity was evaluated by measuring Artemia survival and growth under sublethal exposures (after 26 days). At 25 °C, native A. parthenogenetica from the highly polluted Odiel and Tinto estuary was much more resistant to acute As stress (LC50-24 h, 24.67 mg L(-1)) than A. franciscana (15.78 mg L(-1)) and A. parthenogenetica from unpolluted sites (12.04 mg L(-1))-suggesting that local adaptation to polluted conditions may occur. At 29 °C, resistance of A. parthenogenetica from Odiel decreased significantly, and there were no statistical differences in sensitivity between the three species/populations, suggesting that climate change may enhance the probability of invasion. Resistance increased with developmental stage from nauplii to adults, and was extremely high in cysts which still hatched at As concentrations of up to 6400 mg L(-1). Under sublethal chronic exposure A. franciscana performed better (survival and growth) than A. parthenogenetica, and both species experienced a faster growth when exposed to As, compared with unexposed (control) individuals, probably due to the hormesis. We discuss the ecological implications of our results. PMID:26925327

  13. Physical, biochemical and functional characterization of haemoglobin from three strains of Artemia.

    Science.gov (United States)

    Sugumar, Vasudevan; Munuswamy, Natesan

    2007-02-01

    The brine shrimp, Artemia, an inhabitant of coastal and inland salterns, encounter fluctuations in the salinity which in turn influences the oxygen availability of their habitat. Hence, experiments were performed to analyze variations in haemoglobin structure and patterns of three strains of Artemia from South India and also to reflect the effect of varying oxygen levels in their habitat. Haemoglobins were purified on a DEAE-Sephadex column and haemoglobin types were analyzed by comparing their relative mobility on a non-denaturing medium. Furthermore, their molecular masses were determined by gel filtration in Sepharose column and by dodecylsulfate polyacrylamide gel electrophoresis. Results clearly reveal the presence of three distinct extracellular haemoglobins Hb I, Hb II and Hb III in Tuticorin strain while the other strains displayed only trails or the complete absence of Hb III and Hb II. Estimated molecular masses of these haemoglobins are 235,000-250,000 Da. Denaturation of the reduced and alkylated haemoglobins revealed apparently one polypeptide chain with a molecular mass of 124,000 Da. Upon denaturing gel electrophoresis of native haemoglobin Hb II, it was found that the 124,000 Da, polypeptide was cleaved specifically into two unequally-sized fragments of 50,400 and 79,800 Da. With regard to oxygen affinity, Hb III has a very high affinity for oxygen, an almost negligible Bohr effect and a good physiological adaptation to temperature changes. By combining the three haemoglobins in different proportions Artemia strains must be able to withstand diverging environmental conditions. In particular, the absence of Hb III in Puthalam and its occurrence as a faint band in Thamaraikulam could be correlated to the oxygen levels of their habitats. PMID:17185017

  14. Monitoramento dos extratos brutos de espécies de Polygala (Polygalaceae utilizando Artemia salina

    Directory of Open Access Journals (Sweden)

    A.B.P. Montanher

    2003-01-01

    Full Text Available Extratos de duas espécies de Polygala foram submetidos a um biomonitoramento utilizando o teste de toxicidade frente a Artemia salina, com a finalidade de detectar atividade citotóxica. Os resultados obtidos para o extrato bruto, frações hexânica e diclorometano de Polygala sabulosa Aw. Benn. mostraram-se promissores. No entanto, bioensaios mais específicos devem ser encorajados nos extratos vegetais que apresentam atividade diante deste bioensaio, a fim de confirmar estas conclusões.

  15. The brine shrimp ( Artemia parthenogenetica) as encapsulation organism for prophylactic chemotherapy of fish and prawn

    Science.gov (United States)

    Cao, Ji-Xiang; Bian, Bo-Zhong; Li, Ming-Ren

    1996-06-01

    Brine shrimp ( Artemia parthenogenetica) which had ingested three water-insoluble antibacterial drugs i.e. sulfadiazine(SD), oxytetracycline (OTC) and erythromycin estolate (ERY-Es) were fed to Tilapia and Mysis III of Penaeus orientalis K. The drug contents in the predators were then determined. After administration of drugs to Tilapia and Mysis III, through the bio-encapsulation of the brine shrimp, efficacious therapeutical concentration of OTC and ERY-Es (but not SD) in the predators could be reached and maintained for more than 8 hours.

  16. Quaternary structure of Artemia haemoglobin II: analysis of T and C polymer alignment and interpolymer interface

    Directory of Open Access Journals (Sweden)

    Rawle Vincent L

    2007-04-01

    Full Text Available Abstract Background The brine shrimp Artemia expresses four different types of haemoglobin subunits namely C1, C2, T1 and T2. Two of these four subunits dimerize in different combinations to produce the three isoforms of the heterodimeric Artemia haemoglobin: HbI (C1 and C2, HbII (C1 and T2 and HbIII (T1 and T2. Previous biochemical, biophysical and computational analyses demonstrate that the T and C polymers are rings of nine concatenated globin domains, which are covalently joined by interdomain linkers. Two such rings stacked coaxially give the functional molecule. This research aimed to construct a quaternary structural model of Artemia HbII that shows the interpolymer interface and domain-domain alignment, using the MS3D (mass spectrometry for three dimensional analysis approach. This involved introducing chemical crosslinks between the two polymers, cleaving with trypsin and analyzing the resulting products by mass spectrometry. This was followed by computational analysis of the mass spectrometry data using the program SearchXlinks to identify putatively crosslinked peptides. Results Six putative EGS (ethylene glycol bis [succinimidylsuccinate] crosslinked tryptic peptides were identified. All of them support a model in which the EF helices of all domains are in contact along the interpolymer surface, and Domain 1 of the T-polymer aligns with Domain 1 of the C-polymer. Any two adjacent interpolymer domain pairs contact through the early Helix H and early Helix A. The orientation of domains is different from the subunit proposed model proposed previously by this group. Crosslinking with GMBS (N- [γ-maleimidobutyryloxy]succinimide ester was also performed, and the results show good agreement with this model. Conclusion The interpolymer EF-contact allows the hydrophobic E and F helices to be buried in the interface and therefore allow the complex to solubilize readily to facilitate efficient oxygen transport. Furthermore the EF-contact is a

  17. Non-lethal heat shock protects gnotobiotic Artemia franciscana larvae against virulent Vibrios

    OpenAIRE

    Yik Sung, Y.; Van Damme, E.J.M.; Sorgeloos, P.; Bossier, P

    2007-01-01

    Brine shrimp Artemia were exposed under gnotobiotic conditions to a non-lethal heat shock (NLHS) from 28 to 32, 37 and 40°C. Different recovery periods (2, 6, 12 and 24 h) and different heat-exposure times (15, 30, 45 and 60 min) were tested. After these NLHS, Artemia was subsequently challenged with Vibrio. Challenge tests were performed in stressed and unstressed nauplii at concentrations of 107 cells ml-1 of pathogenic bacteria, Vibrio campbellii and Vibrio proteolyticus. A NLHS with an op...

  18. Live preys in shrimp culture: nutritional and sanitary considerations on the use of Artemia in New Caledonia

    OpenAIRE

    Pham, Dominique; Wabete, Nelly; Maillez, Jean-rene; Broutoi, Francis; Chim, Liet

    2009-01-01

    In aquaculture, Artemia nauplii are commonly used as live prey; and represent 40 % of the total aquaculture feed demands in the early stages. However, the production of Brine shrimp is very unstable from one year to another and in the late 90’s, only 20 % of the world aquaculture need was covered. An insufficient offer leads to higher prices of the Artemia cysts and consequently, the price of shrimp juveniles from hatchery. In New Caledonia, marine aquaculture is mainly based on the blue s...

  19. CINEMATOGRAPHIC ANALYSIS OF INTERNAL WATER FLOWS IN DAPHNIA

    Directory of Open Access Journals (Sweden)

    Moshe Gophen

    2014-10-01

    Full Text Available The internal water flows in Daphnia magna (Straus 1820 were studied by Cinematographic technique (High-Speed Camera. Two routes of internal flows were reported: 1 Lateral which start underneath P2 and flow backward along the carapace edge; and 2 Median which start in front and flow downward between thoracic legs P3, P4 and P5 than turn to tangential direction between the legs (appendages, combs, filters to be rejected. These two reported routes of flow are operated alternately. It is suggested that this pattern is beneficial to the Daphnia as predator risk reduction achieved by alternate two separated outflows resulting in two continuous minor pulses instead of one stronger. It is suggested to be a blur of one pulsated outlet by a succession of two vortices.

  20. Environmental gradients structure Daphnia pulex × pulicaria clonal distribution.

    Science.gov (United States)

    Pantel, J H; Juenger, T E; Leibold, M A

    2011-04-01

    The rarity of eukaryotic asexual reproduction is frequently attributed to the disadvantage of reduced genetic variation relative to sexual reproduction. However, parthenogenetic lineages that evolved repeatedly from sexual ancestors can generate regional pools of phenotypically diverse clones. Various theories to explain the maintenance of this genetic diversity as a result of environmental and spatial heterogeneity [frozen niche variation (FNV), general-purpose genotype] are conceptually similar to community ecological explanations for the maintenance of regional species diversity. We employed multivariate statistics common in community ecological research to study population genetic structure in the freshwater crustacean, Daphnia pulex × pulicaria. This parthenogenetic hybrid arose repeatedly from sexual ancestors. Daphnia pulex × pulicaria populations harboured substantial genetic variation among populations and the clonal composition at each pond corresponded to nutrient levels and invertebrate predator densities. The interclonal selection process described by the FNV hypothesis likely structured our D. pulex × pulicaria populations.

  1. Ecotoxicological testing of gas oils (daphnia magna test)

    Energy Technology Data Exchange (ETDEWEB)

    Altmann, B.R.; Mueller, J.; Wenzel, A.; Hensel, R.

    2002-02-01

    The Water Accomodated Fractions WAF of 4 diesel fuels no. 2 and 4 domestic heating fuels no. 2 of differing origin were analysed on their effect on the mobility of the freshwater crustacean Daphnia Magna. Five loadings per test substance were tested. After an exposition period of 24 h a relationship between loading rates of the WAF and immobility was found for 3 samples, while after 48 h this was observed for all samples. WAF-generation and gas oil data were documented. (orig.) [German] Von 4 Dieselkraftstoff-Gasoelen und 4 Heizoel-Gasoelen EL wurden die Water Accomodated Fractions WAF auf ihre immobilisierende Wirkung auf den Wasserfloh Daphnia Magna untersucht. Von jeder Probe wurden fuenf unterschiedliche Dosierraten geprueft. Nach einer Expositionszeit von 24 Stunden zeigte sich bei 3 Proben und nach 48 Stunden bei allen Proben eine Beziehung zwischen der Dosierrate der Probe und der Immobilitaet. Die Herstellung der WAF und die Daten der Gasoele wurden dokumentiert. (orig.)

  2. Evolution of a transposon in Daphnia hybrid genomes

    Directory of Open Access Journals (Sweden)

    Vergilino Roland

    2013-02-01

    Full Text Available Abstract Background Transposable elements play a major role in genome evolution. Their capacity to move and/or multiply in the genome of their host may have profound impacts on phenotypes, and may have dramatic consequences on genome structure. Hybrid and polyploid clones have arisen multiple times in the Daphnia pulex complex and are thought to reproduce by obligate parthenogenesis. Our study examines the evolution of a DNA transposable element named Pokey in the D. pulex complex. Results Portions of Pokey elements inserted in the 28S rRNA genes from various Daphnia hybrids (diploids and polyploids were sequenced and compared to sequences from a previous study to understand the evolutionary history of the elements. Pokey sequences show a complex phylogenetic pattern. We found evidence of recombination events in numerous Pokey alleles from diploid and polyploid hybrids and also from non-hybrid diploids. The recombination rate in Pokey elements is comparable to recombination rates previously estimated for 28S rRNA genes in the congener, Daphnia obtusa. Some recombinant Pokey alleles were encountered in Daphnia isolates from multiple locations and habitats. Conclusions Phylogenetic and recombination analyses showed that recombination is a major force that shapes Pokey evolution. Based on Pokey phylogenies, reticulation has played and still plays an important role in shaping the diversity of the D. pulex complex. Horizontal transfer of Pokey seems to be rare and hybrids often possess Pokey elements derived from recombination among alleles encountered in the putative parental species. The insertion of Pokey in hotspots of recombination may have important impacts on the diversity and fitness of this transposable element.

  3. Toxicity of perfluorononanoic acid and perfluorooctane sulfonate to Daphnia magna

    OpenAIRE

    Lu, Guang-hua; Jian-chao LIU; Sun, Li-Sha; Lu-jin YUAN

    2015-01-01

    In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-hour acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and rep...

  4. Optimisation of DNA extraction from the crustacean Daphnia.

    Science.gov (United States)

    Athanasio, Camila Gonçalves; Chipman, James K; Viant, Mark R; Mirbahai, Leda

    2016-01-01

    Daphnia are key model organisms for mechanistic studies of phenotypic plasticity, adaptation and microevolution, which have led to an increasing demand for genomics resources. A key step in any genomics analysis, such as high-throughput sequencing, is the availability of sufficient and high quality DNA. Although commercial kits exist to extract genomic DNA from several species, preparation of high quality DNA from Daphnia spp. and other chitinous species can be challenging. Here, we optimise methods for tissue homogenisation, DNA extraction and quantification customised for different downstream analyses (e.g., LC-MS/MS, Hiseq, mate pair sequencing or Nanopore). We demonstrate that if Daphnia magna are homogenised as whole animals (including the carapace), absorbance-based DNA quantification methods significantly over-estimate the amount of DNA, resulting in using insufficient starting material for experiments, such as preparation of sequencing libraries. This is attributed to the high refractive index of chitin in Daphnia's carapace at 260 nm. Therefore, unless the carapace is removed by overnight proteinase digestion, the extracted DNA should be quantified with fluorescence-based methods. However, overnight proteinase digestion will result in partial fragmentation of DNA therefore the prepared DNA is not suitable for downstream methods that require high molecular weight DNA, such as PacBio, mate pair sequencing and Nanopore. In conclusion, we found that the MasterPure DNA purification kit, coupled with grinding of frozen tissue, is the best method for extraction of high molecular weight DNA as long as the extracted DNA is quantified with fluorescence-based methods. This method generated high yield and high molecular weight DNA (3.10 ± 0.63 ng/µg dry mass, fragments >60 kb), free of organic contaminants (phenol, chloroform) and is suitable for large number of downstream analyses. PMID:27190714

  5. Uptake and depuration of gold nanoparticles in Daphnia magna

    DEFF Research Database (Denmark)

    Skjolding, Lars Michael; Kern, Kristina; Hjorth, Rune;

    2014-01-01

    This study presents a series of short-term studies (total duration 48 h) of uptake and depuration of engineered nanoparticles (ENP) in neonate Daphnia magna. Gold nanoparticles (Au NP) were used to study the influence of size, stabilizing agent and feeding on uptake and depuration kinetics...... to assess the uptake and depuration of ENP in D. magna. The findings underlines that the assumptions behind the traditional way of quantifying bioconcentration are not fulfilled when ENPs are studied....

  6. Genetic Structure of Daphnia galeata Populations in Eastern China

    OpenAIRE

    Wenzhi Wei; Sabine Gießler; Justyna Wolinska; Xiaolin Ma; Zhong Yang; Wei Hu; Mingbo Yin

    2015-01-01

    This study presents the first examination of the genetic structure of Daphnia longispina complex populations in Eastern China. Only one species, D. galeata, was present across the eight investigated lakes; as identified by taxon assignment using allelic variation at 15 microsatellite loci. Three genetically differentiated D. galeata subgroups emerged independent of the type of statistical analysis applied. Thus, Bayesian clustering, discriminant analysis based on results from factorial corres...

  7. Optimisation of DNA extraction from the crustacean Daphnia.

    Science.gov (United States)

    Athanasio, Camila Gonçalves; Chipman, James K; Viant, Mark R; Mirbahai, Leda

    2016-01-01

    Daphnia are key model organisms for mechanistic studies of phenotypic plasticity, adaptation and microevolution, which have led to an increasing demand for genomics resources. A key step in any genomics analysis, such as high-throughput sequencing, is the availability of sufficient and high quality DNA. Although commercial kits exist to extract genomic DNA from several species, preparation of high quality DNA from Daphnia spp. and other chitinous species can be challenging. Here, we optimise methods for tissue homogenisation, DNA extraction and quantification customised for different downstream analyses (e.g., LC-MS/MS, Hiseq, mate pair sequencing or Nanopore). We demonstrate that if Daphnia magna are homogenised as whole animals (including the carapace), absorbance-based DNA quantification methods significantly over-estimate the amount of DNA, resulting in using insufficient starting material for experiments, such as preparation of sequencing libraries. This is attributed to the high refractive index of chitin in Daphnia's carapace at 260 nm. Therefore, unless the carapace is removed by overnight proteinase digestion, the extracted DNA should be quantified with fluorescence-based methods. However, overnight proteinase digestion will result in partial fragmentation of DNA therefore the prepared DNA is not suitable for downstream methods that require high molecular weight DNA, such as PacBio, mate pair sequencing and Nanopore. In conclusion, we found that the MasterPure DNA purification kit, coupled with grinding of frozen tissue, is the best method for extraction of high molecular weight DNA as long as the extracted DNA is quantified with fluorescence-based methods. This method generated high yield and high molecular weight DNA (3.10 ± 0.63 ng/µg dry mass, fragments >60 kb), free of organic contaminants (phenol, chloroform) and is suitable for large number of downstream analyses.

  8. Purification and studies on characteristics of cholinesterases from Daphnia magna

    Institute of Scientific and Technical Information of China (English)

    Yan-xia YANG; Li-zhi NIU; Shao-nan LI

    2013-01-01

    Due to their significant value in both economy and ecology,Daphnia had long been employed to investigate in vivo response of cholinesterase (ChE) in anticholinesterase exposures,whereas the type constitution and property of the enzyme remained unclear.A type of ChE was purified from Daphnia magna using a three-step procedure,i.e.,Triton X-100 extraction,ammonium sulfate precipitation,and diethylaminoethyl (DEAE)-SepharoseTM-Fast-Flow chromatography.According to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE),molecular mass of the purified ChE was estimated to be 84 kDa.Based on substrate studies,the purified enzyme preferred butyrylthiocholine iodide (BTCh) [with maximum velocity (Vmax)/Michaelis constant (Km)=8.428 L/(min·mg protein)] to acetylthiocholine iodide (ATCh) [with Vmax/Km=5.346 L/(min·mg protein)] as its substrate.Activity of the purified enzyme was suppressed by high concentrations of either ATCh or BTCh.Inhibitor studies showed that the purified enzyme was more sensitive towards inhibition by tetraisopropylpyrophosphoramide (iso-OMPA) than by 1,5-bis(4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284C51).Result of the study suggested that the purified ChE was more like a type of pseudocholinesterase,and it also suggested that Daphnia magna contained multiple types of ChE in their bodies.

  9. Toxicity Evaluation of Wastewater Treatment Plant Effluents Using Daphnia magna

    Directory of Open Access Journals (Sweden)

    H Movahedian, B Bina, GH Asghari

    2005-04-01

    Full Text Available Toxicity evaluation is an important parameter in wastewater quality monitoring as it provides the complete response of test organisms to all compounds in wastewater. The water flea Daphnia magna straus is the most commonly used zooplankton in toxicological tests. The objective of this study was to evaluate the acute toxicity of effluents from different units of Isfahan Wastewater Treatment Plant (IWTP. The samples were taken from four different physical and biological units. The acute toxicity tests were determined using Daphnia magna. The immobility of Daphnia was determined after 48h. Toxicity results showed that 48h-LC50 and ATU values for raw wastewater were 30% (v/v and 3.33, respectively. It was also found that LC50 values after 48 h for preliminary, primary, and secondary effluents were 32%, 52% and 85% (v/v, respectively. The ATU values for these effluents were 3.1, 1.9, and 1.8, correspondingly. The efficiency levels of preliminary, primary, and secondary units for removal of toxicity were found as 6%, 38.9% and 8%, in that order. Overall, the present investigation indicated that toxicity removal by up to 50% might be achieved in IWPT. Based on the obtained results and regarding the improvement of water quality standards, coupled with public expectations in Iran, it is necessary to consider more stringent water quality policies for regular monitoring and toxicity assessment.

  10. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    Science.gov (United States)

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  11. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    Science.gov (United States)

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  12. Evaluation of the toxicity of the methanolic extract of Caesalpinia Pyramidalis, subjected to gamma radiation, compared to saline artemias; Avaliacao da toxicidade do extrato metanolico de Caesalpinia Pyramidalis, submetido a radiacao gama, frente a artemias salinas

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Juanna G.; Santos, Mariana L.O.; Costa, Michelle C.A.; Siqueira, Williams N.; Silva, Luanna R.S.; Cabral, Daniela L.V.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: marianasantos_ufpe@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    The present study aimed to investigate the possible effect of irradiation of 60 Co in methanol extract of Caesalpinia pyramidalis (catingueira) with function of reducing the toxicity of the extract at concentrations of 1000, 500, 250 and 125 ppm irradiating them with doses of 5 kGy 7 kGy and 10 kGy, using lethality tests with saline Artemias.

  13. A gene catalogue for post-diapause development of an anhydrobiotic arthropod Artemia franciscana

    Directory of Open Access Journals (Sweden)

    Yu Jun

    2009-01-01

    Full Text Available Abstract Background Diapause is a reversible state of developmental suspension and found among diverse taxa, from plants to animals, including marsupials and some other mammals. Although previous work has accumulated ample data, the molecular mechanism underlying diapause and reactivation from it remain elusive. Results Using Artemia franciscana, a model organism to study the development of post-diapause embryos in Arthropod, we sequenced random clones up to a total of 28,039 ESTs from four cDNA libraries made from dehydrated cysts and three time points after rehydration/reactivation, which were assembled into 8,018 unigene clusters. We identified 324 differentially-expressed genes (DEGs, P Conclusion We found that the first 5-hour period after rehydration is most important for embryonic reactivation of Artemia. As the total number of expressed genes increases significantly, the majority of DEGs were also identified in this period, including a group of water-deficient-induced genes. A group of genes with similar functions have been described in plant seeds; for instance, one of the novel LEA members shares ~70% amino-acid identity with an Arabidopsis EM (embryonic abundant protein, the closest animal relative to plant LEA families identified thus far. Our findings also suggested that not only nutrition, but also mRNAs are produced and stored during cyst formation to support rapid development after reactivation.

  14. Peningkatan Kuantitas dan Kualitas Kista Artemia franciscana setelah Pemberian Silase Ikan

    Directory of Open Access Journals (Sweden)

    ENDAH BUDI SULISTYOWATI

    2007-11-01

    Full Text Available Artemia is one of live feed needed in aquaculture as fishes and crustacean. Commercially, Artemia usually sold in dry cysts which can kept for years. The aim of this research were to know increasing quantity and quality A. franciscana cysts after exposing various concentration of fish silage as artificial food and to know optimal concentration of fish silage that can increase quantity and quality A. franciscana cysts. This research was done in Laboratory of Live Feed BBPBAP Jepara Central Java. This research was conducted by 5 treatments. Treatments were grouped based on amount of concentration given, i.e: control (coconut cake with concentrate 10 g/m3, fish silage concentrate 10, 20, 30, and 40 g/m3. Parameter investigated were number of cysts produced by individual female A. franciscana, diameter of A. franciscana cysts, hatching percentage, and hatching rate of A. franciscana cysts. Data were analyzed using ANOVA and continued using Tukeys test at significant level 5%. The result of this research showed that exposing fish silage can increase quantity and quality A. franciscana cysts. They were increase number of cysts production by individual females, decrease cysts diameter, increase hatching percentage and hatching rate. Optimal concentration of fish silage on increase quantity and quality of A. franciscana cysts was 20 g/m3.

  15. Habitat diversity and adaptation to environmental stress in encysted embryos of the crustacean Artemia

    Indian Academy of Sciences (India)

    Joshua A Tanguay; Reno C Reyes; James S Clegg

    2004-12-01

    Encysted embryos (cysts) of the brine shrimp, Artemia, provide excellent opportunities for the study of biochemical and biophysical adaptation to extremes of environmental stress in animals. Among other virtues, this organism is found in a wide variety of hypersaline habitats, ranging from deserts, to tropics, to mountains. One adaptation implicated in the ecological success of Artemia is p26, a small heat shock protein that previous evidence indicates plays the role of a molecular chaperone in these embryos. We add to that evidence here. We summarize recently published work on thermal tolerance and stress protein levels in embryos from the San Francisco Bay (SFB) of California inoculated into experimental ponds in southern Vietnam where water temperatures are much higher. New results on the relative contents of three stress proteins (hsp70, artemin and p26) will be presented along with data on cysts of A. tibetiana collected from the high plateau of Tibet about 4.5 km above sea level. Unpublished results on the stress protein artemin are discussed briefly in the context of this paper, and its potential role as an RNA chaperone. Interestingly, we show that the substantial tolerance of A. franciscana embryos to ultraviolet (UV) light does not seem to result from intracellular biochemistry but, rather, from their surrounding thick shell, a biophysical adaptation of considerable importance since these embryos receive heavy doses of UV in nature.

  16. Assessment of endemic microalgae as potential food for Artemia franciscana culture

    Directory of Open Access Journals (Sweden)

    Juan M Pacheco-Vega

    2015-03-01

    Full Text Available In this study, five microalgal strains were isolated from Bahía de La Paz, Baja California Sur, Mexico and identified as Grammatophora sp., Navícula sp., Rhabdonema sp., Schizochytrium sp., and Nitzschia sp., and their evaluation as potential food for Artemia franciscana. The isolated strains were cultured outdoors and harvested after four days. Chaetoceros muelleri was cultured under laboratory conditions and used as control. The protein, lipid, and carbohydrate composition and the fatty acid profiles of the strains were determined by gas chromatography. To assess the effect of microalgal strains on A. franciscana, decapsulated cysts were cultured at outdoor conditions in 15 L containers. The experiment was conducted for twelve days. Samples from the five different feeding treatments were taken at the beginning and end of the experiment to assess number, size, and weight of Artemia larvae. Treatment with Rhabdonema sp. showed larvae with a lower percentage of polyunsaturated fatty acids (PUFAs while Grammatophora sp. showed those with the greatest PUFA proportion, even more than those fed Chaetoceros muelleri (control. Larvae consuming Schizochytrium sp. had no docosahexanoic (DHA nor eicosapentaenoic (EPA fatty acid content. Growth and survival of A. franciscana did not show significant differences among feed treatments, except when it was fed Nitzschia sp., showing lower survival and dry weight. Treatment based on Schizochytrium sp. and Rhabdonema sp. had a greater A. franciscana size but reduced dry weight; additional tests including two or more algal species for every treatment should be carried out to determine the best yield.

  17. Risk associated with toxic blooms of marine phytoplankton functional groups on Artemia franciscana

    Directory of Open Access Journals (Sweden)

    Ana D’ors

    2014-08-01

    Full Text Available Objective: To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins. Methods: Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum, Prorocentrum lima and Nitzschia N1c1 living cells. Additionally, the results were analyzed using the median-effect/combination index (CI-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups. Results: Biotoxin equivalent values obtained by immunodetection were (2.12±0.10, (8.60±1.30 and (4.32±1.67 pg/cell for saxitoxin, okadaic acid and domoic acid, respectively. The 24-h LC50 values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27 µg/L, significantly below the value obtained for Nitzschia N1c1, which was established at 467.33 µg/L. CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii, which were significantly lower than the toxic effect exhibited by each species studied. Conclusions: These results show that, although these harmful algae represent a serious risk to estuarine zooplankton community, the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.

  18. Cloning and Expression Analysis of p26 Gene in Artemia sinica

    Institute of Scientific and Technical Information of China (English)

    Lijuan JIANG; Lin HOU; Xiangyang ZOU; Ruifeng ZHANG; Jiaqing WANG; Wenjing SUN; Xintao ZHAO; Jialu AN

    2007-01-01

    The protein p26 is a small heat shock protein that functions as a molecular chaperone to protect embryos by preventing irreversible protein damage during embryonic development. A 542 bp fragment of the p26 gene was cloned and sequenced. The fragment encoded 174 amino acid residues and the amino acid sequence contained the α-crystallin domain. Phylogenetic analysis showed that eight Artemia populations were divided into four major groups. Artemia sinica (YC) belonged to the East Asia bisexual group. Expression of the p26 gene at different developmental stages of A. sinica was quantified using real-time quantitative polymerase chain reaction followed by cloning and sequencing. The relationship between the quantity of p26 gene expression and embryonic development was analyzed. The results indicated that massive amounts of p26 were expressed during the development of A. sinica. At the developmental stage of 0 h, A. sinica expressed the highest level of p26. As development proceeded, expression levels of the p26 gene reduced significantly. There was a small quantity of p26 gene expression at the developmental stages of 16 h and 24 h. We concluded that p26 might be involved in protecting the embryo from physiological stress during embryonic development.

  19. Contrasting life history responses to fish released infochemicals of two co-occurring Daphnia species that show different migration behaviour

    NARCIS (Netherlands)

    Vijverberg, J.; Doksaeter, A.; Van Donk, E.

    2006-01-01

    In a previous field study (Flik & Vijverberg 2003) we showed that in an oligotrophic-mesotrophic lake in the Netherlands (L. Maarsseveen) two co-occurring Daphnia species, Daphnia pulicaria and Daphnia galeata × hyalina performed distinct vertical migration behaviour during summer which is induced b

  20. A study of the female produced sex pheromone of Tenebrio molitor (Coleoptera: Tenebrionidae)

    Science.gov (United States)

    Mangat, Jaswinder

    Mating behaviour in the yellow mealworm beetle, Tenebrio molitor , is mediated by several pheromones, including the female-produced 4-methylnonanol (4-MNol). Mating causes a decline in the titre of 4-MNol. The overall goal of this study was to determine the biochemical mechanism(s) responsible for this decline: i.e., whether the decline was due to an inhibition of pheromone biosynthesis and/or a stimulation of pheromone degradation; whether the decline was caused by the physical effect of mating or was due to the transfer of a factor from the male; and to conduct a preliminary investigation of the regulatory and signal transduction mechanisms involved in the regulation of 4-MNol production. In vitro radioassays for 4-MNol biosynthesis and degradation were developed and used to compare the levels of 4-MNol biosynthesis and degradation in virgin and mated females. Mating caused an inhibition of 4-MNol biosynthesis within 2 hours, but did not affect the rate of pheromone degradation. Decapitation of virgin females caused an inhibition of pheromone biosynthesis and did not prevent the inhibitory effect of mating. The inhibitory effect of mating was mimicked in females that were artificially inseminated with male reproductive tract homogenates (MRTH), but not in females similarly "inseminated" with water, saline, or air. Furthermore, 4-MNol biosynthesis could be inhibited in vitro by the addition of MRTH. These findings indicate that the male transferred one or more pheromonostatic factor(s) to the female during copulation that acted directly on the pheromone-producing tissue (the ovaries). In order to investigate the biochemical basis for the inhibition of pheromone biosynthesis after mating, the role of calcium was determined by modulating the level of calcium (using a calcium chelator, an ionophore, and calcium). However, due to the precipitation of calcium with the phosphate present in the buffer solution, we were unable to determine the role of calcium in the

  1. Intentional introduction of Artemia sinica (Anostraca) in the high-altitude Tibetan lake Dangxiong Co: the new population and consequences for the environment and for humans

    Science.gov (United States)

    Jia, Qinxian; Anufriieva, Elena; Liu, Xifang; Kong, Fanjing; Shadrin, Nickolai

    2015-11-01

    The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now. Salt lakes in Tibet may contribute to the solution of the problem. In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000-5 100 m. We found Artemia in 15 of these lakes. The saline lakes with Artemia populations mainly belong to the shallow basin lakes, and the majority of these lakes are small in area. The total area of lakes without Artemia is more than 1 000 km2. Lake Dangxiong Co (Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica. In 2004, 850 g of A. sinica cysts, originating from Qinghai, were introduced in the lake. Surveys in 2006-2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m3 in 2006 to 1950 ind./m3 in 2013. We assume that two subpopulations of A. sinica, separated by depth, may exist in the lake. The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance. Water transparency also increased. Dominance in phytoplankton passed from cyanobacteria to diatoms. Changes occurred not only in the lake ecosystem; the number of water birds using the lakes also dramatically increased. Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.

  2. Nutrient enrichment of Artemia with free methionine%蛋氨酸对卤虫营养强化

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Methionine is indispensable of an essential amino acid for fish growing development , Artemia nauplii is commonly used as the start feed on fish larvae stage. But Artemia in vivo amino acid imbalance, especially methionine deficiency can not meet the nutritional needs of nutrition. Methionine is of great importance to nutrient enrichment of Artemia. Methionine is a common nutritional fortifier . This paper mainly introduces the purpose, methods and results of nutrient enrichment, and discuss the impact of enrichment of Artemia with free methionine.%  蛋氨酸是鱼类生长发育不可缺少的必需氨基酸,仔稚鱼时期常常用卤虫作为仔稚鱼的开口饵料,但卤虫的体内的氨基酸不平衡,尤其是蛋氨酸缺乏难以满足仔稚鱼的营养需求,因此蛋氨酸对卤虫的营养强化有很重要的意义。蛋氨酸是常用的营养强化剂,文章综述了蛋氨酸强化的目的、方法和结果,并讨论了影响蛋氨酸营养强化的因素。

  3. Post-prandial protease activity in the digestive tract of African catfish, Clarias gariepinus, larvae fed decapsulated cysts of Artemia

    NARCIS (Netherlands)

    García Ortega, A.; Verreth, J.; Segner, H.

    2000-01-01

    The alkaline proteolytic activity in the gut of African catfish larvae was studied during short time ranges from 30 min to 4 h after ingestion of decapsulated Artemia cysts. The variation in total protease and trypsin activities during the day was monitored during starvation, after one single meal i

  4. Life-history consequences for Daphnia pulex exposed to pharmaceutical carbamazepine

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Sargant, E.M.; Roessink, I.

    2006-01-01

    The effects of the antiepileptic, analgesic drug carbamazepine on the growth, morphology, and life-history characteristics of Daphnia pulex were examined at nominal concentrations of 0, 0.1, 1, 10, 100, and 200 mu g L-1. At 1 mu g carbamazepine L-1, Daphnia matured and reproduced slightly earlier th

  5. Maternal nutritional state determines the sensitivity of Daphnia magna offspring to Fenvalerate pulse exposure.

    NARCIS (Netherlands)

    B.J. Pieters; M. Liess

    2006-01-01

    Abstract Daphnia populations in the field suffer periodic natural stress conditions such as low food levels. It is known that at low nutritional supply, Daphnia produces fewer but larger offspring, which are acutely less sensitive to chemical stress. We hypothesized that the change in the reproducti

  6. Predator-released compounds, ambient temperature and competitive exclusion among differently sized Daphnia species

    NARCIS (Netherlands)

    Vijverberg, J.; Vos, Matthijs

    2006-01-01

    1. We studied the effects of fish water and temperature on mechanisms of competitive exclusion among two Daphnia species in flow-through microcosms. The large-bodied D. pulicaria outcompeted the medium sized D. galeata × hyalina in fish water, but not in the control treatment. Daphnia galeata × hyal

  7. A spontaneous mutant of microcystin biosynthesis: genetic characterization and effect on Daphnia

    DEFF Research Database (Denmark)

    Kabernick, M.; Rohrlack, T.; Christoffersen, K.;

    2001-01-01

    of microcystins, mainly with the amino acid tyrosine in the molecule. Zooplankton studies with Daphnia galeata and D. pulicaria, using the mutant (MRC) and its' wild type (MRD), showed for the first time that microcystins other than microcystin-LR can be responsible for the poisoning of Daphnia by Microcystis...

  8. Making the Most of the "Daphnia" Heart Rate Lab: Optimizing the Use of Ethanol, Nicotine & Caffeine

    Science.gov (United States)

    Corotto, Frank; Ceballos, Darrel; Lee, Adam; Vinson, Lindsey

    2010-01-01

    Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…

  9. Sudden weaning of angel fish pterophyllum scalare (Lichtenstein) (Pisces; Cichlidae) larvae from brine shrimp (Artemia sp) nauplii to formulated larval feed

    OpenAIRE

    Herath, Sandamali Sakunthala; Atapaththu, Kerthi Sri Senarathna

    2013-01-01

    This study investigated the effects of sudden weaning of angel fish larvae (Pteraphylum scalari) from Artemia nauplii to commercial larval feed. Four days post hatch (DPH) larvae were reared in four different weaning protocols (TR1-TR4) with triplicates in a complete randomize design. Larvae in TR1 and TR4 were exclusively fed Artemia nauplii and dry feed respectively. In TR2 and TR3, larvae were initially fed Artemia nauplii and suddenly wean to formulated feed on 14 DPH and 7 DPH respective...

  10. Cytotoxicity of antimalarial plant extracts from Kenyan biodiversity to the brine shrimp, Artemia salina L. (Artemiidae

    Directory of Open Access Journals (Sweden)

    Joseph Mwanzia Nguta

    2012-07-01

    Full Text Available Artemia salina (Artemiidae, the brine shrimp larva, is an invertebrate used in the alternative test to determine toxicity of chemicals and natural products. In this study the medium lethal concentration fifty (LC50 values of 45 antimalarial plant extracts and positive controls, cyclophosphamide and etoposide were determined using Artemia salina (Artemiidae. Out of the 45 organic extracts screened for activity against Artemia salina larvae, 23 (51% of the crude extracts demonstrated activity at or below 100 μg/mL, and were categorized as having strong cytotoxic activity, 18 (40% of the crude extracts had LC50 values between 100 μg/mL and 500 μg/mL, and were categorized as having moderate cytotoxicity, 2 (4.5% of the crude extracts had LC50 values between 500 μg/mL and 1000 μg/mL, and were considered to have weak cytotoxic activity, while 2 (4.5% of the crude extracts had LC50 values greater than 1000 μg/mL and were considered to be non toxic. Approximately 20% (9 of the aqueous extracts demonstrated activity at or below 100 g/mL and were considered to have strong cytotoxic activity, 40% (18 of the screened aqueous crude extracts had LC50 values between 100 μg/mL and 500 μg/mL and were considered to be moderately cytotoxic, 16% (7 of the crude extracts had LC50 values between 500 μg/mL and 1000 μg/mL and were considered to have weak cytotoxic activity while 24% (11 of the aqueous extracts had LC50 values greater than 1000μg/mL and were categorized as non toxic The positive controls, cyclophosphamide and etoposide exhibited strong cytotoxicity with LC50 values of 95 μg/mL and 6 μg/mL respectively in a 24 hour lethality study, validating their use as anticancer agents. In the current study, 95.5% of all the screened organic extracts and 76% of the investigated aqueous extracts demonstrated LC50 values <1000 g/mL, indicating that these plants could not make safe anti-malarial treatments. This calls for dose adjustment amongst the

  11. Protective effects of ectoine on heat-stressed Daphnia magna.

    Science.gov (United States)

    Adam, Bownik; Zofia, Stępniewska; Tadeusz, Skowroński

    2014-12-01

    Ectoine (ECT) is an amino acid produced and accumulated by halophilic bacteria in stressful conditions in order to prevent the loss of water from the cell. There is a lack of knowledge on the effects of ECT in heat-stressed aquatic animals. The purpose of our study was to determine the influence of ECT on Daphnia magna subjected to heat stress with two temperature gradients: 1 and 0.1 °C/min in the range of 23-42 °C. Time to immobilisation, survival during recovery, swimming performance, heart rate, thoracic limb movement and the levels of heat shock protein 70 kDa 1A (HSP70 1A), catalase (CAT) and nitric oxide species (NOx) were determined in ECT-exposed and unexposed daphnids; we showed protective effects of ECT on Daphnia magna subjected to heat stress. Time to immobilisation of daphnids exposed to ECT was longer when compared to the unexposed animals. Also, survival rate during the recovery of daphnids previously treated with ECT was higher. ECT significantly attenuated a rapid increase of mean swimming velocity which was elevated in the unexposed daphnids. Moreover, we observed elevation of thoracic limb movement and modulation of heart rate in ECT-exposed animals. HSP70 1A and CAT levels were reduced in the presence of ECT. On the other hand, NOx level was slightly elevated in both ECT-treated and unexposed daphnids, however slightly higher NOx level was found in ECT-treated animals. We conclude that the exposure to ectoine has thermoprotective effects on Daphnia magna, however their mechanisms are not associated with the induction of HSP70 1A. PMID:25223383

  12. Digestion of Starch Granules from Maize, Potato and Wheat by Larvae of the the Yellow Mealworm, Tenebrio molitor and the Mexican Bean Weevil, Zabrotes subfasciatus

    OpenAIRE

    Meireles, Elaine A.; Carneiro, Cíntia N. B.; Renato A DaMatta; Samuels, Richard I; Silva, Carlos P

    2009-01-01

    Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut α-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One α-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other α-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chroma...

  13. Intracellular localization of group 3 LEA proteins in embryos of Artemia franciscana.

    Science.gov (United States)

    Boswell, Leaf C; Hand, Steven C

    2014-12-01

    Late embryogenesis abundant (LEA) proteins are accumulated by anhydrobiotic organisms in response to desiccation and improve survivorship during water stress. In this study we provide the first direct evidence for the subcellular localizations of AfrLEA2 and AfrLEA3m (and its subforms) in anhydrobiotic embryos of Artemia franciscana. Immunohistochemistry shows AfrLEA2 to reside in the cytoplasm and nucleus, and the four AfrLEA3m proteins to be localized to the mitochondrion. Cellular locations are supported by Western blots of mitochondrial, nuclear and cytoplasmic fractions. The presence of LEA proteins in multiple subcellular compartments of A. franciscana embryos suggests the need to protect biological structures in many areas of a cell in order for an organism to survive desiccation stress, and may explain in part why a multitude of different LEA proteins are expressed by a single organism. PMID:25311474

  14. Genetic variation in parthenogenetic Artemia from the Shandong Peninsula, P.R.C.

    Science.gov (United States)

    King, Charles E.; Zhao, Yuqi; Liu, Xin; Li, Mingren

    1988-06-01

    Results are presented of a survey of isozyme frequencies in parthenogenetic Artimia from six salterns in the Shandong Peninsula, P.R.C. Three of the eleven enzymes we scored using polyacryamide gel electrophoresis proved to be useful for analysis of electromorph frequency variation. These enzymes are tetrazolium oxidase (TO), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH). Each of these systems showed extensive isozyme variation both within and between salterns. In addition, we have examined the possibility that electromorph frequencies may vary as the result of natural selection for adaptation to specific salinity, or salinity-associated environmental conditions. An indication of clinal variation was found in two series of ponds differing in salinity, however more extensive data are needed before it is possible to conclude that these patterns are the result of natural selection. Finally, the use of isozyme analyses such as ours, for unraveling taxonomic problems in Artemia is discussed.

  15. First secondary metabolites from Herissantia crispa L (Brizicky and the toxicity activity against Artemia salina Leach

    Directory of Open Access Journals (Sweden)

    Danielly Albuquerque da Costa

    2009-01-01

    Full Text Available The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-β-D-glucopyranoside, stigmasterol 3-O-β-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol, 3,5,7,3',4'-pentahydroxyflavone (quercetin, unpublished in the genus Herissantia, besides β-sitosterol, kaempferol 3-O-β-D-(6''-E-p-coumaroil (tiliroside glucopyranoside and kaempferol 3,7-di-O-α-L-ramnopyranoside (lespedin, described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, ¹H and 13C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out.

  16. IDENTIFIKASI DAN UJI AKTIVITAS ANTIKANKER EKSTRAK SPONS Ianthella basta TERHADAP LARVA Artemia salina L.

    Directory of Open Access Journals (Sweden)

    Ni Wayan Sri Sukmarianti

    2013-05-01

    Full Text Available The main purpose of this research is to determine the toxicity of extracts sponge Ianthella basta against Artemia salina larvae and to identify the chemical compounds contained in those toxic isolates. The preliminary test of the anticancer activity has conducted by Brine Shrimp Letalithy (BST test. The results showed that the chloroform extract was the most toxic with LC50 value of 22,39 ppm. Futher, the cloroform extract was separated and purified by coloumn chromatography using eluent of solvent mixture of chloroform : ethyl acetate : n-hexane by 7 : 2 : 1 and 4 fractions were obtained. The most toxic fraction was the fraction C with LC50 value of 35,36 ppm. Based on the GC-MS results, the toxic isolate is allegedly containing chemicals compound of hexadecanoic methyl ester and hexadecanoic acid.

  17. First secondary metabolites from Herissantia crispa L (Brizicky) and the toxicity activity against Artemia salina Leach

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Danielly Albuquerque da; Matias, Wemerson Neves; Lima, Igara Oliveira; Xavier, Aline Lira; Costa, Vivian Bruna Machado; Diniz, Margareth de Fatima Formiga Melo; Agra, Maria de Fatima; Batista, Leonia Maria; Souza, Maria de Fatima Vanderlei de [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica Prof. Delby Fernandes de Medeiros; Silva, Davi Antas e [Universidade Federal Rural de Pernambuco, Serra Talhada, PE (Brazil). Dept. de Quimica

    2009-07-01

    The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-{beta}-D-glucopyranoside, stigmasterol 3-O-{beta}-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides {beta}-sitosterol, kaempferol 3-O-{beta}-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-{alpha}-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, {sup 1}H and {sup 13}C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out. (author)

  18. Environmental plasticity of fish avoidance diapause response in Daphnia magna

    Directory of Open Access Journals (Sweden)

    Mirosław ŚLUSARCZYK

    2004-09-01

    Full Text Available Organisms cope with harsh environmental conditions in various ways: either by tolerating environmental stress (through physiological adaptations, or by avoiding it in space (through migration or time (diapause. Some species rely on a single strategy while others may choose from an array of options when facing different environmental stressors. Planktonic crustaceans may utilise different active (morphological, behavioural, life-history or passive (diapause defences to survive periods of high risk of fish predation. Recent evidence has indicated that resting egg production could be induced in Daphnia magna by chemical cues associated with fish predation. This suggests that contrary to most known cases of diapause, which are triggered well in advance of catastrophic events (here termed "predictive diapause", fish avoidance diapause in D. magna may exhibit a "responsive nature" and be initiated only after intensive predation appears. Experimental evidence discussed here indicates that the reaction of D. magna to chemical signals of fish predation could be conditional and determined by key environmental conditions, which in nature affect relative gains of activity vs dormancy. At high risk of fish predation, the decision of Daphnia to produce resting eggs was disfavoured by high food concentration. This reaction was claimed adaptive since high food allows for higher reproductive rates and better survival of offspring. All this may assure higher benefits due to activity despite some risk of predation (once predation pressure is not fatal to all active descendants and disfavour resting eggs production. Moreover, at moderate food conditions the decision of Daphnia to produce resting eggs was disfavoured by the availability of a dark refuge from fish visual predators and thus likely lowering the risk of being preyed upon. Furthermore, when food was at a moderate level and a dark refuge was not present the decision of Daphnia to produce resting eggs was

  19. Small scale mass culture of Daphnia magna Straus

    Energy Technology Data Exchange (ETDEWEB)

    Rees, J.T.; Oldfather, J.M.

    1980-02-01

    Daphnia magna Straus 1820 was raised on a defined medium in 4-liter flasks with controlled light intensity, temperature, and algal food species. Adult D. magna tolerated high levels of ammonia (up to 108 ..mu..M) at high pH (> 10), although at these levels parthenogenic reproduction may be inhibited. Scenedesmus quadricauda and Ankistrodesmus sp. were satisfactory food sources, and by utilizing Ankistrodesmus densities greater than one animal per ml were achieved. Maintaining the pH at about 7 to 8 seems to be important for successful D. magna culture.

  20. Involvement of cyclin K posttranscriptional regulation in the formation of Artemia diapause cysts.

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    Full Text Available BACKGROUND: Artemia eggs tend to develop ovoviviparously to yield nauplius larvae in good rearing conditions; while under adverse situations, they tend to develop oviparously and encysted diapause embryos are formed instead. However, the intrinsic mechanisms regulating this process are not well understood. PRINCIPAL FINDING: This study has characterized the function of cyclin K, a regulatory subunit of the positive transcription elongation factor b (P-TEFb in the two different developmental pathways of Artemia. In the diapause-destined embryo, Western blots showed that the cyclin K protein was down-regulated as the embryo entered dormancy and reverted to relatively high levels of expression once development resumed, consistent with the fluctuations in phosphorylation of position 2 serines (Ser2 in the C-terminal domain (CTD of the largest subunit (Rpb1 of RNA polymerase II (RNAP II. Interestingly, the cyclin K transcript levels remained constant during this process. In vitro translation data indicated that the template activity of cyclin K mRNA stored in the postdiapause cyst was repressed. In addition, in vivo knockdown of cyclin K in developing embryos by RNA interference eliminated phosphorylation of the CTD Ser2 of RNAP II and induced apoptosis by inhibiting the extracellular signal-regulated kinase (ERK survival signaling pathway. CONCLUSIONS/SIGNIFICANCE: Taken together, these findings reveal a role for cyclin K in regulating RNAP II activity during diapause embryo development, which involves the post-transcriptional regulation of cyclin K. In addition, a further role was identified for cyclin K in regulating the control of cell survival during embryogenesis through ERK signaling pathways.

  1. Maladaptive Sex Ratio Adjustment in the Invasive Brine Shrimp Artemia franciscana.

    Science.gov (United States)

    Lievens, Eva J P; Henriques, Gil J B; Michalakis, Yannis; Lenormand, Thomas

    2016-06-01

    Sex allocation theory is often hailed as the most successful area of evolutionary theory due to its striking success as a predictor of empirical observations [1]. Most naturally occurring sex ratios can be explained by the principle of equal investment in the sexes [2-4] or by cases of "extraordinary" sex allocation [5]. Deviations from the expected sex ratio are often correlated with weak selection or low environmental predictability (e.g., [6, 7]); true cases of aberrant sex allocation are surprisingly rare [8]. Here, we present a case of long-lasting maladaptive sex allocation, which we discovered in invasive populations of the exclusively sexual brine shrimp Artemia franciscana. A. franciscana was introduced to Southern France roughly 500 generations ago [9]; since then, it has coexisted with the native asexual species Artemia parthenogenetica [10]. Although we expect A. franciscana to produce balanced offspring sex ratios, we regularly observed extremely male-biased sex ratios in invasive A. franciscana, which were significantly correlated to the proportion of asexuals in the overall population. We experimentally proved that both invasive- and native-range A. franciscana overproduced sons when exposed to excess females, without distinguishing between conspecific and asexual females. We conclude that A. franciscana adjust their offspring sex ratio in function of the adult sex ratio but are information limited in the presence of asexual females. Their facultative adjustment trait, which is presumably adaptive in their native range, has thus become maladaptive in the invasive range where asexuals occur. Despite this, it has persisted unchanged for hundreds of generations. PMID:27185556

  2. Intracellular water in Artemia cysts (brine shrimp): Investigations by deuterium and oxygen-17 nuclear magnetic resonance.

    Science.gov (United States)

    Kasturi, S R; Seitz, P K; Chang, D C; Hazlewood, C F

    1990-08-01

    The dormant cysts of Artemia undergo cycles of hydration-dehydration without losing viability. Therefore, Artemia cysts serve as an excellent intact cellular system for studying the dynamics of water-protein interactions as a function of hydration. Deuterium spin-lattice (T(1)) and spin-spin (T(2)) relaxation times of water in cysts hydrated with D(2)O have been measured for hydrations between 1.5 and 0.1 g of D(2)O per gram of dry solids. When the relaxation rates (I/T(1), I/T(2)) of (2)H and (17)O are plotted as a function of the reciprocal of hydration (1/H), an abrupt change in slope is observed near 0.6 g of D(2)O (or H(2) (17)O)/gram of dry solids, the hydration at which conventional metabolism is activated in this system. The results have been discussed in terms of the two-site and multisite exchange models for the water-protein interaction as well as protein dynamics models. The (2)H and (17)O relaxation rates as a function of hydration show striking similarities to those observed for anisotropic motion of water molecules in protein crystals.It is suggested here that although the simple two-site exchange model or n-site exchange model could be used to explain our data at high hydration levels, such models are not adequate at low hydration levels (<0.6 g H(2)O/g) where several complex interactions between water and proteins play a predominant role in the relaxation of water nuclei. We further suggest that the abrupt change in the slope of I/T(1) as a function of hydration in the vicinity of 0.6 g H(2)O/g is due to a change in water-protein interactions resulting from a variation in the dynamics of protein motion. PMID:19431762

  3. Risk associated with toxic blooms of marine phytoplankton functional groups on Artemia franciscana

    Institute of Scientific and Technical Information of China (English)

    Ana Dors; Mara Carmen Bartolom; Sebastin Snchez-Fortn

    2014-01-01

    Objective:To study mortality of copepod Artemia franciscana against the occurrence of harmful marine algae and possible toxicological changes exhibited by binary and tertiary combinations of these harmful algae toxins. Methods:Tweenty four hours acute toxicity assays were performed with selected concentrations of Alexandrium minutum, Prorocentrum lima and Nitzschia N1c1 living cells. Additionally, the results were analyzed using the median-effect/combination index (CI)-isobologram equation to assess possible changes in the toxic effect induced by phytoplankton functional groups. Results:Biotoxin equivalent values obtained by immunodetection were (2.12±0.10), (8.60±1.30) and (4.32±1.67) pg/cell for saxitoxin, okadaic acid and domoic acid, respectively. The 24-h LC50 values estimated to saxitoxin and okadaic acid equivalents were 4.06 and 6.27 µg/L, significantly below the value obtained for Nitzschia N1c1, which was established at 467.33 µg/L. CI analysis applied on phytoplankton assemblages showed that both ternary mixture as the binary combinations exhibited antagonic action on toxic effects in Artemia nauplii, which were significantly lower than the toxic effect exhibited by each species studied. Conclusions:These results show that, although these harmful algae represent a serious risk to estuarine zooplankton community, the presence of phytoplankton functional groups within the same bloom can reduce the potential risk compared to the expected risk when each of the phytoplankton groups are evaluated individually.

  4. Uji Sitotoksik Fraksi Etilasetat Daun Bangun-Bangun (Plectranthus amboinicus (Lour.) terhadap Larva Artemia salina Leach dengan Metode Brine Shrimp Lethality Test (BSLT)

    OpenAIRE

    Pardede, E. Roslina

    2016-01-01

    Background: Bangun-Bangun leaves (Plectranthus amboinicus (Lour.) Spreng is one of the plants that have the potential to be developed as a cancer chemopreventive agent. The Purpose: The aim of the study were to find out the cytotoxic effect of ethylacetate fraction bangun-bangun leaves (FEDBB) on Artemia salina Leach larvae. Methods: This experimental study using 800 Artemia salina Leach larvae were divided into one control group negative 1 and 5 positive control group concentration10 μ...

  5. Temperature-dependent effect of filamentous cyanobacteria on Daphnia magna life history traits

    Directory of Open Access Journals (Sweden)

    Piotr DAWIDOWICZ

    2011-08-01

    Full Text Available Filamentous cyanobacteria are unsuitable food for Daphnia due to their poor manageability, poor nutritional value and, in some cases, toxicity. As the strength of harmful effects of cyanobacteria on filter-feeding zooplankton is temperature dependent, the global warming scenarios for eutrophic lakes in temperate zone might include an escalated suppression of Daphnia populations caused by the presence of cyanobacterial filaments. To test this assumption, we conducted life-table experiments with four clones of Daphnia magna fed either a green alga Scenedesmus obliquus or a non-toxic strain of filamentous cyanobacteria Cylindrospermopsis raciborskii in two temperatures (20 °C and 24 °C. Key life history parameters of Daphnia, i.e., age and size at first reproduction, fecundity, and individual growth rate, were measured. Both food and temperature significantly affected Daphnia performance, however, the effect of interaction of these two factors was ambiguous and highly genotype-dependent. We conclude that the temperature increase within the studied range will not necessarily strengthen the suppression of Daphnia growth by filamentous cyanobacteria, but may affect clonal selection within population of Daphnia, thus possibly triggering microevolutionary changes within affected populations.

  6. A new subspecies of Daphnia: Daphnia similoides sinensis%新亚种—中华拟同形溞(Daphnia similoides sinensis)

    Institute of Scientific and Technical Information of China (English)

    顾杨亮; 徐磊; 林秋奇; Henri J.Dumont; 韩博平

    2013-01-01

    记述了一种溞属新亚种:中华拟同形溞Daphnia similoides sinensis,模式标本保存在暨南大学水生生物研究所.在蒋樊治先生的《淡水枝角类》等中国文献中,该种被描述为隆腺溞,直至最近几年才陆续有中国学者报道了中国的拟同形溞,并有较多有关该种的生物学与生态学研究,但一直未见其形态学的研究结果.除此之外,仅台湾学者YOUNG Shuh-Sen公布了台湾的拟同形溞的COI序列.中华拟同形溞与已知印度的Daphnia similoides主要区别在于其雄性第一触角上的嗅毛较短、鞭毛分节不同,鉴于雄性第一触角在分类学上的重要性,将其划分为新亚种.该亚种的COI基因序列与已知台湾的D.similoides有99%的相似度.比较了广东、安徽、浙江和江苏等地的D.similoides种群,它们仅在第一触角处有细微差别.

  7. Feeding adult of Artemia salina (Crustacea-Branchiopoda on the dinoflagellate Gyrodinium corsicum (Gymnodiniales and the Chryptophyta Rhodomonas baltica

    Directory of Open Access Journals (Sweden)

    Rauquírio André Albuquerque Marinho da Costa

    2005-07-01

    Full Text Available Experiments were carried out on feeding performance and survival rates of adult Artemia salina exposed to no axenic strains of the dinoflagellate Gyrodinium corsicum and of the Chryptophyta Rhodomonas baltica. Filtration rates on R. baltica and G. corsicum varied from 3.35 to 7.14 ml.artemia-1.h-1 and from 2.97 to 15.86 ml.artemia-1.h-1, respectively. The ingestion rates observed for A. salina did not indicate any digestive dysfunction or physiological impairment for organisms fed on G. corsicum and their functional response were similar to those observed for other organisms like copepod fed on different food concentrations. Mortality rates oscillated from 2.5% to 100% when A. salina was fed on R. baltica or G. corsicum, respectively. Highest mortality rates observed for organisms fed on G. corsicum indicated that this dinoflagellate presented a hazard effect on A. salina that was not possible to confirm if it was related to toxin production or to nutritive inadequacy of this dinoflagellate as food for organisms of this species.Experimentos foram desenvolvidos para estudar as taxas de alimentação e de sobrevivência de Artemia salina alimentada com cepas não tóxicas do dinoflagelado Gyrodinium corsicum e da Chryptophyta Rhodomonas baltica. As taxas de filtração sobre R. baltica e G. corsicum variaram entre 3,35 e 7,14 ml.artemia-1.h-1 e 2,97 e 15,86 ml.artemia-1.h-, respectivamente. As taxas de ingestão observadas para A. salina não indicaram disfunção digestiva ou prejuízo fisiológico nos organismos alimentados com G. corsicum, sendo a resposta funcional destes organismos similar a observada em copépodos alimentados com diferentes concentrações de alimento. As taxas de mortalidade de A. salina oscilaram entre 2,5 e 100% quando alimentada com R. baltica e G. corsicum, respectivamente. As maiores taxas de mortalidade observadas para os organismos alimentados com G. corsicum indicam que este dinoflagelado apresenta algum efeito

  8. The effects of dietary administration with chemical treated Saccharomyces cerevisiae strain YG3-1 on the growth of aquatic invertebrates in Artemia

    Institute of Scientific and Technical Information of China (English)

    Behnam Shekarchi; Ali Nekuiefard; Ramin Manaffar

    2016-01-01

    Objective: To investigate the biological effects of β-glucans in cell wall of new identified strain Saccharomyces cerevisiae strain YG3-1 on the growth of aquatic invertebrates, in Artemia as model organism. Methods: All yeasts used in the present study were isolated from Rainbow trout intestine and then cultured in yeast extract-peptone-glycerol medium. Activation of β-glucan in yeasts was performed by chemical treatment with 2-mercaptoethanol (2ME) (3.5% v/v). Then nauplii and larvae individuals of Artemia urmiana and Artemia franciscana (two different species of Artemia as test organisms) were fed with 2ME-treated yeasts during the culture. At the end of experiment, after feeding individual length (total length and growth rate) in adult individuals of Artemia was measured. Results: Following this administration, growth in both species of Artemia was improved (P Conclusions: This study suggested that 2ME-treated Saccharomyces cerevisiae strain YG3-1 yeasts can be used for enhancing the growth of other aquatic invertebrates like shrimps as probiotic supplement and growth promoter.

  9. Hybridization and the Origin of Contagious Asexuality in Daphnia pulex.

    Science.gov (United States)

    Xu, Sen; Spitze, Ken; Ackerman, Matthew S; Ye, Zhiqiang; Bright, Lydia; Keith, Nathan; Jackson, Craig E; Shaw, Joseph R; Lynch, Michael

    2015-12-01

    Hybridization plays a potentially important role in the origin of obligate parthenogenesis (OP) in many organisms. However, it remains controversial whether hybridization directly triggers the transition from sexual reproduction to obligate asexuality or a hybrid genetic background enables asexual species to persist. Furthermore, we know little about the specific genetic elements from the divergent, yet still hybridizing lineages responsible for this transition and how these elements are further spread to create other OP lineages. In this study, we address these questions in Daphnia pulex, where cyclically parthenogenetic (CP) and OP lineages coexist. Ancestry estimates and whole-genome association mapping using 32 OP isolates suggest that a complex hybridization history between the parental species D. pulex and D. pulicaria is responsible for the introgression of a set of 647 D. pulicaria single nucleotide polymorphism alleles that show perfect association with OP. Crossing experiments using males of OP lineages and females of CP lineages strongly support a polygenic basis for OP. Single-sperm analyses show that although normal meiotic recombination occurs in the production of haploid sperm by males of OP lineages, a significant proportion of such sperm are polyploid, suggesting that the spread of asexual elements through these males (i.e., contagious asexuality) is much less efficient than previously envisioned. Although the current Daphnia genome annotation does not provide mechanistic insight into the nature of the asexuality-associated alleles, these alleles should be considered as candidates for future investigations on the genetic underpinnings of OP.

  10. Interclonal differences in age-specific performance in Daphnia magna

    Directory of Open Access Journals (Sweden)

    Barbara PIETRZAK

    2011-08-01

    Full Text Available Clonal organisms are often characterized by indeterminate growth and it is more likely in these organisms that delayed senescence evolves. Daphnia is characterized by both clonality and indeterminate growth, yet evidence for its senescence has been collected. In addition, differences in the dynamics of age-specific parameters were seen between environmentally developed phenotypes within a genotype as well as between genotypes, including between sister species. The aim of the present study was to test for interclonal differences within a species and to examine the course of basic life history and age-specific fitness parameters throughout life of Daphnia magna females originating from two different habitats, pond and lake. Clones differed in size at subsequent reproductions, but this did not result in differences in fecundity, although number of offspring in a clutch increased both with size and age of a female. There were also interclonal differences in lifespan and age-specific measures of fitness, but apart from lifespan, habitat of origin did not have significant effects on life history traits.

  11. Multigenerational cadmium acclimation and biokinetics in Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Guan Rui [Atmospheric Marine Coastal Environment Program (AMCE), and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Hong Kong (China); Wang Wenxiong [Atmospheric Marine Coastal Environment Program (AMCE), and Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Hong Kong (China)]. E-mail: wwang@ust.hk

    2006-05-15

    A Cd exposure (3 {mu}g L{sup -1}) experiment was conducted for six successive generations to investigate the responses to chronic Cd stress in Daphnia magna. We observed a biphasic accumulation of Cd in the six generations and suggested a similar pattern with respect to daphnids' tolerance. Cd assimilation efficiencies, daphnid growth, and reproduction corresponded to the changes of tolerance, which was partially accounted for by metallothionein induction. When maternally exposed neonates grew in Cd-free water for one or two generations, their growth, MT concentration and biokinetic parameters partially or totally recovered. The rapid recovery suggests the high potential for ecological restoration from Cd pollution. Our results indicate that the tolerance of sensitive D. magna clones to Cd was dependent on long-term or multigenerational exposure. The tolerance developed within the first several generations might not be maintained, and the animals may become even more sensitive to Cd stress in subsequent generations. - Tolerance of sensitive Daphnia magna clones to cadmium was dependent on long-term or multigenerational exposure.

  12. Prospecção fitoquímica de Sonchus oleraceus e sua toxicidade sobre o microcrustáceo Artemia salina Phytochemical prospecting of Sonchus oleraceus and its toxicity to Artemia salina

    Directory of Open Access Journals (Sweden)

    J.M. Lima

    2009-03-01

    Full Text Available A espécie vegetal Sonchus oleraceus é uma planta daninha presente em diversas culturas no Brasil e de utilização na medicina popular. Neste trabalho, realizou-se a prospecção fitoquímica dessa espécie com extratos em etanol, água e diclorometano, bem como testes de toxicidade sobre o microcrustáceo Artemia salina. O extrato aquoso apresentou em sua composição açúcares redutores, compostos fenólicos, taninos, flavonóides e cumarinas. No extrato etanólico, observaram-se os mesmos compostos qualificados no extrato aquoso, com exceção de cumarinas. Em diclorometano, verificou se a presença de saponinas, derivados triterpênicos e esteróides. No teste de toxicidade sobre Artemia salina, os dados convergiram para frações de extrato aquoso de 5.117,2 ppm, indicando ser um extrato de baixa toxicidade.Sonchus oleraceus is a common weed in Brazil, also used as a medicinal plant. Phytochemical prospecting of this species was carried out in this work using extracts obtained in ethanol, water and dichloromethane. A toxicity study of the aqueous extract was also conducted, using the micro crustaceous Artemia salina. The aqueous extract presented sugar reducers, phenolic compounds, tannins, flavonoids and coumarins in its composition. The compounds found in the aqueous extract were also detected in the ethanol extract, except for the coumarins. Saponin, triterpenes and steroids were identified in the dichloromethane extract. The toxicity test on Artemia salina pointed to aqueous extract fractions of 5,117.2 ppm, indicative of low toxicity.

  13. Characteristic properties of proteins from pre-ecdysial cuticle of larvae and pupae of the mealworm Tenebrio molitor.

    Science.gov (United States)

    Andersen, S O

    2002-09-01

    Proteins extracted from the cuticle of pharate larvae and pupae of the mealworm Tenebrio molitor are more soluble at low temperatures than at higher temperatures, a behaviour characteristic of hydrophobic proteins. When the temperature of an unfractionated cuticular extract is raised from 4 to 25 degrees C the solution becomes turbid, droplets of a heavy, protein-rich phase are formed, which gradually settles, leaving an upper protein-poor phase, indicating that the aggregation process is a coacervation. The aggregation of the dissolved cuticular proteins is influenced by changes in temperature, pH, and ionic strength. The process has been studied by measuring development of turbidity in unfractionated cuticular extracts and in solutions of three purified proteins from Tenebrio pharate larvae and pupae (TmLPCP-A1a, TmLPCP-E1a, and TmLPCP-G1a), while temperature, pH or ionic strength of the solutions were varied. Protein aggregation was also studied by determination of changes in fluorescence intensity, when the hydrophobicity probe, 8-anilinonaphthalenesulfonic acid (ANS) was added to solutions of the cuticular proteins. Only when the protein solutions had developed a measurable turbidity was an increase in ANS-fluorescence observed, indicating formation of tightly packed clusters of hydrophobic amino acid residues during aggregation. The temperature range for aggregation depends upon protein concentration: the higher the concentration the lower and more narrow is the temperature range within which aggregation occurs. The tendency for the individual cuticular proteins to aggregate is most pronounced near their isoelectric points, and most of the cuticular proteins have alkaline isoelectric points. The influence of salts on the tendency of the proteins to aggregate varies among the proteins and depends upon how close they are to their isoelectric point. A solution containing both protein TmLPCP-A1a and TmLPCP-E1a becomes more turbid and develops a more intense ANS

  14. Study of model systems to test the potential function of Artemia group 1 late embryogenesis abundant (LEA) proteins.

    Science.gov (United States)

    Warner, Alden H; Guo, Zhi-hao; Moshi, Sandra; Hudson, John W; Kozarova, Anna

    2016-01-01

    Embryos of the brine shrimp, Artemia franciscana, are genetically programmed to develop either ovoviparously or oviparously depending on environmental conditions. Shortly upon their release from the female, oviparous embryos enter diapause during which time they undergo major metabolic rate depression while simultaneously synthesize proteins that permit them to tolerate a wide range of stressful environmental events including prolonged periods of desiccation, freezing, and anoxia. Among the known stress-related proteins that accumulate in embryos entering diapause are the late embryogenesis abundant (LEA) proteins. This large group of intrinsically disordered proteins has been proposed to act as molecular shields or chaperones of macromolecules which are otherwise intolerant to harsh conditions associated with diapause. In this research, we used two model systems to study the potential function of the group 1 LEA proteins from Artemia. Expression of the Artemia group 1 gene (AfrLEA-1) in Escherichia coli inhibited growth in proportion to the number of 20-mer amino acid motifs expressed. As well, clones of E. coli, transformed with the AfrLEA-1 gene, expressed multiple bands of LEA proteins, either intrinsically or upon induction with isopropyl-β-thiogalactoside (IPTG), in a vector-specific manner. Expression of AfrLEA-1 in E. coli did not overcome the inhibitory effects of high concentrations of NaCl and KCl but modulated growth inhibition resulting from high concentrations of sorbitol in the growth medium. In contrast, expression of the AfrLEA-1 gene in Saccharomyces cerevisiae did not alter the growth kinetics or permit yeast to tolerate high concentrations of NaCl, KCl, or sorbitol. However, expression of AfrLEA-1 in yeast improved its tolerance to drying (desiccation) and freezing. Under our experimental conditions, both E. coli and S. cerevisiae appear to be potentially suitable hosts to study the function of Artemia group 1 LEA proteins under environmentally

  15. Design, operation, and potential of a culture system for the continuous production of Artemia nauplii

    OpenAIRE

    Lavens, P.; Sorgeloos, P

    1987-01-01

    A flow-through system is described for the controlled production of Artemia nauplii. High densities of adult brine shrimp are induced to ovoviviparity through diet manipulation, optimal culture water exchange, and high constant oxygen levels. The nauplii produced are separated from the culture tank effluents in a special recuperation filter system. The culture water is recirculated over a rotating biodisc, a cross-flow sieve, and a plate separator.The potential of this nauplii production syst...

  16. 卤虫属分类研究进展%Progress on Researches of Taxonomy on Genus Artemia

    Institute of Scientific and Technical Information of China (English)

    张伟峰; 郝浩永; 陈莉

    2008-01-01

    卤虫(Anemia)属于节肢动物门(Phylum Arthropoda),甲壳纲(Class Crustacea),鳃足亚纲(SubclassBranchiopoda),无甲目(Order Anostraca),卤虫科(Family Artemidae).世界卤虫根据生殖方式可分为两性生殖卤虫和孤雌生殖卤虫两大类.利用生殖隔离实验将世界两性卤虫分为8个种:Anemiafranciscana Kellogg、Artemia persimilis Piccinelli et Prosdoeimi、Anemia rnonica Verrill、Anemia salina Linnaeus、Artemia urmianaGünther、Anemia tunisiana Bowen et Sterling、Anemia sinica Cai和Anemia tibetiana Abatzopouios,Zhang et Sorge-loos.其中,我国发现有A.sinica和A.tibetiana两种两性卤虫.孤雌生殖卤虫统称为Artemia parthenogenetica,并在其后加上产地的地名以示区别.

  17. Multiple {gamma}-glutamylation: A novel type of post-translational modification in a diapausing Artemia cyst protein

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Mai [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Ikeda, Yuka [Institute of High Polymer Research, Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda 386-8567 (Japan); Kanzawa, Hideaki [Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Sakamoto, Mika [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Goto, Mina [Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Tsunasawa, Susumu [Analytical and Measuring Instruments Division, Shimadzu Corporation, Nishinokyo Kuwabaracho 1, Nakagyo-Ku, Kyoto 604-8511 (Japan); Uchiumi, Toshio, E-mail: uchiumi@bio.sc.niigata-u.ac.jp [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Odani, Shoji [Bioscience Course, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan); Department of Biology, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-Ku, Niigata 950-2181 (Japan)

    2010-03-26

    A highly hydrophilic, glutamate-rich protein was identified in the aqueous phenol extract from the cytosolic fraction of brine shrimp (Artemia franciscana) diapausing cysts and termed Artemia phenol soluble protein (PSP). Mass spectrometric analysis revealed the presence of many protein peaks around m/z 11,000, separated by 129 atomic mass units; this value corresponds to that of glutamate, which is strongly suggestive of heterogeneous polyglutamylation. Polyglutamylation has long been known as the functionally important post-translational modification of tubulins, which carry poly(L-glutamic acid) chains of heterogeneous length branching off from the main chain at the {gamma}-carboxy groups of a few specific glutamate residues. In Artemia PSP, however, Edman degradation of enzymatic peptides revealed that at least 13, and presumably 16, glutamate residues were modified by the attachment of a single L-glutamate, representing a hitherto undescribed type of post-translational modification: namely, multiple {gamma}-glutamylation or the addition of a large number of glutamate residues along the polypeptide chain. Although biological significance of PSP and its modification is yet to be established, suppression of in vitro thermal aggregation of lactate dehydrogenase by glutamylated PSP was observed.

  18. Coadaptation: lessons from the brine shrimp Artemia, "the aquatic Drosophila" (Crustacea; Anostraca Coadaptación: lecciones desde el camarón de salmuera Artemia, "la Drosophila acuática" (Crustacea; Anostraca

    Directory of Open Access Journals (Sweden)

    GONZALO GAJARDO

    2001-03-01

    Full Text Available During the fifties Brncic and the Dobzhansky's school, using the fruit fly Drosophila as a test organism, introduced the term integration of the genotype, or genetic coadaptation, which has had great impact on thinking in today's evolutionary biology. In this work we use the brine shrimp Artemia - in many respects a sort of aquatic Drosophila- as a model organism to evaluate the relationship between population structure, potential for divergence and the degree of morphological and/or genetic change. These aspects, tightly linked with the organization of the genotype, are important to understanding how recombination and adaptive release of genetic and phenotypic variation affect the speciation process in Artemia. Analysis of genetic (allozyme, diploid and chromocentre numbers, morphological (Mahalanobis distances and reproductive data (cross-fertility tests available for populations of the bisexual, endemic species of the Americas, Artemia franciscana and A. persimilis, indicate that: (i A. franciscana and A. persimilis are morphologically distinct in correspondence with observed genetic differences (D Nei > 1; 2n = 42 and 44; 12.5 and 1.5 mean chromocentre numbers, respectively; (ii populations from Chile and other South American localities (mainly A. franciscana display high levels of genetic variability and a trend to develop large genetic distances between populations; (iii the plasticity of Artemia gene pool is associated, at least in part, with ecological heterogeneity. Hence an adaptive divergence mode is thought to best define the speciation process in Artemia; (iv the succesful production of laboratory hybrids in the allopatric Artemia populations studied in the Americas, a feature seen in other anostracods, could be explained by the fact that formerly allopatric populations have not achieved later sympatry, as required by the allopatric speciation paradigmEn los años cincuenta Brncic y la escuela de Dobzhansky introdujeron el t

  19. Effect of body size on toxicity of zinc in neonates of four differently sized Daphnia species

    NARCIS (Netherlands)

    Vesela, S.; Vijverberg, J.

    2007-01-01

    The sensitivity of neonates of four Daphnia species to zinc was tested in relation to their mean body size. These mean sizes of these four Daphnia spp were: D. magna, 0.813 ± 0.055 mm, D.␣pulicaria, 0.745 ± 0.063 mm, D. pulex, 0.645 ± 0.044 mm and D. galeata, 0.611 ± 0.058 mm. A positive relationshi

  20. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    OpenAIRE

    Petrusek, Adam; Jaromir SEDA

    2011-01-01

    Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. ...

  1. Effects of He-Ne laser on Daphnia magna Straus manifested in subsequent generations

    Science.gov (United States)

    Vorob'yeva, O. V.; Filenko, O. F.; Isakova, E. F.; Vorobieva, N. N.; Rybaltovskii, A. O.; Yusupov, V. I.; Bagratashvili, V. N.

    2015-11-01

    The effects of He-Ne laser irradiation (including visible laser light 632.8 nm in wavelength and an attendant electromagnetic field from the laser apparatus) on the fertility, newborn quality and linear dimensions of the body of Cladocera Daphnia magna Straus were determined. It is shown that the attendant electromagnetic field generated by the laser apparatus can have significant impact on the results of low-intensity laser therapy. The laser light exposure of daphnia to a dose range of 1.7-1300 mJ cm-2 stimulates the integral functions of the daphnia’s body. At the same time, the attendant electromagnetic field (72 mA m-1 in the frequency range of 0.02-20 kHz and 400 mA m-1 in the frequency range of 3-4 MHz) causes the appearance of quickly dying and/or abnormal newborn (up to a small percent) that has never been observed in the control. Anomalies of daphnia mainly consisted of swimming antenna pathologies. Moreover, under the influence of the attendant electromagnetic field on parental daphnia only, these anomalies appear even in several subsequent generations of newborn. The negative impact on daphnia disappears completely after the suppression of the attendant electromagnetic field to laboratory background level. It is shown that laser light can partially compensate the negative impact of the attendant electromagnetic field on Daphnia.

  2. Daphnia lumholtzi Sars, 1885 (Cladocera: Daphniidae invades Argentina

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    Alexey A. Kotov

    2014-04-01

    Full Text Available The extent of freshwater biological invasions is difficult to predict. The thermophilic Daphnia lumholtzi Sars, 1885 (Cladocera: Daphniidae has successfully invaded a large section of temperate North America from an Old World source, damaging ecosystems and fisheries. The species was later reported introduced into Mexico and Brazil. Here we report D. lumholtzi in Argentina - the most southerly record in the New World for this species. Our genetic analyses establish haplotype identity with North American specimens, consistent with the colonization of South America from North America. The detection dates of the records in South America and the association with the Paraná River, provide evidence that river ways play a role in expansion of D. lumholtzi. The invasion of D. lumholtzi has now reached a similar wide latitudinal span to the distribution in the Old World.

  3. SMALL SCALE MASS CULTURE OF DAPHNIA MAGNA STRAUS

    Energy Technology Data Exchange (ETDEWEB)

    Rees, John T.; Oldfather, Joan M.

    1980-03-01

    Daphnia magna Straus 1820 was reared on a defined medium in 4-liter flasks under controlled conditions of light, temperature and species of algal food. Adult D. magna were found to be tolerant to high levels of ammonia, up to 108 {micro}M, at high pH (>10), although parthenogenic reproduction may be inhibited at these high levels. Scenedesmus quadricauda and Ankistrodesmus sp. were found to be satisfactory food sources. Densities of greater than one animal per ml in culture were attained utilizing Ankistrodesmus sp. as a food source at a pH of 7.7. Maintenance of pH at around 7-8 appears to be important to successful D. magna culture.

  4. Cardioactive effects of diphenhydramine and curcumin in Daphnia magna

    Directory of Open Access Journals (Sweden)

    Noelle Erin Romero

    2009-01-01

    Full Text Available Although used as a model for examining the cardioactive effects of various compounds, the neuromuscular regulation of the heart of the crustacean Daphnia magna (D. magna is not well understood. In the present study, we sought to determine how the heart rate of D. magna was affected by two previously untested compounds: curcumin and diphenhydramine (DPHM. DPHM produces a number of cardiotoxic side effects in vertebrates, particularly sinus tachycardia. Curcumin acts as a monoamine oxidase inhibitor (MAOI and was expected toincrease the heart rate of D. magna. DPHM was found unexpectedly to lower the heart rate of D. magna with time. Curcumin increased heart rate when administered in higher concentrations. However, co-administration of curcumin with DPHM negated this effect. These findings may be explained by the potential role of histamine as a sympathetic cardiac neurotransmitter in D. magna.

  5. Effect of lindane on the clearance rate of daphnia magna

    Science.gov (United States)

    Hartgers; Heugens; Deneer

    1999-05-01

    The impact of the insecticide lindane (gamma-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 &mgr;g L-1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 &mgr;g L-1). The onset of the effect was rapid; after 2 h of exposure to approximately 241 &mgr;g L-1 of lindane a significant decrease in CR was observed. Daphnids recovered rapidly after transfer to clean water; after 24 h of exposure to approximately 250 &mgr;g L-1 lindane, transfer into clean water resulted in recovery to 80% of control levels within 2 h and complete recovery within 24 h. PMID:10227859

  6. Responses of Daphnia magna to pulsed exposures of arsenic.

    Science.gov (United States)

    Hoang, Tham C; Gallagher, Jeffrey S; Klaine, Stephen J

    2007-06-01

    Research on the toxicity of arsenic has focused on sublethal effects that do not provide sufficient information for risk estimation. While most studies have focused on organism response to constant arsenic exposures, organisms in nature are exposed to fluctuating As concentrations. Consequently, results obtained from standardized bioassays with constant exposures may not adequately characterize risk to indigenous biota. This research was designed to characterize the response of Daphnia magna to fluctuating arsenic exposures during 21-day experiments. At concentrations > or =3000 microg/L As, 21-day pulsed exposure mortality increased as a function of exposure concentration and duration. In addition, 21-day pulsed exposure mortality increased with increasing recovery time. Pulsed As exposure did not affect the growth of D. magna over 21 days. Twenty-one day accumulative reproduction of D. magna was only affected by pulsed exposures of high As concentration and long durations. PMID:17497644

  7. Multigenerational cadmium acclimation and biokinetics in Daphnia magna.

    Science.gov (United States)

    Guan, Rui; Wang, Wen-Xiong

    2006-05-01

    A Cd exposure (3 microg L(-1)) experiment was conducted for six successive generations to investigate the responses to chronic Cd stress in Daphnia magna. We observed a biphasic accumulation of Cd in the six generations and suggested a similar pattern with respect to daphnids' tolerance. Cd assimilation efficiencies, daphnid growth, and reproduction corresponded to the changes of tolerance, which was partially accounted for by metallothionein induction. When maternally exposed neonates grew in Cd-free water for one or two generations, their growth, MT concentration and biokinetic parameters partially or totally recovered. The rapid recovery suggests the high potential for ecological restoration from Cd pollution. Our results indicate that the tolerance of sensitive D. magna clones to Cd was dependent on long-term or multigenerational exposure. The tolerance developed within the first several generations might not be maintained, and the animals may become even more sensitive to Cd stress in subsequent generations. PMID:16202491

  8. Genetic structure of Daphnia galeata populations in Eastern China.

    Directory of Open Access Journals (Sweden)

    Wenzhi Wei

    Full Text Available This study presents the first examination of the genetic structure of Daphnia longispina complex populations in Eastern China. Only one species, D. galeata, was present across the eight investigated lakes; as identified by taxon assignment using allelic variation at 15 microsatellite loci. Three genetically differentiated D. galeata subgroups emerged independent of the type of statistical analysis applied. Thus, Bayesian clustering, discriminant analysis based on results from factorial correspondence analysis, and UPGMA clustering consistently showed that populations from two neighbouring lakes were genetically separated from a mixture of genotypes found in other lakes, which formed another two subgroups. Clonal diversity was high in all D. galeata populations, and most samples showed no deviation from Hardy-Weinberg equilibrium, indicating that clonal selection had little effect on the genetic diversity. Overall, populations did not cluster by geographical origin. Further studies will show if the observed pattern can be explained by natural colonization processes or by recent anthropogenic impact on predominantly artificial lakes.

  9. Inferring Deleterious-Mutation Parameters in Natural Daphnia Populations

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    Deng Hong-Wen

    1998-01-01

    Full Text Available Deng and Lynch (1, 2 proposed to characterize deleterious genomic mutations from changes in the mean and genetic variance of fitness traits upon selfing in outcrossing populations. Such observations can be readily acquired in cyclical parthenogens. Selfing and life-table experiments were performed for two such Daphnia populations. A significant inbreeding depression and an increase of genetic variance for all traits analyzed were observed. Deng and Lynch's (2 procedures were employed to estimate the genomic mutation rate (U, mean dominance coefficient ( , mean selection coefficient ( , and scaled genomic mutational variance ( . On average, , , and (^ indicates an estimate are 0.84, 0.30, 0.14 and 4.6E-4 respectively. For the true values, the and are lower bounds, and and upper bounds.

  10. Experimental assessment of environmental influences on the stable isotopic composition of Daphnia pulicaria and their ephippia

    Science.gov (United States)

    Schilder, J.; Tellenbach, C.; Möst, M.; Spaak, P.; van Hardenbroek, M.; Wooller, M. J.; Heiri, O.

    2015-02-01

    The stable isotopic composition of fossil resting eggs (ephippia) of Daphnia spp. is being used to reconstruct past environmental conditions in lake ecosystems. However, the underlying assumption that the stable isotopic composition of the ephippia reflects the stable isotopic composition of the parent Daphnia, of their diet and of the environmental water have yet to be confirmed in a controlled experimental setting. We performed experiments with Daphnia pulicaria cultures, which included a control treatment conducted at 12 °C in filtered lake water and with a diet of fresh algae, and three treatments in which we manipulated the stable carbon isotopic composition (δ13C value) of the algae, stable oxygen isotopic composition (δ18O value) of the water, and the water temperature, respectively. The stable nitrogen isotopic composition (δ15N value) of the algae was similar for all treatments. At 12 °C, differences in algal δ13C values and in δ18O values of water are reflected in those of Daphnia. The differences between ephippia and Daphnia stable isotope ratios were similar in the different treatments (δ13C: + 0.2 ± 0.4‰ (SD); δ15N: -1.6 ± 0.4‰; δ18O: -0.9 ± 0.4‰) indicating that changes in dietary δ13C and δ18O values of water are passed on to these fossilizing structures. A higher water temperature (20 °C) resulted in lower δ13C values in Daphnia and ephippia than in the other treatments with the same food source and in a minor change in the difference between δ13C values of ephippia and Daphnia (to -1.3 ± 0.3‰). This may have been due to microbial processes or increased algal respiration rates in the experimental containers, which may not affect Daphnia in natural environments. There was no significant difference in the offset between δ18O and δ15N values of ephippia and Daphnia between the 12 °C and 20 °C treatments, but the δ18O values of Daphnia and ephippia were on average 1.2‰ lower at 20 °C compared with 12 °C. We conclude

  11. Expression, purification and activity determination of the beetle tenebrio molitor antifreeze protein afp84c in escherichia coli

    International Nuclear Information System (INIS)

    Summary: A cDNA encoding antifreeze protein (AFP84c) was cloned by RT-PCR from the larva of the yellow mealworm Tenebrio molitor. The coding fragment of 252 bp encodes a protein of 84 amino acid residues and was fused to the expression vectors pMAL-c2X and pMAL-p2X. The expression plasmids pMAL-c2X-afp84c and pMAL-p2X-afp84c were constructed and transformed into Escherischia coli strains TBI, respectively. Strategy of optimization of induction conditions were used for expression of the highly disulfide-bonded beta-helix-contained protein with the activity of antifreeze in pMALTM expression system. The target fusion protein was released from the cytoplasm and periplasm by sonication and cold osmotic shock procedure respectively. Recombinant AFP84c was purified by amylose affinity column. The purified target protein displayed a single band in SDS-PAGE. Expressed AFP84c exhibits to increase low temperature resistance of bacteria. (author)

  12. Tenebrio molitor meal in rainbow trout (Oncorhynchus mykiss diets: effects on animal performance, nutrient digestibility and chemical composition of fillets

    Directory of Open Access Journals (Sweden)

    Marco Belforti

    2015-12-01

    Full Text Available This study evaluated the effects of diets containing Tenebrio molitor (TM larvae meal on growth performances, somatic indexes, nutrient digestibility, dorsal muscle proximate and fatty acid (FA compositions of rainbow trout. Three hundred sixty fish were randomly divided into three groups with four replicates each. The groups were fed diets differing in TM inclusion: 0% (TM0, 25% (TM25 and 50% (TM50 as fed weight basis. Weight gain was not affected by treatment. Feeding rate was significantly higher in TM0 than TM50. Feed conversion ratio was significantly higher in TM0 than TM25 and TM50, while an opposite trend was observed for protein efficiency ratio and specific growth rate. The survival rate was significantly lower in TM0 than TM25 and TM50. The apparent digestibility of protein was significantly lower in the TM50 group than the other groups, while the apparent digestibility of dry matter, organic matter and lipids was unaffected by treatment. If compared to control, the protein and lipid contents of fillets were respectively increased and decreased following TM inclusion in the diet. The Σn3/Σn6 FA ratio of fish dorsal muscle was linearly (TM0>TM25>TM50 reduced by TM inclusion in the diet. Results suggested that TM could be used during the growing phase in trout farming; however, additional studies on specific feeding strategies and diet formulations are needed to limit its negative effects on the lipid fraction of fillets.

  13. Immunomodulatory effects of supercritical fluid CO2 extracts from freeze-dried powder of Tenebrio molitor larvae (yellow mealworm

    Directory of Open Access Journals (Sweden)

    QingFeng TANG

    2016-01-01

    Full Text Available Abstract In order to take full advantage of Tenebrio molitor larvae (yellow mealworm resources, the supercritical CO2 fluid freeze-dried powder of T. molitor larvae (fdTML extraction on the immune systems of mice was carried out. The results about the effects of supercritical CO2 fluid fdTML extraction on carbon expurgation and phagocytosis of peritoneal macrophages experiments of mice indicated that the fdTML extraction enhanced observably carbon expurgatory index, phagocytic rate and phagocytic index. The fdTML extraction could stimulate response of delayed hypersensitivity. The proliferation of ConA-induced mitogenic reponse for spleen lymphocyte was also increased. The amount of hemolytic antibody in mice serum increased compared with those of the control group mice. The half of hemolysis values in serum of treated mice increased compared to the control group. Furthermore, serum NO content in all treatment groups was higher than that of the control group whereas acid phosphatase and alkaline phosphatase activity was only significantly higher relative to the control group. Our findings suggest that supercritical CO2 fluid the fdTML extraction has potential as a health food supplement.

  14. Cloning, Characterization and Effect of TmPGRP-LE Gene Silencing on Survival of Tenebrio Molitor against Listeria monocytogenes Infection

    Directory of Open Access Journals (Sweden)

    Yeon Soo Han

    2013-11-01

    Full Text Available Peptidoglycan recognition proteins (PGRPs are a family of innate immune molecules that recognize bacterial peptidoglycan. PGRP-LE, a member of the PGRP family, selectively binds to diaminopimelic acid (DAP-type peptidoglycan to activate both the immune deficiency (Imd and proPhenoloxidase (proPO pathways in insects. A PGRP-LE-dependent induction of autophagy to control Listeria monocytogenes has also been reported. We identified and partially characterized a novel PGRP-LE homologue, from Tenebrio molitor and analyzed its functional role in the survival of the insect against infection by a DAP-type PGN containing intracellular pathogen, L. monocytogenes. The cDNA is comprised of an open reading frame (ORF of 990 bp and encodes a polypeptide of 329 residues. TmPGRP-LE contains one PGRP domain, but lacks critical residues for amidase activity. Quantitative RT-PCR analysis showed a broad constitutive expression of the transcript at various stages of development spanning from larva to adult. RNAi mediated knockdown of the transcripts, followed by a challenge with L. monocytogenes, showed a significant reduction in survival rate of the larvae, suggesting a putative role of TmPGRP-LE in sensing and control of L. monocytogenes infection in T. molitor. These results implicate PGRP-LE as a defense protein necessary for survival of T. molitor against infection by L. monocytogenes.

  15. Incidence of diapause varies among populations of Daphnia pulicaria.

    Science.gov (United States)

    Cáceres, Carla E; Tessier, Alan J

    2004-11-01

    Dormancy is a common way in which organisms survive environmental conditions that would be lethal to the active individual. However, while dormant, individuals forego reproduction. Hence theory suggests an optimal time in which to enter dormancy, depending on risks associated with both remaining active and entering dormancy. When these relative risks differ among habitats, dormancy strategies are predicted to vary as well. For freshwater zooplankton, it has been suggested that sensitivity to the cues that initiate dormancy should be selected against when females have the opportunity to remain in the water column year round. We tested this prediction with 12 populations of lake-dwelling Daphnia pulicaria (Crustacea: Cladocera). Differences among lakes in basin morphometry, predators and resources create a gradient of risk for Daphnia in the water column. Some populations persist in high numbers year round while others are abundant only in spring. We used this difference in persistence ability as an estimate of risk in the water-column. For 3 years of field sampling we found consistent differences among the lake populations in the incidence of dormancy. In some populations, only a small fraction of females switched to producing dormant eggs each year whereas in others the majority of eggs produced in the late spring were dormant. In general, populations that experienced predictably low abundances in the active form exhibited higher incidence of dormancy than did populations that persisted in high abundance year round, but there were exceptions. Our results confirm that the incidence of dormancy varies considerably among populations in a fashion consistent with general theory, but suggest that persistence in the water column is not the sole predictor of the diapause strategy found in any particular lake.

  16. Betaproteobacteria Limnohabitans strains increase fecundity in the crustacean Daphnia magna: symbiotic relationship between major bacterioplankton and zooplankton in freshwater ecosystem.

    Science.gov (United States)

    Peerakietkhajorn, Saranya; Kato, Yasuhiko; Kasalický, Vojtěch; Matsuura, Tomoaki; Watanabe, Hajime

    2016-09-01

    How symbioses between bacteria and aquatic animals influence food webs in freshwater ecosystems is a fundamental question in ecology. We investigated symbiosis between a crustacean zooplankton Daphnia magna and its dominant bacterial symbiont Limnohabitans, an abundant and globally distributed freshwater Betaproteobacteria. Aposymbiotic juvenile Daphnia were prepared and exposed to any of four Limnohabitans sp. - Limnohabitans strains DM1, 2KL-3, 2KL-7 and Limnohabitans planktonicus strain II-D5, all previously found in D. magna digestive tract or culture. Re-infected Daphnia were cultured until they produced the first clutch of juveniles. Limnohabitans strain DM1 and L. planktonicus strain II-D5 successfully re-infected Daphnia through single exposure at the first instar juvenile stage. In contrast to aposymbiotic Daphnia that produced non-viable juveniles, re-infected Daphnia produced viable juveniles and increased fecundity to levels of that of symbiotic Daphnia. Re-infected Daphnia did not increase their number of eggs nor growth rates. Limnohabitans strains 2KL-7 and 2KL-3 could not recover fecundity even in multiple exposures during culture. This study shows the functional evidence demonstrating that a single bacterium Limnohabitans regulates fecundity of the consumer Daphnia through symbiosis. Our results indicated that symbiotic relationship between major bacterioplankton and zooplankton is important for maintaining the population of zooplankton in freshwater ecosystems. PMID:26014379

  17. Fertilizers for Daphnia sp. (Crustacea, Cladocera production in experimental tanks Fertilizantes para produção de Daphnia sp. (Crustacea, Cladocera em tanques experimentais

    Directory of Open Access Journals (Sweden)

    Patrícia de Souza Lima Cunha

    2010-05-01

    Full Text Available The current study was aimed at investigating the use of different fertilizers - dicalcium phosphate, biosolid and quail feces - as a strategy for water fertilization in Daphnia sp production. It was used twenty-four 100-L tanks of asbestos cement distributed in a completely randomized split-plot design with six replicates, with plots in the three kinds of fertilizers (biosolid, dicalcium phosphate, and quail feces and a control without fertilization (WF and subplots at the times of assessment (days 8 and 13. It was assessed the biomass production of Daphnia sp. and the following water quality parameters: chlorophyll a, electrical conductivity, pH, dissolved oxygen, temperature, ammonia and organic nitrogen, total phosphorus and total hardness. There was a significant correlation between the values of chlorophyll a and biomass weight of Daphnia sp, which indicates interactions between phytoplankton and zooplankton communities. The maximum weight of Daphnia sp. biomass is found in tanks fertilized with quail feces (35.98 g, followed by the biosolid (16.80 g, control without fertilization (6.75 g and dicalcium phosphate (5.24 g.Este trabalho foi conduzido com o objetivo de avaliar a utilização de fertilizantes - fosfato bicálcico, biossólido e fezes de codorna - na água de produção de Daphnia sp. Foram utilizados 24 tanques de cimento-amianto, cada um com volume útil de 100 L, em um delineamento inteiramente ao acaso em parcelas subdivididas com seis repetições, tendo nas parcelas os tipos de fertilizantes e um controle, sem adubação, e nas subparcelas as épocas de avaliação (dias 8 e 13. Foram avaliados a produção da biomassa de Daphnia sp. e os seguintes parâmetros de qualidade da água: clorofila a, condutividade elétrica, pH, oxigênio dissolvido, temperatura, nitrogênio amoniacal e orgânico, fósforo total e dureza total. Observou-se correlação significativa entre os valores de clorofila a e o peso da biomassa de Daphnia

  18. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    OpenAIRE

    Pablo Mayorga; Karen R. Pérez; Sully M. Cruz; Armando Cáceres

    2010-01-01

    Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest) and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest), were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq.) Kunth ex ...

  19. Vibrio hispanicus sp. nov., isolated from Artemia sp. and sea water in Spain.

    Science.gov (United States)

    Gomez-Gil, B; Thompson, F L; Thompson, C C; Garcia-Gasca, A; Roque, A; Swings, J

    2004-01-01

    Three Gram-negative, small, motile, rod-shaped bacteria were isolated from Artemia sp. and sea water in Barcelona, Spain, during 1990 and 1991. They were fermentative, oxidase-positive, sensitive to vibriostatic agent O/129, arginine dihydrolase-positive, lysine and ornithine decarboxylase-negative and grew in the absence of NaCl. They differed from phenotypically related species by their ability to grow at 4 degrees C and utilize L-rhamnose. Cloning of the 16S rRNA gene of the type strain produced two different 16S rRNA gene sequences, which differed by 15 bases (0.99%); comparison of these sequences with those deposited in GenBank showed close relationships with Vibrio proteolyticus (97.6% similarity), Vibrio diazotrophicus (97.9%), Vibrio campbellii (96.8%) and Vibrio alginolyticus (96.8%), among others. DNA-DNA hybridization levels with the closest phylogenetically related Vibrio species were Vibrio, for which the name Vibrio hispanicus sp. nov. is proposed, with the type strain LMG 13240T (=CAIM 525T=VIB 213T).

  20. Impacts of harvesting on brine shrimp (Artemia franciscana) in Great Salt Lake, Utah, USA.

    Science.gov (United States)

    Sura, Shayna A; Belovsky, Gary E

    2016-03-01

    Selective harvesting can cause evolutionary responses in populations via shifts in phenotypic characteristics, especially those affecting life history. Brine shrimp (Artemia franciscana) cysts in Great Salt Lake (GSL), Utah, USA are commercially harvested with techniques that select against floating cysts. This selective pressure could cause evolutionary changes over time. Our objectives are to (1) determine if there is a genetic basis to cyst buoyancy, (2) determine if cyst buoyancy and nauplii mortality have changed over time, and (3) to examine GSL environmental conditions over time to distinguish whether selective harvesting pressure or a trend in environmental conditions caused changes in cyst buoyancy and nauplii mortality. Mating crosses between floating and sinking parental phenotypes with two food concentrations (low and high) indicated there is a genetic basis to cyst buoyancy. Using cysts harvested from 1991-2011, we found cyst buoyancy decreased and nauplii mortality increased over time. Data on water temperature, salinity, and chlorophyll a concentration in GSL from 1994 to 2011 indicated that although water temperature has increased over time and chlorophyll a concentration has decreased over time, the selective harvesting pressure against floating cysts is a better predictor of changes in cyst buoyancy and nauplii mortality over time than trends in environmental conditions. Harvesting of GSL A. franciscana cysts is causing evolutionary changes, which has implications for the sustainable management and harvesting of these cysts. Monitoring phenotypic characteristics and life-history traits of the population should be implemented and appropriate responses taken to reduce the impacts of the selective harvesting. PMID:27209783

  1. Experimental taphonomy of Artemia reveals the role of endogenous microbes in mediating decay and fossilization.

    Science.gov (United States)

    Butler, Aodhán D; Cunningham, John A; Budd, Graham E; Donoghue, Philip C J

    2015-06-01

    Exceptionally preserved fossils provide major insights into the evolutionary history of life. Microbial activity is thought to play a pivotal role in both the decay of organisms and the preservation of soft tissue in the fossil record, though this has been the subject of very little experimental investigation. To remedy this, we undertook an experimental study of the decay of the brine shrimp Artemia, examining the roles of autolysis, microbial activity, oxygen diffusion and reducing conditions. Our findings indicate that endogenous gut bacteria are the main factor controlling decay. Following gut wall rupture, but prior to cuticle failure, gut-derived microbes spread into the body cavity, consuming tissues and forming biofilms capable of mediating authigenic mineralization, that pseudomorph tissues and structures such as limbs and the haemocoel. These observations explain patterns observed in exceptionally preserved fossil arthropods. For example, guts are preserved relatively frequently, while preservation of other internal anatomy is rare. They also suggest that gut-derived microbes play a key role in the preservation of internal anatomy and that differential preservation between exceptional deposits might be because of factors that control autolysis and microbial activity. The findings also suggest that the evolution of a through gut and its bacterial microflora increased the potential for exceptional fossil preservation in bilaterians, providing one explanation for the extreme rarity of internal preservation in those animals that lack a through gut. PMID:25972468

  2. Interference from ordinarily used solvents in the outcomes of Artemia salina lethality test

    Directory of Open Access Journals (Sweden)

    Sahgal Geethaa

    2013-01-01

    Full Text Available Methanol, ethanol, Tween 20 and dimethyl sulfoxide (DMSO are widely used as dissolving agents in Artemia salina lethality test (aka brine shrimp lethality test [BSLT] to screen the pharmaceutical properties of natural products. Nevertheless, there is lack of toxicity level of these solvents against brine shrimp. High concentration of these organic solvent might be toxic for this zoology invertebrate and interfere in the experimental outcomes. To avoid this, permissible concentration of the solvents used in BSLT was identified. BSLT was performed to evaluate the toxicity effect of Tween 20, methanol, ethanol and DMSO at 24 h post-treatment time point against A. salina. The suggested maximum working concentration (v/v for DMSO, methanol, ethanol was found to be 1.25% and that for Tween 20 was 0.16%. LC 50 for the solvents were 8.5% (DMSO, 6.4% (methanol, 3.4% (ethanol and 2.5% (Tween 20. The findings have shown a toxicity level among the solvents in descending order as Tween 20 > ethanol > methanol > DMSO. DMSO is a safer solvent to be used in BSLT compared with other tested solvents, whereas Tween 20 has been shown to be the most stringent solvent among the tested solvents. The findings are resourcefully useful to avoid interference of solvents in the assessment of natural products using BSLT.

  3. A Novel Porous Carrier Found in Nature for Nanocomposite Materials Preparation: A Case Study of Artemia Egg Shell-Supported TiO2 for Formaldehyde Removal

    Directory of Open Access Journals (Sweden)

    Sufeng Wang

    2015-01-01

    Full Text Available Artemia egg shells have an asymptotic sized pore structure (pore diameter: 500 nm–2500 nm, which could be used as a porous carrier for the preparation of nanocomposite materials. The objective of the present study was to prepare shell-supported TiO2 using a naturally porous carrier, Artemia egg shell, and to exhibit a case study of shell-supported TiO2 for formaldehyde removal. Characterization of shell-TiO2 using SEM-EDS, TEM, and XRD proved that Artemia shell with asymptotic reduction pores (pore diameter: 500 nm–2500 nm can be used as the carrier for nanocomposite materials. Artemia egg shell-supported TiO2 in polycrystalline-like nanostructures can be used for the high efficiency removal (adsorption and degradation of formaldehyde under visible light. Our results suggest that iron, one of the shell’s components, should broaden the absorption of visible light and enhance the photocatalytic efficiency of nanotitanium dioxide under visible light. Due to their interesting absorption and formaldehyde removal qualities, Artemia egg shell, as a novel naturally porous carrier for nanocomposite materials preparation, especially in the preparation of nanocatalysts, is worthy of further study.

  4. Chronic toxicity of diphenhydramine hydrochloride and erythromycin thiocyanate to Daphnia, Daphnia magna, in a continuous exposure test system

    Science.gov (United States)

    Meinertz, J.R.; Schreier, T.M.; Bernardy, J.A.; Franz, J.L.

    2010-01-01

    Diphenhydramine hydrochloride (DH; Benadryl TM, an over-the-counter antihistamine) and erythromycin thiocyanate (ET; a commonly used macrolide antibiotic) are pharmaceutical compounds whose chronic toxicity to Daphnia magna had not been characterized. Continuous exposure to DH concentrations about 5 times greater than the maximum reported environmental concentration of 0.023 lg/L for 21 days or to ET concentrations about 40 times the maximum reported environmental concentration of 6 (mu or u)g/L for 21 days did not significantly impact D. magna survival and production. In this study the no observable effect concentration for DH was 0.12 (mu or u)g/L and for ET was 248 (mu or u)g/L.

  5. NUTRIENT COMPOSITION DEGRADATION OF DAPHNIA PULICARIA BY A HIGHLY PREVALENT CHYTRIDIOMYCETE FUNGAL PATHOGEN (POLYCARYUM LEAVE) DURING NATURALLY OCCURRING LAKE-WIDE EPIDEMICS.

    Science.gov (United States)

    Despite evidence illustrating that chytridiomycete fungal infection can be highly prevalent in Daphnia (>80%) and that infected individuals are preferentially consumed by fish, no studies have measured the nutritional consequences of using chytrid-infected Daphnia as a food sourc...

  6. 黄粉虫桃酥的工艺配方%Researcll on Technology and Formula of Tenebrio molitor Linneeus Walnut Cookie

    Institute of Scientific and Technical Information of China (English)

    李汉臣; 赵希艳; 陈姣

    2012-01-01

    以传统桃酥配方为基础加入黄粉虫脱脂粉,通过对不同原料配比的研究,使桃酥形态、色泽、组织状态、滋味各指标最佳,以丰富桃酥品种。试验时以感官评分为评价指标,主要考虑黄粉虫添加量、水的添加量、糖的添加量、烤箱温度对桃酥品质的影响,在单因素试验的基础上采用正交分析的方法,确定最佳工艺配方:面粉量为900 g,黄粉虫脱脂粉添加量100 g,水的添加量110 g,白糖400 g,植物油450 g,膨松剂20 g(碳酸氢钠8 g,碳酸氢铵12 g),烤箱温度180/150℃(面火/底火)。%In order to enrich the types of walnut cake,fatless Tenebrio molitor Linneeus powder was mixed into traditional formula and varied ratios of materials were researched. The content of fatless Tenebrio molitor Lin- neeus powder,water and sugar and baking temperature were researched through sensory score in single factor experiment and orthogonal test. The optimum formulation determined is :flour 90 g,fatless Tenebrio molitor Lin- neeus powder 10 g,water 11 g,sugar 40 g,oil 45 g,raising agent 2 g,baking temperature 180/150C (the a- bove/the below).

  7. Translocation of 40 nm diameter nanowires through the intestinal epithelium of Daphnia magna.

    Science.gov (United States)

    Mattsson, Karin; Adolfsson, Karl; Ekvall, Mikael T; Borgström, Magnus T; Linse, Sara; Hansson, Lars-Anders; Cedervall, Tommy; Prinz, Christelle N

    2016-10-01

    Nanowires (NWs) have unique electrical and optical properties of value for many applications including lighting, sensing, and energy harnessing. Consumer products containing NWs increase the risk of NWs being released in the environment, especially into aquatic ecosystems through sewage systems. Daphnia magna is a common, cosmopolitan freshwater organism sensitive to toxicity tests and represents a likely entry point for nanoparticles into food webs of aquatic ecosystems. Here we have evaluated the effect of NW diameter on the gut penetrance of NWs in Daphnia magna. The animals were exposed to NWs of two diameters (40 and 80 nm) and similar length (3.6 and 3.8 μm, respectively) suspended in water. In order to locate the NWs in Daphnia, the NWs were designed to comprise one inherently fluorescent segment of gallium indium phosphide (GaInP) flanked by a gallium phosphide (GaP) segment. Daphnia mortality was assessed directly after 24 h of exposure and 7 days after exposure. Translocation of NWs across the intestinal epithelium was investigated using confocal fluorescence microscopy directly after 24 h of exposure and was observed in 89% of Daphnia exposed to 40 nm NWs and in 11% of Daphnia exposed to 80 nm NWs. A high degree of fragmentation was observed for NWs of both diameters after ingestion by the Daphnia, although 40 nm NWs were fragmented to a greater extent, which could possibly facilitate translocation across the intestinal epithelium. Our results show that the feeding behavior of animals may enhance the ability of NWs to penetrate biological barriers and that penetrance is governed by the NW diameter. PMID:27181920

  8. On the presence of Daphnia galeata in Lake Orta (N. Italy

    Directory of Open Access Journals (Sweden)

    Marina MANCA

    2006-08-01

    Full Text Available Lake Orta is a very interesting environment because of its history of heavy chronic pollution and biota re-colonization. It was the first deep lake in Italy in which allozyme techniques were used to investigate clonal diversity. In 1986, a newly established Daphnia obtusa population, able to colonize stressed environments, resulted composed by just one multilocus genotype, detected through an analysis of 27 different allozymes, fifteen of which active and stable for up to 12 generations. This result was interpreted as indicative of a colonization by a single clone, able to establish after a strong selection. This species was allochthonous for the lake, and in 1996 was replaced by a Daphnia longispina of the same morphotype as that originally described from its pelagic environment, the latter apparently remaining the only Daphnia species also in the lake’s littoral until 2001, i.e. until a regular sampling to monitor the lake was accomplished. During an accidental sampling in 2004, for detecting the occurrence and prevalence of parasites in Daphnia parental species and hybrids in several lakes located North and South of the Alps, Daphnia galeata was first found in Lake Orta’s pelagic environment, as revealed by morphological and allozyme analyses. Lake Orta zooplankton was then resampled in June 2006, to detect species as well as clonal composition of the Daphnia population, using the same techniques of morphotype and allozyme analyses. We expected to find low clone diversity and the occurrence of hybrids, whose success is enhanced in disturbed environments. Although preliminary, our results confirm that clone diversity Lake Orta’s Daphnia population is low, thus suggesting a recent colonization by D. galeata and providing evidence for a founder effect. In addition, the detection of the M variant at the AO locus, we interpret as a rare allele of D. galeata/D. longispina hybrids, perfectly fits the hypothesis of an enhancement of hybrid

  9. Avaliação da bioatividade dos extratos de cúrcuma (Curcuma longa L., Zingiberaceae em Artemia salina e Biomphalaria glabrata Bioactivity evaluation of the turmeric (Curcuma longa L., Zingiberaceae extracts in Artemia salina and Biomphalaria glabrata

    Directory of Open Access Journals (Sweden)

    Carlos R. M. da Silva Filho

    2009-12-01

    Full Text Available A cúrcuma é o rizoma limpo, em boas condições, seco e moído da Curcuma longa L., uma planta herbácea da família Zingiberaceae. Visando novas alternativas para o controle da esquistossomose, os extratos de Curcuma longa L. foram testados para a avaliação da atividade moluscicida contra caramujos adultos da espécie Biomphalaria glabrata, e toxicidade (ensaio de letalidade com Artemia salina. A oleoresina e o óleo essencial de cúrcuma foram ativos contra Artemia salina (CL50 = 80,43 e CL50 = 319,82 μg/mL, respectivamente e também ativos contra os indivíduos adultos de Biomphalaria glabrata (CL50 = 58,3 e CL50 = 46,73 μg/mL, respectivamente. A partir dos resultados obtidos pôde ser concluído que ambos os extratos podem constituir uma alternativa no controle da população desses caramujos e na redução da esquistossomose.The turmeric is the clean rhizome at good conditions, dried and powdered of Curcuma longa L., an herbaceous plant of Zingiberaceae family. Aiming new alternatives for Schistosomiasis control, the Curcuma longa L. extracts were tested for molluscicidal activity evaluation against adult snails of Biomphalaria glabrata specie, and the toxicity (Brine Shrimp Lethality-BSL-bioassay. The oleoresin and the essential oil of turmeric were active against Artemia salina (CL50 = 80.43 and CL50 = 319.82 μg.mL-1, respectively and also active against the adult snails of Biomphalaria glabrata (CL50 = 58.3 and CL50 = 46.73 μg.mL-1, respectively. From the obtained results it was concluded that both extracts can constitute an alternative to population control of these snails and in the reduction of Schistosomiasis.

  10. Effects of food type on the life history of Daphnia clones from lakes differing in trophic state. II. Daphnia cucullata feeding on mixed diets

    NARCIS (Netherlands)

    Repka, S.

    1997-01-01

    1. The effects of feeding on suboptimal foods were investigated in Daphnia cucullata a zooplankton common in many types of lakes. Eleven clones of D. cucullata were collected from four lakes of varying trophic levels and fed a high (1 mg C l1) concentration of one of two diets: (i) a 1 : 9 mixture o

  11. Identification of the glycerol kinase gene and its role in diapause embryo restart and early embryo development of Artemia sinica.

    Science.gov (United States)

    Cheng, Cheng; Yao, Feng; Chu, Bing; Li, Xuejie; Liu, Yan; Wu, Yang; Mei, Yanli; Wang, Peisheng; Hou, Lin; Zou, Xiangyang

    2014-03-01

    Glycerol kinase (GK) catalyzes the rate-limiting step in glycerol utilization by transferring a phosphate from ATP to glycerol, yielding glycerol 3-phosphate, which is an important intermediate for both energy metabolism and glycerolipid production. Artemia sinica has an unusual diapause process under stress conditions of high salinity, low temperature and lack of food. In the process, diapause embryos of A. sinica (brine shrimp) accumulate high concentrations of glycerol as a cryoprotectant to prevent low temperature damage to embryos. Upon embryo restart, glycerol is converted into glucose and other carbohydrates. Therefore, GK plays an important role in the diapause embryo restart process. However, the role of GK in diapause termination of embryo development in A. sinica remains unknown. In the present study, a 2096 bp full-length cDNA of gk from A. sinica (As-gk) was obtained, encoding putative 551 amino acids, 60.6 kDa protein. As a crucial enzyme in glycerol uptake and metabolism, GK has been conserved structurally and functionally during evolution. The expression pattern of As-gk was investigated by quantitative real-time PCR and Western blotting. Expression locations of As-gk were analyzed using in situ hybridization. As-gk was widely distributed in the early embryo and several main parts of Artemia after differentiation. The expression of As-GK was also induced by stresses such as cold exposure and high salinity. This initial research into the expression pattern and stress response of GK in Artemia provides a sound basis for further understanding of the function and regulation of genes in early embryonic development in A. sinica and the stress response. PMID:24365596

  12. High prevalence of cestodes in Artemia spp. throughout the annual cycle: relationship with abundance of avian final hosts

    Science.gov (United States)

    Sánchez, Marta I.; Nikolov, Pavel N.; GEorgieva, Darina D.; Georgiev, Boyko B.; Vasileva, Gergana P.; Pankov, Plamen; Paracuellos, Mariano; Lafferty, Kevin D.; Green, Andy J.

    2013-01-01

    Brine shrimp, Artemia spp., act as intermediate hosts for a range of cestode species that use waterbirds as their final hosts. These parasites can have marked influences on shrimp behavior and fecundity, generating the potential for cascading effects in hypersaline food webs. We present the first comprehensive study of the temporal dynamics of cestode parasites in natural populations of brine shrimp throughout the annual cycle. Over a 12-month period, clonal Artemia parthenogenetica were sampled in the Odiel marshes in Huelva, and the sexual Artemia salina was sampled in the Salinas de Cerrillos in Almería. Throughout the year, 4–45 % of A. parthenogenetica were infected with cestodes (mean species richness = 0.26), compared to 27–72 % of A. salina (mean species richness = 0.64). Ten cestode species were recorded. Male and female A. salina showed similar levels of parasitism. The most prevalent and abundant cestodes were those infecting the most abundant final hosts, especially the Greater Flamingo Phoenicopterus ruber. In particular, the flamingo parasite Flamingolepis liguloides had a prevalence of up to 43 % in A. parthenogenetica and 63.5 % in A. salina in a given month. Although there was strong seasonal variation in prevalence, abundance, and intensity of cestode infections, seasonal changes in bird counts were weak predictors of the dynamics of cestode infections. However, infection levels of Confluaria podicipina in A. parthenogenetica were positively correlated with the number of their black-necked grebe Podiceps nigricollis hosts. Similarly, infection levels of Anomotaenia tringae and Anomotaenia microphallos in A. salina were correlated with the number of shorebird hosts present the month before. Correlated seasonal transmission structured the cestode community, leading to more multiple infections than expected by chance.

  13. Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp,Artemia sinica

    Institute of Scientific and Technical Information of China (English)

    周茜; 吴长功; 董波; 李富花; 刘凤岐; 相建海

    2010-01-01

    Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica.Fourteen differentially displayed protein spots were detected and seven of them were identified.Three spots were up-expressed and identified:actin, heat shock protein 70,and chaperone subunit 1;three down-regulated proteins were identified:arginine kinase,elongation factor-2,and glycine-rich protein;and a newly expressed protein was identified as peroxiredoxin....

  14. A cost-effectiveness analysis of live feeds in juvenile turbot Scophthalmus maximus (Linnaeus, 1758) farming: copepods versus Artemia

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw; Nielsen, Rasmus; Nielsen, Max;

    2016-01-01

    items (copepods and Artemia) in juvenile turbot farming. Unit cost of production and profit are compared between the two feeding regimes using a unique data set from an existing turbot fry production facility in Denmark. The result reveals that copepods are not only biochemically superior...... but they are also economically a cost-effective alternative. Thus, a commercial use of copepods will significantly reduce the production costs for turbot. Furthermore, the unexploited economic potential can be utilized for the successful farming of other high-valued marine finfish species such as tuna, flounders...

  15. Naked eye instant reversible sensing of Cu(2+) and its in situ imaging in live brine shrimp Artemia.

    Science.gov (United States)

    Nair, Ratish R; Raju, M; Patel, Neha P; Raval, Ishan H; Suresh, E; Haldar, Soumya; Chatterjee, Pabitra B

    2015-08-21

    A Cu(2+)-specific colorimetric reversible fluorescent receptor was designed and synthesized which showed a naked eye observable colour change from colourless to pink on addition of an aqueous buffer (pH 7.4) solution of 30 ppb Cu(2+). Short response time (≤5 s) and low detection limit (nearly 3 ppb) make suitable as a reliable "dip-in" open eye sensor for Cu(2+). Bio-imaging application in live brine shrimp Artemia enabled to detect Cu(2+) at as low as 10 ppb exposure. PMID:26145434

  16. Effect of low doses of ionizing radiation, azoxystrobin and selected heavy metals on the model organism of species Artemia franciscana

    International Nuclear Information System (INIS)

    The aim of our study was to observe the effect of low doses of ionizing radiation, azoxystrobin, zinc and chrome on the lethality of Artemia franciscana. Significant increase of the lethality was observed after 72 and 96 hours of exposure to azoxystrobin and chrome as well as to azoxystrobin, chrome and irradiation. On the other hand, we observed significant decrease of the lethality in the groups exposed to pesticide and chrome or pesticide and zinc in combination with ionizing radiation with the dose of 50 Gy at time interval of 96 hours in comparison to non-irradiated groups. (authors)

  17. Assessment of Cytotoxic Activity of Three Plants of Pigweed, Bermuda grass and Burdock via Artemia Salina Test

    OpenAIRE

    parisa sadighara; tahere aliesfahani; mahdie jafari; atousa ziaei; tahere farkhondeh

    2010-01-01

    Introduction: Pigweed is a weed which grows in the pastures of Iran. Local people use the plant leaves to cook traditional food. Bermuda grass with its rapid growth and distribution is regarded a real threat to prairies and it can lead to tremors syndrome in cattle and sheep. Burdock which also grows in many parts of Iran is used as a medicinal herb. In this study, the cytotoxicity potential of the three plants was assessed via Artemia Salina test. Methods: Pigweed, Bermuda grass and burdock ...

  18. Contrasting migration behaviour of Daphnia pulicaria and D. galeata × hyalina, in avoidance of predation by 0+perch (Perca fluviatilis)

    NARCIS (Netherlands)

    Flik, B.J.G.; Vijverberg, J.

    2003-01-01

    In spring and early summer, a small population of the large-bodied Daphnia pulicaria coexists with a much larger population of the medium-sized hybrid Daphnia galeata × hyalina in the epilimnion of Lake Maarsseveen (The Netherlands). When large shoals of juvenile perch (Perca fluviatilis) appear in

  19. Melanization and pathogenicity in the insect, Tenebrio molitor, and the crustacean, Pacifastacus leniusculus, by Aeromonas hydrophila AH-3.

    Directory of Open Access Journals (Sweden)

    Chadanat Noonin

    Full Text Available Aeromonas hydrophila is the most common Aeromonas species causing infections in human and other animals such as amphibians, reptiles, fish and crustaceans. Pathogenesis of Aeromonas species have been reported to be associated with virulence factors such as lipopolysaccharides (LPS, bacterial toxins, bacterial secretion systems, flagella, and other surface molecules. Several mutant strains of A. hydrophila AH-3 were initially used to study their virulence in two animal species, Pacifastacus leniusculus (crayfish and Tenebrio molitor larvae (mealworm. The AH-3 strains used in this study have mutations in genes involving the synthesis of flagella, LPS structures, secretion systems, and some other factors, which have been reported to be involved in A. hydrophila pathogenicity. Our study shows that the LPS (O-antigen and external core is the most determinant A. hydrophila AH-3 virulence factor in both animals. Furthermore, we studied the immune responses of these hosts to infection of virulent or non-virulent strains of A. hydrophila AH-3. The AH-3 wild type (WT containing the complete LPS core is highly virulent and this bacterium strongly stimulated the prophenoloxidase activating system resulting in melanization in both crayfish and mealworm. In contrast, the ΔwaaE mutant which has LPS without O-antigen and external core was non-virulent and lost ability to stimulate this system and melanization in these two animals. The high phenoloxidase activity found in WT infected crayfish appears to result from a low expression of pacifastin, a prophenoloxidase activating enzyme inhibitor, and this gene expression was not changed in the ΔwaaE mutant infected animal and consequently phenoloxidase activity was not altered as compared to non-infected animals. Therefore we show that the virulence factors of A. hydrophila are the same regardless whether an insect or a crustacean is infected and the O-antigen and external core is essential for activation of the

  20. Metabolic restructuring during energy-limited states: insights from Artemia franciscana embryos and other animals.

    Science.gov (United States)

    Hand, Steven C; Menze, Michael A; Borcar, Apu; Patil, Yuvraj; Covi, Joseph A; Reynolds, Julie A; Toner, Mehmet

    2011-05-01

    Many life history stages of animals that experience environmental insults enter developmental arrested states that are characterized by reduced cellular proliferation, with or without a concurrent reduction in overall metabolism. In the case of the most profound metabolic arrest reported in invertebrates, i.e., anaerobic quiescence in Artemia franciscana embryos, acidification of the intracellular milieu is a major factor governing catabolic and anabolic downregulation. Release of ions from intracellular compartments is the source for approximately 50% of the proton equivalents needed for the 1.5 unit acidification that is observed. Recovery from the metabolic arrest requires re-sequestration of the protons with a vacuolar-type ATPase (V-ATPase). The remarkable facet of this mechanism is the ability of embryonic cells to survive the dissipation of intracellular ion gradients. Across many diapause-like states, the metabolic reduction and subsequent matching of energy demand is accomplished by shifting energy metabolism from oxidative phosphorylation to aerobic glycolysis. Molecular pathways that are activated to induce these resilient hypometabolic states include stimulation of the AMP-activated protein kinase (AMPK) and insulin signaling via suite of daf (dauer formation) genes for diapause-like states in nematodes and insects. Contributing factors for other metabolically depressed states involve hypoxia-inducible factor-1 and downregulation of the pyruvate dehydrogenase complex. Metabolic similarities between natural states of stasis and some cancer phenotypes are noteworthy. Reduction of flux through oxidative phosphorylation helps prevent cell death in certain cancer types, similar to the way it increases viability of dauer stages in Caenorhabditis elegans. Mechanisms that underlie natural stasis are being used to pre-condition mammalian cells prior to cell biostabilization and storage.

  1. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae.

    Science.gov (United States)

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    2016-01-01

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100μg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs. PMID:26422775

  2. Liposomes with diverse compositions are protected during desiccation by LEA proteins from Artemia franciscana and trehalose.

    Science.gov (United States)

    Moore, Daniel S; Hansen, Richard; Hand, Steven C

    2016-01-01

    Intracellular accumulation of Late Embryogenesis Abundant (LEA) proteins and the disaccharide trehalose is associated with cellular desiccation tolerance in a number of animal species. Two LEA proteins from anhydrobiotic embryos of the brine shrimp Artemia franciscana were tested for the ability to protect liposomes of various compositions against desiccation-induced damage in the presence and absence of trehalose. Damage was assessed by carboxyfluorescein leakage after drying and rehydration. Further, using a cytoplasmic-localized (AfrLEA2) and a mitochondrial-targeted (AfrLEA3m) LEA protein allowed us to evaluate whether each may preferentially stabilize membranes of a particular lipid composition based on the protein's subcellular location. Both LEA proteins were able to offset damage during drying of liposomes that mimicked the lipid compositions of the inner mitochondrial membrane (with cardiolipin), outer mitochondrial membrane, and the inner leaflet of the plasma membrane. Thus liposome stabilization by AfrLEA3m or AfrLEA2 was not dependent on lipid composition, provided physiological amounts of bilayer and non-bilayer-forming lipids were present (liposomes with a non-biological composition of 100% phosphatidylcholine were not protected by either protein). Additive protection by LEA proteins plus trehalose was dependent on the lipid composition of the target membrane. Minimal additional damage occurred to liposomes stored at room temperature in the dried state for one week compared to liposomes rehydrated after 24h. Consistent with the ability to stabilize lipid bilayers, molecular modeling of the secondary structures for AfrLEA2 and AfrLEA3m revealed bands of charged amino acids similar to other amphipathic proteins that interact directly with membranes. PMID:26518519

  3. Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina.

    Science.gov (United States)

    Rocha-Filho, Cláudio A A; Albuquerque, Lidiane P; Silva, Luanna R S; Silva, Patrícia C B; Coelho, Luana C B B; Navarro, Daniela M A F; Albuquerque, Monica C P A; Melo, Ana Maria M A; Napoleão, Thiago H; Pontual, Emmanuel V; Paiva, Patrícia M G

    2015-08-01

    This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL(-1)). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL(-1)) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL(-1)) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL(-1)). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina. PMID:25867917

  4. Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina.

    Science.gov (United States)

    Rocha-Filho, Cláudio A A; Albuquerque, Lidiane P; Silva, Luanna R S; Silva, Patrícia C B; Coelho, Luana C B B; Navarro, Daniela M A F; Albuquerque, Monica C P A; Melo, Ana Maria M A; Napoleão, Thiago H; Pontual, Emmanuel V; Paiva, Patrícia M G

    2015-08-01

    This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL(-1)). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL(-1)) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL(-1)) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL(-1)). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina.

  5. Recreating the seawater mixture composition of HOCs in toxicity tests with Artemia franciscana by passive dosing

    International Nuclear Information System (INIS)

    The toxicity testing of hydrophobic organic compounds (HOCs) in aquatic media is generally challenging, and this is even more problematic for mixtures. The hydrophobic properties of these compounds make them difficult to dissolve, and subsequently to maintain constant exposure concentrations. Evaporative and sorptive losses are highly compound-specific, which can alter not only total concentrations, but also the proportions between the compounds in the mixture. Therefore, the general aim of this study was to explore the potential of passive dosing for testing the toxicity of a PAH mixture that recreates the mixture composition found in seawater from a coastal area of Spain, the Bay of Algeciras. First, solvent spiking and passive dosing were compared for their suitability to determine the acute toxicity to Artemia franciscana nauplii of several PAHs at their respective solubility limits. Second, passive dosing was applied to recreate the seawater mixture composition of PAHs measured in a Spanish monitoring program, to test the toxicity of this mixture at different levels. HPLC analysis was used to confirm the reproducibility of the dissolved exposure concentrations for the individual PAHs and mixtures. This study shows that passive dosing has some important benefits in comparison with solvent spiking for testing HOCs in aquatic media. These include maintaining constant exposure concentrations, leading to higher reproducibility and a relative increase in toxicity. Passive dosing is also able to faithfully reproduce real mixtures of HOCs such as PAHs, in toxicity tests, reproducing both the levels and proportions of the different compounds. This provides a useful approach for studying the toxicity of environmental mixtures of HOCs, both with a view to investigating their toxicity but also for determining safety factors before such mixtures result in detrimental effects.

  6. The effects of feeding with synbiotic (Pediococcus acidilactici and fructooligosaccharide) enriched adult Artemia on skin mucus immune responses, stress resistance, intestinal microbiota and performance of angelfish (Pterophyllum scalare).

    Science.gov (United States)

    Azimirad, Mahmood; Meshkini, Saeed; Ahmadifard, Nasrollah; Hoseinifar, Seyed Hossein

    2016-07-01

    The aim of this study was to evaluate the effects of feeding on synbiotic (Pediococcus acidilactici and fructooligosaccharide) enriched adult Artemia franciscana on skin mucus immune responses, stress resistance, intestinal microbiota and growth performance of angelfish (Pterophyllum scalare). Three hundred and sixty fish with initial weight 3.2 ± 0.13 g were randomly divided into twelve aquaria (50 L) assigned to four groups in triplicates. Fish were fed for 7 weeks with dietary treatments, including treatment 1: feeding adult Artemia without enrichment (control group), treatment 2: feeding adult Artemia enriched with lyophilised probiotic P. acidilactici (700 mg L(-1)), 3: feeding adult Artemia enriched with prebiotic fructooligosaccharide (FOS) (100 mg L(-1)), group 4: feeding adult Artemia enriched with synbiotic (P. acidilactici (700 mg L(-1)) + FOS (100 mg L(-1))). Skin mucus immune responses (lysozyme activity, total Immunoglobulin and protease), stress resistance against environmental stress (acute decrease of temperature and increase salinity), intestinal microbiota as well as growth indices were measured at the end of feeding trial. Artemia enriched with synbiotic significantly improved growth performance compared to other treatments (P < 0.05). The highest weight gain and specific growth rate (SGR) was observed in synbiotic fed fish (P < 0.05). Compared to the other treatments, the population of lactic acid bacteria was significantly higher in the intestinal microbiota of fish fed synbiotic supplemented diet (P < 0.05). In the environmental stress challenge test, the maximum resistance to abrupt decrease of temperature (17 °C) or elevation of salinity (12 g per liter) was observed in the synbiotic treatment. Also, the total immunoglobulin and lysozyme activity level of skin mucus was significantly elevated in fish fed Artemia enriched with synbiotic (P < 0.05). These results revealed that feeding angelfish with synbiotic

  7. Physiological responses of Daphnia pulex to acid stress

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    Pirow Ralph

    2009-04-01

    Full Text Available Abstract Background Acidity exerts a determining influence on the composition and diversity of freshwater faunas. While the physiological implications of freshwater acidification have been intensively studied in teleost fish and crayfish, much less is known about the acid-stress physiology of ecologically important groups such as cladoceran zooplankton. This study analyzed the extracellular acid-base state and CO2 partial pressure (PCO2, circulation and ventilation, as well as the respiration rate of Daphnia pulex acclimated to acidic (pH 5.5 and 6.0 and circumneutral (pH 7.8 conditions. Results D. pulex had a remarkably high extracellular pH of 8.33 and extracellular PCO2 of 0.56 kPa under normal ambient conditions (pH 7.8 and normocapnia. The hemolymph had a high bicarbonate concentration of 20.9 mM and a total buffer value of 51.5 meq L-1 pH-1. Bicarbonate covered 93% of the total buffer value. Acidic conditions induced a slight acidosis (ΔpH = 0.16–0.23, a 30–65% bicarbonate loss, and elevated systemic activities (tachycardia, hyperventilation, hypermetabolism. pH 6.0 animals partly compensated the bicarbonate loss by increasing the non-bicarbonate buffer value from 2.0 to 5.1 meq L-1 pH-1. The extracellular PCO2 of pH 5.5 animals was significantly reduced to 0.33 kPa, and these animals showed the highest tolerance to a short-term exposure to severe acid stress. Conclusion Chronic exposure to acidic conditions had a pervasive impact on Daphnia's physiology including acid-base balance, extracellular PCO2, circulation and ventilation, and energy metabolism. Compensatory changes in extracellular non-bicarbonate buffering capacity and the improved tolerance to severe acid stress indicated the activation of defense mechanisms which may result from gene-expression mediated adjustments in hemolymph buffer proteins and in epithelial properties. Mechanistic analyses of the interdependence between extracellular acid-base balance and CO2 transport

  8. Small RNA Sequencing Based Identification of MiRNAs in Daphnia magna.

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    Ercan Selçuk Ünlü

    Full Text Available Small RNA molecules are short, non-coding RNAs identified for their crucial role in post-transcriptional regulation. A well-studied example includes miRNAs (microRNAs which have been identified in several model organisms including the freshwater flea and planktonic crustacean Daphnia. A model for epigenetic-based studies with an available genome database, the identification of miRNAs and their potential role in regulating Daphnia gene expression has only recently garnered interest. Computational-based work using Daphnia pulex, has indicated the existence of 45 miRNAs, 14 of which have been experimentally verified. To extend this study, we took a sequencing approach towards identifying miRNAs present in a small RNA library isolated from Daphnia magna. Using Perl codes designed for comparative genomic analysis, 815,699 reads were obtained from 4 million raw reads and run against a database file of known miRNA sequences. Using this approach, we have identified 205 putative mature miRNA sequences belonging to 188 distinct miRNA families. Data from this study provides critical information necessary to begin an investigation into a role for these transcripts in the epigenetic regulation of Daphnia magna.

  9. Evaluation of acute toxicity and teratogenic effects of plant growth regulators by Daphnia magna embryo assay.

    Science.gov (United States)

    Wang, Kai-Sung; Lu, Chi-Yuan; Chang, Shih-Hsien

    2011-06-15

    This study selected common plant growth regulators (Atonik, Cytokinin, Ethephon, Gibberellic acid and Paclobutrazol) to investigate their biological toxicity to the waters of the important biological indicator Daphnia magna. The methods used in this study included traditional neonate acute toxicity test, new Daphnia embryo toxicity test, and teratogenic embryo test. The study concluded that the acute toxicity of the five PGRs to Daphnia neonate had EC(50) value range of 1.9-130.5 mg l(-1), while acute toxicity of PGRs on Daphnia embryo had EC(50) value range of 0.2-125 mg l(-1); the Daphnia embryos' LOEC values (0.05-48 mg l(-1)) for the five PGRs were lower than embryo EC(50) values. The toxic ratios of 48 h EC(50) (neonate)/48 h LOEC (embryo) for 5 PGRs were 19-512 times. The study found that teratogenic effects of Paclobutrazol and Cytokinin induced in embryo were higher than those of most other PGRs. Microscopic observation of the teratogenic effects showed that all 5 PGRs induced malformations of the second antenna, rostrum, Malpighian tube, sensory bristles, and tail spine as well as function loss and death.

  10. The components of the Daphnia pulex immune system as revealed by complete genome sequencing

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    Blaxter Mark L

    2009-04-01

    Full Text Available Abstract Background Branchiopod crustaceans in the genus Daphnia are key model organisms for investigating interactions between genes and the environment. One major theme of research on Daphnia species has been the evolution of resistance to pathogens and parasites, but lack of knowledge of the Daphnia immune system has limited the study of immune responses. Here we provide a survey of the immune-related genome of D. pulex, derived from the newly completed genome sequence. Genes likely to be involved in innate immune responses were identified by comparison to homologues from other arthropods. For each candidate, the gene model was refined, and we conducted an analysis of sequence divergence from homologues from other taxa. Results and conclusion We found that some immune pathways, in particular the TOLL pathway, are fairly well conserved between insects and Daphnia, while other elements, in particular antimicrobial peptides, could not be recovered from the genome sequence. We also found considerable variation in gene family copy number when comparing Daphnia to insects and present phylogenetic analyses to shed light on the evolution of a range of conserved immune gene families.

  11. Daphnias: from the individual based model to the large population equation

    CERN Document Server

    Metz, J A J

    2012-01-01

    The class of deterministic 'Daphnia' models treated by Diekmann et al. (J Math Biol 61: 277-318, 2010) has a long history going back to Nisbet and Gurney (Theor Pop Biol 23: 114-135, 1983) and Diekmann et al. (Nieuw Archief voor Wiskunde 4: 82-109, 1984). In this note, we formulate the individual based models (IBM) supposedly underlying those deterministic models. The models treat the interaction between a general size-structured consumer population ('Daphnia') and an unstructured resource ('algae'). The discrete, size and age-structured Daphnia population changes through births and deaths of its individuals and throught their aging and growth. The birth and death rates depend on the sizes of the individuals and on the concentration of the algae. The latter is supposed to be a continuous variable with a deterministic dynamics that depends on the Daphnia population. In this model setting we prove that when the Daphnia population is large, the stochastic differential equation describing the IBM can be approxima...

  12. COMMUNICATION: Stochastic resonance and the evolution of Daphnia foraging strategy

    Science.gov (United States)

    Dees, Nathan D.; Bahar, Sonya; Moss, Frank

    2008-12-01

    Search strategies are currently of great interest, with reports on foraging ranging from albatrosses and spider monkeys to microzooplankton. Here, we investigate the role of noise in optimizing search strategies. We focus on the zooplankton Daphnia, which move in successive sequences consisting of a hop, a pause and a turn through an angle. Recent experiments have shown that their turning angle distributions (TADs) and underlying noise intensities are similar across species and age groups, suggesting an evolutionary origin of this internal noise. We explore this hypothesis further with a digital simulation (EVO) based solely on the three central Darwinian themes: inheritability, variability and survivability. Separate simulations utilizing stochastic resonance (SR) indicate that foraging success, and hence fitness, is maximized at an optimum TAD noise intensity, which is represented by the distribution's characteristic width, σ. In both the EVO and SR simulations, foraging success is the criterion, and the results are the predicted characteristic widths of the TADs that maximize success. Our results are twofold: (1) the evolving characteristic widths achieve stasis after many generations; (2) as a hop length parameter is changed, variations in the evolved widths generated by EVO parallel those predicted by SR. These findings provide support for the hypotheses that (1) σ is an evolved quantity and that (2) SR plays a role in evolution.

  13. Intragenic tandem repeats in Daphnia magna: structure, function and distribution

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    Du Pasquier Louis

    2009-10-01

    Full Text Available Abstract Background Expressed sequence tag (EST databases provide a valuable source of genetic data in organisms whose genome sequence information is not yet compiled. We used a published EST database for the waterflea Daphnia magna (Crustacea:Cladocera to isolate variable number of tandem repeat (VNTR markers for linkage mapping, Quantitative Trait Loci (QTL, and functional studies. Findings Seventy-four polymorphic markers were isolated and characterised. Analyses of repeat structure, putative gene function and polymorphism indicated that intragenic tandem repeats are not distributed randomly in the mRNA sequences; instead, dinucleotides are more frequent in non-coding regions, whereas trinucleotides (and longer motifs involving multiple-of-three nucleotide repeats are preferentially situated in coding regions. We also observed differential distribution of repeat motifs across putative genetic functions. This indicates differential selective constraints and possible functional significance of VNTR polymorphism in at least some genes. Conclusion Databases of VNTR markers situated in genes whose putative function can be inferred from homology searches will be a valuable resource for the genetic study of functional variation and selection.

  14. Influence of organism age on metal toxicity to Daphnia magna.

    Science.gov (United States)

    Hoang, Tham C; Klaine, Stephen J

    2007-06-01

    Aquatic organisms living in surface water experience contaminant exposure at different life stages. While some investigators have examined the influence of organism age on the toxicity of pollutants, the general assumption in toxicology has been that young organisms were more sensitive than older organisms. In fact, some standardized toxicity tests call for the use of organisms less than 24 h old. This research characterized the age sensitivity of the water flea Daphnia magna to copper, zinc, selenium, and arsenic. During 21-d toxicity tests, organisms were exposed to a single 12-h pulse of either 70 microg/L Cu, 750 microg/L Zn, 1000 microg/L Se, or 5000 microg/L As at different ages ranging from 3 h to 10 d old. Mortality and reproduction were compiled over 21 d. During the juvenile stage, mortality increased and cumulative reproduction decreased with age, respectively. However, mortality decreased and cumulative reproduction increased with age when organisms became adult. Peak sensitivity occurred in 4-d-old organisms exposed to Cu and Zn, while 2- to 3-d-old organisms were most sensitive to As and Se. Growth of D. magna over 21 d was not affected by the 12-h pulse of Cu, Zn, Se, or As given at any organism age. This indicates the recovery of the organisms after exposure termination. PMID:17571686

  15. Development of resistance to cyfluthrin and naphthalene among Daphnia magna.

    Science.gov (United States)

    Brausch, John M; Smith, Philip N

    2009-07-01

    In this study, Daphnia magna were exposed to a pyrethroid insecticide (cyfluthrin) or a polycyclic aromatic hydrocarbon (naphthalene) for 12 generations to evaluate development of resistance followed by a 12 generation recovery period. Twenty-four hour old D. magna were exposed to concentrations of each chemical resulting in 50-70% mortality to select for the least sensitive individuals. LC50 values, survival, reproductive output, and time to first brood in stressor-exposed and control D. magna were recorded for each generation. Significant changes in LC50 values were observed after 4 generations and then declined after 6-10 generations post-exposure. D. magna were 5 times less sensitive to cyfluthrin and 3 times less sensitive to naphthalene as compared to controls after 12 generations of exposure. There were no differences in survival, time to first brood, or total number of offspring produced between control and either of the resistant F13 D. magna. Cyfluthrin exposed D. magna exhibited cross-resistance to DDT and methyl parathion, and naphthalene resistant D. magna were less sensitive than controls to both pyrene and benz(a)anthracene. When the cytochrome P450 inhibitor piperonyl butoxide was used in conjunction with cyfluthrin and naphthalene the sensitivity of resistant and control D. magna were equal, suggesting P450s were responsible for conveying resistance. This study demonstrates that life history and organisms' capacity to develop resistance is important to consider ensuring accuracy of ecological risk assessments. PMID:19399609

  16. Characterizing the toxicity of pulsed selenium exposure to Daphnia magna.

    Science.gov (United States)

    Hoang, Tham C; Klaine, Stephen J

    2008-03-01

    The acute toxicity of selenium (Se) to aquatic biota has been studied extensively for decades. However, most studies have used a constant concentration aqueous exposure of Se to an invertebrate species. Since constant concentration exposure of toxicants to invertebrates is unusual in the environment, episodic exposure or pulsed exposures may represent true risk to aquatic biota more accurately. This research was designed to characterize the toxicity effects of pulsed Se exposure to Daphnia magna. Selenium exposure was varied during a 21-d chronic toxicity test to examine the effects of exposure concentration, duration, and recovery on survival, growth, and reproduction of D. magna. While D. magna did not die during exposures, latent mortality was observed. Latent mortality increased with exposure concentration and duration. Hence, standard toxicity test using continuous exposures would underestimate Se toxicity. Risk assessment method using results of continuous exposure would underestimate risk of Se to biota. For double-pulse exposures, cumulative mortality on day 21 was higher when time interval between pulses was shorter. With the same total exposure time, continuous exposure caused higher toxicity than did pulsed exposures due to recovery and tolerance development in D. magna after earlier pulses. Growth and reproduction of surviving D. magna were not affected by pulsed Se exposure due to recovery of D. magna after removal of the pulses. Based on these results, risk assessment for Se should take latent effects and the effect of recovery in to account. PMID:18190947

  17. Biokinetics and tolerance development of toxic metals in Daphnia magna.

    Science.gov (United States)

    Tsui, Martin Tsz-Ki; Wang, Wen-Xiong

    2007-05-01

    Daphnia magna is widespread in many freshwater systems of temperate regions and frequently is used to test metal toxicity. Recently, studies have been performed to determine metal biokinetics and development of tolerance in this important zooplankton species. In the present paper, we review the recent progress in these areas and suggest possible directions for future studies. Substantial differences exist in aqueous uptake, dietary assimilation, and elimination of several metals (Cd, Se, Zn, Ag, Hg, and MeHg) by D. magna. The routes of uptake are metal-specific, with Se and MeHg being accumulated predominantly through diet. All metals except Ag can be biomagnified from algae to D. magna, providing that metal concentrations in algae and algal food density are relatively low. Methylmercury is biomagnified in all situations. As a route for metal elimination in D. magna, maternal transfer is especially important for Se, Zn, and MeHg. On the other hand, the effect of single-generation exposure to metals on D. magna is very different from multigeneration exposure, which often results in a significantly higher metal tolerance. Moreover, D. magna easily loses metal tolerance developed through long-term exposure. Recovery from metal stress can temporarily increase the sensitivity of D. magna to metal toxicity. Finally, metallothionein-like protein is responsible for minimizing metal toxicity in D. magna. The results inferred from these studies can be extrapolated to other aquatic invertebrates as well as to other pollutants in the aquatic environment. PMID:17521151

  18. Acute toxicities of six manufactured nanomaterial suspensions to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Xiaoshan; Zhu Lin [Nankai University, Key Laboratory of Pollution Processes and Environmental Criteria (Nankai University), Ministry of Education, College of Environmental Science and Engineering (China); Chen Yongsheng, E-mail: yschen@asu.ed [Arizona State University, Department of Civil and Environmental Engineering (United States); Tian Shengyan [Tianjin University of Science and Technology, College of Marine Science and Technology (China)

    2009-01-15

    The rapid growth of nanotechnology is stimulating research on the potential environmental impacts of manufactured nanomaterials (MNMs). This paper summarizes a comprehensive study on the 48-h acute toxicity of water suspensions of six MNMs (i.e., ZnO, TiO{sub 2}, Al{sub 2}O{sub 3}, C{sub 60}, SWCNTs, and MWCNTs) to Daphnia magna, using immobilization and mortality as toxicological endpoints. The results show that the acute toxicities of all MNMs tested are dose dependent. The EC{sub 50} values for immobilization ranged from 0.622 mg/L (ZnO NPs) to 114.357 mg/L (Al{sub 2}O{sub 3} NPs), while the LC{sub 50} values for mortality ranged from 1.511 mg/L (ZnO NPs) to 162.392 mg/L (Al{sub 2}O{sub 3} NPs). In these tests, TiO{sub 2}, Al{sub 2}O{sub 3}, and carbon-based nanomaterials were more toxic than their bulk counterparts. Moreover, D. magna were found to ingest nanomaterials from the test solutions through feeding behaviors, which indicates that the potential ecotoxicities and environmental health effects of these MNMs cannot be neglected.

  19. Toxicity of perfluorononanoic acid and perfluorooctane sulfonate to Daphnia magna

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    Guang-hua LU

    2015-01-01

    Full Text Available In order to study toxicological effects of perfluorononanoic acid (PFNA, perfluorooctane sulfonate (PFOS, and their mixtures (PFNA/PFOS on Daphnia magna (D. magna, a suite of comprehensive toxicity tests were conducted, including a 48-hour acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21-day life cycle. The biomarkers, including acetylcholinesterase (AChE, superoxide dismutase (SOD, and catalase (CAT activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including AChE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.

  20. Toxicity of perfluorononanoic acid and perfluorooctane sulfonate to Daphnia magna

    Institute of Scientific and Technical Information of China (English)

    Guang-hua Lu; Jian-chao Liu; Li-sha Sun; Lu-jin Yuan

    2015-01-01

    In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21-day life cycle. The biomarkers, including acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including AChE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.

  1. Does local adaptation to resources explain genetic differentiation among Daphnia populations?

    Science.gov (United States)

    Allen, Michael R; Thum, Ryan A; Cáceres, Carla E

    2010-08-01

    Substantial genetic differentiation is frequently observed among populations of cyclically parthenogenetic zooplankton despite their high dispersal capabilities and potential for gene flow. Local adaptation has been invoked to explain population genetic differentiation despite high dispersal, but several neutral models that account for basic life history features also predict high genetic differentiation. Here, we study genetic differentiation among four populations of Daphnia pulex in east central Illinois. As with other studies of Daphnia, we demonstrate substantial population genetic differentiation despite close geographic proximity (explain genetic differentiation among these Daphnia populations and that other factors related to extinction/colonization dynamics, a long approach to equilibrium F(ST) or substantial genetic drift due to a low number of individuals hatching from the egg bank each season may explain genetic differentiation.

  2. Aphanizomenon gracile increases in width in the presence of Daphnia. A defence mechanism against grazing?

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    Slawek Cerbin

    2013-10-01

    Full Text Available Filamentous cyanobacteria are frequently consumed by grazers like Daphnia, which can break filaments and make them more readily available to filter-feeders. However, various defence mechanisms against grazing have also been observed in cyanobacteria. Data concerning changes in the morphology of filamentous algae, especially their width in the presence of a grazer, are scarce. Field studies of filament morphology of cyanobacteria relate their changes to nutrient availability and temperature. Moreover, filament morphology displays significant differences in filament length and width among seasons. We hypothesised that the morphological changes in filament observed in the field – especially their width – could be a defence mechanism that is induced by the presence of a grazer, such as Daphnia. Thus, two experiments were conducted in order to test the influence of Daphnia (direct grazing and infochemicals together in the first experiment and the chemicals it released (grazing excluded, only chemicals present in the second experiment on Aphanizomenon gracile’s morphology, in controlled laboratory conditions. Aphanizomenon filaments became significantly shorter and thicker in both experiments. However, Daphnia’s grazing combined with excreted chemicals had stronger effect than chemicals alone. To our knowledge, this is the first report describing the shortening and thickening of filaments in the presence of Daphnia infochemicals. It seems that the Aphanizomenon filaments in the presence of Daphnia switch their growing mode and invest more heavily in width than length. Our results support the hypothesis that Daphnia is at least partly responsible for the changes in filament width observed in the field. This could be a strategy that helps Aphanizomenon to withstand grazer’s pressure during early stages of a bloom.

  3. Competition impedes the recovery of Daphnia magna from repeated insecticide pulses.

    Science.gov (United States)

    Dolciotti, Ida; Foit, Kaarina; Herkelrath, Anna; Liess, Matthias

    2014-02-01

    The effects of multiple insecticide pulses on non-target organisms have rarely been investigated in combination with relevant biotic interactions, such as competition. In this study, we examined the effects of two repeated pulses of the insecticide pirimicarb (3, 10, 24 μg/L) on populations of Daphnia magna with or without competition. To investigate the influence of competition, half of the test systems were supplemented with the pirimicarb-insensitive species Culex pipiens. The pesticide pulses were followed by a recovery period of 28 days, which corresponded to approximately three generation times for D. magna. The one-species setup with the Daphnia populations and the two-species setup with both the Daphnia and Culex populations had a precontamination period of 30 days so that intra- and interspecific competitions were present prior to the insecticide pulse. Short-term effects on the survival of the Daphnia population were observed in both setups immediately after each insecticide pulse at the highest concentration level. In the one-species setup, the short-term effects on population survival were increased by intraspecific competition. However, the Daphnia populations in the one-species setup recovered and reached the control level within approximately two weeks after each insecticide pulse. In contrast, in the two-species setup at the highest concentration, we observed culmination of insecticide effects: the Daphnia populations did not recover and their abundance was below the control level until the end of the observation time. Their recovery was impeded by the presence of the competing species C. pipiens for at least four weeks. At low concentrations, no culmination of effects was observed. We conclude that repeated toxicant pulses on populations that are challenged with interspecific competition may result in a multigenerational culmination of toxicant effects. PMID:24373889

  4. Group 1 LEA proteins contribute to the desiccation and freeze tolerance of Artemia franciscana embryos during diapause.

    Science.gov (United States)

    Toxopeus, Jantina; Warner, Alden H; MacRae, Thomas H

    2014-11-01

    Water loss either by desiccation or freezing causes multiple forms of cellular damage. The encysted embryos (cysts) of the crustacean Artemia franciscana have several molecular mechanisms to enable anhydrobiosis-life without water-during diapause. To better understand how cysts survive reduced hydration, group 1 late embryogenesis abundant (LEA) proteins, hydrophilic unstructured proteins that accumulate in the stress-tolerant cysts of A. franciscana, were knocked down using RNA interference (RNAi). Embryos lacking group 1 LEA proteins showed significantly lower survival than control embryos after desiccation and freezing, or freezing alone, demonstrating a role for group 1 LEA proteins in A. franciscana tolerance of low water conditions. In contrast, regardless of group 1 LEA protein presence, cysts responded similarly to hydrogen peroxide (H2O2) exposure, indicating little to no function for these proteins in diapause termination. This is the first in vivo study of group 1 LEA proteins in an animal and it contributes to the fundamental understanding of these proteins. Knowing how LEA proteins protect A. franciscana cysts from desiccation and freezing may have applied significance in aquaculture, where Artemia is an important feed source, and in the cryopreservation of cells for therapeutic applications. PMID:24846336

  5. Probing the phenomenon of trained immunity in invertebrates during a transgenerational study, using brine shrimp Artemia as a model system.

    Science.gov (United States)

    Norouzitallab, Parisa; Baruah, Kartik; Biswas, Priyanka; Vanrompay, Daisy; Bossier, Peter

    2016-01-01

    The invertebrate's innate immune system was reported to show some form of adaptive features, termed trained immunity. However, the memory characteristics of innate immune system and the mechanisms behind such phenomena remain unclear. Using the invertebrate model Artemia, we verified the possibility or impossibility of trained immunity, examining the presence or absence of enduring memory against homologous and heterologous antigens (Vibrio spp.) during a transgenerational study. We also determined the mechanisms behind such phenomenon. Our results showed the occurrence of memory and partial discrimination in Artemia's immune system, as manifested by increased resistance, for three successive generations, of the progenies of Vibrio-exposed ancestors towards a homologous bacterial strain, rather than to a heterologous strain. This increased resistance phenotype was associated with elevated levels of hsp70 and hmgb1 signaling molecules and alteration in the expression of key innate immunity-related genes. Our results also showed stochastic pattern in the acetylation and methylation levels of H4 and H3K4me3 histones, respectively, in the progenies whose ancestors were challenged. Overall results suggest that innate immune responses in invertebrates have the capacity to be trained, and epigenetic reprogramming of (selected) innate immune effectors is likely to have central place in the mechanisms leading to trained immunity. PMID:26876951

  6. Assessment of Cytotoxic Activity of Three Plants of Pigweed, Bermuda grass and Burdock via Artemia Salina Test

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    parisa sadighara

    2010-01-01

    Full Text Available Introduction: Pigweed is a weed which grows in the pastures of Iran. Local people use the plant leaves to cook traditional food. Bermuda grass with its rapid growth and distribution is regarded a real threat to prairies and it can lead to tremors syndrome in cattle and sheep. Burdock which also grows in many parts of Iran is used as a medicinal herb. In this study, the cytotoxicity potential of the three plants was assessed via Artemia Salina test. Methods: Pigweed, Bermuda grass and burdock were collected from Ghaemshahr in the North of Iran. The leaves were dried and the essence of the three plants was extracted. The larvaes were hatched from cysts of Artemia salina at 26˚C in filtered seawater. The plant extracts with different concentration (10,100 and 1000ppm were added to the solution larvaes. Results: The LC50 values (the concentration which needed to die half the larvaes were measured for pigweed, Bermuda grass and burdock at 1640, 990, and 840 ppm, respectively. Conclusion: The results indicate that compared to the two other species, there is more priority for burdock to be studied in further studies for identification and assessment of toxicity

  7. Preparation of Chitosan from Brine Shrimp (Artemia urmiana Cyst Shells and Effects of Different Chemical Processing Sequences on the Physicochemical and Functional Properties of the Product

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    Farnood Shokouhi Sabet Jalali

    2008-06-01

    Full Text Available Chitosan (CS was prepared from Artemia urmiana cyst shells using the same chemical process as described for the other crustacean species, with minor adjustments in the treatment conditions. The influence of modifications of the CS production process on the physiochemical and functional properties of the CS obtained was examined. The study results indicate that Artemia urmiana cyst shells are a rich source of chitin as 29.3-34.5% of the shell’s dry weight consisted of this material. Compared to crab CS (selected as an example of CS from a different crustacean source Artemia CS exhibited a medium molecular weight (4.5-5.7 ×105 Da, lower degree of deacetylation (67-74% and lower viscosity (29-91 centiposes. The physicochemical characteristics (e.g., ash, nitrogen and molecular weight and functional properties (e.g., water binding capacity and antibacterial activity of the prepared Artemia CSs were enhanced, compared to control and commercial samples, by varying the processing step sequence.

  8. Preparation of chitosan from brine shrimp (Artemia urmiana) cyst shells and effects of different chemical processing sequences on the physicochemical and functional properties of the product.

    Science.gov (United States)

    Tajik, Hossein; Moradi, Mehran; Rohani, Seyed Mehdi Razavi; Erfani, Amir Mehdi; Jalali, Farnood Shokouhi Sabet

    2008-06-06

    Chitosan (CS) was prepared from Artemia urmiana cyst shells using the same chemical process as described for the other crustacean species, with minor adjustments in the treatment conditions. The influence of modifications of the CS production process on the physiochemical and functional properties of the CS obtained was examined. The study results indicate that Artemia urmiana cyst shells are a rich source of chitin as 29.3-34.5% of the shell's dry weight consisted of this material. Compared to crab CS (selected as an example of CS from a different crustacean source) Artemia CS exhibited a medium molecular weight (4.5-5.7 x10(5) Da), lower degree of deacetylation (67-74%) and lower viscosity (29-91 centiposes). The physicochemical characteristics (e.g., ash, nitrogen and molecular weight) and functional properties (e.g., water binding capacity and antibacterial activity) of the prepared Artemia CSs were enhanced, compared to control and commercial samples, by varying the processing step sequence.

  9. Habitat use and diet selection of northward migrating waders in the Sivash (Ukraine): the use of brine shrimp Artemia salina in a variably saline lagoon complex.

    NARCIS (Netherlands)

    Verkuil, Y.; Have, van der T.M.; Winden, van der J.; Chernichko, I.I.

    2003-01-01

    Wader species migrating through the Sivash (Ukraine) use hypersaline and brackish lagoons. We studied the use of the two habitat types, and focused on the profitability of Brine Shrimp Artemia salina, prey species in hypersaline lagoons for Dunlins Calidris alpina, Curlew Sandpipers Calidris ferrugi

  10. Habitat use and diet selection of northward migrating waders in the Sivash (Ukraine) : The use of Brine Shrimp Artemia salina in a variably saline lagoon complex

    NARCIS (Netherlands)

    Verkuil, Y; Van der Have, TM; Van der Winden, J; Chernichko, [No Value

    2003-01-01

    Wader species migrating through the Sivash (Ukraine) use hypersaline and brackish lagoons. We studied the use of the two habitat types, and focused on the profitability of Brine Shrimp Artemia salina, prey species in hypersaline lagoons for Dunlins Calidris alpina, Curlew Sandpipers Calidris ferrugi

  11. Culture of Artemia on rice bran: the conversion of a waste-product into highly nutritive animal protein

    OpenAIRE

    Sorgeloos, P.; Baeza-Mesa, M.; Bossuyt, E.; Bruggeman, E.; Dobbeleir, J.; Versichele, D.; Laviña, E.; Bernardino, A.

    1980-01-01

    The age-old problem of finding a cheap and suitable food for Artemia is finally solved with rice bran, in fact a waste-product which is available at a very low price in many countries all over the world.

  12. Quiescence in Artemia franciscana embryos: reversible arrest of metabolism and gene expression at low oxygen levels.

    Science.gov (United States)

    Hand, S C

    1998-04-01

    Depression of the production and consumption of cellular energy appears to be a prerequisite for the survival of prolonged bouts of anoxia. A correlation exists between the degree of metabolic depression under anoxia and the duration of anoxia tolerance. In the case of brine shrimp (Artemia franciscana) embryos, oxygen deprivation induces a reversible quiescent state that can be tolerated for several years with substantial survivorship. A global arrest of cytoplasmic translation accompanies the transition into anoxia, and rates of protein synthesis in mitochondria from these embryos appears to be markedly reduced in response to anoxia. Previous evidence suggests that the acute acidification of intracellular pH (pHi) by over 1.0 unit during the transition into anoxia contributes to the depression of biosynthesis, but message limitation does not appear to play a role in the down-regulation in either cellular compartment. The ontogenetic increase in mRNA levels for a mitochondrial-encoded subunit of cytochrome c oxidase (COX I) and for nuclear-encoded actin is blocked by anoxia and aerobic acidosis (artificial quiescence imposed by intracellular acidification under aerobic conditions). Further, the levels of COX I and actin mRNA do not decline appreciably during 6 h bouts of quiescence, even though protein synthesis is acutely arrested across this same period. Thus, the constancy of mRNA levels during quiescence indicates that reduced protein synthesis is not caused by message limitation but, instead, is probably controlled at the translational level. This apparent stabilization of mRNA under anoxia is mirrored in an extension of protein half-life. The ubiquitin-dependent pathway for protein degradation is depressed under anoxia and aerobic acidosis, as judged by the acute drop in levels of ubiquitin-conjugated proteins. Mitochondrial protein synthesis is responsive to both acidification of pHi and removal of oxygen per se. Matrix pH declines in parallel with pHi, and

  13. Oxygen-binding characteristics of three extracellular haemoglobins of Artemia salina.

    Science.gov (United States)

    D'Hondt, J; Moens, L; Heip, J; D'Hondt, A; Kondo, M

    1978-06-01

    The oxygen-binding characteristics of the three extracellular haemoglobins of brine shrimp (Artemia salina) were studied in vitro by using highly purified preparations. Haemoglobin I is induced last in the development of brine shrimps when functional gills are formed. It has the lowest oxygen affinity (p(50) 5.34mmHg), an intermediate Bohr effect (ø -0.09 at 20 degrees C) above pH8 and a temperature-sensitivity (DeltaH -44.8 to -45.6kJ/mol at pH8-9) comparable with those observed with other invertebrate haemoglobins [Weber & Heidemann (1977) Comp. Biochem. Physiol. A57, 151-155]. Haemoglobin II, which is the first to be induced, soon after hatching of nauplius larvae, persists generally throughout the whole adult life. It has an intermediate oxygen affinity (p(50) 3.7mmHg), the highest Bohr effect (ø -0.21 at 20 degrees C) above pH8 and a similar temperature-sensitivity (DeltaH -46.0 to -54.8kJ/mol at pH8-9) as haemoglobin I. However, haemoglobin III, which is induced second several hours after the induction of haemoglobin II but disappearing from the haemolymph in the middle of adult life, has the highest oxygen affinity (p(50) 1.8mmHg), the lowest Bohr effect (ø -0.03 at 20 degrees C) above pH8.5 and a high resistance against temperature variation between 10 and 25 degrees C at pH8.5-9 (DeltaH -22.6 to -23.0kJ/mol). At pH7.5-8, haemoglobin III exhibits a similar temperature-sensitivity under 30 degrees C as do other haemoglobins. All three haemoglobins have a rather low co-operativity, with Hill coefficients (h 1.6-1.9 at pH8.5), which are dependent on both pH and temperature. The highest co-operativity was observed at 20 degrees C and pH9 for haemoglobins I and II, whereas it was at 27 degrees C and pH8.5 for haemoglobin III. Thus the oxygen-binding behaviour of haemoglobin III in vitro is significantly different from those of haemoglobins I and II and indicates possibly its specific physiological role in vivo in the adaptive process in the natural

  14. Transcriptome profiling of the intoxication response of Tenebrio molitor larvae to Bacillus thuringiensis Cry3Aa protoxin.

    Directory of Open Access Journals (Sweden)

    Brenda Oppert

    Full Text Available Bacillus thuringiensis (Bt crystal (Cry proteins are effective against a select number of insect pests, but improvements are needed to increase efficacy and decrease time to mortality for coleopteran pests. To gain insight into the Bt intoxication process in Coleoptera, we performed RNA-Seq on cDNA generated from the guts of Tenebrio molitor larvae that consumed either a control diet or a diet containing Cry3Aa protoxin. Approximately 134,090 and 124,287 sequence reads from the control and Cry3Aa-treated groups were assembled into 1,318 and 1,140 contigs, respectively. Enrichment analyses indicated that functions associated with mitochondrial respiration, signalling, maintenance of cell structure, membrane integrity, protein recycling/synthesis, and glycosyl hydrolases were significantly increased in Cry3Aa-treated larvae, whereas functions associated with many metabolic processes were reduced, especially glycolysis, tricarboxylic acid cycle, and fatty acid synthesis. Microarray analysis was used to evaluate temporal changes in gene expression after 6, 12 or 24 h of Cry3Aa exposure. Overall, microarray analysis indicated that transcripts related to allergens, chitin-binding proteins, glycosyl hydrolases, and tubulins were induced, and those related to immunity and metabolism were repressed in Cry3Aa-intoxicated larvae. The 24 h microarray data validated most of the RNA-Seq data. Of the three intoxication intervals, larvae demonstrated more differential expression of transcripts after 12 h exposure to Cry3Aa. Gene expression examined by three different methods in control vs. Cry3Aa-treated larvae at the 24 h time point indicated that transcripts encoding proteins with chitin-binding domain 3 were the most differentially expressed in Cry3Aa-intoxicated larvae. Overall, the data suggest that T. molitor larvae mount a complex response to Cry3Aa during the initial 24 h of intoxication. Data from this study represent the largest genetic sequence

  15. Efeito alelopático e toxicidade frente à Artemia salina Leach dos extatos do fruto de Euterpe edulis Martius Allelopathic effects and toxicity against Artemia salina Leach of extracts of the fruit of Euterpe edulis Martius

    Directory of Open Access Journals (Sweden)

    Cristina Peitz de Lima

    2011-06-01

    Full Text Available Alelopatia é um processo envolvendo metabólitos secundários produzidos por plantas que infl uenciam o crescimento e desenvolvimento de sistemas agrícolas. Devido à toxicidade dos herbicidas sintéticos para o meio ambiente e para a saúde humana tem-se aumentado o interesse na exploração da alelopatia como uma alternativa para o controle de plantas daninhas. O presente trabalho avaliou efeito dos extratos dos frutos de Euterpe edulis Martius sobre o desenvolvimento de cipselas e plântulas de Lactuca sativa Linné, foram determinados o índice de velocidade de germinação, o crescimento da radícula e do hipocótilo. Para a avaliação da toxicidade dos extratos foi realizado o ensaio de toxicidade frente ao microcrustáceo Artemia salina Leach determinando-se a CL50 e percentual de mortalidade. A fração remanescente demonstrou efeito alelopático, pois todas as concentrações alteraram os valores do índice de velocidade de germinação e as concentrações de 0,2 e 0,4 mg inibiram tanto o crescimento da radícula quanto o crescimento do hipocótilo. No ensaio de toxicidade todos os extratos apresentaram CL50 superior a 1000 ppm e 0% de mortalidade das artemias, indicando a não toxicidade dos extratos.Allelopathy is a process involving secondary metabolites produced by plants that influence growth and development of agricultural systems. Because of the toxicity of synthetic herbicides to the environment and human health, there has been increased interest in exploiting allelopathy as an alternative for weed control. This study evaluated the eff ect of extracts of Euterpe edulis Martius fruits on the development of cypselae and seedlings of Lactuca sativa Linné; the germination speed index, radicle and hypocotyl growth were determined. To evaluate the toxicity of the extracts the toxicity test against Artemia salina Leach was used, where the LC50 and mortality rate were determined. Th e remaining fraction showed allelopathic effect

  16. Increasing toxicity of enrofloxacin over four generations of Daphnia magna.

    Science.gov (United States)

    Dalla Bona, Mirco; Lizzi, Francesca; Borgato, Arianna; De Liguoro, Marco

    2016-10-01

    The effects of both continuous and alternate exposure to 2mgL(-1) of enrofloxacin (EFX) on survival, growth and reproduction were evaluated over four generations of Daphnia magna. Mortality increased, reaching 100% in most groups by the end of the third generation. Growth inhibition was detected in only one group of the fourth generation. Reproduction inhibition was >50% in all groups and, in second and third generations, groups transferred to pure medium showed a greater inhibition of reproduction than those exposed to EFX. To verify whether the effects observed in these groups could be explained by the perinatal exposure to the antibacterial, a reproduction test with daphnids obtained from in vitro exposed D. magna embryos was also carried out. Perinatal exposure to EFX seemed to act as an 'all-or-nothing' toxicity effect as 31.4% of embryos died, but the surviving daphnids did not show any inhibition of reproduction activity. However, the embryonic mortality may at least partially justify the inhibition of reproduction observed in exposed groups along the multigenerational test. Concluding, the multigenerational test with D. magna did show disruption to a population that cannot be evidenced by the official tests. The increasing deterioration across generations might be inferred as the consequence of heritable alterations. Whilst the concentration tested was higher than those usually detected in the natural environment, the increasing toxicity of EFX across generations and the possible additive toxicity of fluoroquinolone mixtures, prevent harm to crustacean populations by effects in the real context from being completely ruled out. PMID:27379980

  17. Comparative toxicity of leachates from 52 textiles to Daphnia magna.

    Science.gov (United States)

    Dave, Göran; Aspegren, Pia

    2010-10-01

    The environmental aspects of textiles are very complex and include production, processing, transport, usage, and recycling. Textiles are made from a variety of materials and can contain a large number of chemicals. Chemicals are used during production of fibres, for preservation and colouring and they are released during normal wear and during washing. The aim of this study was to investigate the release to water of toxic chemicals from various textiles. Altogether 52 samples of textiles made from cotton (21), linen (4), cotton and linen (7), cellulose (3), synthetic fibres (7), cotton and synthetic fibres (8) and wool (2). Seven were eco-labelled. All textiles were cut into squares and placed into Petri dishes with 50 ml ISO test medium in a concentration series (4-256 cm(2)/50 ml) and tested for acute toxicity to Daphnia magna. Estimated EC50s were converted into weight/volume, and 48-h EC50s ranged between 182 g/L. It was not possible to detect any difference between fibre type and toxicity (ANOVA), but a significantly higher toxicity was found for printed versus unprinted cotton and cotton/linen textiles, while the opposite was found for synthetic textiles. Eco-labelled products were evenly distributed on a toxicity scale, which means that eco-labelling in its present form does not necessarily protect users or the environment from exposure to toxic chemicals. Therefore, the results from the present study suggest that bioassays and toxicity tests should become an integrated part of textile environmental quality control programs.

  18. Genes mirror geography in Daphnia magna.

    Science.gov (United States)

    Fields, Peter D; Reisser, Céline; Dukić, Marinela; Haag, Christoph R; Ebert, Dieter

    2015-09-01

    Identifying the presence and magnitude of population genetic structure remains a major consideration in evolutionary biology as doing so allows one to understand the demographic history of a species as well as make predictions of how the evolutionary process will proceed. Next-generation sequencing methods allow us to reconsider previous ideas and conclusions concerning the distribution of genetic variation, and what this distribution implies about a given species evolutionary history. A previous phylogeographic study of the crustacean Daphnia magna suggested that, despite strong genetic differentiation among populations at a local scale, the species shows only moderate genetic structure across its European range, with a spatially patchy occurrence of individual lineages. We apply RAD sequencing to a sample of D. magna collected across a wide swath of the species' Eurasian range and analyse the data using principle component analysis (PCA) of genetic variation and Procrustes analytical approaches, to quantify spatial genetic structure. We find remarkable consistency between the first two PCA axes and the geographic coordinates of individual sampling points, suggesting that, on a continent-wide scale, genetic differentiation is driven to a large extent by geographic distance. The observed pattern is consistent with unimpeded (i.e. no barriers, landscape or otherwise) migration at large spatial scales, despite the fragmented and patchy nature of favourable habitats at local scales. With high-resolution genetic data similar patterns may be uncovered for other species with wide geographic distributions, allowing an increased understanding of how genetic drift and selection have shaped their evolutionary history.

  19. The first-generation Daphnia magna linkage map

    Directory of Open Access Journals (Sweden)

    De Meester Luc

    2010-09-01

    Full Text Available Abstract Background Daphnia magna is a well-established model species in ecotoxicology, ecology and evolution. Several new genomics tools are presently under development for this species; among them, a linkage map is a first requirement for estimating the genetic background of phenotypic traits in quantitative trait loci (QTL studies and is also very useful in assembling the genome. It also enables comparative studies between D. magna and D. pulex, for which a linkage map already exists. Results Here we describe the first genetic linkage map of D. magna. We generated 214 F2 (intercross clonal lines as the foundation of the linkage analysis. The linkage map itself is based on 109 microsatellite markers, which produced ten major linkage groups ranging in size from 31.1 cM to 288.5 cM. The total size of this linkage map extends to 1211.6 Kosambi cM, and the average interval for the markers within linkage groups is 15.1 cM. The F2 clones can be used to map QTLs for traits that differ between the parental clones. We successfully mapped the location of two loci with infertility alleles, one inherited from the paternal clone (Iinb1 and the other from the maternal clone (Xinb3. Conclusions The D. magna linkage map presented here provides extensive coverage of the genome and a given density of markers that enable us to detect QTLs of moderate to strong effects. It is similar in size to the linkage map of D. pulex.

  20. Zebrafish fed on recombinant Artemia expressing epinecidin-1 exhibit increased survival and altered expression of immunomodulatory genes upon Vibrio vulnificus infection.

    Science.gov (United States)

    Jheng, Yu-Hsuan; Lee, Lin-Han; Ting, Chen-Hung; Pan, Chieh-Yu; Hui, Cho-Fat; Chen, Jyh-Yih

    2015-01-01

    Artemia has been used extensively in aquaculture as fodder for larval fish, shrimp, and shellfish. Epinecidin-1, an antimicrobial peptide, was isolated from grouper (Epinephelus coioides) in 2005. Epinecidin-1 has been previously reported to possess antimicrobial activity against several Gram-positive and Gram-negative bacterial species, including Staphylococcus coagulase, Pseudomonas aeruginosa, Streptococcus pyogenes, and Vibrio vulnificus. In this study, we used electroporation to introduce plasmid DNA encoding a green fluorescent protein (EGFP)-epinecidin-1 fusion protein under the control of the cytomegalovirus (CMV) promoter into decapsulated Artemia cysts. Optimization of various properties (including cyst weight (0.2 g), plasmid concentration (50 μg/100 μl), and pulse voltage (150 V), length (10 ms), and number (2)) resulted in a hatching rate of 41.15%, a transfection efficiency of 49.81%, and a fluorescence intensity (A.U.) of 47.46. The expression of EGFP-epinecidin-1 was first detected by quantitative RT-PCR at 120 h post-electroporation, and protein was identified by Western blot at the same time. Furthermore, the EGFP-epinecidin-1 protein inhibited V. vulnificus (204) growth, as demonstrated by zone of inhibition studies. Zebrafish fed on transgenic Artemia expressing CMV-gfp-epi combined with commercial fodder were more resistant to infection by V. vulnificus (204): survival rate was enhanced by over 70% at 7, 14, and 21 days post-infection, and bacterial numbers in the liver and intestine were reduced. In addition, feeding of transgenic Artemia to zebrafish affected the immunomodulatory response to V. vulnificus (204) infection; expression of immune-responsive genes, including hepcidin and defbl2, was altered, as shown by qPCR. These findings suggest that feeding transgenic Artemia expressing CMV-gfp-epi to larval fish has antimicrobial effects, without the drawbacks of introducing drug residues or inducing bacterial drug resistance.

  1. The potential role of As-sumo-1 in the embryonic diapause process and early embryo development of Artemia sinica.

    Directory of Open Access Journals (Sweden)

    Bing Chu

    Full Text Available During embryonic development of Artemia sinica, environmental stresses induce the embryo diapause phenomenon, required to resist apoptosis and regulate cell cycle activity. The small ubiquitin-related modifier-1 (SUMO, a reversible post-translational protein modifier, plays an important role in embryo development. SUMO regulates multiple cellular processes, including development and other biological processes. The molecular mechanism of diapause, diapause termination and the role of As-sumo-1 in this processes and in early embryo development of Artemia sinica still remains unknown. In this study, the complete cDNA sequences of the sumo-1 homolog, sumo ligase homolog, caspase-1 homolog and cyclin B homolog from Artemia sinica were cloned. The mRNA expression patterns of As-sumo-1, sumo ligase, caspase-1, cyclin B and the location of As-sumo-1 were investigated. SUMO-1, p53, Mdm2, Caspase-1, Cyclin B and Cyclin E proteins were analyzed during different developmental stages of the embryo of A. sinica. Small interfering RNA (siRNA was used to verify the function of sumo-1 in A. sinica. The full-length cDNA of As-sumo-1 was 476 bp, encoding a 92 amino acid protein. The As-caspases-1 cDNA was 966 bp, encoding a 245 amino-acid protein. The As-sumo ligase cDNA was 1556 bp encoding, a 343 amino acid protein, and the cyclin B cDNA was 739 bp, encoding a 133 amino acid protein. The expressions of As-sumo-1, As-caspase-1 and As-cyclin B were highest at the 10 h stage of embryonic development, and As-sumo ligase showed its highest expression at 0 h. The expression of As-SUMO-1 showed no tissue or organ specificity. Western blotting showed high expression of As-SUMO-1, p53, Mdm2, Caspase-1, Cyclin B and Cyclin E at the 10 h stage. The siRNA caused abnormal development of the embryo, with increased malformation and mortality. As-SUMO-1 is a crucial regulation and modification protein resumption of embryonic diapause and early embryo development of A. sinica.

  2. Light-induced swimming of Daphnia: can laboratory experiments predict diel vertical migration?

    NARCIS (Netherlands)

    Van Gool, E.

    1997-01-01

    Vertical displacement velocity of a Daphnia galeata x hyalina clone was quantified in relation to changes in the relative rate of light change. An increase in the latter variable triggers an enhanced swimming response, and this response is again elicited when a second increase in the rate of relativ

  3. Linking genes to communities and ecosystems: Daphnia as an ecogenomic model.

    Science.gov (United States)

    Miner, Brooks E; De Meester, Luc; Pfrender, Michael E; Lampert, Winfried; Hairston, Nelson G

    2012-05-22

    How do genetic variation and evolutionary change in critical species affect the composition and functioning of populations, communities and ecosystems? Illuminating the links in the causal chain from genes up to ecosystems is a particularly exciting prospect now that the feedbacks between ecological and evolutionary changes are known to be bidirectional. Yet to fully explore phenomena that span multiple levels of the biological hierarchy requires model organisms and systems that feature a comprehensive triad of strong ecological interactions in nature, experimental tractability in diverse contexts and accessibility to modern genomic tools. The water flea Daphnia satisfies these criteria, and genomic approaches capitalizing on the pivotal role Daphnia plays in the functioning of pelagic freshwater food webs will enable investigations of eco-evolutionary dynamics in unprecedented detail. Because its ecology is profoundly influenced by both genetic polymorphism and phenotypic plasticity, Daphnia represents a model system with tremendous potential for developing a mechanistic understanding of the relationship between traits at the genetic, organismal and population levels, and consequences for community and ecosystem dynamics. Here, we highlight the combination of traits and ecological interactions that make Daphnia a definitive model system, focusing on the additional power and capabilities enabled by recent molecular and genomic advances. PMID:22298849

  4. Chronic toxicity of silver nanoparticles to Daphnia magna under different feeding conditions

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Skjolding, Lars Michael; Gergs, Andre;

    2015-01-01

    availability on toxicity. This was done through a series of Daphnia magna 21-day reproduction tests (OECD 211) using 30 nm citric acid stabilized AgNP aimed at studying the influence of food abundance on the reproductive toxicity of AgNP in D. magna. The experiments were carried out as static renewal tests...

  5. The effect of temperature on the sensitivity of Daphnia magna to cyanobacteria is genus dependent.

    Science.gov (United States)

    Hochmuth, Jennifer D; De Schamphelaere, Karel A C

    2014-10-01

    In the present study, the authors investigated the effects of 6 different genera of cyanobacteria on multiple endpoints of Daphnia magna in a 21-d life table experiment conducted at 3 different temperatures (15 °C, 19 °C, and 23 °C). The specific aims were to test if the effect of temperature on Daphnia's sensitivity to cyanobacteria differed among different cyanobacteria and if the rank order from most to least harmful cyanobacteria to Daphnia reproduction changed or remained the same across the studied temperature range. Overall, the authors observed a decrease in harmful effects on reproduction with increasing temperature for Microcystis, Nodularia, and Aphanizomenon, and an increase in harmful effects with increasing temperature for Anabaena and Oscillatoria. No effect of temperature was observed on Daphnia sensitivity to Cylindrospermopsis. Harmful effects of Microcystis and Nodularia on reproduction appear to be mirrored by a decrease in length. On the other hand, harmful effects of Anabaena, Aphanizomenon, and Oscillatoria on reproduction were correlated with a decrease in intrinsic rate of natural increase, which was matched by a later onset of reproduction in exposures to Oscillatoria. In addition, the results suggest that the cyanobacteria rank order of harmfulness may change with temperature. Higher temperatures may increase the sensitivity of D. magna to the presence of some cyanobacteria (Anabaena and Oscillatoria) in their diet, whereas the harmful effects of others (Microcystis, Nodularia, and Aphanizomenon) may be reduced by higher temperatures.

  6. Predator-induced phenotypic plasticity in Daphnia pulex: Uncoupling morphological defenses and life history shifts

    NARCIS (Netherlands)

    Repka, S.; Pihlajamaa, K.

    1996-01-01

    Chemical cues from a predator Chaoborus sp. induce morphological defense (neck spine) and life history shifts (later reproduction, decreased fecundity but larger juvenile size) in the waterflea Daphnia pulex. These shifts have been interpreted either as costs of defense or as separate adaptation. In

  7. Genomic integration and germline transmission of plasmid injected into crustacean Daphnia magna eggs.

    Directory of Open Access Journals (Sweden)

    Yasuhiko Kato

    Full Text Available The water flea, Daphnia, has been the subject of study in ecology, evolution, and environmental sciences for decades. Over the last few years, expressed sequence tags and a genome sequence have been determined. In addition, functional approaches of overexpression and gene silencing based on microinjection of RNAs into eggs have been established. However, the transient nature of these approaches prevents us from analyzing gene functions in later stages of development. To overcome this limitation, transgenesis would become a key tool. Here we report establishment of a transgenic line using microinjection of plasmid into Daphnia magna eggs. The green fluorescent protein (GFP gene fused with the D. magna histone H2B gene under the control of a promoter/enhancer region of the elongation factor 1α-1 (EF1α-1 gene, EF1α-1::H2B-GFP, was used as a reporter providing high resolution visualization of active chromatin. Transgenic lines were obtained from 0.67% of the total fertile adults that survived the injections. One of the transgenic animals, which exhibited fluorescence in the nuclei of cells during embryogenesis and oogenesis, had two copies of EF1α-1::H2B-GFP in a head-to-tail array. This is the first report of a transgenesis technique in Daphnia and, together with emerging genome sequences, will be useful for advancing knowledge of the molecular biology of Daphnia.

  8. Mixture toxicity of three toxicants with similar and dissimilar modes of action to Daphnia magna

    DEFF Research Database (Denmark)

    Syberg, K.; Engell-Kofoed, Anders Elleby; Pedersen, H.;

    2008-01-01

    the predictive capability of the models, we conducted Daphnia magna 48 h immobilization experiments with three toxicants with known modes of action (dimethoate, pirimicarb and linear alkyl benzene sulfonate) singly, and in binary and ternary mixtures. Our results indicate that CA and IA predict binary mixtures...

  9. Behavior and chronic toxicity of two differently stabilized silver nanoparticles to Daphnia magna

    DEFF Research Database (Denmark)

    Sakka, Yvonne; Skjolding, Lars Michael; Mackevica, Aiga;

    2016-01-01

    NP to Daphnia magna over a 21-day period with two different stabilizers (citrate and detergent), representative for charge and sterical stabilizers, respectively. This was coupled with a series of short-term experiments, such as mass balance and uptake/depuration testing, to investigate the behavior of both...

  10. Influences of the coating on silver nanoparticle toxicity in a chronic test with Daphnia magna

    DEFF Research Database (Denmark)

    Sakka, Y.; Mackevica, Aiga; Skjolding, Lars Michael;

    2015-01-01

    coated AgNP in a chronic Daphnia test. One type of AgNP was coated with citrate (cAgNP), the other AgNP were generally uncoated (pAgNP; p= pure), but sterically stabilized by an organic dispersant. Particles with a similar shape and diameter were chosen. The focus of the study was to relate observed...

  11. Transcriptomic alterations in Daphnia magna embryos from mothers exposed to hypoxia.

    Science.gov (United States)

    Lai, Keng-Po; Li, Jing-Woei; Chan, Christine Ying-Shan; Chan, Ting-Fung; Yuen, Karen Wing-Yee; Chiu, Jill Man-Ying

    2016-08-01

    Hypoxia occurs when dissolved oxygen (DO) falls below 2.8mgL(-1) in aquatic environments. It can cause trans-generational effects not only in fish, but also in the water fleas Daphnia. In this study, transcriptome sequencing analysis was employed to identify transcriptomic alterations induced by hypoxia in embryos of Daphnia magna, with an aim to investigate the mechanism underlying the trans-generational effects caused by hypoxia in Daphnia. The embryos (F1) were collected from adults (F0) that were previously exposed to hypoxia (or normoxia) for their whole life. De novo transcriptome assembly identified 18270 transcripts that were matched to the UniProtKB/Swiss-Prot database and resulted in 7419 genes. Comparative transcriptome analysis showed 124 differentially expressed genes, including 70 up- and 54 down-regulated genes under hypoxia. Gene ontology analysis further highlighted three clusters of genes which revealed acclimatory changes of haemoglobin, suppression in vitellogenin gene family and histone modifications. Specifically, the expressions of histone H2B, H3, H4 and histone deacetylase 4 (HDAC4) were deregulated. This study suggested that trans-generational effects of hypoxia on Daphnia may be mediated through epigenetic regulations of histone modifications. PMID:27399157

  12. Population developmental stage determines the recovery potential of Daphnia magna populations after fenvalerate application.

    NARCIS (Netherlands)

    B.J. Pieters; M. Liess

    2006-01-01

    Abstract: This study investigated the responses of Daphnia magna populations to pulsed exposures of the pyrethroid insecticide Fenvalerate applied during an early and a late stage of population development, and analyzed the dynamics of the subsequent recovery. A novel digital observation technique w

  13. Synergistic Effects of Different Food Species on Life-History Traits of Daphnia-Galeata

    NARCIS (Netherlands)

    Boersma, M.; Vijverberg, J.

    1995-01-01

    In this paper we describe the life history consequences of feeding Daphnia galeata with different food types in different concentrations. We fed the animals with four concentrations of two green algae Scenedesmus obliquus and Chlamydomonas globosa, given separately as well as in a 1:1 mixture. Growt

  14. Life-History Variation and the Coexistence of a Daphnia Hybrid with Its Parental Species

    NARCIS (Netherlands)

    Spaak, P.; Hoekstra, J.F.

    1995-01-01

    Life history variation and genotype composition were studied in two species of the Daphnia longispina group: the relatively large D. galeata (1.4 mm) and the smaller D. cucullata (0.9 mm). Several multi-locus genotypes of these species were compared with genotypes of their interspecific hybrid, D. c

  15. A rapid bioassay for detecting saxitoxins using a Daphnia acute toxicity test

    Energy Technology Data Exchange (ETDEWEB)

    Ferrao-Filho, Aloysio da S., E-mail: aloysio@ioc.fiocruz.b [Laboratorio de Avaliacao e Promocao da Saude Ambiental, Departamento de Biologia, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ 21045-900 (Brazil); Soares, Maria Carolina S., E-mail: mcarolsoares@gmail.co [Departamento de Engenharia Sanitaria e Ambiental Faculdade de Engenharia, Universidade Federal de Juiz de Fora, Juiz de Fora, MG 36036-900 (Brazil); Freitas de Magalhaes, Valeria, E-mail: valeria@biof.ufrj.b [Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Rio de Janeiro, RJ 21949-900 (Brazil); Azevedo, Sandra M.F.O., E-mail: sazevedo@biof.ufrj.b [Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Rio de Janeiro, RJ 21949-900 (Brazil)

    2010-06-15

    Bioassays using Daphnia pulex and Moina micrura were designed to detect cyanobacterial neurotoxins in raw water samples. Phytoplankton and cyanotoxins from seston were analyzed during 15 months in a eutrophic reservoir. Effective time to immobilize 50% of the exposed individuals (ET{sub 50}) was adopted as the endpoint. Paralysis of swimming movements was observed between approx0.5-3 h of exposure to lake water containing toxic cyanobacteria, followed by an almost complete recovery of the swimming activity within 24 h after being placed in control water. The same effects were observed in bioassays with a saxitoxin-producer strain of Cylindrospermopsis raciborskii isolated from the reservoir. Regression analysis showed significant relationships between ET{sub 50}vs. cell density, biomass and saxitoxins content, suggesting that the paralysis of Daphnia in lake water samples was caused by saxitoxins found in C. raciborskii. Daphnia bioassay was found to be a sensitive method for detecting fast-acting neurotoxins in natural samples, with important advantages over mouse bioassays. - A new Daphnia bioassay, as an alternative to the mouse bioassay, is able to detect effects of fast-acting, potent neurotoxins in raw water.

  16. Involvement of Daphnia pulicaria Sir2 in regulating stress response and lifespan.

    Science.gov (United States)

    Schumpert, Charles A; Anderson, Craig; Dudycha, Jeffry L; Patel, Rekha C

    2016-02-01

    The ability to appropriately respond to proteotoxic stimuli is a major determinant of longevity and involves induction of various heat shock response (HSR) genes, which are essential to cope with cellular and organismal insults throughout lifespan. The activity of NAD+-dependent deacetylase Sir2, originally discovered in yeast, is known to be essential for effective HSR and longevity. Our previous work on HSR inDaphnia pulicaria indicated a drastic reduction of the HSR in older organisms. In this report we investigate the role of Sir2 in regulating HSR during the lifespan of D. pulicaria. We cloned Daphnia Sir2 open reading frame (ORF) to characterize the enzyme activity and confirmed that the overall function of Sir2 was conserved in Daphnia. The Sir2 mRNA levels increased while the enzyme activity declined with age and considering that Sir2 activity regulates HSR, this explains the previously observed age-dependent decline in HSR. Finally, we tested the effect of Sir2 knockdown throughout adult life by using our new RNA interference (RNAi) method by feeding. Sir2 knockdown severely reduced both the median lifespan as well as significantly increased mortality following heat shock. Our study provides the first characterization and functional study of Daphnia Sir2.

  17. Cyanobacterial protease inhibitor microviridin J causes a lethal molting disruption in Daphnia pulicaria.

    Science.gov (United States)

    Rohrlack, Thomas; Christoffersen, Kirsten; Kaebernick, Melanie; Neilan, Brett A

    2004-08-01

    Laboratory experiments identified microviridin J as the source of a fatal molting disruption in Daphnia species organisms feeding on Microcystis cells. The molting disruption was presumably linked to the inhibitory effect of microviridin J on daphnid proteases, suggesting that hundreds of further cyanobacterial protease inhibitors must be considered potentially toxic to zooplankton.

  18. Daphnia as a model organism in limnology and aquatic biology: introductory remarks

    Directory of Open Access Journals (Sweden)

    Adam PETRUSEK

    2011-08-01

    Full Text Available Cladocerans of the genus Daphnia are keystone pelagic filter feeders in many temperate ponds and lakes. They have also become popular model organisms in various biological disciplines, from aquatic ecology to biomedical sciences. The crucial features that make these organisms excellent experimental models are their cyclical parthenogenetic life cycle together with easy culturing and handling. Thanks to these characteristics, the number of publications dealing with Daphnia is rapidly growing. The special insert to the Journal of Limnology on Daphnia biology contains contributions that deal directly or indirectly with the reproduction and development of these water fleas, in relation to various ecological factors. These include predator-prey interactions and their impact on morphology, population dynamics, or senescence-related traits, growth of daphnids on a diet consisting of invasively spreading cyanobacteria, and also the impact of extreme floods on a Daphnia population (and particularly on its dormant ephippial egg bank in a reservoir. Here, we discuss these presented works, and point out the potential lines of research that may improve the generalisation of their findings.

  19. What goes down must come up: symmetry in light-induced migration behaviour of Daphnia

    NARCIS (Netherlands)

    Van Gool, E.; Ringelberg, J.

    2003-01-01

    During a short period of the year, Daphnia may perform a phenotypically induced diel vertical migration. For this to happen, light-induced swimming reactions must be enhanced both at dawn and at dusk. Enhanced swimming in response to light intensity increase can be elicited by fish-associated kairom

  20. Effects of medium renewal and handling stress on life history traits in Daphnia

    NARCIS (Netherlands)

    Rousseaux, S.; Vanoverbeke, J.; Aerts, J.; Declerck, S.A.J.

    2010-01-01

    The zooplankton genus Daphnia is used as a model organism in ecological, ecotoxicological and evolutionary research. It is often used in experimental laboratory setups to examine life history traits under a variety of factors inducing stress. One type of stress, handling stress because of manipulati

  1. EFFECTIVE CONCENTRATIONS OF 6 CONTAMINANTS TO LEMMA MINOR, PIMEPHALES PROMELA, DAPHNIA MAGNA, AND CERIODAPHNIA DUBIA

    Science.gov (United States)

    The research presented here resulted in EC50 and LOEC values for the contaminants copper, cadmium, diazinon, atrazine, and cyanide to the species Lemna Minor, Pimephales promelas, Daphnia magna, and Ceriodaphnia dubia. Observed values were used as benchmarks for assessing the se...

  2. Toxicity of various silver nanoparticles compared to silver ions in Daphnia magna

    Directory of Open Access Journals (Sweden)

    Asghari Saba

    2012-04-01

    Full Text Available Abstract Background To better understand the potential ecotoxicological impacts of silver nanoparticles released into freshwater environments, the Daphnia magna 48-hour immobilization test was used. Methods The toxicities of silver nitrate, two types of colloidal silver nanoparticles, and a suspension of silver nanoparticles were assessed and compared using standard OECD guidelines. Also, the swimming behavior and visible uptake of the nanoparticles by Daphnia were investigated and compared. The particle suspension and colloids used in the toxicity tests were well-characterized. Results The results obtained from the exposure studies showed that the toxicity of all the silver species tested was dose and composition dependent. Plus, the silver nanoparticle powders subsequently suspended in the exposure water were much less toxic than the previously prepared silver nanoparticle colloids, whereas the colloidal silver nanoparticles and AgNO3 were almost similar in terms of mortality. The silver nanoparticles were ingested by the Daphnia and accumulated under the carapace, on the external body surface, and connected to the appendages. All the silver species in this study caused abnormal swimming by the D. magna. Conclusion According to the present results, silver nanoparticles should be classified according to GHS (Globally Harmonized System of classification and labeling of chemicals as "category acute 1" to Daphnia neonates, suggesting that the release of nanosilver into the environment should be carefully considered.

  3. What Can Molecular Markers Tell Us About the Evolutionary History of Daphnia Species Complexes

    NARCIS (Netherlands)

    Schwenk, K.; Ender, A.; Streit, B.

    1995-01-01

    Despite the wealth of information on the ecology of Daphnia species, the systematics and phylogeny of the genus is still unresolved. The taxonomic uncertainties are based in part on the phenomenon of interspecific hybridization, which has been well documented for species of the D. galeata/cucullata/

  4. Food mediated life history strategies in Daphnia magna: their relevance to ecotoxicological evaluations.

    NARCIS (Netherlands)

    Enserink, E.L.

    1995-01-01

    The waterflea Daphnia magna is a widely used test organism in ecotoxicological studies. Acute and chronic laboratory tests yield basic information for the development of water quality standards, assessment of potential hazards of (new) chemicals, waste water licences and sanitation measures for cont

  5. Bioavailability and effect of pirimicarb on Daphnia magna in a laboratory freshwater/sediment system

    DEFF Research Database (Denmark)

    Kusk, K.O.

    1996-01-01

    In tests with newborn and one-week-old Daphnia magna, 48-h EC(50) values of 21-24 mu g/L and 16 mu g/L pirimicarb, respectively, were found. Older animals thus were as sensitive to pirimicarb as newborn animals. In an experiment with sediment included in the test system, all mother animals surviv...

  6. Differences in orientation behaviour underlie interclonal differences in phototaxis in Daphnia magna

    NARCIS (Netherlands)

    Van Gool, E.

    1999-01-01

    I studied the orientation direction of the body and the eye in response to contrasts in Daphnia magna. The orientation of the body was studied on pinned, but freely rotating daphnids, and on freely swimming daphnids. The orientation direction of the eye was studied on daphnids with a fixed position

  7. Density and depth variations of Daphnia multilocus genotypes during a summer period in Lake Maarsseveen

    NARCIS (Netherlands)

    Ringelberg, J.; van Gool, E.; Brehm, Michaela

    2004-01-01

    The genotype composition of a Daphnia population complex during a summer period in Lake Maarsseveen (The Netherlands) was determined by allozyme analysis. The depth distribution, diel vertical migration and several parameters of the total population were measured. Young-of-the-year (0+) perch (Perca

  8. Food availability affects the strength of mutualistic host-microbiota interactions in Daphnia magna.

    Science.gov (United States)

    Callens, Martijn; Macke, Emilie; Muylaert, Koenraad; Bossier, Peter; Lievens, Bart; Waud, Michael; Decaestecker, Ellen

    2016-04-01

    The symbiotic gut microbial community is generally known to have a strong impact on the fitness of its host. Nevertheless, it is less clear how the impact of symbiotic interactions on the hosts' fitness varies according to environmental circumstances such as changes in the diet. This study aims to get a better understanding of host-microbiota interactions under different levels of food availability. We conducted experiments with the invertebrate, experimental model organism Daphnia magna and compared growth, survival and reproduction of conventionalized symbiotic Daphnia with germ-free individuals given varying quantities of food. Our experiments revealed that the relative importance of the microbiota for the hosts' fitness varied according to dietary conditions. The presence of the microbiota had strong positive effects on Daphnia when food was sufficient or abundant, but had weaker effects under food limitation. Our results indicate that the microbiota can be a potentially important factor in determining host responses to changes in dietary conditions. Characterization of the host-associated microbiota further showed that Aeromonas sp. was the most prevalent taxon in the digestive tract of Daphnia.

  9. Observações preliminares sobre a toxicidade do ϒBHC e do cloreto de mercúrio à Artemia salina Preliminary observations on the toxicity of ϒBHC and mercuric cloride on Artemia salina

    Directory of Open Access Journals (Sweden)

    Salvador Airton Gaeta

    1983-01-01

    Full Text Available São apresentados os resultados de bioensaios com larvas de Artemia salinacolocadas em misturas de γBHC e HgCl2, a fim de se compararem os efeitos das mesmas com aqueles obtidos quando essas duas substancias atuam isoladamente. A CL50 para o yBHC foi quase que o dobro do valor para o HgCl2. O efeito da primeira dose foi observado para aproximadamente 16% da população (CL16, enquanto que, para o γBHC, o foi em 2,3% da população (CL2,3. Assim, as doses subseqüentes foram mais efetivas para o HgCl2 que para o γBHC. A dose efetiva 50% (ED50 ê mais ou menos igual para o γBHC e para o γBHC + HgCl2, mas em doses altas o YBHC seria mais efetivo, enquanto que em doses baixas a mistura e que o seria.Results of bio-assays using Artemia salina larvae in γBHC-HgCl2 mixture are presented. The results obtained are compared with those obtained using the two chemicals separately. The LC50 for γBHC was almost double that for HgCl2. The effect due to the primary dose of HgCl2 was observed for approximately 16% of the population (LC2.3 while for γBHC the population percentage was 2.3 (LC2.3. As a consequence, subsequent doses were more effective for HgCl2 than for γBHC. The effective dose 50% (ED50 is about the same for γBHC and for γBHC + HgCl2 mixture, though in higher doses BHC would be more effective, while in smaller doses the mixture would predominate.

  10. An experimental test of the ability of Daphnia galeata resting egg production in Lake Biwa

    Directory of Open Access Journals (Sweden)

    Narumi K. Tsugeki

    2014-02-01

    Full Text Available The Daphnia galeata population in Lake Biwa (Japan had almost ceased producing resting eggs by the 1980s. To examine whether D. galeata had lost the ability to produce resting eggs, or if chemical contamination was inhibiting resting egg production, individuals collected in fall (November and late winter (March, were reared in the laboratory. More than 50% of these D. galeata individuals produced resting eggs irrespective of the month of collection, when reared with food supplied at a level lower than that available during the maternal generation. The results reflect that D. galeata in Lake Biwa have a high ability to produce resting eggs when appropriate stimuli are provided. As chemical substances, such as endocrine disrupters, are known to inhibit resting egg production in Daphnia and these accumulate in lake sediments, we tested whether Daphnia individuals produce resting eggs when reared in sediment-conditioned lake water. In sediment-conditioned lake water, only a few Daphnia that were collected in March produced resting eggs, while 50% of the individuals collected in November produced resting eggs. Thus, D. galeata collected from Lake Biwa are able to produce resting eggs, but genetic variation likely leads to variation in resting egg production in the presence of chemical contaminants. These results suggest that the recent decrease in the resting egg production of Daphnia populations in lake Biwa is mainly due to a decrease in the strength of the environmental queue that stimulates resting egg production rather than a genetic shift to strains that have a lower ability to produce resting eggs; yet, we cannot rule out the possibility that a chemical contamination plays a role in the decrease of resting egg production.

  11. Effects of extreme floods on the Daphnia ephippial egg bank in a long narrow reservoir

    Directory of Open Access Journals (Sweden)

    Adam PETRUSEK

    2011-08-01

    Full Text Available Ephippial egg banks are important reservoirs of dormant stages that allow the recovery of Daphnia populations after unfavourable periods. Although the contribution of hatchlings from ephippia to a population in the water column is probably of minor importance in permanent water bodies with a year-round Daphnia persistence, this may differ after major disturbances. In 2006, two 500-year floods hit the long and narrow Vranov Reservoir (Czech Republic, in which we had investigated zooplankton densities and ephippia distribution in the sediment in preceding years. In this study, we evaluated the impact of those extraordinary floods on the population of the Daphnia longispina complex, and particularly on the local dormant egg bank. We considered two alternative hypotheses related to the egg bank: that either the substantial input of new material with the flood completely buried and therefore reset the existing egg bank, or that the sediment including ephippia was redistributed in the reservoir after the flood and dormant eggs could be exposed to hatching stimuli. A year after the floods, we did not observe any sediment layer that would be devoid of ephippia. However, we observed a significant increase in the proportion of empty ephippia and a decrease in the proportion of those containing eggs. We attribute these changes to disturbance of the sediment due to the floods, which caused redistribution of ephippia stored in the sediment and those detached from the reservoir shoreline. Dormant eggs inside ephippia deposited to shallow parts of reservoir after the floods could therefore receive and respond to hatching stimuli. Hatching from ephippia may have contributed to Daphnia recovery after the spring flood; however, a significant proportion of the Daphnia population probably survived the summer flood protected in the epilimnetic refuge of the thermally stratified environment.

  12. Mating behaviours of Daphnia pulicaria, a cyclic parthenogen: comparisons with copepods

    Science.gov (United States)

    Brewer, M. C.

    1998-01-01

    The pre-and post-contact mating behaviours of Daphnia pulicaria are investigated by direct observations of vertical distributions, swimming behaviours and male-female interactions. Analysis of vertical distributions in a 1 m deep, thermally stratified migration chamber reveals that females were always located in the upper layer of the water column but males exhibited a bimodal depth distribution, in which an individual's depth was a function of body length and water temperature. The observed distributions of males may be the result of several interacting pressures; predation avoidance, life-history optimization, and avoidance of assortative mating. Male swimming behaviour was faster and orthogonal to that of females, which is in agreement with the predictions of encounter-rate maximization models. Video recordings of males and females interacting in a 1-litre vessel showed that males both pursued and contacted other males more often than females. Thus, there was no evidence that Daphnia are able to use water-borne chemical signals to locate and identify potential mates. However, the average duration of male-female contacts (13.8 s) was much longer than those between males (1.6 s), suggesting that males can determine the sex of contacted individuals.Daphnia mating behaviour is significantly more complex than previously acknowledged. In contrast to the conventional view of Daphnia males swimming more-or-less randomly and mating with any individual encountered, they exhibit behaviours which increase the potential of mating with females while reducing the risk of predation. Several male behaviours, such as 'scanning' and the performance of area-restricted spirals upon encounter, are similar to those reported for some copepods and may be common to zooplankton that lack sophisticated chemosensory abilities. The possibility that Daphnia may also be able to assess such important female attributes as species and reproductive status is discussed.

  13. Pengaruh pemberian pakan berupa campuran pelet ikan, ulat tepung (Tenebrio molitor, dan ganggang merah (Gracilaria foliifera terhadap pertumbuhan dan kelulushidupan ikan sidat (Anguilla bicolor

    Directory of Open Access Journals (Sweden)

    MUHAMMAD A. AZIZ HENDITAMA

    2015-05-01

    Full Text Available Henditama MAA, Harini M, Budiharjo A. 2015. The effect of giving mixtured feed of fish pellet, mealworm (Tenebrio molitor and red algae (Gracilaria foliifera to the growth and survival rate of eel (Anguilla bicolor. Bioteknologi 12: 22-28. High demand of eels (Anguilla bicolor in the world has not followed by the capability of domestic production. The purpose of this research are to determine the effect and the precise composition of the feed mixture in the form of fish pellets, mealworms (Tenebrio molitor, red algae (Gracilaria foliifera to the growth and survival rate of eels. This research used completely randomized design with four variations of mixtured feed in the form of fish pellet, mealworms, and red algae specifically P1 (100% ; 0% ; 0%, P2 (75% ; 20% ; 5%, P3 (50% ; 45% ; 5%, P4 (25% ; 70% ; 5%. This research also has been done in 90 days with feeding in twice a day. The data of growth, survival rate, and water quality was collected once a week. The data result has been analized by ANOVA. The data result showed that have a real different to continue to the next analysis of DMRT with test level 5% to locate the differences between treatments. The eels growth after feeding a mixture feed in the form of fish pellets, mealworms, and red alga, specifically: P1 (K 26.3167 gram; P2 20.3167 gram; P3 28.2500 gram; and P4 22.0000 gram. The eels survival rate, specifically P1 (K 26.67%; P2 33.33%; P3 30%; dan P4 26.67%. Furthemore, the exact composition that give the best effect of growth and survival rate to eels is 50% fish pellets, 45% mealworms and 5% red alga.

  14. Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus larvae using Artemia nauplii and formulated diet

    Directory of Open Access Journals (Sweden)

    Naser Agh

    2013-07-01

    Full Text Available High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate of first-feeding larvae were fed according to four main feeding regimes: (1 live food (live nauplii of brine shrimp Artemia urmiana; (2 indirect transition (5 days live food followed by gradual transition to formulated diet; (3 direct transition (using different combinations of live and formulated diet from the start feeding onwards; (4 formulated feed (FD from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food.

  15. Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp, Artemia sinica

    Science.gov (United States)

    Zhou, Qian; Wu, Changgong; Dong, Bo; Li, Fuhua; Liu, Fengqi; Xiang, Jianhai

    2010-03-01

    Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica. Fourteen differentially displayed protein spots were detected and seven of them were identified. Three spots were up-expressed and identified: actin, heat shock protein 70, and chaperone subunit 1; three down-regulated proteins were identified: arginine kinase, elongation factor-2, and glycine-rich protein; and a newly expressed protein was identified as peroxiredoxin. The study indicates the involvement of all the differentially expressed proteins in the early responses of protein expression, and in the survival of A. sinica in the presence of copper and other heavy metals; the findings improve understanding of the organism’s adaptive responses and resistance.

  16. Analysis of toxicity of Anacardium occidentale L. extract submitted to ionizing radiation on embryos of Biomphalaria glabrata and Artemia salina

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Hianna A.M.F.; Sa, Jose L.F.; Lima, Claudia S.A.; Amancio, Francisco F.; Melo, Ana M.M.A., E-mail: hiannaamfs@gmail.com, E-mail: luismuma6@gmail.com, E-mail: claudia.salima@gmail.com, E-mail: amancioff@bol.com.br, E-mail: amdemelo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia; Ribeiro, Luanna R.S.; Santos, Gustavo H.F.; Silva, Edvane B., E-mail: luannaribeiro_lua@hotmail.com, E-mail: santosghf@hotmail.com, E-mail: edvborges@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia

    2013-07-01

    The use of gamma radiation as a sterilization method for herbs, herbal medicines and foods, shows positive results regarding the retention of such products, economy and safety of the method. However, it is known that this method of processing plant material can cause chemical changes in these products related to the type of material, its components and the dose received. Evaluated, in the present study, the action of gamma radiation as a modifier of toxicity extract of Anacardium occidentale Linn. To evaluate the toxicity of the extract irradiated at doses of 5.0, 7.5 and 10.0 kGy and concentrations of 250, 500 and 1000 mg/L was used bioassays with Artemia salina and Biomphalaria glabrata. For the test to A. salina, 520 specimens were used divided into groups of 10 larvae. For the bioassay with B. glabrata, 3900 specimens were used divided into groups of, approximately, 100 embryos. Larvae of A. salina and embryos were subjected to extracts irradiated and unirradiated for 24 hours. The bioassay with A. salina, showed a decrease, compared to extract unirradiated and irradiated at doses of 5.0 and 7.5 kGy, of extract irradiated with 10 kGy, where the mortality did not differ from the control group. In tests with embryos was observed an increase in the toxicity of the extract at a dose of 7.5 kGy and a decrease in the dose of 10.0 kGy. The radiation promoted changes in the toxicity of leaves extracts of Anacardium occidentale Linn. on embryos of Biomphalaria glabrata and Artemia salina. (author)

  17. Phototoxic effects of titanium dioxide nanoparticles on Daphnia magna

    Science.gov (United States)

    Mansfield, Charles M.

    Titanium dioxide nanoparticles (TiO2-NP) are one of the most abundantly utilized nanomaterials in the world. Studies have demonstrated the mechanism of acute toxicity in TiO2-NP to be the production of reactive oxygen species (ROS) leading to oxidative stress and mortality in exposed organisms. It has also been demonstrated that the anatase crystalline conformation is capable of catalyzing the cleavage of water molecules to further increase the concentration of ROS in the presence of ultraviolet radiation. This photoenhanced toxicity significantly lowers the toxicity threshold of TiO2-NP to environmentally relevant concentrations (ppb). The goal of this study was to determine whether dietary uptake and accumulation of TiO2-NP in the aquatic filter feeder Daphnia magna resulted in photoenhanced toxicity. D. magna and S. caprincornatum were exposed to aqueous solutions of 20ppm and 200ppm TiO2-NP for 24hrs and then transferred to clean moderately hard water. Samples were taken at various time points, dried, and TiO 2 quantified using ICP-MS. Toxicity assays were run on D. magna using three TiO2-NP (20ppm, 200ppm) exposure protocols and two ultraviolet radiation treatments. The first exposure group was exposed to aqueous solutions of TiO2-NP for the duration of the test. The second exposure group was exposed to TiO2-NP for an hour and then transferred to clean water. The third exposure group was fed S. capricornatum that had been allowed to adsorb TiO2-NP. All samples were then placed in an outdoor UV exposure system and exposed to either full spectrum sunlight (with UV) or filtered sunlight (no UV). Here we show that TiO2 uptake peaked at one hour of exposure likely due to sedimentation of the particles out of suspension, thus decreasing bioavailability for the duration of the test. Interestingly, when D. magna were moved to clean water, aqueous concentrations of TiO2 increase as a result of depuration from the gut tract. Data also suggests these excreted particles

  18. Co-feeding of microalgae and bacteria may result in increased N assimilation in Artemia as compared to mono-diets, as demonstrated by a 15N isotope uptake laboratory study

    OpenAIRE

    Toi, H.T.; Boeckx, P.; Sorgeloos, P.; Bossier, P.; Van Stappen, G.

    2014-01-01

    This study investigated the effect of the co-feeding of bacteria and microalgae on nitrogen (N) assimilation in an Artemia franciscana gnotobiotic laboratory culture test. Two strains of bacteria were used, HT3 and HT6, isolated from previous Artemia laboratory cultures. These were fed in combination with microalga Dunaliella tertiolecta strains, either the high quality DT 19/6B or the low quality DT 19/27 strain. Each combination of algae and bacteria was offered in different proportions, i....

  19. The effect of small doses of toxic cyanobacterial food on temperature response of Daphnia galeata: Is bigger better?

    NARCIS (Netherlands)

    De Senerpont Domis, L.N.; Bartosiewicz, M.; Davis, C.; Cerbin, S.

    2013-01-01

    1.Growing evidence shows that cyanobacterial blooms thrive in warmer temperatures, underlining the importance of understanding the relationship between cyanobacterial food, temperature and performance of the key freshwater herbivore Daphnia. 2.To evaluate potential effects of toxic cyanobacterial fo

  20. Morphology and ecology of Daphnia middendorffiana, Fisher 1851 (Crustacea, Daphniidae) from four new populations in the Alps

    OpenAIRE

    Tiberti, Rocco

    2011-01-01

    Daphnia middendorffiana has an arctic, circumpolar distribution, with some isolated southerly populations restricted to mountainous areas, including the Alps. In this paper, new records of Daphnia middendorffiana on the Alps are reported. The species was regularly recorded in several samples collected from 2006 to 2009 in four high altitude lakes in the Gran Paradiso National Park (GPNP) during the ice free period. This is the third finding for the Alps and the described populations are the l...

  1. Mesozoic fossils (>145 Mya suggest the antiquity of the subgenera of Daphnia and their coevolution with chaoborid predators

    Directory of Open Access Journals (Sweden)

    Taylor Derek J

    2011-05-01

    Full Text Available Abstract Background The timescale of the origins of Daphnia O. F. Mueller (Crustacea: Cladocera remains controversial. The origin of the two main subgenera has been associated with the breakup of the supercontinent Pangaea. This vicariance hypothesis is supported by reciprocal monophyly, present day associations with the former Gondwanaland and Laurasia regions, and mitochondrial DNA divergence estimates. However, previous multilocus nuclear DNA sequence divergence estimates at Daphnia. Results We describe new fossils of ephippia from the Khotont site in Mongolia associated with the Jurassic-Cretaceous boundary (about 145 MYA that are morphologically similar to several modern genera of the family Daphniidae, including the two major subgenera of Daphnia, i.e., Daphnia s. str. and Ctenodaphnia. The daphniid fossils co-occurred with fossils of the predaceous phantom midge (Chaoboridae. Conclusions Our findings indicate that the main subgenera of Daphnia are likely much older than previously known from fossils (at least 100 MY older or from nuclear DNA estimates of divergence. The results showing co-occurrence of the main subgenera far from the presumed Laurasia/Gondwanaland dispersal barrier shortly after formation suggests that vicariance from the breakup of Pangaea is an unlikely explanation for the origin of the main subgenera. The fossil impressions also reveal that the coevolution of a dipteran predator (Chaoboridae with the subgenus Daphnia is much older than previously known -- since the Mesozoic.

  2. The effects of Amax yeast fed to Persian sturgeon (Acipencer persicus) larvae via bioenrichment of Daphnia magna

    OpenAIRE

    Mohammad Lashkar Boloki; Hojatollah Jafaryan; Moein Faramarzi; Hosein Adineh

    2011-01-01

    This study was carried out to evaluate the effect of the product of commercial live bakers’ yeast ( Saccharomyces cerevisiae ) so called Amax on the growth and survival of Persian sturgeon( Acipenser persicus ) larvae via enrichment of Daphnia magna . The blends of Amax were used in three concentrations of 50, 100, 150 mg L-1 with Daphnia in suspension of broth. Every day Daphnia by one of concentrations was bioencapsulated for 10 hours and Persian sturgeon larvae were fed on it. The Aci...

  3. Síntese de 1,3,5-triazinas substituídas e avaliação da toxicidade frente a Artemia Salina leach Synthesis of substituted 1,3,5-triazines and toxicity evaluation against Artemia Salina leach

    Directory of Open Access Journals (Sweden)

    Márcia Ferreira Cavalcante

    2000-02-01

    Full Text Available The synthesis of ten symmetrically and unsymmetrically substituted 1,3,5-triazines by Phase Transfer Catalysis (PTC method is described. Their toxicities were determined against Artemia salina Leach. The LD50 values have also been obtained for these compounds.

  4. Toxicity of β-adrenergic receptor blockers to Daphnia (Daphnia magna)%β-受体阻断药物对大型蚤的毒性研究

    Institute of Scientific and Technical Information of China (English)

    施嘉琛; 尚楠; 张晶; 邵兵

    2011-01-01

    Objective To investigate the toxicity of 5 p-adrenergic receptor blockerg (bisoprolol, propranolol, sotalol, atenolol and metoprolol) to crustacean Daphnia magna. Methods The ECM of five f3-adrenergic receptor blockerg were evaluated on the 48 h toxicity experiments according to the standard protocol established by OECD. The two strongest toxic blockers were chosen to study the 21 day toxicity to physiological change of daphnia. Results The ECM of five p-adrenergic receptor blockers were 6-169 mg/L. The toxicities (48 h ECW value, mg/L) in decreasing order were propranolol, bisoprolol, sotalol, atenolol and metoprolol. The 21 day toxicity study showed both propranolol and bisoprolol owning toxic effects to daphnia. The physiological change include the delay of first pregnancy and first brood, decrease of the number of broods per female and shorten of body length. Conclusion Since the p-adrenergic receptor blockers were toxicity to Daphnia magna which was a commonly used test animal in aquatic toxicology, the management of these medicines should be concern on the ecotoxicology.%目的 研究五种常用β-受体阻断药物(比索洛尔、普萘洛尔、索他洛尔、阿替洛尔和美托洛尔)对大型蚤(Daphnia magna)的毒理学效应.方法 根据OECD操作规程,开展5种目标药物对大型蚤的48 h毒性实验,获得各药物的半数抑制浓度EC50.再对48 h毒性效应较强的两种药物开展21d毒性实验,考察相关生理学指标的变化.结果5种药物的48 h半数抑制浓度EC50为6~169 mg/L.其毒性顺序为普萘洛尔>比索洛尔>索他洛尔>阿替洛尔>美托洛尔.普萘洛尔和比索洛尔的21d毒性试验结果表明两种药物对大型蚤的生理指标均存在毒理学效应,包括怀卵和产蚤时间延迟、产蚤数减少及体长缩短等.结论 β-受体阻断药物对大型蚤(Daphnia magna)存在毒理学效应,加强该类药物的使用和管理具有现实的生态毒理学意义.

  5. Comparison of bioassays using the anostracan crustaceans Artemia salina and Thamnocephalus platyurus for plant extract toxicity screening Comparação de bioensaios com os crustáceos Artemia salina e Thamnocephalus platyurus para abordagem de extratos de plantas com toxicidade

    Directory of Open Access Journals (Sweden)

    Pablo Mayorga

    2010-12-01

    Full Text Available Three lethality bioassays, using the salt-water crustacean Artemia salina Leach, Artemiidae, (conventional 96 microwell plate test and the Artoxkit M microbiotest and the freshwater crustacean Thamnocephalus platyurus Packard, Thamnocephalidae, (Thamnotoxkit F microbiotest, were compared using extracts of ten Guatemalan plant species. It was previously observed that five of them have anti-Artemia activity. These were: Solanum americanum Mill., Solanaceae, Gliricidia sepium (Jacq. Kunth ex Walp., Fabaceae, Neurolaena lobata (L. Cass., Asteraceae, Petiveria alliacea L., Phytolaccaceae, and Ocimum campechianum Mill., Lamiaceae. The five others: Curatella americana L., Dilleniaceae, Prunus barbata Koehne, Rosaceae, Quercus crispifolia Trel., Fagaceae, Rhizophora mangle L., Rhizophoraceae, and Smilax domingensis Willd., Smilacaceae, do not. All plants without anti-Artemia activity had no lethal effects in both assays with A. salina. For the plants with anti-Artemia activity the Artoxkit M was not sensitive to G. sepium and the conventional Artemia test was not sensitive to S. americanum, G. sepium and N. lobata. All the plant extracts, except for that of C. americana, had lethal effects on T. platyurus and the lethal median concentration (LC50 levels for this organism were in all cases substantially lower than those of the salt-water test species. This study revealed that T. platyurus is a promising test species worth further in depth investigation for toxicity screening of plant extracts with potential medicinal properties.Três bioensaios de letalidade com o crustáceo de água salgada Artemia salina Leach, Artemiidae, (teste convencional em microplaca de 96 poós Artoxkit microbiotest M e o crustáceo de água doce Thamnocephalus platyurus Packard, Thamnocephalidae (Thamnotoxkit microbiotest F, foram comparados utilizando extratos de dez espécies de plantas da Guatemala. Foi previamente observado que cinco delas possuem atividade anti-Artemia

  6. A case study to optimise and validate the brine shrimp Artemia franciscana immobilisation assay with silver nanoparticles: The role of harmonisation.

    Science.gov (United States)

    Kos, Monika; Kahru, Anne; Drobne, Damjana; Singh, Shashi; Kalčíková, Gabriela; Kühnel, Dana; Rohit, Rekulapelly; Gotvajn, Andreja Žgajnar; Jemec, Anita

    2016-06-01

    Brine shrimp Artemia sp. has been recognised as an important ecotoxicity and nanotoxicity test model organism for salt-rich aquatic environments, but currently there is still no harmonised testing protocol which would ensure the comparable results for hazard identification. In this paper we aimed to design the harmonised protocol for nanomaterial toxicity testing using Artemia franciscana and present a case study to validate the protocol with silver nanoparticles (AgNPs). We (i) revised the existing nanotoxicity test protocols with Artemia sp. (ii) optimised certain methodological steps based on the experiments with AgNPs and potassium dichromate (K2Cr2O7) as a soluble reference chemical and (iii) tested the optimised protocol in an international inter-laboratory exercise conducted within the EU FP7 NanoValid project. The intra- and inter-laboratory reproducibility of the proposed protocol with a soluble reference chemical K2Cr2O7 was good, which confirms the suitability of this assay for conventional chemicals. However, the variability of AgNPs toxicity results was very high showing again that nanomaterials are inherently challenging for toxicity studies, especially those which toxic effect is linked to shed metal ions. Among the identified sources for this variability were: the hatching conditions, the type of test plate incubation and the illumination regime. The latter induced variations assumingly due to the changes in bioavailable silver species concentrations. Up to our knowledge this is the first inter-laboratory comparison of the Artemia sp. toxicity study involving nanomaterials. Although the inter-laboratory exercise revealed poor repeatability of AgNPs toxicity results, this study provides valuable information regarding the importance of harmonisation of all steps in the test procedure. Also, the presented AgNPs toxicity case study may serve as a platform for further validation steps with other types of NMs. PMID:26895539

  7. Evaluation of growth and survival rate of Artemia parthenogenetica feed with micro algae (Isochrysis galbana and Chlorella vulgaris and bakery yeast (Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Mehdi Dehghan

    2011-10-01

    Full Text Available This study was done to evaluate growth and survival rate of Maharloo lake artemia (ArtemiaParthenogenetica (Bowen & Sterling, 1978 which feed with two species of microalgae (IsochrysisGalbana and Chlorella vulgaris and bakery yeast (Saccharomyces cerevisiae with different nutritiousingredients for 15 days. We evaluated them in 3rd, 7th, 11th and 15thdays of cultivation period for 4 times. This experiment was done in completely randomized design with 4 treatments (3 treatments and 1 control and each treatment has 3 replicates. Artemia parthenogenetica nauplii were feed with three different types of food that includes Isochrysis galbana microalgae (T1, Chlorella vulgaris (T2 and Saccharomyces cerevisiae yeast (T4. Control had feed with blend of these three matters. After 15 days the highest survival rate was observed in control (84.00 and the lowest one was related to the T4 (59.58 which feed with Saccharomyces cerevisiae yeast (p<0.05. The highest growth rate was observed in T4, T3, followed by T1 and T2 respectively. Achievement results showed significantdifferences between control and other treatments (p<0.05. This study proved that treatments whichfeed with blend of two micro algae's species and bakery yeast have higher survival ability than theother treatments.

  8. Sudden weaning of angel fish pterophyllum scalare (Lichtenstein) (Pisces; Cichlidae) larvae from brine shrimp (Artemia sp) nauplii to formulated larval feed.

    Science.gov (United States)

    Herath, Sandamali Sakunthala; Atapaththu, Kerthi Sri Senarathna

    2013-12-01

    This study investigated the effects of sudden weaning of angel fish larvae (Pteraphylum scalari) from Artemia nauplii to commercial larval feed. Four days post hatch (DPH) larvae were reared in four different weaning protocols (TR1-TR4) with triplicates in a complete randomize design. Larvae in TR1 and TR4 were exclusively fed Artemia nauplii and dry feed respectively. In TR2 and TR3, larvae were initially fed Artemia nauplii and suddenly wean to formulated feed on 14 DPH and 7 DPH respectively. The experiment was lasted for 28 days. At the end of the experiment, final mean weight (FW), total length (FL), height (FH), Daily Weight Gain (DWG), Specific Growth Rate (SGR), survival and stress index were compared. Significantly highest (P < 0.05) FW, DWG and SGR were observed in TR1 and TR2 while former values of TR3 were not significantly different from TR1. Highest FL observed in TR1 and TR2 while FL of TR2 was statistically similar to that of TR3. The poorest growth was observed in larvae solely fed formulated feed. Survival and the stress index were independent from weaning methods. Although sudden weaning is possible on 7 DPH, larvae showed comparatively higher growth when switch off to formulate feed on 14 DPH. PMID:23626927

  9. Anticipation of Artemia sp. supply in the larviculture of the barber goby Elacatinus figaro (Gobiidae: Teleostei influenced growth, metamorphosis and alkaline protease activity

    Directory of Open Access Journals (Sweden)

    Maria Fernanda da Silva-Souza

    2015-09-01

    Full Text Available The barber goby Elacatinus figaro is considered endangered due to overexploitation by the ornamental industry. Farming marine ornamental fishes, especially the threatened ones, can be one of the measures to minimize the pressure on the natural stocks. Among the priority issues for their production is the determination of the most appropriate feeding management. The feeding protocol commonly used in the larviculture of barber goby, when the start of Artemia sp. offer occurred at the 18th DAH (days after hatching (treatment T18, was modified, by anticipating brine shrimp supply in 6 days (treatment T12. Alkaline proteases activity, growth and metamorphosis of larvae were evaluated in both protocols. Juveniles at T12 showed higher weight (0.04 ± 0.001 g and lower activity of total alkaline proteases (1.3 ± 0.2 mU mg-1 protein compared to T18 (0.02 ± 0.001 g; 2.8 ± 0.4 mU mg-1 protein, respectively. With anticipation of brine shrimp, the commencing and end of larval transformation was observed earlier (at 24 and 34 DAH, respectively in comparison to those with the supply of Artemia sp. at 18 DAH (27 and 41 DAH, respectively. Thus, the Artemia sp. anticipation was beneficial during the larviculture of the barber goby, considering that larvae reached metamorphosis earlier.

  10. Epidemiology of a Daphnia-multiparasite system and its implications for the red queen.

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    Stuart K J R Auld

    Full Text Available The Red Queen hypothesis can explain the maintenance of host and parasite diversity. However, the Red Queen requires genetic specificity for infection risk (i.e., that infection depends on the exact combination of host and parasite genotypes and strongly virulent effects of infection on host fitness. A European crustacean (Daphnia magna--bacterium (Pasteuria ramosa system typifies such specificity and high virulence. We studied the North American host Daphnia dentifera and its natural parasite Pasteuria ramosa, and also found strong genetic specificity for infection success and high virulence. These results suggest that Pasteuria could promote Red Queen dynamics with D. dentifera populations as well. However, the Red Queen might be undermined in this system by selection from a more common yeast parasite (Metschnikowia bicuspidata. Resistance to the yeast did not correlate with resistance to Pasteuria among host genotypes, suggesting that selection by Metschnikowia should proceed relatively independently of selection by Pasteuria.

  11. Accumulation of dieldrin in an alga (Scenedesmus obliquus), Daphnia magna, and the guppy (Poecilia reticulata)

    Science.gov (United States)

    Reinert, Robert E.

    1972-01-01

    Scenedesmus obliquus, Daphnia magna, and Poecilia reticulata accumulated dieldrin directly from water; average concentration factors (concentration in organism, dry weight, divided by concentration in water) were 1282 for the alga, 13,954 for D. magna, and 49,307 (estimated) for the guppy. The amount accumulated by each species at equilibrium (after about 1.5, 3-4, and 18 days, respectively) was directly proportional to the concentration of dieldrin in the water. Daphnia magna and guppies accumulated more dieldrin from water than from food that had been exposed to similar concentrations in water. When guppies were fed equal daily rations of D. magna containing different concentrations of insecticide, the amounts of dieldrin accumulated by the fish were directly proportional to the concentration in D. magna; when two lots of guppies were fed different quantities of D. magna (10 and 20 organisms per day) containing identical concentrations of dieldrin, however, the amounts accumulated did not differ substantially.

  12. Toxicity of aqueous C70-gallic acid suspension in Daphnia magna.

    Science.gov (United States)

    Seda, Brandon C; Ke, Pu-Chun; Mount, Andrew S; Klaine, Stephen J

    2012-01-01

    The present study assessed the toxic effects of stable aqueous colloidal suspensions of gallic-acid-stabilized C(70) fullerene on Daphnia magna. The suspensions were stabilized through noncovalent surface modification with gallic acid. In addition to whole-organism responses, changes in antioxidative processes in D. magna were quantified. Acute toxicity was observed with 96LC50 for C(70) -gallic acid of 0.4 ± 0.1 mg/L C(70) . Daphnia magna fecundity was significantly reduced in 21-d bioassays at C(70) -gallic aqcid concentrations below quantifiable limits. Antioxidant enzyme activities of glutathione peroxidase and superoxide dismutase as well as lipid peroxidation suggested that exposed organisms experienced oxidative stress. Microscopic techniques used to determine cellular toxicity via apoptosis proved unsuccessful.

  13. Toxicity of Nanoscale CuO and ZnO to Daphnia magna

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-zhou; LU Guang-hua; XIA Jun; JIN Shao-ge

    2012-01-01

    The potential effects of nanoscale CuO(nCuO),nanoscale ZnO(nZnO)and their mixtures on Daphnia magna were investigated,including 48-h acute toxicity and 21-d chronic toxicity tests as well as a feeding experiment.The results of acute toxicity show that nCuO/nZnO mixture was the most toxic followed by nCuO and nZnO.The nanoparticles(NPs)inhibited both the growth and reproduction of Daphnia magna during the testing period.Concentration dependence was apparent in all the cases and the intrinsic rate of natural increase was confirmed to be a very sensitive parameter to NPs exposure.Binary mixture appeared to be more toxic than the corresponding individual exposures at most cases except for the feeding behavior.

  14. Titanium Dioxide Nanoparticles Increase Sensitivity in the Next Generation of the Water Flea Daphnia magna

    OpenAIRE

    Mirco Bundschuh; Frank Seitz; Rosenfeldt, Ricki R.; Ralf Schulz

    2012-01-01

    The nanoparticle industry is expected to become a trillion dollar business in the near future. Therefore, the unintentional introduction of nanoparticles into the environment is increasingly likely. However, currently applied risk-assessment practices require further adaptation to accommodate the intrinsic nature of engineered nanoparticles. Combining a chronic flow-through exposure system with subsequent acute toxicity tests for the standard test organism Daphnia magna, we found that juvenil...

  15. Ecology, Virulence, and Phylogeny of Blastulidium paedophthorum, a Widespread Brood Parasite of Daphnia spp.

    OpenAIRE

    Duffy, Meghan A.; James, Timothy Y.; Longworth, Alan

    2015-01-01

    Parasitism is now recognized as a major factor impacting the ecology and evolution of plankton, including Daphnia. Parasites that attack the developing embryos of daphniids, known as brood parasites, were first described in the early 1900s but have received relatively little study. Here, we link previous morphological descriptions of the oomycete brood parasite Blastulidium paedophthorum with information on its phylogenetic placement, ecology, and virulence. Based on the morphology and phylog...

  16. Response of Daphnia's antioxidant system to spatial heterogeneity in Cyanobacteria concentrations in a lowland reservoir.

    Directory of Open Access Journals (Sweden)

    Adrianna Wojtal-Frankiewicz

    Full Text Available Many species and clones of Daphnia inhabit ecosystems with permanent algal blooms, and they can develop tolerance to cyanobacterial toxins. In the current study, we examined the spatial differences in the response of Daphnia longispina to the toxic Microcystis aeruginosa in a lowland eutrophic dam reservoir between June (before blooms and September (during blooms. The reservoir showed a distinct spatial pattern in cyanobacteria abundance resulting from the wind direction: the station closest to the dam was characterised by persistently high Microcystis biomass, whereas the upstream stations had a significantly lower biomass of Microcystis. Microcystin concentrations were closely correlated with the cyanobacteria abundance (r = 0.93. The density of daphniids did not differ among the stations. The main objective of this study was to investigate how the distribution of toxic Microcystis blooms affects the antioxidant system of Daphnia. We examined catalase (CAT activity, the level of the low molecular weight antioxidant glutathione (GSH, glutathione S-transferase (GST activity and oxidative stress parameters, such as lipid peroxidation (LPO. We found that the higher the abundance (and toxicity of the cyanobacteria, the lower the values of the antioxidant parameters. The CAT activity and LPO level were always significantly lower at the station with the highest M. aeruginosa biomass, which indicated the low oxidative stress of D. longispina at the site with the potentially high toxic thread. However, the low concentration of GSH and the highest activity of GST indicated the occurrence of detoxification processes at this site. These results demonstrate that daphniids that have coexisted with a high biomass of toxic cyanobacteria have effective mechanisms that protect them against the toxic effects of microcystins. We also conclude that Daphnia's resistance capacity to Microcystis toxins may differ within an ecosystem, depending on the bloom

  17. Hormetic response of cholinesterase from Daphnia magna in chronic exposure to triazophos and chlorpyrifos

    Institute of Scientific and Technical Information of China (English)

    Shaonan Li; Yajun Tan

    2011-01-01

    In vivo activity of cholinesterase (ChE) in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 μg/L and 0.01 to 2.00 μg/L, respectively.For exposure to triazophos, ChE was induced up to 176.5% at 1.5 μg/L and day 10 when measured by acetylthiocholine (ATCh), whereas it was induced up to 174.2% at 0.5 μg/L and day 10 when measured by butyrylthiocholine (BTCh).For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectivly, with both maximal inductions detected at 0.l μg/L and day 8.Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days.Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition.In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture.This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population.

  18. Single nucleotide polymorphism discovery from expressed sequence tags in the waterflea Daphnia magna

    Directory of Open Access Journals (Sweden)

    Souche Erika L

    2011-06-01

    Full Text Available Abstract Background Daphnia (Crustacea: Cladocera plays a central role in standing aquatic ecosystems, has a well known ecology and is widely used in population studies and environmental risk assessments. Daphnia magna is, especially in Europe, intensively used to study stress responses of natural populations to pollutants, climate change, and antagonistic interactions with predators and parasites, which have all been demonstrated to induce micro-evolutionary and adaptive responses. Although its ecology and evolutionary biology is intensively studied, little is known on the functional genomics underpinning of phenotypic responses to environmental stressors. The aim of the present study was to find genes expressed in presence of environmental stressors, and target such genes for single nucleotide polymorphic (SNP marker development. Results We developed three expressed sequence tag (EST libraries using clonal lineages of D. magna exposed to ecological stressors, namely fish predation, parasite infection and pesticide exposure. We used these newly developed ESTs and other Daphnia ESTs retrieved from NCBI GeneBank to mine for SNP markers targeting synonymous as well as non synonymous genetic variation. We validate the developed SNPs in six natural populations of D. magna distributed at regional scale. Conclusions A large proportion (47% of the produced ESTs are Daphnia lineage specific genes, which are potentially involved in responses to environmental stress rather than to general cellular functions and metabolic activities, or reflect the arthropod's aquatic lifestyle. The characterization of genes expressed under stress and the validation of their SNPs for population genetic study is important for identifying ecologically responsive genes in D. magna.

  19. Hormetic response of cholinesterase from Daphnia magna in chronic exposure to triazophos and chlorpyrifos.

    Science.gov (United States)

    Li, Shaonan; Tan, Yajun

    2011-01-01

    In vivo activity of cholinesterase (ChE) in Daphnia magna was measured at different time points during 21-day exposure to triazophos and chlorpyrifos ranging from 0.05 to 2.50 microg/L and 0.01 to 2.00 microg/L, respectively. For exposure to triazophos, ChE was induced up to 176.5% at 1.5 microg/L and day 10 when measured by acetylthiocholine (ATCh), whereas it was induced up to 174.2% at 0.5 microg/L and day 10 when measured by butyrylthiocholine (BTCh). For exposure to chlorpyrifos, ChE was induced up to 134.0% and 160.5% when measured by ATCh and BTCh, respectively, with both maximal inductions detected at 0.1 microg/L and day 8. Obvious induction in terms of ChE activity was also detected in daphnia removed from exposures 24 hr after their birth and kept in a recovery culture for 21 days. Results indicated that the enzyme displayed symptoms of hormesis, a characteristic featured by conversion from low-dose stimulation to high-dose inhibition. In spite of that, no promotion in terms of reproduction rate and body size was detected at any tested concentrations regardless of whether the daphnia were collected at end of the 21-day exposure or at end of a 21-day recovery culture. This suggested that induction of ChE caused by anticholinesterases had nothing to do with the prosperity of the daphnia population. PMID:21790060

  20. Climate Effects on High Latitude Daphnia via Food Quality and Thresholds.

    Directory of Open Access Journals (Sweden)

    Anna Przytulska

    Full Text Available Climate change is proceeding rapidly at high northern latitudes and may have a variety of direct and indirect effects on aquatic food webs. One predicted effect is the potential shift in phytoplankton community structure towards increased cyanobacterial abundance. Given that cyanobacteria are known to be a nutritionally poor food source, we hypothesized that such a shift would reduce the efficiency of feeding and growth of northern zooplankton. To test this hypothesis, we first isolated a clone of Daphnia pulex from a permafrost thaw pond in subarctic Québec, and confirmed that it was triploid but otherwise genetically similar to a diploid, reference clone of the same species isolated from a freshwater pond in southern Québec. We used a controlled flow-through system to investigate the direct effect of temperature and indirect effect of subarctic picocyanobacteria (Synechococcus on threshold food concentrations and growth rate of the high latitude clone. We also compared the direct effect of temperature on both Daphnia clones feeding on eukaryotic picoplankton (Nannochloropsis. The high latitude clone had a significantly lower food threshold for growth than the temperate clone at both 18 and 26°C, implying adaptation to lower food availability even under warmer conditions. Polyunsaturated fatty acids were present in the picoeukaryote but not the cyanobacterium, confirming the large difference in food quality. The food threshold for growth of the high latitude Daphnia was 3.7 (18°C to 4.2 (26°C times higher when fed Synechococcus versus Nannochloropsis, and there was also a significant negative effect of increased temperature and cyanobacterial food on zooplankton fatty acid content and composition. The combined effect of temperature and food quality on the performance of the high latitude Daphnia was greater than their effects added separately, further indicating the potentially strong indirect effects of climate warming on aquatic food web

  1. Daphnia magna shows reduced infection upon secondary exposure to a pathogen

    OpenAIRE

    McTaggart, Seanna J.; Wilson, Philip J.; Little, Tom J.

    2012-01-01

    Previous pathogen exposure is an important predictor of the probability of becoming infected. This is deeply understood for vertebrate hosts, and increasingly so for invertebrate hosts. Here, we test if an initial pathogen exposure changes the infection outcome to a secondary pathogen exposure in the natural host–pathogen system Daphnia magna and Pasteuria ramosa. Hosts were initially exposed to an infective pathogen strain, a non-infective pathogen strain or a control. The same hosts underwe...

  2. Transcriptomic, biochemical and individual markers in transplanted Daphnia magna to characterize impacts in the field

    OpenAIRE

    Campos, Bruno; Malik, Amrita; Tauler, Romà; Barata, Carlos

    2014-01-01

    Daphnia magna individuals were transplanted across 12 sites from three Spanish river basins (Llobregat, Ebro, Jucar) showing different sources of pollution. Gene transcription, feeding and biochemical responses in the field were assessed and compared with those obtained in re-constituted water treatments spiked with organic eluates obtained from water samples collected at the same locations and sampling periods. Up to 166 trace contaminants were detected in water and classified by their mode ...

  3. Climate Effects on High Latitude Daphnia via Food Quality and Thresholds

    Science.gov (United States)

    Przytulska, Anna; Bartosiewicz, Maciej; Rautio, Milla; Dufresne, France; Vincent, Warwick F.

    2015-01-01

    Climate change is proceeding rapidly at high northern latitudes and may have a variety of direct and indirect effects on aquatic food webs. One predicted effect is the potential shift in phytoplankton community structure towards increased cyanobacterial abundance. Given that cyanobacteria are known to be a nutritionally poor food source, we hypothesized that such a shift would reduce the efficiency of feeding and growth of northern zooplankton. To test this hypothesis, we first isolated a clone of Daphnia pulex from a permafrost thaw pond in subarctic Québec, and confirmed that it was triploid but otherwise genetically similar to a diploid, reference clone of the same species isolated from a freshwater pond in southern Québec. We used a controlled flow-through system to investigate the direct effect of temperature and indirect effect of subarctic picocyanobacteria (Synechococcus) on threshold food concentrations and growth rate of the high latitude clone. We also compared the direct effect of temperature on both Daphnia clones feeding on eukaryotic picoplankton (Nannochloropsis). The high latitude clone had a significantly lower food threshold for growth than the temperate clone at both 18 and 26°C, implying adaptation to lower food availability even under warmer conditions. Polyunsaturated fatty acids were present in the picoeukaryote but not the cyanobacterium, confirming the large difference in food quality. The food threshold for growth of the high latitude Daphnia was 3.7 (18°C) to 4.2 (26°C) times higher when fed Synechococcus versus Nannochloropsis, and there was also a significant negative effect of increased temperature and cyanobacterial food on zooplankton fatty acid content and composition. The combined effect of temperature and food quality on the performance of the high latitude Daphnia was greater than their effects added separately, further indicating the potentially strong indirect effects of climate warming on aquatic food web processes. PMID

  4. Variation in copper effects on kairomone-mediated responses in Daphnia pulicaria.

    Science.gov (United States)

    DeMille, C M; Arnott, S E; Pyle, G G

    2016-04-01

    Chemical signals play an integral role in many predator-prey relationships but their effectiveness can be altered by environmental conditions. Prey species can detect predator kairomones, which induce anti-predator defenses. An example of this predator-prey relationship exists between Daphnia spp. and Chaoborus spp.; however, when living in water contaminated with low concentrations of copper (Cu) Daphnia can fail to respond to Chaoborus kairomone and, in turn, become more susceptible to predation. This has implications for Daphnia living in regions with Cu contamination, such as areas where mining activity has resulted in increased levels of metals in the surrounding lakes. We examined kairomone-mediated responses of multiple Daphnia pulicaria clones obtained from 8 lakes in Ontario, Canada, in the absence and presence of environmentally-relevant Cu concentrations. Life history traits and morphological anti-predator defenses were assessed using neonates collected from mothers that were exposed to kairomone and Cu treatments. We found that kairomone-mediated responses and Cu-tolerance varied among D. pulicaria clones. Clones exposed to kairomone, in the absence of Cu additions, had diverse responses, including larger neonates, delayed reproduction, or altered brood size relative to no-kairomone controls. These kairomone-induced responses act as antipredator defense strategies against Chaoborus by preventing predation or stabilizing population growth. When exposed to Cu, two clones were able to respond to kairomone, while four clones no longer induced a response to kairomone. This variation in non-lethal effects of Cu on aquatic organisms suggests that toxicity tests should incorporate multiple genotypes and include predator-prey interactions.

  5. An evaluation of biotic ligand models predicting acute copper toxicity to Daphnia magna in wastewater effluent

    OpenAIRE

    Constantino, C.; Scrimshaw, M; Comber, S; Churchley, J.

    2011-01-01

    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 SETAC. The toxicity of Cu to Daphnia magna was investigated in a series of 48-h immobilization assays in effluents from four wastewater treatment works. The assay results were compared with median effective concentration (EC50) forecasts produced by the HydroQual biotic ligand model (BLM), the refined D. magna BLM, and a modified BLM that was constructed by integrating t...

  6. A novel protocol for assessing aquatic pollution, based on the feeding inhibition of Daphnia magna

    OpenAIRE

    Kovács A.; Abdel-Hameid N.-A.; Ács A.; Á. Ferincz; Kováts N.

    2012-01-01

    In this study, sensitivity of a novel acute bioassay based on the feeding activity of Daphnia magna was assessed, using 2 and 4 h of exposure. For calibration purposes, results were compared with those of the standard immobility test as described by the ISO 6341:1996 standard. Using potassium dichromate as the reference chemical, after 4 h of exposure the proposed protocol showed similar sensitivity in comparison with the stan...

  7. Acute toxicity bioassays using Daphnia magna Straus (Cladocera, Daphniidae) maintained in a modified culture medium

    OpenAIRE

    Mónica Núñez; Jasmin Hurtado

    2013-01-01

    Daphnia magna is a test organism used in ecotoxicological assays of freshwater; however, traditional culture systems for this organism could result expensive, for that the aim of this research was to developed a new economic culture medium. With this purpose, 10 strains of D. magna were isolated, their population development was evaluated by total count of organisms and pregnant females using 3 different culture media: (A) alfalfa juice, (B) solved yeast and (C) a mixture of alfalfa juice plu...

  8. Toxicity Assessment of Perchloroethylene and Intermediate Products after Advanced Oxidation Process by Daphnia Magna Bioassay

    OpenAIRE

    Mahdi Kargar; Kazem Naddafi; Ramin Nabizadeh

    2014-01-01

    Background and objective: Perchloroethylene is a chlorinated hydrocarbon used as a solvent in many industries and services activities such as dry cleaning and auto industry as degreasing. We carried out a bioassay using Daphnia Magna in order to determine the ecological effects of wastewater treatment through applying advanced oxidation processes (ultrasonic, ultraviolet irradiation and hydrogen peroxide processes) for removal of perchloroethylene. Materials and Methods: Due to the sensiti...

  9. Development and evaluation of new behavioral indexes for a biological early warning system using Daphnia magna

    OpenAIRE

    T. Y. Jeong; J. Jeon; Kim, S. D.

    2014-01-01

    New behavioral indexes including combined index (CI), distribution index (DI), toxic index (TI), and altitude index (AI) for a biological early warning system (BEWS) were developed and evaluated using Daphnia magna in this study. The sensitivity and stability of each index were compared to evaluate the performance of the indexes through a real-time exposure test with a synthetic copper solution. The applicability of the CI to the field sample was evaluated through an effluen...

  10. Food mediated life history strategies in Daphnia magna: their relevance to ecotoxicological evaluations.

    OpenAIRE

    Enserink, E.L.

    1995-01-01

    The waterflea Daphnia magna is a widely used test organism in ecotoxicological studies. Acute and chronic laboratory tests yield basic information for the development of water quality standards, assessment of potential hazards of (new) chemicals, waste water licences and sanitation measures for contaminated sediments. Environmental risk assessment also includes extrapolation from laboratory to field, for which theoretical models are applied. Reliable results can only be obtained if:toxicity t...

  11. Competitive outcome of Daphnia-Simocephalus experimental microcosms: salinity versus priority effects.

    Directory of Open Access Journals (Sweden)

    Cláudia Loureiro

    Full Text Available Competition is a major driving force in freshwaters, especially given the cyclic nature and dynamics of pelagic food webs. Competition is especially important in the initial species assortment during colonization and re-colonization events, which depends strongly on the environmental context. Subtle changes, such as saline intrusion, may disrupt competitive relationships and, thus, influence community composition. Bearing this in mind, our objective was to assess whether low salinity levels (using NaCl as a proxy alter the competitive outcome (measured as the rate of population biomass increase of Daphnia-Simocephalus experimental microcosms, taking into account interactions with priority effects (sequential species arrival order. With this approach, we aimed to experimentally demonstrate a putative mechanism of differential species sorting in brackish environments or in freshwaters facing secondary salinization. Experiments considered three salinity levels, regarding NaCl added (0.00, 0.75 and 1.50 g L(-1, crossed with three competition scenarios (no priority, priority of Daphnia over Simocephalus, and vice-versa. At lower NaCl concentrations (0.00 and 0.75 g L(-1, Daphnia was a significantly superior competitor, irrespective of the species inoculation order, suggesting negligible priority effects. However, the strong decrease in Daphnia population growth at 1.50 g L(-1 alleviated the competitive pressure on Simocephalus, causing an inversion of the competitive outcome in favour of Simocephalus. The intensity of this inversion depended on the competition scenario. This salinity-mediated disruption of the competitive outcome demonstrates that subtle environmental changes produce indirect effects in key ecological mechanisms, thus altering community composition, which may lead to serious implications in terms of ecosystem functioning (e.g. lake regime shifts due to reduced grazing and biodiversity.

  12. Parasite variation and the evolution of virulence in a Daphnia-microparasite system

    OpenAIRE

    Little, T J; Chadwick, W.; Watt, K.

    2008-01-01

    Understanding genetic relationships amongst the life-history traits of parasites is crucial for testing hypotheses on the evolution of virulence. This study therefore examined variation between parasite isolates (the bacterium Pasteuria ramosa) from the crustacean Daphnia magna. From a single wild-caught infected host we obtained 2 P. ramosa isolates that differed substantially in the mortality they caused. Surprisingly, the isolate causing higher early mortality was, on average, less success...

  13. Toxicity to Daphnia pulex and QSAR predictions for polycyclic hydrocarbons representative of Great Lakes contaminants

    Science.gov (United States)

    Passino-Reader, D.R.; Hickey, J.P.; Ogilvie, L.M.

    1997-01-01

    The objectives of this study were (1) to determine the toxicity of several types of polycyclic hydrocarbons characteristic of Great Lakes samples to Daphnia pulex, a Great Lakes zooplankter, (2) to investigate the influence of different structural characteristics on toxicity, and (3) to determine the linear solvation energy relationship (LSER) parameters and model that describe these compounds. These results will be related to comparative toxicity of other Great Lakes environmental compounds and to their application in site specific risk assessment.

  14. DNA transposons and the role of recombination in mutation accumulation in Daphnia pulex

    OpenAIRE

    Schaack, Sarah; Choi, Eunjin; Lynch, Michael; Pritham, Ellen J

    2010-01-01

    Background We identify DNA transposons from the completed draft genome sequence of Daphnia pulex, a cyclically parthenogenetic, aquatic microcrustacean of the class Branchiopoda. In addition, we experimentally quantify the abundance of six DNA transposon families in mutation-accumulation lines in which sex is either promoted or prohibited in order to better understand the role of recombination in transposon proliferation. Results We identified 55 families belonging to 10 of the known superfam...

  15. Systems biology meets stress ecology: linking molecular and organismal stress responses in Daphnia magna

    OpenAIRE

    Heckmann, L. H.; Sibly, R.M; Connon, R.; Hooper, H. L.; Hutchinson, T H; Maund, S.J.; Hill, C. J.; Bouetard, A.; Callaghan, A

    2008-01-01

    Background: Ibuprofen and other nonsteroidal anti-inflammatory drugs have been designed to interrupt eicosanoid metabolism in mammals, but little is known of how they affect nontarget organisms. Here we report a systems biology study that simultaneously describes the transcriptomic and phenotypic stress responses of the model crustacean Daphnia magna after exposure to ibuprofen. Results: Our findings reveal intriguing similarities in the mode of action of ibuprofen between vertebrates and inv...

  16. A rapid bioassay for detecting saxitoxins using a Daphnia acute toxicity test.

    Science.gov (United States)

    Ferrão-Filho, Aloysio da S; Soares, Maria Carolina S; de Magalhães, Valéria Freitas; Azevedo, Sandra M F O

    2010-06-01

    Bioassays using Daphnia pulex and Moina micrura were designed to detect cyanobacterial neurotoxins in raw water samples. Phytoplankton and cyanotoxins from seston were analyzed during 15 months in a eutrophic reservoir. Effective time to immobilize 50% of the exposed individuals (ET50) was adopted as the endpoint. Paralysis of swimming movements was observed between approximately 0.5-3 h of exposure to lake water containing toxic cyanobacteria, followed by an almost complete recovery of the swimming activity within 24 h after being placed in control water. The same effects were observed in bioassays with a saxitoxin-producer strain of Cylindrospermopsis raciborskii isolated from the reservoir. Regression analysis showed significant relationships between ET50 vs. cell density, biomass and saxitoxins content, suggesting that the paralysis of Daphnia in lake water samples was caused by saxitoxins found in C. raciborskii. Daphnia bioassay was found to be a sensitive method for detecting fast-acting neurotoxins in natural samples, with important advantages over mouse bioassays. PMID:20359802

  17. The complete mitochondrial genome of the Chinese Daphnia pulex (Cladocera, Daphniidae

    Directory of Open Access Journals (Sweden)

    Xuexia Geng

    2016-09-01

    Full Text Available Daphnia pulex has played an important role in fresh-water ecosystems. In this study, the complete mitochondrial genome of Daphnia pulex from Chaohu, China was sequenced for the first time. It was accomplished using long-PCR methods and a primer-walking sequencing strategy with genus-specific primers. The mitogenome was found to be 15,306 bp in length. It contained 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a typical control region. This research revealed an overall A+T content of 64.50%. All of the 22 typical animal tRNA genes had a classical clover-leaf structure except for trnS1, in which its DHU arm simply formed a loop. The lengths of small and large rRNA were 744 bp and 1,313 bp, respectively. The A+T-rich region was 723 bp in length, which is longer than that from the North American species (689 bp. In terms of structure and composition, many similarities were found between the Chinese and North American Daphnia pulex.

  18. The chemoreceptor genes of the waterflea Daphnia pulex: many Grs but no Ors

    Directory of Open Access Journals (Sweden)

    Robertson Hugh M

    2009-04-01

    Full Text Available Abstract Background Chemoreception is vitally important for all animals, yet little is known about the genetics of chemoreception in aquatic organisms. The keystone species Daphnia pulex, a well known crustacean, is the first aquatic invertebrate to have its genome sequenced. This has allowed us the initial investigation of chemoreceptor genes in an aquatic invertebrate, and to begin the study of chemoreceptor evolution across the arthropod phylum. Results We describe 58 Grs (gustatory receptors, belonging to the insect chemoreceptor superfamily, which were identified bioinformatically in the draft genome of the crustacean waterflea Daphnia pulex. No genes encoding proteins similar to the insect odorant receptors (Ors were identified. These 58 Grs form 3 distinctive subfamilies of 37, 12, and 5 genes, as well as a highly divergent singleton (Gr58. In addition, Grs55–57 share distinctive amino acid motifs and cluster with the sugar receptors of insects, and may illuminate the origin of this distinctive subfamily. ESTs, tiling array, and PCR amplification results support 34 predicted gene models, and preliminary expression data comparing the sexes indicates potential female-biased expression for some genes. Conclusion This repertoire of 58 chemoreceptors presumably mediates the many chemoperception abilities of waterfleas. While it is always possible that the entire Or gene lineage was lost at some point in the history of Daphnia pulex, we think it more likely that the insect Or lineage is indeed a relatively recently expanded gene lineage concomitant with the evolution of terrestriality in the insects or their hexapod ancestors.

  19. NUTRITIONAL VALUE OF PLANKTONIC CLADOCERAN DAPHNIA MAGNA FOR COMMON CARP (Cyprinus carpio FRY FEEDING

    Directory of Open Access Journals (Sweden)

    Ivan Bogut

    2010-01-01

    Full Text Available Chemical composition and contents of amino acids and fatty acids in the planktonic cladoceran Daphnia magna were investigated, aiming to evaluate its value for feeding of young carp. Crude protein, crude fat, crude fibre, ash and moisture contents were analyzed according to standard laboratory procedures. Amino acids content was determined by LKB 4101 automatic analyzer and that of fatty acids by Chrompack CP 9000 chromatograph, using a flame ionizing detector. Protein contents amounted to 1.18 and 39.24% of fresh and dry mass, respectively. These amounts of proteins completely meet nutritional requirements both of carp fry and its older categories and other omnivorous fishes. Raw fat and fibre contents in dry weight were 4.98 and 4.32%, respectively, which is suitable for the commercial carp breeding. Methionine and phenylalanine are partially in deficit, whereas other essential amino acids identified in dry mass of Daphnia magna were present in amounts adequate for all carp categories. The proportions of saturated and unsaturated fatty acids in lipids of Daphnia magna were 18.70 and 66.20%, respectively. Among the unsaturated fatty acids, the omega–3 group was present with 27.30%. The omega–3 : omega–6 fatty acids ratio was 5.68:1, which fully meets the carp nutrition requirements.

  20. Effects of bifenthrin on Daphnia magna during chronic toxicity test and the recovery test.

    Science.gov (United States)

    Ye, Wei-Hong; Wen, Yue-Zhong; Liu, Wei-Ping; Wang, Zhong-Qiang

    2004-01-01

    The acute and chronic toxic effects of bifenthrin on Daphnia magna were studied. The results showed that 24 h-EC50, 48 h-LC50 and 96 h-LC50 of bifenthrin on D. magna were 3.24, 12.40 and 1.40 microg/L respectively. And the LOEC and NOEC of bifenthrin were 0.02 and 0.004 microg/L respectively. The recovery test of bifenthrin on Daphnia magna was presented. Daphnia magna (F0 generation) were exposed during 21 d to different bifenthrin concentrations. Offspring (animals from the first and third brood: F1 (1st) and F1 (3rd), respectively) were transferred to a free pesticide medium during a 21 d recovery period. In this recovery study, survival, growth, reproduction (mean total young per female, onset of reproduction and number broods per female) and the intrinsic rate of natural increase (r) were assessed as parameters. Reproduction such as number of young per female as well as length was still reduced in F1 (1st) generation daphnids from parentals (F0) exposed to the bifenthrin. However F, (3rd) individuals from parentals exposed to pesticide concentrations were able to restore reproduction when a recovery period of 21 d was allowed, but the length of F, (3rd) from parentals exposed to the 0.5 and 0.75 microg/L bifenthrin concentration was still significantly effected (P < 0.05). PMID:15559825

  1. Maternal effects of inducible tolerance against the toxic cyanobacterium Microcystis aeruginosa in the grazer Daphnia carinata

    International Nuclear Information System (INIS)

    Cyanobacterial blooms are becoming potent agents of natural selection in aquatic ecosystems because of their high production of some toxins and increased frequency in recent decades with eutrophication and climate change. Maternal exposure to the toxic Microcystis aeruginosa significantly increased the intrinsic rates of population increase, average life span, and net reproductive rates of a clone of the planktonic grazer Daphnia carinata in an offspring environment where cyanobacteria were present, but not for two additional clones. Offspring from mothers exposed to M. aeruginosa had lower intrinsic rates of population increase, average life span, and net reproductive rates than individuals from unexposed mothers when fed exclusively a green alga. These results suggest that benefits, costs, and clonal variations of maternal effects of inducible tolerance should be considered when trying to understand ecological consequences of cyanobacterial blooms since they can shape the trophic interactions between cyanobacteria and daphnids. -- Highlights: •Maternal exposure to Microcystis aeruginosa significantly increased the offspring tolerance in a Daphnia carinata clone. •Another two clones, however, failed to response to maternal exposure. •Offspring from exposed mothers had lower fitness when fed exclusively a green alga. -- Capsule: Maternal exposure to the toxic Microcystis aeruginosa increased offspring fitness in one of three Daphnia carinata clones and carried a cost

  2. Toxicological Monitoring of a Water Supply Reservoir by Acute Assays with Daphnia Pulex

    Directory of Open Access Journals (Sweden)

    Carlos Daniel Ramos Contreras

    2015-05-01

    Full Text Available Daphnia pulex assays (48 hours were performed to determine acute toxicity of water samples from La Fe reservoir, Antioquia, Colombia. Eight sampling campaigns were done between March 2010 and June 2012, a period that included rainfall episodes. Samples were taken from the water column at three depths and from lotic areas. Physicochemical properties such as pH, electrical conductivity, temperature and dissolved oxygen were measured both in field and laboratory, and concentrations of dissolved iron (Fe, manganese (Mn, aluminium (Al, lead (Pb, cadmium (Cd and chromium (Cr were assessed. The overall results for the physicochemical properties remained at expected levels for natural waters with slightly higher conductivities in samples collected from bottom and some tributaries. The results of the toxicity tests showed significant mortalities in only 28% of assays. A higher mortality of Daphnia pulex was detected for tests performed during periods of higher precipitation (August 2010, February and July 2011 mainly for samples taken near the confluence of natural tributaries. No significant relationships between physicochemical variables and mortality of Daphnia pulex were found.DOI: http://dx.doi.org/10.5755/j01.erem.71.1.9788

  3. Mating behavior of Daphnia: impacts of predation risk, food quantity, and reproductive phase of females.

    Directory of Open Access Journals (Sweden)

    Geung-Hwan La

    Full Text Available High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic Daphnia. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of Daphnia obtusa males including contact frequency and duration using video analysis. Mating-related behavior involved male-female contact (mating as well as male-male contact (fighting. Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in Daphnia is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies.

  4. Mimicking Daphnia magna bioassay performance by an electronic tongue for urban water quality control

    Energy Technology Data Exchange (ETDEWEB)

    Kirsanov, Dmitry, E-mail: d.kirsanov@gmail.com [Laboratory of Chemical Sensors, St. Petersburg State University, St. Petersburg (Russian Federation); Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation); Legin, Evgeny [Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation); Sensor Systems LLC, St. Petersburg (Russian Federation); Zagrebin, Anatoly; Ignatieva, Natalia; Rybakin, Vladimir [Institute of Limnology, Russian Academy of Sciences, St. Petersburg (Russian Federation); Legin, Andrey [Laboratory of Chemical Sensors, St. Petersburg State University, St. Petersburg (Russian Federation); Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation)

    2014-05-01

    Highlights: • -Daphnia magna bioassay can be simulated with multisensor system. • Urban water toxicity can be predicted from potentiometric ET data. • Independent test set validation confirms statistical significance of the results. - Abstract: Toxicity is one of the key parameters of water quality in environmental monitoring. However, being evaluated as a response of living beings (as their mobility, fertility, death rate, etc.) to water quality, toxicity can only be assessed with the help of these living beings. This imposes certain restrictions on toxicity bioassay as an analytical method: biotest organisms must be properly bred, fed and kept under strictly regulated conditions and duration of tests can be quite long (up to several days), thus making the whole procedure the prerogative of the limited number of highly specialized laboratories. This report describes an original application of potentiometric multisensor system (electronic tongue) when the set of electrochemical sensors was calibrated against Daphnia magna death rate in order to perform toxicity assessment of urban waters without immediate involvement of living creatures. PRM (partial robust M) and PLS (projections on latent structures) regression models based on the data from this multisensor system allowed for prediction of toxicity of unknown water samples in terms of biotests but in the fast and simple instrumental way. Typical errors of water toxicity predictions were below 20% in terms of Daphnia death rate which can be considered as a good result taking into account the complexity of the task.

  5. The complete mitochondrial genome of the Chinese Daphnia pulex (Cladocera, Daphniidae).

    Science.gov (United States)

    Geng, Xuexia; Cheng, Ruixue; Xiang, Tianyi; Deng, Bin; Wang, Yaling; Deng, Daogui; Zhang, Haijun

    2016-01-01

    Daphnia pulex has played an important role in fresh-water ecosystems. In this study, the complete mitochondrial genome of Daphnia pulex from Chaohu, China was sequenced for the first time. It was accomplished using long-PCR methods and a primer-walking sequencing strategy with genus-specific primers. The mitogenome was found to be 15,306 bp in length. It contained 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a typical control region. This research revealed an overall A+T content of 64.50%. All of the 22 typical animal tRNA genes had a classical clover-leaf structure except for trnS1, in which its DHU arm simply formed a loop. The lengths of small and large rRNA were 744 bp and 1,313 bp, respectively. The A+T-rich region was 723 bp in length, which is longer than that from the North American species (689 bp). In terms of structure and composition, many similarities were found between the Chinese and North American Daphnia pulex. PMID:27667940

  6. Daphnia fed algal food grown at elevated temperature have reduced fitness

    Directory of Open Access Journals (Sweden)

    Anna B. Sikora

    2014-05-01

    Full Text Available Lake water temperature is negatively correlated with fatty acids content and P:C ratio in green algae. Hence, elevated temperature may indirectly reduce the fitness of Daphnia due to induced decrease in algal food quality. The aim of this study was to test the hypotheses that quality of algal food decreases with increasing temperature of its culture and that large-bodied Daphnia are more vulnerable to the temperature-related deterioration of algal food quality than small-bodied ones. Laboratory life-table experiments were performed at 20°C with large-bodied D. pulicaria and small-bodied D. cucullata fed with the green alga Scenedesmus obliquus, that had been grown at temperatures of 16, 24 or 32°C. The somatic growth rates of both species decreased significantly with increasing algal culture temperature and this effect was more pronounced in D. pulicaria than in D. cucullata. In the former species, age at first reproduction significantly increased and clutch size significantly decreased with increasing temperature of algae growth, while no significant changes in these two parameters were observed in the latter species. The proportion of egg-bearing females decreased with increasing algal culture temperature in both species. The results of this study support the notion that the quality of algal food decreases with increasing water temperature and also suggest that small-bodied Daphnia species might be less vulnerable to temperature-related decreases in algal food quality than large-bodied ones.

  7. Uptake, retention and internalization of quantum dots in Daphnia is influenced by particle surface functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Feswick, A., E-mail: afeswick@yahoo.ca [Center for Environmental and Human Toxicology, University of Florida, PO Box 110885, Gainesville, FL 32611 (United States); Canadian Rivers Institute, University of New Brunswick, PO Box 5050, Saint John NB, CA (United States); Griffitt, R.J., E-mail: joe.griffitt@usm.edu [Department of Coastal Sciences, University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 (United States); Siebein, K., E-mail: kerry.siebein@nist.gov [Major Analytical Instrumentation Center, University of Florida, PO Box 116400, Gainesville, FL 32611 (United States); Barber, D.S., E-mail: barberd@vetmed.ufl.edu [Center for Environmental and Human Toxicology, University of Florida, PO Box 110885, Gainesville, FL 32611 (United States)

    2013-04-15

    Highlights: ► Daphnia underwent a waterborne exposure of PEG, NH{sub 2} and COOH functionalized quantum dot nanoparticles. ► There was preferential retention of COOH nanoparticles. ► TEM demonstrated that NH{sub 2} and COOH nanoparticles were internalized in cells adjacent to the GI tract. ► This cellular internalization was confirmed using energy dispersive spectroscopy. -- Abstract: Nanomaterials are a diverse group of compounds whose inevitable release into the environment warrants study of the fundamental processes that govern the ingestion, uptake and accumulation in aquatic organisms. Nanomaterials have the ability to transfer to higher trophic levels in aquatic ecosystems, and recent evidence suggests that the surface chemistry of both the nanoparticle and biological membrane can influence uptake kinetics. Therefore, our study investigates the effect of surface functionalization on uptake, internalization and depuration in Daphnia spp. Uncharged (polyethylene glycol; PEG), positively charged (amino-terminated: NH{sub 2}) and negatively charged (carboxyl-modified; COOH) cadmium selenide/zinc sulfide quantum dots were used to monitor ingestion, uptake and depuration of nanometals in Daphnia magna and Ceriodaphnia dubia over 24 h of exposure. These studies demonstrated that particles with higher negative charge (COOH quantum dots) were taken up to a greater extent by Daphnia (259.17 ± 17.70 RFU/20 Daphnia) than either the NH{sub 2} (150.01 ± 18.91) or PEG quantum dots (95.17 ± 9.78), however this is likely related to the functional groups attached to the nanoparticles as there were no real differences in zeta potential. Whole body fluorescence associates well with fluorescent microscopic images obtained at the 24 h timepoint. Confocal and electron microscopic analysis clearly demonstrated that all three types of quantum dots could cross the intestinal epithelial barrier and be translocated to other cells. Upon cessation of exposure, elimination of

  8. Aquatic toxicity of cartap and cypermethrin to different life stages of Daphnia magna and Oryzias latipes.

    Science.gov (United States)

    Kim, Younghee; Jung, Jinyong; Oh, Sorin; Choi, Kyungho

    2008-01-01

    Cartap and cypermethrin, which are among the most widely used pesticides in many countries, are considered safe because of their low mammalian toxicity and their low persistence in the environment. However, recent findings of endocrine-disrupting effects and developmental neurotoxicity have raised concerns about the potential ecological impacts of these pesticides. We evaluated the aquatic toxicity of cartap [S,S'-(2-dimethylaminotrimethylene) bis(thiocarbamate), unspecified hydrochloride] and cypermethrin [(RS)-alpha-cyano-3-phenoxybenzyl-(1RS,3RS,1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate], both individually and combined, on different life stages of the freshwater cladoceran Daphnia magna and a freshwater teleost, Japanese medaka (Oryzias latipes). The 96-hr Daphnia median effective concentrations (EC50s) for cartap and cypermethrin were 91.0 microg/L and 0.00061 microg/L, respectively. Rapid recovery of Daphnia was observed after short-term pulsed exposure to cartap and cypermethrin; there were no adverse effects on reproduction or survival 20 d after a 24 hr exposure to cartap up to 1240 microg/L and cypermethrin up to 1.9 microg/L. Chronic continuous exposure (for 21 d) of 7-d-old Daphnia to cypermethrin significantly reduced the intrinsic population growth rate in a concentration-dependent manner. However, because the intrinsic population growth rates were all above zero, populations did not decrease even at the highest experimental concentration of 200 ng/L. Exposure of Daphnia neonates (< 24 hr old) to cypermethrin for 21 d caused significant, sub-lethal reproduction-related problems, such as increased time to first brood, reduced brood size, and reduced total brood number, at 0.0002, 0.002, and 0.2 ng/L cypermethrin, but the intrinsic population growth rate was not significantly affected. Oryzias latipes was relatively more resistant to both pesticides. In particular, embryos appeared to be more resistant than juveniles or adults

  9. Aquatic toxicity of cartap and cypermethrin to different life stages of Daphnia magna and Oryzias latipes.

    Science.gov (United States)

    Kim, Younghee; Jung, Jinyong; Oh, Sorin; Choi, Kyungho

    2008-01-01

    Cartap and cypermethrin, which are among the most widely used pesticides in many countries, are considered safe because of their low mammalian toxicity and their low persistence in the environment. However, recent findings of endocrine-disrupting effects and developmental neurotoxicity have raised concerns about the potential ecological impacts of these pesticides. We evaluated the aquatic toxicity of cartap [S,S'-(2-dimethylaminotrimethylene) bis(thiocarbamate), unspecified hydrochloride] and cypermethrin [(RS)-alpha-cyano-3-phenoxybenzyl-(1RS,3RS,1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate], both individually and combined, on different life stages of the freshwater cladoceran Daphnia magna and a freshwater teleost, Japanese medaka (Oryzias latipes). The 96-hr Daphnia median effective concentrations (EC50s) for cartap and cypermethrin were 91.0 microg/L and 0.00061 microg/L, respectively. Rapid recovery of Daphnia was observed after short-term pulsed exposure to cartap and cypermethrin; there were no adverse effects on reproduction or survival 20 d after a 24 hr exposure to cartap up to 1240 microg/L and cypermethrin up to 1.9 microg/L. Chronic continuous exposure (for 21 d) of 7-d-old Daphnia to cypermethrin significantly reduced the intrinsic population growth rate in a concentration-dependent manner. However, because the intrinsic population growth rates were all above zero, populations did not decrease even at the highest experimental concentration of 200 ng/L. Exposure of Daphnia neonates (cypermethrin for 21 d caused significant, sub-lethal reproduction-related problems, such as increased time to first brood, reduced brood size, and reduced total brood number, at 0.0002, 0.002, and 0.2 ng/L cypermethrin, but the intrinsic population growth rate was not significantly affected. Oryzias latipes was relatively more resistant to both pesticides. In particular, embryos appeared to be more resistant than juveniles or adults, which may be

  10. Controlling Harmful Cyanobacteria: Taxa-Specific Responses of Cyanobacteria to Grazing by Large-Bodied Daphnia in a Biomanipulation Scenario.

    Science.gov (United States)

    Urrutia-Cordero, Pablo; Ekvall, Mattias K; Hansson, Lars-Anders

    2016-01-01

    Lake restoration practices based on reducing fish predation and promoting the dominance of large-bodied Daphnia grazers (i.e., biomanipulation) have been the focus of much debate due to inconsistent success in suppressing harmful cyanobacterial blooms. While most studies have explored effects of large-bodied Daphnia on cyanobacterial growth at the community level and/or on few dominant species, predictions of such restoration practices demand further understanding on taxa-specific responses in diverse cyanobacterial communities. In order to address these questions, we conducted three grazing experiments during summer in a eutrophic lake where the natural phytoplankton community was exposed to an increasing gradient in biomass of the large-bodied Daphnia magna. This allowed evaluating taxa-specific responses of cyanobacteria to Daphnia grazing throughout the growing season in a desired biomanipulation scenario with limited fish predation. Total cyanobacterial and phytoplankton biomasses responded negatively to Daphnia grazing both in early and late summer, regardless of different cyanobacterial densities. Large-bodied Daphnia were capable of suppressing the abundance of Aphanizomenon, Dolichospermum, Microcystis and Planktothrix bloom-forming cyanobacteria. However, the growth of the filamentous Dolichospermum crassum was positively affected by grazing during a period when this cyanobacterium dominated the community. The eutrophic lake was subjected to biomanipulation since 2005 and nineteen years of lake monitoring data (1996-2014) revealed that reducing fish predation increased the mean abundance (50%) and body-size (20%) of Daphnia, as well as suppressed the total amount of nutrients and the growth of the dominant cyanobacterial taxa, Microcystis and Planktothrix. Altogether our results suggest that lake restoration practices solely based on grazer control by large-bodied Daphnia can be effective, but may not be sufficient to control the overgrowth of all

  11. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquus

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing

  12. Daphnia growth on microcystin-producing and microcystin-free Microcystis aeruginosa in different mixtures with the green alga Scenedesmus obliquues

    NARCIS (Netherlands)

    Lürling, M.

    2003-01-01

    The hypothesis that negative effects of Microcystis on Daphnia growth and reproduction can be explained from the presence of microcystin in the Microcystis cells was tested by comparing the effects on Daphnia life history characteristics of a microcystin-free mutant strain and microcystin-containing

  13. Effects of the cyanobacterial neurotoxin B-N-methylamino-L-alamine (BMAA) on the survival, mobility and reproduction of Daphnia magna

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.; Faassen, E.J.; Eenennaam, van J.S.

    2011-01-01

    In short-term tests and chronic life table assays, Daphnia magna was exposed to the cyanobacterial neurotoxic non-protein amino acid ß-N-methylamino-l-alanine (BMAA). BMAA was not acutely lethal to Daphnia (LC50–48h > 10 000 µg L-1), but reduced mobility (IC50–48h 40 µg L-1) and affected life his

  14. Copper(II) complexes with 2-pyridineformamide-derived thiosemicarbazones: Spectral studies and toxicity against Artemia salina

    Science.gov (United States)

    Ferraz, Karina O.; Wardell, Solange M. S. V.; Wardell, James L.; Louro, Sonia R. W.; Beraldo, Heloisa

    2009-07-01

    The copper(II) complexes [Cu(H2Am4DH)Cl 2] ( 1), [Cu(H2Am4Me)Cl 2] ( 2), [Cu(H2Am4Et)Cl 2] ( 3) and [Cu(2Am4Ph)Cl] ( 4) with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me), N(4)-ethyl (H2Am4Et) and N(4)-phenyl (H2Am4Ph) derivatives were studied by means of infrared and EPR spectral techniques. The crystal structure of 4 was determined. The studied compounds proved to be toxic to Artemia salina, suggesting that they could present cytotoxic activity against solid tumors. Among the free thiosemicarbazones H2Am4Ph presented higher toxicity than all other compounds, which showed comparable effects. In the case of complexes 2 and 3 toxicity is probably attributable to the complex as an entity or to a synergistic effect involving the thiosemicarbazone and copper. H2Am4Ph and complexes 2 and 3 revealed to be the most promising compounds as potential antineoplasic agents.

  15. Primary Screening of the Bioactivity of Brackishwater Cyanobacteria: Toxicity of Crude Extracts to Artemia salina Larvae and Paracentrotus lividus Embryos

    Directory of Open Access Journals (Sweden)

    Viviana R. Lopes

    2010-03-01

    Full Text Available Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations.

  16. Reporting a new siderophore based Ca(2+) selective chemosensor that works as a staining agent in the live organism Artemia.

    Science.gov (United States)

    Raju, M; Nair, Ratish R; Raval, Ishan H; Haldar, Soumya; Chatterjee, Pabitra B

    2015-11-21

    A Ca(2+)-specific chemosensor involving acyclic non-ether and non-carboxylato-type metal chelating ligands is rare. The tetradentate OONO artificial receptor, HL, possessing a sulfur-containing intermediate siderophore aeruginic acid, tethered to a rhodamine 6G based signalling unit in a single molecule has been synthesized. The fluoroionophore required excitation in the visible wavelength (510 nm) and showed highly selective and sensitive detection of Ca(2+) ions in 100% water solution in HEPES buffer at physiological pH (7.4). The probe HL, with LOD as low as 70 nM, behaves reversibly and showed nearly 17-fold enhanced selectivity for Ca(2+) over other cell abundant alkali and alkaline metal ions such as Na(+), K(+), Li(+), and Mg(2+) without any intervention. Job's plot, (1)H NMR titration and ESI-MS data provided corroborative evidence in support of 1 : 1 association between HL and Ca(2+). From a wide range of transition and heavy metal ions series, HL also binds Cu(2+). However, the use of l-cysteine removes the interference from Cu(2+) and results in highly selective detection specificity of HL for Ca(2+). As a reversible "off-on-off" fluorescent chemosensor, it is possible to detect Ca(2+) at as low as 5 μM in the midgut region of the gastrointestinal tract of the live animal Artemia, a brine shrimp. PMID:26460620

  17. Depression of nuclear transcription and extension of mRNA half-life under anoxia in Artemia franciscana embryos.

    Science.gov (United States)

    van Breukelen, F; Maier, R; Hand, S C

    2000-04-01

    Transcriptional activity, as assessed by nuclear run-on assays, was constant during 10 h of normoxic development for embryos of the brine shrimp Artemia franciscana. Exposure of embryos to only 4 h of anoxia resulted in a 79.3+/-1 % decrease in levels of in-vivo-initiated transcripts, and transcription was depressed by 88. 2+/-0.7 % compared with normoxic controls after 24 h of anoxia (means +/- s.e.m., N=3). Initiation of transcription was fully restored after 1 h of normoxic recovery. Artificially lowering the intracellular pH of aerobic embryos to the value reflective of anoxia (pH 6.7) showed that acidification alone explained over half the transcriptional arrest. Initiation of transcription was not rescued by application of 80 % carbon monoxide under anoxia, which suggests that heme-based oxygen sensing is not involved in this global arrest. When these transcriptional data are combined with the finding that mRNA levels are unchanged for at least 6 h of anoxia, it is clear that the half-life of mRNA is extended at least 8.5-fold compared with that in aerobic embryos. In contrast to the activation of compensatory mechanisms to cope with anoxia that occurs in mammalian cells, A. franciscana embryos enter a metabolically depressed state in which gene expression and mRNA turnover are cellular costs apparently not compatible with survival and in which extended tolerance supercedes the requirement for continued metabolic function. PMID:10708633

  18. Does a Change from Whole to Powdered Food (Artemia franciscana eggs Increase Oviposition in the Ladybird Coleomegilla maculata?

    Directory of Open Access Journals (Sweden)

    Eric W. Riddick

    2015-09-01

    Full Text Available The limited availability of alternative foods to replace natural prey hinders cost-effective mass production of ladybird beetles for augmentative biological control. We compared the effects of powdered vs. whole Artemia franciscana (A. franciscana (brine shrimp eggs with or without a dietary supplement on development and reproduction of Coleomegilla maculata (C. maculata (Coleoptera: Coccinellidae. We tested the hypotheses that (1 powdered A. franciscana eggs are more suitable than whole eggs; and (2 palmitic acid, a common fatty acid in natural prey, i.e., aphids, is an effective dietary supplement. Development time, pre-imaginal survival, sex ratio, and body weight of adults did not differ significantly amongst individuals fed powdered vs. whole eggs, with or without 5% palmitic acid. Significantly more oviposition occurred when females were fed powdered eggs than whole eggs and powdered eggs with 5% palmitic acid than whole eggs with or without 5% palmitic acid. A weak functional relationship was found between pre-oviposition time and total oviposition by females fed powdered eggs with 5% palmitic acid; pre-oviposition time decreased as oviposition increased. Food treatments had no significant differential effect on progeny (egg hatch rate. In conclusion, a simple change in A. franciscana egg texture and particle size (i.e., blending whole eggs into a dust-like powder increases oviposition in C. maculata. Supplementing powdered eggs with 5% palmitic acid might accelerate oogenesis (egg maturation in some females.

  19. The effects of Amax yeast fed to Persian sturgeon (Acipencer persicus larvae via bioenrichment of Daphnia magna

    Directory of Open Access Journals (Sweden)

    Mohammad Lashkar Boloki

    2011-07-01

    Full Text Available This study was carried out to evaluate the effect of the product of commercial live bakers’ yeast ( Saccharomyces cerevisiae so called Amax on the growth and survival of Persian sturgeon( Acipenser persicus larvae via enrichment of Daphnia magna . The blends of Amax were used in three concentrations of 50, 100, 150 mg L-1 with Daphnia in suspension of broth. Every day Daphnia by one of concentrations was bioencapsulated for 10 hours and Persian sturgeon larvae were fed on it. The Acipenser persicus larvae were fed from Daphnia on the base of the 50 percent of their body weight five times a day. The control group was fed on not enriched Daphnia. The gained body weight in experimental treatments of sturgeon larvae had significant difference compared to control treatment (p0.05. The Amax had significant positive effects on survival rate in comparison with control treatment (p<0.05. The experiments indicated that the product of Saccharomyces cerevisiae has a high ability to increase the growth parameters and feeding efficiency in cultivation system of sturgeon fish.

  20. Feasibility of feeding yellow mealworm (Tenebrio molitor L.) in bioregenerative life support systems as a source of animal protein for humans

    Science.gov (United States)

    Li, LeYuan; Zhao, ZhiRuo; Liu, Hong

    2013-11-01

    In bioregenerative life support systems, using inedible plant biomass to feed animals can provide animal protein for astronauts, while at the same time treating with wastes so as to increase the degree of system closure. In this study, the potential of yellow mealworms (Tenebrio molitor L.) as an animal candidate in the system was analyzed. The feasibility of feeding T. molitor with inedible parts of wheat and vegetable was studied. To improve the feed quality of wheat straw, three methods of fermentation were tested. A feeding regime was designed to contain a proper proportion of bran, straw and old leaves. The results showed that T. molitor larvae fed on the plant waste diets grew healthily, their fresh and dry weight reached 56.15% and 46.76% of the larvae fed on a conventional diet (control), respectively. The economic coefficient of the larvae was 16.07%, which was 88.05% of the control. The protein and fat contents of the larvae were 76.14% and 6.44% on dry weigh basis, respectively. Through the processes of facultative anaerobic fermentation and larval consumption, the straw lost about 47.79% of the initial dry weight, and its lignocellulose had a degradation of about 45.74%. Wheat germination test indicated that the frass of T. molitor needs a certain treatment before the addition to the cultivation substrate.

  1. Effects of Scleroderma sichuanensis Xiao (Hymenoptera: Bethylidae) venom and parasitism on nutritional content regulation in host Tenebrio molitor L. (Coleoptera: Tenebrionidae).

    Science.gov (United States)

    Zhuo, Zhi-Hang; Yang, Wei; Xu, Dan-Ping; Yang, Chun-Ping; Yang, Hua

    2016-01-01

    To explore the mechanisms by which the wasp Scleroderma sichuanensis Xiao regulates the physiology and biochemistry of its host, effects of S. sichuanensis venom and parasitism on host the Tenebrio molitor L. pupae were examined. Significant differences in nutritional content were noted between parasitized and non-parasitized pupae and between venom- and phosphate buffered saline-injected pupae. When pupae were injected with venom, the fat body could not be disintegrated into granules; however, when pupae were parasitized, fat-body disintegration occurred. Electrophoresis showed no differences in hemolymph protein content between parasitized pupae and those injected with venom, indicating that the wasp did not have narrow-spectrum peptides. These findings confirmed that S. sichuanensis was a typical idiobiont ectoparasitoid wasp, and that nutrient regulation was similar between idiobiont and koinobiont wasps. The strong similarities between the two treatments suggest that venom injection is a major factor responsible for changes in host nutrient content. The wasp fed mainly on reducing sugars, free amino acids, and fat-body tissues; larval fat bodies were derived from hemolymph and from host tissue. Our findings suggest that lipid catabolism might be accelerated, and that lipid biosynthesis might be inhibited, when host pupae are parasitized or injected with venom. In addition to venom, physiological and biochemical changes that occur during the parasitic process might be caused by venom, ovarian proteins, saliva, or secretions. PMID:27441136

  2. Safety assessment of freeze-dried powdered Tenebrio molitor larvae (yellow mealworm) as novel food source: Evaluation of 90-day toxicity in Sprague-Dawley rats.

    Science.gov (United States)

    Han, So-Ri; Lee, Byoung-Seok; Jung, Kyung-Jin; Yu, Hee-Jin; Yun, Eun-Young; Hwang, Jae Sam; Moon, Kyoung-Sik

    2016-06-01

    Worldwide demand for novel food source has grown and edible insects are a promising food sources for humans. Tenebrio molitor, as known as yellow mealworm, has advantages of being rich in protein, and easy to raise as a novel food source. The objective of this study was to evaluate subchronic toxicity, including potential hypersensitivity, of freeze-dried powdered T. molitor larvae (fdTML) in male and female Sprague-Dawley rats. The fdTML was administered orally once daily at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 90 days. A toxicological assessment was performed, which included mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings, histopathologic examination and allergic reaction. There were no fdTML- related findings in clinical signs, urinalysis, hematology and serum chemistry, gross examination, histopathologic examination or allergic reaction. In conclusion, the No Observed Adverse Effect Level (NOAEL) for fdTML was determined to be in excess of 3000 mg/kg/day in both sexes of rats under the experimental conditions of this study. PMID:26993751

  3. Ganho de peso e comportamento de oviposição de Podisus nigrispinus utilizando lagartas de Spodoptera frugiperda e larvas de Tenebrio molitor como presas

    Directory of Open Access Journals (Sweden)

    Oliveira Harley Nonato de

    2004-01-01

    Full Text Available Esse trabalho avaliou o efeito de diferentes presas e da combinação destas sobre percevejo Podisus nigrispinus. O delineamento experimental foi inteiramente casualizado com três tratamentos e 60 repetições. No tratamento um (T1, os percevejos receberam como alimento, lagartas de Spodoptera frugiperda, de 4o estádio, durante todo o seu ciclo de vida, no tratamento dois (T2, larvas de Tenebrio molitor, também durante o todo ciclo, enquanto que, no tratamento três (T3, foram oferecidas lagartas de S. frugiperda do 2masculine ao 4masculine estádios, e larvas de T. molitor do 4masculine estádio até o final do ciclo de vida. O ganho de peso em todas as fases ninfais e em adultos de até terceiro dia mostrou valores semelhantes de incremento, para todas as dietas utilizadas. No entanto, para os percevejos alimentados, com S. frugiperda (T1, observaram-se uma maior produção de ovos num menor período, com 80% dos ovos até 31masculine dia, enquanto que, no tratamento com larvas de T. molitor (T2, os mesmos 80% foram conseguidos somente no 45masculine dia, e no tratamento com a combinação de presas (T3, no 48masculine dia.

  4. Action of amorphous diatomaceous earth against different stages of the stored product pests Tribolium confusum, Tenebrio molitor, Sitophilus granarius and Plodia interpunctella.

    Science.gov (United States)

    Mewis; Ulrichs

    2001-04-01

    Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study tested the use and action of diatomaceous earth against several stored product pests. Fossil Shield(R) applied to wooden plates was lethal to adult Tenebrio molitor and Tribolium confusum, but larvae of the mealworm were unaffected. Beetles died within 14 days exposure in the absence of food to a dose of 2 and 4 g/m(2), but mortality was reduced in those fed grain bran. Fossil Shield(R) was lethal to first instar larvae of Plodia interpunctella, but not lethal to older larval stages. Two-week old larvae of T. confusum were more sensitive to diatomaceous earth than P. interpunctella at the same age. Contact with diatomaceous earth caused adult Sitophilus granarius, T. molitor and T. confusum to lose weight and reduced their water content, suggesting disruption of "the water barrier". Death of stored product insects treated with diatomaceous earth decreased with increased r.h., due to reduced transpiration through the cuticle. High r.h. delays, or above 60% can prevent, the drying action of diatomaceous earth.

  5. The Silencing of a 14-3-3ɛ Homolog in Tenebrio molitor Leads to Increased Antimicrobial Activity in Hemocyte and Reduces Larval Survivability.

    Science.gov (United States)

    Seo, Gi Won; Jo, Yong Hun; Seong, Jeong Hwan; Park, Ki Beom; Patnaik, Bharat Bhusan; Tindwa, Hamisi; Kim, Sun-Am; Lee, Yong Seok; Kim, Yu Jung; Han, Yeon Soo

    2016-01-01

    The 14-3-3 family of phosphorylated serine-binding proteins acts as signaling molecules in biological processes such as metabolism, division, differentiation, autophagy, and apoptosis. Herein, we report the requirement of 14-3-3ɛ isoform from Tenebrio molitor (Tm14-3-3ɛ) in the hemocyte antimicrobial activity. The Tm14-3-3ɛ transcript is 771 nucleotides in length and encodes a polypeptide of 256 amino acid residues. The protein has the typical 14-3-3 domain, the nuclear export signal (NES) sequence, and the peptide binding residues. The Tm14-3-3ɛ transcript shows a significant three-fold expression in the hemocyte of T. molitor larvae when infected with Escherichia coli Tm14-3-3ɛ silenced larvae show significantly lower survival rates when infected with E. coli. Under Tm14-3-3ɛ silenced condition, a strong antimicrobial activity is elicited in the hemocyte of the host inoculated with E. coli. This suggests impaired secretion of antimicrobial peptides (AMP) into the hemolymph. Furthermore, a reduction in AMP secretion under Tm14-3-3ɛ silenced condition would be responsible for loss in the capacity to kill bacteria and might explain the reduced survivability of the larvae upon E. coli challenge. This shows that Tm14-3-3ɛ is required to maintain innate immunity in T. molitor by enabling antimicrobial secretion into the hemolymph and explains the functional specialization of the isoform. PMID:27556493

  6. Molecular cloning and characterization of autophagy-related gene TmATG8 in Listeria-invaded hemocytes of Tenebrio molitor.

    Science.gov (United States)

    Tindwa, Hamisi; Jo, Yong Hun; Patnaik, Bharat Bhusan; Lee, Yong Seok; Kang, Sang Sun; Han, Yeon Soo

    2015-07-01

    Macroautophagy (hereinafter called autophagy) is a highly regulated process used by eukaryotic cells to digest portions of the cytoplasm that remodels and recycles nutrients and disposes of unwanted cytoplasmic constituents. Currently 36 autophagy-related genes (ATG) and their homologs have been characterized in yeast and higher eukaryotes, including insects. In the present study, we identified and functionally characterized the immune function of an ATG8 homolog in a coleopteran insect, Tenebrio molitor (TmATG8). The cDNA of TmATG8 comprises of an ORF of 363 bp that encodes a protein of 120 amino acid residues. TmATG8 transcripts are detected in all the developmental stages analyzed. TmAtg8 protein contains a highly conserved C-terminal glycine residue (Gly116) and shows high amino acid sequence identity (98%) to its Tribolium castaneum homolog, TcAtg8. Loss of function of TmATG8 by RNAi led to a significant increase in the mortality rates of T. molitor larvae against Listeria monocytogenes. Unlike dsEGFP-treated control larvae, TmATG8-silenced larvae failed to turn-on autophagy in hemocytes after injection with L. monocytogenes. These data suggest that TmATG8 play a role in mediating autophagy-based clearance of Listeria in T. molitor. PMID:25727880

  7. 浮萍饲喂黄粉虫的效益分析%Effects and profits of feeding Tenebrio molitor with Lemna minor

    Institute of Scientific and Technical Information of China (English)

    郑燕玲; 赖锦洪; 杨靖; 谢思; 羊海军

    2015-01-01

    以传统饲料配方为对照,测试添加不同用量浮萍(Lemna minor)对黄粉虫(Tenebrio molitor)幼虫生长发育及蛋白、粗脂肪含量等指标的影响.结果表明,黄粉虫幼虫对新鲜浮萍适口性良好;新鲜浮萍投饲比例大于80%,对黄粉虫幼虫的生长发育有阻滞,但对其蛋白、粗脂肪含量无显著影响(P>0.05);以鲜浮萍∶麦麸质量百分比为65%∶35%配置,可使饲料成本降低33.95%,且不影响黄粉虫的饲喂周期、产量和质量.利用新鲜浮萍饲喂黄粉虫幼虫是可行的,通过构建“浮萍-黄粉虫”食物链,可显著降低养殖成本,增加经济效益和生态效益,促进黄粉虫养殖行业发展.

  8. Artemia (Crustacea, Anostraca in Chile: a review of basic and applied biology Artemia Crustacea, Anostraca en Chile: revisión de la biología básica y aplicada

    Directory of Open Access Journals (Sweden)

    Patricio De los Rios-Escalante

    2012-09-01

    Full Text Available The brine shrimp Artemia in Chile has been studied since the 1980s, initially on populations inhabiting shallow coastal and inland mountain ponds, and saltworks in northern and central Chile. Based on morphometric and molecular evidence, these populations were identified as A. franciscana. In the 1990s, A. persimilis was recorded from southern Patagonia, a species previously considered endemic to Argentina. Recently, two new populations of A.franciscana have been recorded, from one saline coastal pond in northern Chile and from a saltwork in central Chile. The scope for further research to increase both understanding of the strain characterization and basic population ecology descriptions of the Chilean brine shrimps and improve their conservation status is discussed. It is suggested that future studies should investigate first the management of local brine shrimp population for local aquaculture or conservation resources, other direction would be the effects of ultraviolet radiation (UVR exposition that is notoriously high in brine shrimp habitats. This last factor is very important because the UVR is an important mutagen on the genetic structure of the populations. In this scenario, it is suggest a carefully management for introduced brine shrimp populations for local aquaculture for avoid alterations in native populations that due their genetic isolation would need conservation procedures for avoid local extinctions.El camarón de salmuera o Artemia ha sido estudiado en Chile desde la década de 1980, las primeras descripciones de poblaciones fueron para lagunas someras en zonas costeras y de montana, y en salinas artificiales en la zona central y norte de Chile. Sobre la base de evidencias morfométricas y moleculares estas poblaciones fueron descritas como A. franciscana. En la década de 1990, se describió la presencia de A. persimilis en la zona sur de la Patagonia, lo cual fue una ampliación del rango de distribución significativa

  9. Chitobiase activity as an indicator of altered survival, growth and reproduction in Daphnia pulex and Daphnia magna (Crustacea: Cladocera) exposed to spinosad and diflubenzuron.

    Science.gov (United States)

    Duchet, Claire; Mitie Inafuku, Marília; Caquet, Thierry; Larroque, Michel; Franquet, Evelyne; Lagneau, Christophe; Lagadic, Laurent

    2011-05-01

    Chitobiase is involved in exoskeleton degradation and recycling during the moulting process in arthropods. In aquatic species, the moulting fluid is released into the aqueous environment, and chitobiase activity present therein can be used to follow the dynamics of arthropod populations. Here, chitobiase activity was used for monitoring the impact of mosquito candidate larvicides on Daphnia pulex and Daphnia magna under laboratory conditions. Both species were exposed to spinosad (2, 4, 8 μg L(-1)) and diflubenzuron (0.2, 0.4, 0.8 μg L(-1)) for 14 days. Bacillus thuringiensis var. israelensis (Bti; 0.25, 0.5, 1 μL L(-1)) was used as the reference larvicide. Chitobiase activity, adult survival, individual growth and fecundity, expressed as the number of neonates produced, were measured every 2 days. Average Exposure Concentrations of spinosad were ten-fold lower than the nominal concentrations, whereas only a slight deviation was observed for diflubenzuron. In contrast to Bti, spinosad and diflubenzuron significantly affected both species in terms of adult survival, and production of neonates. As compared to D. pulex, D. magna was more severely affected by diflubenzuron, at low and medium concentrations, with reduced adult growth and much lower chitobiase activity. Chitobiase activity was positively correlated with the individual body length, number of neonates produced between two consecutive observation dates, and number of females and neonates. In addition, the significant positive correlations between chitobiase activity measured on the last sampling date before the first emission of neonates and the cumulative number of neonates produced during the whole observation period strongly support the potential of the activity of this chitinolytic enzyme as a proxy for assessing the dynamics of arthropod populations exposed to larvicides used for mosquito control.

  10. Laboratory evaluation of the toxicity of Perfluorooctane Sulfonate (PFOS) on Selenastrum capricornutum, Chlorella vulgaris, Lemna gibba, Daphnia magna, and Daphnia pulicaria.

    Science.gov (United States)

    Boudreau, T M; Sibley, P K; Mabury, S A; Muir, D G C; Solomon, K R

    2003-04-01

    Perfluorooctane sulfonate (PFOS) is an anthropogenic compound found in trace amounts in many environmental compartments far from areas of production. This, along with the highly persistent nature of PFOS, presents a concern for possible effects in aquatic ecosystems. The objective of this study was to determine the toxicity of PFOS in representative freshwater organisms. Toxicity testing using standard laboratory protocols was performed on the green algae Selenastrum capricornutum and Chlorella vulgaris, the floating macrophyte Lemna gibba, and the invertebrates Daphnia magna and Daphnia pulicaria. No observable effect concentration (NOEC) values were generated from the most sensitive endpoints for all organisms. Autotroph inhibition of growth NOEC values were 5.3, 8.2, and 6.6 mg/L for S. capricornutum, C. vulgaris, and L. gibba, respectively. The 48-h immobility NOEC values for D. magna and D. pulicaria were 0.8 and 13.6 mg/L, respectively. In comparison to immobility, the 21-day lethality NOEC for D. magna was 5.3 mg/L. Based on effect (immobility) values, the most sensitive of all test organisms was D. magna. The most sensitive organism based on 50% inhibition of growth (IC(50)) was L. gibba, with an IC(50) value of 31.1 mg/L determined from wet weight. This is 4.3 times less than the LC(50) for D. pulicaria, which was 134 mg/L. Significant adverse effects (p 134 mg/L. The results indicate that under laboratory conditions PFOS is acutely toxic to freshwater organisms at concentrations at or near 100 mg/L. Based on known environmental concentrations of PFOS, which occur in the low ng/L to low microg/L range, there is no apparent risk to freshwater systems. However, further work is required to investigate long-term effects in these and other freshwater organisms.

  11. Effects of bifenthrin on Daphnia magna during chronic toxicity test and the recovery test

    Institute of Scientific and Technical Information of China (English)

    YE Wei-hong; WEN Yue-zhong; LIU Wei-ping; WANG Zhong-qiang

    2004-01-01

    The acute and chronic toxic effects of bifenthrin on Daphnia magna were studied. The results showed that 24 h-EC50, 48 h-LC50 and 96 h-LC50 of bifenthrin on D. magna were 3.24, 12.40 and 1.40 μg/L respectively. And the LOEC and NOEC of bifenthrin were 0.02 and 0.004 μg/L respectively. The recovery test of bifenthrin on Daphnia magna was presented. Daphnia magna(F0 generation) were exposed during 21 d to different bifenthrin concentrations. Offspring(animals from the first and third brood: F1(1st) and F1(3rd), respectively) were transferred to a free pesticide medium during a 21-day recovery period. In this recovery study, survival, growth, reproduction(mean total young per female, onset of reproduction and number broods per female) and the intrinsic rate of natural increase (r) were assessed as parameters. Reproduction such as number of young per female as well as length was still reduced in F1(1st) generation daphnids from parentals(F0) exposed to the bifenthrin. However F1(3rd) individuals from parentals exposed to pesticide concentrations were able to restore reproduction when a recovery period of 21 d was allowed, but the length of F1(3rd) from parentals exposed to the 0.5 and 0.75 μg/L bifenthrin concentration was still significantly effected(P<0.05).

  12. Population level effects of multiwalled carbon nanotubes in Daphnia magna exposed to pulses of triclocarban.

    Science.gov (United States)

    Simon, Anne; Preuss, Thomas G; Schäffer, Andreas; Hollert, Henner; Maes, Hanna M

    2015-08-01

    Due to the rapid increase of carbon nanotubes (CNT) applications and their inevitable release into the aquatic environment, CNT may interact with and further influence the fate and transport of other pollutants such as triclocarban (TCC). TCC is a high-production-volume chemical that is widely used as an antimicrobial agent, is continually released into the aquatic environment, and is biologically active and persistent. In the present study, the population test with Daphnia magna was performed over 93 days. Different treatments were examined: (a) control, (b) solvent control, (c) 1 mg CNT/L from the beginning, (d) 1 mg CNT/L as of day 14, (e) control with a 2-day pulse of 25 µg TCC/L on day 14, 41 µg TCC/L (day 54), and 61 µg TCC/L (day 68) and (f) same pulses of TCC with co-exposure to 1 mg CNT/L. Significant changes in all three size classes were observed as a result of the long-term exposure to 1 mg CNT/L. Increasing in number of neonates, and decreasing in number of juveniles and adults were observed. Moreover, daphnids were significantly smaller when they were exposed to MWCNT. The exposure with TCC led to size-dependent mortality in Daphnia magna populations and a subsequent recovery. Lower toxicity of TCC was observed, with the presence of MWCNT in the medium. The reported effects of TCC on population level were compared to the output of an individual-based Daphnia magna population model, in order to verify the model predictions with laboratory data. PMID:26003833

  13. Desiccation of rock pool habitats and its influence on population persistence in a Daphnia metacommunity.

    Directory of Open Access Journals (Sweden)

    Florian Altermatt

    Full Text Available Habitat instability has an important influence on species' occurrence and community composition. For freshwater arthropods that occur in ephemeral rock pools, the most drastic habitat instabilities are droughts and the intermittent availability of water. However, although the desiccation of a rock pool is detrimental for planktonic populations, it may also bring certain benefits: the exclusion of predators or parasites, for example, or the coexistence of otherwise competitively exclusive species. The commonness of drought resistant resting stages in many aquatic organisms shows the ecological significance of droughts. We measured daily evaporation in 50 rock pools inhabited by three Daphnia species D. magna, D. longispina and D. pulex over one summer. Daily evaporation and ultimately desiccation showed significantly seasonally influenced correlation with pool surface area, presence of vegetation, ambient temperature, wind and standardized evaporation measures. We used the estimates from this analysis to develop a simulation model to predict changes in the water level in 530 individual pools on a daily basis over a 25-year period. Eventually, hydroperiod lengths and desiccation events could be predicted for all of these rock pools. We independently confirmed the validity of this simulation by surveying desiccation events in the 530 rock pools over a whole season in 2006. In the same 530 rock pools, Daphnia communities had been recorded over the 25 years the simulation model considered. We correlated pool-specific occupation lengths of the three species with pool-specific measures of desiccation risk. Occupation lengths of all three Daphnia species were positively correlated with maximum hydroperiod length and negatively correlated with the number of desiccation events. Surprisingly, these effects were not species-specific.

  14. Daphnia HR96 is a promiscuous xenobiotic and endobiotic nuclear receptor

    Energy Technology Data Exchange (ETDEWEB)

    Karimullina, Elina [Environmental Toxicology Program, Clemson University, Clemson, SC 29634 (United States); Institute of Plant and Animal Ecology, Russian Academy of Sciences, Ural Branch, Yekaterinburg 620144 (Russian Federation); Li Yangchun; Ginjupalli, Gautam K. [Environmental Toxicology Program, Clemson University, Clemson, SC 29634 (United States); Baldwin, William S., E-mail: baldwin@clemson.edu [Environmental Toxicology Program, Clemson University, Clemson, SC 29634 (United States); Biological Sciences, Clemson University, Clemson, SC (United States)

    2012-07-15

    Daphnia pulex is the first crustacean to have its genome sequenced. The genome project provides new insight and data into how an aquatic crustacean may respond to environmental stressors, including toxicants. We cloned Daphnia pulex HR96 (DappuHR96), a nuclear receptor orthologous to the CAR/PXR/VDR group of nuclear receptors. In Drosophila melanogaster, (hormone receptor 96) HR96 responds to phenobarbital exposure and has been hypothesized as a toxicant receptor. Therefore, we set up a transactivation assay to test whether DappuHR96 is a promiscuous receptor activated by xenobiotics and endobiotics similar to the constitutive androstane receptor (CAR) and the pregnane X-receptor (PXR). Transactivation assays performed with a GAL4-HR96 chimera demonstrate that HR96 is a promiscuous toxicant receptor activated by a diverse set of chemicals such as pesticides, hormones, and fatty acids. Several environmental toxicants activate HR96 including estradiol, pyriproxyfen, chlorpyrifos, atrazine, and methane arsonate. We also observed repression of HR96 activity by chemicals such as triclosan, androstanol, and fluoxetine. Nearly 50% of the chemicals tested activated or inhibited HR96. Interestingly, unsaturated fatty acids were common activators or inhibitors of HR96 activity, indicating a link between diet and toxicant response. The omega-6 and omega-9 unsaturated fatty acids linoleic and oleic acid activated HR96, but the omega-3 unsaturated fatty acids alpha-linolenic acid and docosahexaenoic acid inhibited HR96, suggesting that these two distinct sets of lipids perform opposing roles in Daphnia physiology. This also provides a putative mechanism by which the ratio of dietary unsaturated fats may affect the ability of an organism to respond to a toxic insult. In summary, HR96 is a promiscuous nuclear receptor activated by numerous endo- and xenobiotics.

  15. Trophic transfer of gold nanoparticles from Euglena gracilis or Chlamydomonas reinhardtii to Daphnia magna

    International Nuclear Information System (INIS)

    Understanding the trophic transfer of nanoparticles (NPs) is important because NPs are small enough to easily penetrate into organisms. In this study, we evaluated the trophic transfer of gold NPs (AuNPs) within the aquatic food chain. We observed AuNPs transfer from 2 species of primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna). Also, bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. The reasons for the difference in Au accumulation may be the physical structure of these organisms, and the surface area that is available for interaction with NPs. C. reinhardtii has a cell wall that may act as a barrier to the penetration of NPs. The size of E. gracilis is larger than that of C. reinhardtii. This study demonstrates the trophic transfer of AuNPs from a general producer to a consumer in an aquatic environment. - Highlights: • This study evaluated the trophic transfer of AuNPs in an aquatic food chain. • Chlamydomonas reinhardtii and Euglena gracilis were selected as the primary producers. • Daphnia magna was used as the primary consumer. • The bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. • AuNPs were transferred from C. reinhardtii and E. gracilis to D. magna. - Gold nanoparticles can transfer from primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna) in an aquatic environment

  16. Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Fabianne, E-mail: ribeiro.f@ua.pt [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal); Gallego-Urrea, Julián Alberto [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Jurkschat, Kerstin; Crossley, Alison [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Hassellöv, Martin [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Taylor, Cameron [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Soares, Amadeu M.V.M.; Loureiro, Susana [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal)

    2014-01-01

    Silver nanoparticles (AgNP) have gained attention over the years due to the antimicrobial function of silver, which has been exploited industrially to produce consumer goods that vary in type and application. Undoubtedly the increase of production and consumption of these silver-containing products will lead to the entry of silver compounds into the environment. In this study we have used Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio as model organisms to investigate the toxicity of AgNP and AgNO{sub 3} by assessing different biological endpoints and exposure periods. Organisms were exposed following specific and standardized protocols for each species/endpoints, with modifications when necessary. AgNP were characterized in each test-media by Transmission Electron Microscopy (TEM) and experiments were performed by Dynamic Light Scattering (DLS) to investigate the aggregation and agglomeration behavior of AgNP under different media chemical composition and test-period. TEM images of AgNP in the different test-media showed dissimilar patterns of agglomeration, with some agglomerates inside an organic layer, some loosely associated particles and also the presence of some individual particles. The toxicity of both AgNO{sub 3} and AgNP differ significantly based on the test species: we found no differences in toxicity for algae, a small difference for zebrafish and a major difference in toxicity for Daphnia magna. - Highlights: •Effects of silver nanoparticles and nitrate were compared in three aquatic species. •The presence of food on the immobilization assay for Daphnia magna significantly decreased AgNP toxicity. •AgNP and AgNO{sub 3} differ in toxicity according to the test species and endpoint. •AgNP and AgNO{sub 3} induced dissimilar abnormalities on zebrafish embryos' development. •AgNP behavior in the test media will rule its bioavailability and uptake and therefore toxicity.

  17. Gene response profiles for Daphnia pulex exposed to the environmental stressor cadmium reveals novel crustacean metallothioneins

    Directory of Open Access Journals (Sweden)

    Davey Jennifer C

    2007-12-01

    Full Text Available Abstract Background Genomic research tools such as microarrays are proving to be important resources to study the complex regulation of genes that respond to environmental perturbations. A first generation cDNA microarray was developed for the environmental indicator species Daphnia pulex, to identify genes whose regulation is modulated following exposure to the metal stressor cadmium. Our experiments revealed interesting changes in gene transcription that suggest their biological roles and their potentially toxicological features in responding to this important environmental contaminant. Results Our microarray identified genes reported in the literature to be regulated in response to cadmium exposure, suggested functional attributes for genes that share no sequence similarity to proteins in the public databases, and pointed to genes that are likely members of expanded gene families in the Daphnia genome. Genes identified on the microarray also were associated with cadmium induced phenotypes and population-level outcomes that we experimentally determined. A subset of genes regulated in response to cadmium exposure was independently validated using quantitative-realtime (Q-RT-PCR. These microarray studies led to the discovery of three genes coding for the metal detoxication protein metallothionein (MT. The gene structures and predicted translated sequences of D. pulex MTs clearly place them in this gene family. Yet, they share little homology with previously characterized MTs. Conclusion The genomic information obtained from this study represents an important first step in characterizing microarray patterns that may be diagnostic to specific environmental contaminants and give insights into their toxicological mechanisms, while also providing a practical tool for evolutionary, ecological, and toxicological functional gene discovery studies. Advances in Daphnia genomics will enable the further development of this species as a model organism for

  18. Evaluation of Toxic, Cytotoxic, Mutagenic, and Antimutagenic Activities of Natural and Technical Cashew Nut Shell Liquids Using the Allium cepa and Artemia salina Bioassays

    OpenAIRE

    Aracelli de Sousa Leite; Alisson Ferreira Dantas; George Laylson da Silva Oliveira; Gomes Júnior, Antonio L.; Sidney Gonçalo de Lima; Antônia Maria das Graças Lopes Citó; de Freitas, Rivelilson M.; Melo-Cavalcante, Ana Amélia de C.; José Arimateia Dantas Lopes

    2015-01-01

    The cashew nut releases a substance that is known as cashew nut shell liquid (CNSL). There are both natural (iCNSL) and technical (tCNSL) cashew nut shell liquids. This study used an Artemia salina bioassay to evaluate the toxic effects of iCNSL and tCNSL cashew nut shell liquids. It also evaluated the toxicity, cytotoxicity, and mutagenicity of CNSL and its effects on the damage induced by copper sulfate (CuSO4·5H2O) on the meristems’ root of Allium cepa. Effects of the damage induced by CuS...

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

    OpenAIRE

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

    1993-01-01

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

  20. Evaluation of toxic effects with transition metal ions, EDTA, SBTI and acrylic polymers on Aedes aegypti (L., 1762 (Culicidae and Artemia salina (Artemidae

    Directory of Open Access Journals (Sweden)

    Eduardo José de Arruda

    2011-06-01

    Full Text Available This work aimed to evaluate the toxicity of some insecticides compounds on Aedes aegypti and Artemia salina larvae. Bioassays were carried out to evaluate the toxic effect after of 24 and 72 h using the compounds or associations. The LC10, LC50 and LC90 values were obtained and utilized for toxicity comparations. For Ae. aegypti, LC50 were 32.65 mg L-1 in 24 h for Na2[EDTA-Cu(II] and total mortality in 72 h for SAP-Na2[EDTA-Cu(II].

  1. Group 3 late embryogenesis abundant proteins from embryos of Artemia franciscana: structural properties and protective abilities during desiccation.

    Science.gov (United States)

    Boswell, Leaf C; Menze, Michael A; Hand, Steven C

    2014-01-01

    Group 3 late embryogenesis abundant (LEA) proteins are highly hydrophilic, and their expression is associated with desiccation tolerance in both plants and animals. Here we show that two LEA proteins from embryos of Artemia franciscana, AfrLEA2 and AfrLEA3m, are intrinsically disordered in solution but upon desiccation gain secondary structure, as measured by circular dichroism. Trifluoroethanol and sodium dodecyl sulfate are both shown to induce α-helical structure in AfrLEA2 and AfrLEA3m. Bioinformatic predictions of secondary-structure content for both proteins correspond most closely to conformations measured in the dry state. Because some LEA proteins afford protection to desiccation-sensitive proteins during drying and subsequent rehydration, we tested for this capacity in AfrLEA2 and AfrLEA3m. The protective capacities vary, depending on the target enzyme. For the cytoplasmic enzyme lactate dehydrogenase, neither AfrLEA2 nor AfrLEA3m, with or without trehalose present, was able to afford protection better than that provided by bovine serum albumin (BSA) under the same conditions. However, for another cytoplasmic enzyme, phosphofructokinase, both AfrLEA2 and AfrLEA3m in the presence of trehalose were able to afford protection far greater than that provided by BSA with trehalose. Finally, for the mitochondrial enzyme citrate synthase, 400-μg/mL AfrLEA3m without trehalose provided significantly more protection than the same concentration of either AfrLEA2 or BSA. PMID:25244376

  2. Profiles of nuclear and mitochondrial encoded mRNAs in developing and quiescent embryos of Artemia franciscana.

    Science.gov (United States)

    Hardewig, I; Anchordoguy, T J; Crawford, D L; Hand, S C

    1996-05-24

    Embryos of the brine shrimp Artemia franciscana are able to withstand long bouts of environmental anoxia by entering a quiescent state during which metabolism is greatly depressed. Recent evidence supports a global arrest of protein synthesis during quiescence. In this study we measured the amounts of mRNA for a mitochondrial-encoded subunit of cytochrome c oxidase (COX I) and for nuclear-encoded actin during aerobic development, anaerobiosis, and aerobic acidosis (artificial quiescence imposed by intracellular acidification under aerobic conditions). The levels of both COX I and actin transcripts increased significantly during aerobic development. COX I mRNA levels were tightly correlated with previous measures of COX catalytic activity, which suggests that COX synthesis could be regulated by message concentration during aerobic development. The ontogenetic increase for these mRNAs was blocked by anoxia and aerobic acidosis. Importantly, the levels of COX I and actin mRNA did not decline appreciably during the 6 h bouts of quiescence, even though protein synthesis is acutely arrested by these same treatments. Thus, the constancy of mRNA levels during quiescence indicate that reduced protein synthesis is not caused by message limitation, but rather, is likely controlled at the translational level. One advantage of this regulatory mechanism is the conservation of mRNA molecules during quiescence, which would potentially favor a quick resumption of translation as soon as oxygen is returned to the embryos. Finally, because anoxia and aerobic acidosis are both characterized by acidic intracellular pH, the reduction in pH may serve, directly or indirectly, as one signal regulating levels of mRNA in this embryo during quiescence. PMID:8817476

  3. Bird migratory flyways influence the phylogeography of the invasive brine shrimp Artemia franciscana in its native American range

    Directory of Open Access Journals (Sweden)

    Joaquín Muñoz

    2013-11-01

    Full Text Available Since Darwin’s time, waterbirds have been considered an important vector for the dispersal of continental aquatic invertebrates. Bird movements have facilitated the worldwide invasion of the American brine shrimp Artemia franciscana, transporting cysts (diapausing eggs, and favouring rapid range expansions from introduction sites. Here we address the impact of bird migratory flyways on the population genetic structure and phylogeography of A. franciscana in its native range in the Americas. We examined sequence variation for two mitochondrial gene fragments (COI and 16S for a subset of the data in a large set of population samples representing the entire native range of A. franciscana. Furthermore, we performed Mantel tests and redundancy analyses (RDA to test the role of flyways, geography and human introductions on the phylogeography and population genetic structure at a continental scale. A. franciscana mitochondrial DNA was very diverse, with two main clades, largely corresponding to Pacific and Atlantic populations, mirroring American bird flyways. There was a high degree of regional endemism, with populations subdivided into at least 12 divergent, geographically restricted and largely allopatric mitochondrial lineages, and high levels of population structure (ΦST of 0.92, indicating low ongoing gene flow. We found evidence of human-mediated introductions in nine out of 39 populations analysed. Once these populations were removed, Mantel tests revealed a strong association between genetic variation and geographic distance (i.e., isolation-by-distance pattern. RDA showed that shared bird flyways explained around 20% of the variance in genetic distance between populations and this was highly significant, once geographic distance was controlled for. The variance explained increased to 30% when the factor human introduction was included in the model. Our findings suggest that bird-mediated transport of brine shrimp propagules does not result

  4. Optimización del enriquecimiento de nauplios de Artemia mediante el uso de emulsiones lipídicas formuladas a partir de aceites sintéticos ricos en DHA

    OpenAIRE

    Viciano Delibano, Elena

    2015-01-01

    Los nauplios de Artemia se utilizan como presa viva en criaderos de organimos marinos de todo el mundo debido a su disponibilidad y digestibilidad, pero su valor nutricional no se ajusta a las demandas o necesidades de las larvas de peces, moluscos o crustáceos marinos, ya que carecen de los ácidos grasos esenciales (EFA, Essential Fatty Acids) para estos organismos. Por tanto, es indispensable llevar a cabo un enriquecimiento de los nauplios de Artemia. El enriquecimiento consiste en incubac...

  5. Hazard assessment for a pharmaceutical mixture detected in the upper Tennessee River using Daphnia magna

    OpenAIRE

    Wolfe, D.; Schorr, M.; Hanson, M; C. H. Nelson; Richards, S M

    2015-01-01

    Widespread use of pharmaceuticals has resulted in mixture concentrations ranging from mg/L in effluent to µg/L concentrations in surface water. In a 2008 study, 13 pharmaceuticals, ranging in amounts from 0.0028 to 0.1757 µg/l, were identified in the Tennessee River, USA and its tributaries. In order to address the need for risk assessment of environmentally relevant pharmaceutical mixtures, Daphnia magna 21-d life cycle tests were performed on a mixture of 11 of the 13 pharmaceuticals as wel...

  6. Long-term changes in pigmentation of arctic Daphnia provide potential for reconstructing aquatic UV exposure

    Science.gov (United States)

    Nevalainen, Liisa; Rantala, Marttiina V.; Luoto, Tomi P.; Ojala, Antti E. K.; Rautio, Milla

    2016-07-01

    Despite the biologically damaging impacts of solar ultraviolet radiation (UV) in nature, little is known about its natural variability, forcing mechanisms, and long-term effects on ecosystems and organisms. Arctic zooplankton, for example the aquatic keystone genus Daphnia (Crustacea, Cladocera) responds to biologically damaging UV by utilizing photoprotective strategies, including pigmentation. We examined the preservation and content of UV-screening pigments in fossil Daphnia remains (ephippia) in two arctic lake sediment cores from Cornwallis Island (Lake R1), Canada, and Spitsbergen (Lake Fugledammen), Svalbard. The aims were to document changes in the degree of UV-protective pigmentation throughout the past centuries, elucidate the adaptive responses of zooplankton to long-term variations in UV exposure, and estimate the potential of fossil zooplankton pigments in reconstructing aquatic UV regimes. The spectroscopic absorbance measurements of fossil Daphnia ephippia under UV (280-400 nm) and visible light (400-700 nm) spectral ranges indicated that melanin (absorbance maxima at UV wavebands 280-350 nm) and carotenoids (absorbance maxima at 400-450 nm) pigments were preserved in the ephippia in both sediment cores. Downcore measurements of the most important UV-protective pigment melanin (absorbance measured at 305 and 340 nm) showed marked long-term variations in the degree of melanisation. These variations likely represented long-term trends in aquatic UV exposure and were positively related with solar radiation intensity. The corresponding trends in melanisation and solar activity were disrupted at the turn of the 20th century in R1, but remained as strong in Fugledammen. The reversed trends in the R1 core were simultaneous with a significant aquatic community reorganization taking place in the lake, suggesting that recent environmental changes, likely related to climate warming had a local effect on pigmentation strategies. This time horizon is also

  7. Trans-generational effects of parental exposure to ionizing radiation in Daphnia

    Energy Technology Data Exchange (ETDEWEB)

    Sarapultseva, Elena I. [Institute of Nuclear Power Engineering National Research Nuclear University ' MEPhI' - INPE NRNU MEPhI, Studgorodok,1, Obninsk, Kaluga region, 249040 (Russian Federation)

    2014-07-01

    We are currently studying the direct and trans-generational effects of exposure to ionizing radiation on fecundity and reproductive success of the exposed Daphnia magna and their non-exposed progeny. As the long-term survival of species strongly depends on the individual fertility and survival of their offspring, changes in the reproductive process are regarded as one of the most significant sub-lethal effects of environmental pollution. We have recently shown that?-irradiation at doses of 100 and 1000 mGy significantly compromised fecundity and reproductive success of the directly exposed D. magna and their non-exposed first-generation offspring. We have also observed the decrease in the size of the irradiated Daphnia. These effects were also observed among the non-exposed first-generation progeny of irradiated parents, thus implying the manifestation of trans-generational effects in Daphnia. As the compromised fertility was observed among majority of the offspring of irradiated parents, it cannot be attributed to segregation of deleterious mutations induced in the germ line of irradiated parents and is most likely underlined by epigenetic mechanisms. The results of our study also provide further support for the hypothesis of non-targeted effects of ionizing radiation. We have recently shown that compromised viability of irradiated D. magna can be attributed cytotoxic effects of irradiation. Our results suggest that the observed cytotoxic effects are mostly attributed to substantially elevated levels of free-radicals detected in the irradiated parents and their first-generation offspring. It would therefore appear that the compromised viability may be attributed to the cytotoxic effects resulted from epigenetic changes affecting some metabolic pathways involved in detoxification of free-radicals. Additionally we have analyzed more distant progeny of irradiated in doses of 100 and 1000 mGy Daphnia. Some potential mechanisms underlying non-targeted effects

  8. Trans-generational effects of parental exposure to ionizing radiation in Daphnia

    International Nuclear Information System (INIS)

    We are currently studying the direct and trans-generational effects of exposure to ionizing radiation on fecundity and reproductive success of the exposed Daphnia magna and their non-exposed progeny. As the long-term survival of species strongly depends on the individual fertility and survival of their offspring, changes in the reproductive process are regarded as one of the most significant sub-lethal effects of environmental pollution. We have recently shown that?-irradiation at doses of 100 and 1000 mGy significantly compromised fecundity and reproductive success of the directly exposed D. magna and their non-exposed first-generation offspring. We have also observed the decrease in the size of the irradiated Daphnia. These effects were also observed among the non-exposed first-generation progeny of irradiated parents, thus implying the manifestation of trans-generational effects in Daphnia. As the compromised fertility was observed among majority of the offspring of irradiated parents, it cannot be attributed to segregation of deleterious mutations induced in the germ line of irradiated parents and is most likely underlined by epigenetic mechanisms. The results of our study also provide further support for the hypothesis of non-targeted effects of ionizing radiation. We have recently shown that compromised viability of irradiated D. magna can be attributed cytotoxic effects of irradiation. Our results suggest that the observed cytotoxic effects are mostly attributed to substantially elevated levels of free-radicals detected in the irradiated parents and their first-generation offspring. It would therefore appear that the compromised viability may be attributed to the cytotoxic effects resulted from epigenetic changes affecting some metabolic pathways involved in detoxification of free-radicals. Additionally we have analyzed more distant progeny of irradiated in doses of 100 and 1000 mGy Daphnia. Some potential mechanisms underlying non-targeted effects

  9. Genomics, transcriptomics, and peptidomics of Daphnia pulex neuropeptides and protein hormones

    DEFF Research Database (Denmark)

    Dircksen, Heinrich; Neupert, Susanne; Predel, Reinhard;

    2011-01-01

    We report 43 novel genes in the water flea Daphnia pulex encoding 73 predicted neuropeptide and protein hormones as partly confirmed by RT-PCR. MALDI-TOF mass spectrometry identified 40 neuropeptides by mass matches and 30 neuropeptides by fragmentation sequencing. Single genes encode adipokinetic......, neuroparsin, two neuropeptide-F splice forms, three periviscerokinins (but no pyrokinins), pigment dispersing hormone, proctolin, Met(4)-proctolin, short neuropeptide-F, three RYamides, SIFamide, two sulfakinins, and three tachykinins. There are two genes for a preprohormone containing orcomyotropin...

  10. 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

  11. Masculinización del cíclido nativo Tenhuayaca, Petenia splendida (Günther, 1862, usando nauplios de Artemia como vehículo del esteroide 17-α metiltestosterona Mazculinization of the native cichlid Tenhuayaca, Petenia splendida (Günther, 1862, using Artemia nauplii as vehicle of the steroid 17-α methyltestosterone

    Directory of Open Access Journals (Sweden)

    Juan Manuel Vidal-López

    2009-12-01

    Full Text Available El uso de esteroides para producir poblaciones monosexo en cíclidos, ha sido ampliamente utilizado con el objetivo de evitar el proceso de reproducción y sobrepoblación de los estanques de cultivo, por medio de su aplicación a través del alimento balanceado. Sin embargo, cíclidos como la tenhuayaca, la cual tiene un alto potencial acuícola en el sureste de México y Centroamérica, durante su fase larvaria no aceptan el alimento balanceado, por lo que el uso de Artemia como vehículo para la administración de esteroides sintéticos ha sido propuesto recientemente. En el presente estudio se evaluó la masculinización de crías de Petenia splendida mediante la utilización de nauplios de Artemia como vehículo del esteroide 17-α metiltestosterona (MT, para lo cual se utilizaron larvas de primera alimentación a las cuales se les suministraron nauplios de Artemia como vehículo de la MT durante 5, 10, 20, 28, 45 y 60 días de alimentación, respectivamente y un tratamiento sin MT. Se determinó que los mayores porcentajes de masculinización y supervivencia, (96% de machos, 85% respectivamente se presentaron cuando se alimentaron las larvas con nauplios por 60 días. En el tratamiento control solamente se obtuvo un 56% de machos con una supervivencia de 83%, por lo cual concluimos que el uso de presas vivas como vehículo de la MT es adecuado para la producción de crías de P. splendida.At world-wide level the use of steroids to obtain all-male population in cichlids, has been widely used with the objective to avoid the reproduction process and to canalize the energy of the food in weight gain. In this sense, the application of steroids has been commonly through the artificial diets. Nevertheless, for some cichlid such as tenhuayaca or bay snook Petenia splendida, which is considered an appropriate species for aquaculture in the Southeastern of Mexico and Central America, the use of artificial diets during the larval period is not

  12. The introduction of yellow mealworm (Tenebrio Molitor L.) into BLSS as a source of animal protein for humans: experiments and modeling

    Science.gov (United States)

    Li, Leyuan; Liu, lh64. Hong; Ruo Zhao, Zhi

    2012-07-01

    In bioregenerative life support systems, using inedible plant biomass to feed animals can provide animal protein for astronauts, while at the same time treating with wastes so as to increase the degree of system closure and the efficiency of material cycling. In this study, an analysis and demonstration on the potential of yellow mealworms (Tenebrio molitor L.) as an animal candidate in the system was presented. The feasibility of feeding T. molitor with inedible parts of wheat and vegetables was studied. Moreover, a process for straw fermentation was selected. T. molitor was fed on wheat bran for the first 10 days, and then gradually, fermented straw was added. Old leaves of Chinese cabbage were used as supplementary feedstuff. The results showed that T. molitor larvae fed on this diet survived and grew normally, their fresh and dry weight achieved 56.15% and 46.76% of the larvae fed on a conventional diet, respectively. The bioconversion rate of the larvae was 16.07%, which was 88.05% of the conventional diet group. The protein and fat contents were 76.14% and 6.44% on dry weigh, respectively. Through the processes of anaerobic fermentation and mealworm consumption, the straw lost about 47.79% of the initial dry weight, and its lignocellulose had a degradation of about 45.74%. Wheat germination test indicated that the frass of T. molitor has the potential to be utilized as plant cultivation substrate after certain treatment. Stoichiometric modeling of BLSS containing T. molitor was also conducted.

  13. Depressing Antidepressant: Fluoxetine Affects Serotonin Neurons Causing Adverse Reproductive Responses in Daphnia magna.

    Science.gov (United States)

    Campos, Bruno; Rivetti, Claudia; Kress, Timm; Barata, Carlos; Dircksen, Heinrich

    2016-06-01

    Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants. As endocrine disruptive contaminants in the environment, SSRIs affect reproduction in aquatic organisms. In the water flea Daphnia magna, SSRIs increase offspring production in a food ration-dependent manner. At limiting food conditions, females exposed to SSRIs produce more but smaller offspring, which is a maladaptive life-history strategy. We asked whether increased serotonin levels in newly identified serotonin-neurons in the Daphnia brain mediate these effects. We provide strong evidence that exogenous SSRI fluoxetine selectively increases serotonin-immunoreactivity in identified brain neurons under limiting food conditions thereby leading to maladaptive offspring production. Fluoxetine increases serotonin-immunoreactivity at low food conditions to similar maximal levels as observed under high food conditions and concomitantly enhances offspring production. Sublethal amounts of the neurotoxin 5,7-dihydroxytryptamine known to specifically ablate serotonin-neurons markedly decrease serotonin-immunoreactivity and offspring production, strongly supporting the effect to be serotonin-specific by reversing the reproductive phenotype attained under fluoxetine. Thus, SSRIs impair serotonin-regulation of reproductive investment in a planktonic key organism causing inappropriately increased reproduction with potentially severe ecological impact. PMID:27128505

  14. Ecotoxicogenomic Approaches for Understanding Molecular Mechanisms of Environmental Chemical Toxicity Using Aquatic Invertebrate, Daphnia Model Organism

    Directory of Open Access Journals (Sweden)

    Hyo Jeong Kim

    2015-05-01

    Full Text Available Due to the rapid advent in genomics technologies and attention to ecological risk assessment, the term “ecotoxicogenomics” has recently emerged to describe integration of omics studies (i.e., transcriptomics, proteomics, metabolomics, and epigenomics into ecotoxicological fields. Ecotoxicogenomics is defined as study of an entire set of genes or proteins expression in ecological organisms to provide insight on environmental toxicity, offering benefit in ecological risk assessment. Indeed, Daphnia is a model species to study aquatic environmental toxicity designated in the Organization for Economic Co-operation and Development’s toxicity test guideline and to investigate expression patterns using ecotoxicology-oriented genomics tools. Our main purpose is to demonstrate the potential utility of gene expression profiling in ecotoxicology by identifying novel biomarkers and relevant modes of toxicity in Daphnia magna. These approaches enable us to address adverse phenotypic outcomes linked to particular gene function(s and mechanistic understanding of aquatic ecotoxicology as well as exploration of useful biomarkers. Furthermore, key challenges that currently face aquatic ecotoxicology (e.g., predicting toxicant responses among a broad spectrum of phytogenetic groups, predicting impact of temporal exposure on toxicant responses necessitate the parallel use of other model organisms, both aquatic and terrestrial. By investigating gene expression profiling in an environmentally important organism, this provides viable support for the utility of ecotoxicogenomics.

  15. Application of enriched stable isotope technique to the study of copper bioavailability in Daphnia magna

    Institute of Scientific and Technical Information of China (English)

    Wenhong Fan; Chenguang Wu; Chunmei Zhao; Tao Yu; Yuan Zhang

    2011-01-01

    The biokinetics of Cu in Daphnia magna, including dissolved uptake, assimilation and efflux, has been determined using a gamma 67Cu radiotracer methodology.However, this gamma emitting radioisotope is not readily available due to its very short half-life.In the present study, we employed a stable isotope tracer (65Cu) to determine the Cu biokinetics and compared our results to those determined using 67Cu.The dissolved uptake rate constant of 65Cu was 3.36 L/(g·day), which is higher than that of 67Cu (1.32 L/(g·day)).With increasing food concentrations from 2×104 to 1×105 cells/mL, the Cu assimilation efficiency (AE) decreased from 46% to 11%,compared to a decrease from 27% to 16% when determined using 67Cu.The efflux of Cu from Daphnia magna was quantified following both dissolved and dietary uptake.The efflux of waterborne Cu was comparable to that of dietborne Cu and the efflux rate constant (0.32-0.52 day-1) was higher than that determined by 67Cu (0.19-0.20 day-1).By considering different water properties and handling procedure between the two experiments, we believe that these differences are reasonable.Overall, this study demonstrated that the enriched stable isotope tracer technique is a powerful tool to investigate metal bioavailability and maybe a good alternative to radioactive measurements.

  16. Synthesis, characterization and toxicological evaluation of Cr₂O₃ nanoparticles using Daphnia magna and Aliivibrio fischeri.

    Science.gov (United States)

    Puerari, Rodrigo Costa; da Costa, Cristina H; Vicentini, Denice S; Fuzinatto, Cristiane F; Melegari, Silvia P; Schmidt, Éder C; Bouzon, Zenilda L; Matias, William G

    2016-06-01

    Chromium III oxide (Cr2O3) nanoparticles (NPs) are used in pigments for ceramics, dyes, paints and cosmetics. However, few studies addressing the toxic potential of these NPs have been reported in the literature. Thus, this research aimed to evaluate the acute and chronic effects of Cr2O3 NPs through acute toxicity tests with Daphnia magna and Aliivibrio fischeri and chronic toxicity tests with Daphnia magna. Cr2O3 NPs were synthesized by the sol-gel method and characterized through TEM, X-Ray diffraction (XRD), zeta potential (ZP) and surface area analysis. In the acute toxicity tests the EC(50,48h) value obtained with D. magna was 6.79 mg L(-1) and for A. fischeri the EC(50,15min) value was 16.10 mg L(-1) and the EC(50,30min) value was 12.91 mg L(-1). Regarding the chronic toxicity tests with D. magna, effects on longevity (OEC=1.00 mg L(-1)), reproduction (OEC=1.00 mg L(-1)) and growth (OEC=0.50 mg L(-1)) were observed. On the SEM and TEM images, ultrastructural alterations in the organelles of exposed organisms were also observed. Thus, toxicological studies with NPs are of great importance in order to reduce the risk of environmental contamination. PMID:26890188

  17. Reproductive switching analysis of Daphnia similoides between sexual female and parthenogenetic female by transcriptome comparison

    Science.gov (United States)

    Zhang, Ya-Nan; Zhu, Xiu-Yun; Wang, Wen-Ping; Wang, Yi; Wang, Lu; Xu, Xiao-Xue; Zhang, Kun; Deng, Dao-Gui

    2016-01-01

    The water flea Daphnia are planktonic crustaceans commonly found in freshwater environment that can switch their reproduction mode from parthenogenesis to sexual reproduction to adapt to the external environment. As such, Daphnia are great model organisms to study the mechanism of reproductive switching, the underlying mechanism of reproduction and development in cladocerans and other animals. However, little is known about the Daphnia’s reproductive behaviour at a molecular level. We constructed a genetic database of the genes expressed in a sexual female (SF) and a parthenogenetic female (PF) of D. similoides using Illumina HiSeq 2500. A total of 1,763 differentially expressed genes (865 up- and 898 down-regulated) were detected in SF. Of the top 30 up-regulated SF unigenes, the top 4 unigenes belonged to the Chitin_bind_4 family. In contrast, of the top down-regulated SF unigenes, the top 3 unigenes belonged to the Vitellogenin_N family. This is the first study to indicate genes that may have a crucial role in reproductive switching of D. similoides, which could be used as candidate genes for further functional studies. Thus, this study provides a rich resource for investigation and elucidation of reproductive switching in D. similoides. PMID:27671106

  18. The rate-size trade-off structures intraspecific variation in Daphnia ambigua life history parameters.

    Directory of Open Access Journals (Sweden)

    John P DeLong

    Full Text Available The identification of trade-offs is necessary for understanding the evolution and maintenance of diversity. Here we employ the supply-demand (SD body size optimization model to predict a trade-off between asymptotic body size and growth rate. We use the SD model to quantitatively predict the slope of the relationship between asymptotic body size and growth rate under high and low food regimes and then test the predictions against observations for Daphnia ambigua. Close quantitative agreement between observed and predicted slopes at both food levels lends support to the model and confirms that a 'rate-size' trade-off structures life history variation in this population. In contrast to classic life history expectations, growth and reproduction were positively correlated after controlling for the rate-size trade-off. We included 12 Daphnia clones in our study, but clone identity explained only some of the variation in life history traits. We also tested the hypothesis that growth rate would be positively related to intergenic spacer length (i.e. the growth rate hypothesis across clones, but we found that clones with intermediate intergenic spacer lengths had larger asymptotic sizes and slower growth rates. Our results strongly support a resource-based optimization of body size following the SD model. Furthermore, because some resource allocation decisions necessarily precede others, understanding interdependent life history traits may require a more nested approach.

  19. Multigenerational effect of perfluorooctane sulfonate (PFOS) on the individual fitness and population growth of Daphnia magna.

    Science.gov (United States)

    Jeong, Tae-Yong; Yuk, Min-Su; Jeon, Junho; Kim, Sang Don

    2016-11-01

    We investigated the multigenerational effect of PFOS to individual fitness (e.g., body weight, acetylcholinesterase and glutathione S-transferase) and population growth (e.g., offspring number and time to first brood) of Daphnia magna during continuous and discontinuous exposures. The intrinsic rate of population growth was also calculated. In the continuous exposure, population growth-related adverse effects were detected during all test periods, and the adverse effect tended to be weaker in later generations. On the other hand, individual fitness-related adverse effects were observed from F1 not in F0 and deteriorated as the generation number increased. These results imply that individual fitness worsens although the population growth is restored in later generations. Upon discontinuous exposure, a few but significant adverse effects were observed during the non-exposure period and highest effects were detected during the re-exposure period. This encourages the study of different exposure scenarios, which may result in unexpected and higher PFOS toxicity. Consequently, this study confirms adverse effects of PFOS to Daphnia magna in multigenerational period and supports reasons for studies linking individual fitness changes to population dynamics and covering diverse exposure scenarios to evaluate the risk of PFOS in a water environment. PMID:27396314

  20. Larger Daphnia at lower temperature: a role for cell size and genome configuration?

    Science.gov (United States)

    Jalal, Marwa; Wojewodzic, Marcin W; Laane, Carl Morten M; Hessen, Dag O

    2013-09-01

    Experiments with Daphnia magna and Daphnia pulex raised at 10 and 20 °C yielded larger adult size at the lower temperature. This must reflect increased cell size, increased cell numbers, or a combination of both. As it is difficult to achieve good estimates on cell size in crustaceans, we, therefore, measured nucleus and genome size using flow cytometry at 10 and 20 °C. DNA was stained with propidium iodide, ethidium bromide, and DAPI. Both nucleus and genome size estimates were elevated at 10 °C compared with 20 °C, suggesting that larger body size at low temperature could partly be accredited to an enlarged nucleus and thus cell size. Confocal microscopy observations confirmed the staining properties of fluorochromes. As differences in nucleotide numbers in response of growth temperature within a life span is unlikely, these results seem accredited to changed DNA-fluorochrome binding properties, presumably reflecting increased DNA condensation at low temperature. This implies that genome size comparisons may be impacted by ambient temperature in ectotherms. It also suggests that temperature-induced structural changes in the genome could affect cell size and for some species even body size.

  1. Strain difference in sensitivity to 3,4-dichloroaniline and insect growth regulator, fenoxycarb, in Daphnia magna

    DEFF Research Database (Denmark)

    Oda, S.; Tatarazako, N.; Dorgerloh, M;

    2007-01-01

    Acute and reproductive toxicity tests were conducted on seven strains of Daphnia magna from six laboratories in five countries. 3,4-Dichloroaniline (DCA) and fenoxycarb were used as test chemicals. Acute toxicity tests revealed that estimated EC50 (50% effective concentration) values for DCA varied...

  2. Ontwikkeling van sedimenttoxiciteits-toetsen. II De chronische toxiciteit van sediment gecontamineerd met chloorpyrifos voor Daphnia magna

    NARCIS (Netherlands)

    Roghair CJ; Wolters MAH; Huijs MPA

    1993-01-01

    This report presents several experiments carried out in a study to develop standardized sediment toxicity tests. The prolonged toxicity of chlorpyriphos (CPF) to the waterflea Daphnia magna was determined in a sediment/water-system, an elutriate and in Dutch Standard Water. The toxicity of CPF could

  3. Joint effects of a mixture of 14 chemicals on mortality and inhibition of reproduction of Daphnia magna

    NARCIS (Netherlands)

    Hermens, J.L.M.; Canton, H.; Steyger, N.; Wegman, R.

    1984-01-01

    The toxicity to Daphnia magna of a mixture of 14 aquatic pollutants with several chemical structures and probable modes of action was determined. The joint effect of this mixture on acute mortality was compared with the effects on inhibition of reproduction. The joint toxicity in the reproduction te

  4. Modeling responses of Daphnia magna to pesticide pulse exposure under varying food conditions: intrinsic versus apparent sensitivity.

    NARCIS (Netherlands)

    Pieters, Barry J; Jager, Tjalling; Kraak, Michiel H S; Admiraal, Wim

    2006-01-01

    Recent studies showed that limiting food conditions resulted in either increased or decreased sensitivity of Daphnia magna to toxicants. It remained unclear whether these contrasting food-dependent alterations in toxicity resulted from differences in intrinsic sensitivity of the daphnids or from cha

  5. The effects of food and temperature regimes on life-history responses to fish kairomones in Daphnia hyalina x galeata

    NARCIS (Netherlands)

    Doksaeter, A.; Vijverberg, J.

    2001-01-01

    Life-history responses to two concentrations of fish released info-chemicals at two temperature and food regimes were investigated for one clone of Daphnia hyalina x galeata. The presence of fish kairomones had a negative impact on size at maturity, carbon allocation to individual eggs and size of n

  6. Is the fatty acid composition of Daphnia galeata determined by the fatty acid composition of the ingested diet?

    NARCIS (Netherlands)

    Weers, P.M.M.; Siewertsen, K.; Gulati, R.D.

    1997-01-01

    1. The fatty acid (FA) composition of Daphnia galeata and their algal food was analysed and showed many similarities, however, some significant differences were also found in the relative abundance of the FA C16:4 omega 3 and docosahexaenoic acid (DHA). Their relative abundances were much lower in d

  7. Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria

    NARCIS (Netherlands)

    Cerbin, S.; Kraak, M.H.S.; De Voogt, P.; Visser, P.M.; Van Donk, E.

    2010-01-01

    The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different,

  8. Combined and single effects of pesticide carbaryl and toxic microcystis aeruginosa on the life history of Daphnia pulicaria

    NARCIS (Netherlands)

    S. Cerbin; M.H.S. Kraak; P. de Voogt; P.M. Visser; E. van Donk

    2010-01-01

    The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different,

  9. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

    DEFF Research Database (Denmark)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc;

    2016-01-01

    populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five...

  10. Development and validation of an individual based Daphnia magna population model: The influence of crowding on population dynamics

    NARCIS (Netherlands)

    Preuss, T.G.; Hammers-Wirtz, M.; Hommen, U.; Rubach, M.N.; Ratte, H.T.

    2009-01-01

    An individual-based model was developed to predict the population dynamics of Daphnia magna at laboratory conditions from individual life-history traits observed in experiments with different feeding conditions. Within the model, each daphnid passes its individual life cycle including feeding on alg

  11. The effects of probiotic bacillus for promotion of growth and feeding parameters in beluga (Huso huso larvae via feeding by bioencapsulated Artemia

    Directory of Open Access Journals (Sweden)

    Hojatollah Jafaryan

    2010-12-01

    Full Text Available In this study five species of probiotic bacillus as bacterial blend under the commercial title ofProtexin aquatic were used for bioencapsulation of Artemia urmiana (Gunther, 1899. This experimentwas conducted in a completely random design. A. urmiana naupli I was used as a vector to carryprobiotic bacillus to digestive tract of Huso huso (Linnaeus, 1758 larvae. Nauplii with threeconcentrations of bacteria, 1×105, 2×105 and 3×105 bacteria per milliliter in suspension of broth for 10hours were bioencapsulated and beluga larvae were fed by them. Beluga larvae were fed 50 percent oftheir body weight for 6 times a day. The control treatment was fed by unbioencapsulated artemia nauplii.The results indicated that the probiotic bacillus could influence on growth and feeding parameters inbeluga larvae. The final body weight and specific growth rate (SGR for weight in experimentaltreatments had significant difference in comparison to control treatment (P0.05. In experimentaltreatments the Food efficiency was increased significantly in comparison with control. The probioticbacillus had significant positive effects on conversion efficiency ratio (CER, Daily growth coefficient(DGC and average weight gain (AWG in comparison to control treatment (P-1 significantly increased (P<0.05.

  12. Potencial toxicológico frente Artemia Salina em plantas condimentares comercializadas no município de Campina Grande-PB

    Directory of Open Access Journals (Sweden)

    Emmanuel Moreira Pereira

    2015-03-01

    Full Text Available O conhecimento do potencial toxicológico das plantas é um fator primordial para estipular o limite consumível. Objetivou-se nesse trabalho avaliar o potencial toxicológico de plantas condimentares frente Artemia salina, expostas às concentrações dos extratos das plantas erva-doce (Pimpinella anisum L., pimenta malagueta (Capsicum frutescens, endro (Anethum graveolens L. e alecrim (Rosmarinus officinalis L.. O trabalho foi desenvolvido no Laboratório de Engenharia de Alimentos - LEA pertencente ao Centro de Tecnologia e Recursos Naturais da Universidade Federal de Campina Grande-PB. A erva doce apresentou uma baixa toxicidade, atingindo uma DL50 de 428ppm do extrato. Já a pimenta malagueta exibiu um comportamento similar, atingindo o seu potencial toxicológico máximo na terceira diluição com DL50 716,1ppm. Para o endro, observou-se uma baixa taxa de mortalidade, consequentemente foi considerada não toxica, apresentando a DL50, com 2.624,5ppm. O alecrim apresentou baixos percentuais de mortalidade em náuplios de Artemia, sendo a DL50 com 3.720,6ppm, sendo considerado não toxico. No entanto necessita-se de estudos mais aprofundados para caracterizar a composição química das plantas estudadas e um teste in vivo para as que apresentaram baixa toxicidade.

  13. The long-term effects of acute exposure to ionising radiation on survival and fertility in Daphnia magna.

    Science.gov (United States)

    Sarapultseva, Elena I; Dubrova, Yuri E

    2016-10-01

    The results of recent studies have provided strong evidence for the transgenerational effects of parental exposure to ionising radiation and chemical mutagens. However, the transgenerational effects of parental exposure on survival and fertility remain poorly understood. To establish whether parental irradiation can affect the survival and fertility of directly exposed organisms and their offspring, crustacean Daphnia magna were given 10, 100, 1000 and 10,000mGy of acute γ-rays. Exposure to 1000 and 10,000mGy significantly compromised the viability of irradiated Daphnia and their first-generation progeny, but did not affect the second-generation progeny. The fertility of F0 and F1Daphnia gradually declined with the dose of parental exposure and significantly decreased at dose of 100mGy and at higher doses. The effects of parental irradiation on the number of broods were only observed among the F0Daphnia exposed to 1000 and 10,000mGy, whereas the brood size was equally affected in the two consecutive generations. In contrast, the F2 total fertility was compromised only among progeny of parents that received the highest dose of 10,000mGy. We propose that the decreased fertility observed among the F2 progeny of parents exposed to 10,000mGy is attributed to transgenerational effects of parental irradiation. Our results also indicate a substantial recovery of the F2 progeny of irradiated F0Daphnia exposed to the lower doses of acute γ-rays. PMID:27288911

  14. Role of B-esterases in assessing toxicity of organophosphorus (chlorpyrifos, malathion) and carbamate (carbofuran) pesticides to Daphnia magna.

    Science.gov (United States)

    Barata, Carlos; Solayan, Arun; Porte, Cinta

    2004-02-10

    In this study, the cladoceran Daphnia magna was exposed to two model organophosphorous and one carbamate pesticides including malathion, chlorpyrifos and carbofuran to assess acetylcholinesterase (AChE) and carboxylesterase (CbE) inhibition and recovery patterns and relate those responses with individual level effects. Our results revealed differences in enzyme inhibition and recovery patterns among the studied esterase enzymes and pesticides. CbE was more sensitive to organophosphorous than AChE, whereas both CbE and AChE showed equivalent sensitivities to the carbamate carbofuran. Recovery patterns of AChE and CbE activities following exposure to the studied pesticides were similar with 80-100% recoveries taking place 12 and 96 h after exposure to organophosphorous and carbamates pesticides, respectively. The physiological role of AChE and CbE inhibition patterns in Daphnia was examined by using organophosphorous and carbamate compounds alone and with specific inhibitors of CbE. Under exposure to organophosphorous pesticides, survival of Daphnia juveniles was impaired at AChE inhibition levels higher than 50% whereas under exposure to the carbamate carbofuran low levels of AChE inhibition affected mortality. Inhibition of CbE by 80-90% increased toxicity to organophosphorous and carbamate pesticides by up to two- and four-fold, respectively. Our results suggest that both AChE and CbE enzymes are involved in determining toxicity of Daphnia to the studied chemicals and that AChE inhibition levels higher than 50% can be considered of environmental concern to Daphnia species. PMID:15036868

  15. 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...

  16. Sampling Daphnia's expressed genes: preservation, expansion and invention of crustacean genes with reference to insect genomes

    Directory of Open Access Journals (Sweden)

    Bauer Darren J

    2007-07-01

    Full Text Available Abstract Background Functional and comparative studies of insect genomes have shed light on the complement of genes, which in part, account for shared morphologies, developmental programs and life-histories. Contrasting the gene inventories of insects to those of the nematodes provides insight into the genomic changes responsible for their diversification. However, nematodes have weak relationships to insects, as each belongs to separate animal phyla. A better outgroup to distinguish lineage specific novelties would include other members of Arthropoda. For example, crustaceans are close allies to the insects (together forming Pancrustacea and their fascinating aquatic lifestyle provides an important comparison for understanding the genetic basis of adaptations to life on land versus life in water. Results This study reports on the first characterization of cDNA libraries and sequences for the model crustacean Daphnia pulex. We analyzed 1,546 ESTs of which 1,414 represent approximately 787 nuclear genes, by measuring their sequence similarities with insect and nematode proteomes. The provisional annotation of genes is supported by expression data from microarray studies described in companion papers. Loci expected to be shared between crustaceans and insects because of their mutual biological features are identified, including genes for reproduction, regulation and cellular processes. We identify genes that are likely derived within Pancrustacea or lost within the nematodes. Moreover, lineage specific gene family expansions are identified, which suggest certain biological demands associated with their ecological setting. In particular, up to seven distinct ferritin loci are found in Daphnia compared to three in most insects. Finally, a substantial fraction of the sampled gene transcripts shares no sequence similarity with those from other arthropods. Genes functioning during development and reproduction are comparatively well conserved between

  17. Mechanistic study of the toxicity of ionizing radiation in Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Parisot, F.; Alonzo, F. [Institut de Radioprotection et de Surete Nucleaire, IRSN/PRP-ENV/SERIS/LECO, Laboratoire d' Ecotoxicologie des Radionucleides, Cadarache (France); Bourdineaud, J.P. [UMR CNRS 5805 EPOC - OASU Station Marine d' Arcachon Universite Bordeaux 1, Arcachon (France); Poggiale, J.C. [Mediterranean Institute of Oceanography - MIO - UMR 7294 Pytheas Institute - OSU, Aix-Marseille University, Marseille (France)

    2014-07-01

    In the last decade, the ecological impact of ionizing radiation has emerged as a growing scientific concern for ecosystems protection. However, the assessment of potential radiological effects on the environment is hampered by both a gap of available scientific data and a lack in proven methods. Understanding how ionizing radiation affects wildlife at biologically and ecologically relevant scales is a major issue in environmental protection. This issue is one of the objectives of the Strategic Research Agenda (SRA) developed in the framework of the European program STAR (Strategy for Allied Radioecology). In this context, the present PhD project aims to evaluate chronic effects of external Cs-137 gamma radiation at low doses on a representative species of aquatic ecosystems, the cladoceran crustacean Daphnia magna. More precisely, the objectives of this study are to evaluate multi-generational effects of irradiation on: (i) genotoxic effects and their potential consequences on survival, somatic growth and fecundity, (ii) the energy budget and (iii) the population dynamics of Daphnia. An experimental design was developed to expose daphnids to low doses of ionizing radiation ranging from 0,008 to 32 mGy.h{sup -1} across 3 successive generations (75 days). DNA damages were assessed using random amplified polymorphic DNA and real time PCR (RAPD - PCR). Effects on survival, somatic growth and fecundity were monitored for 21-25 days in each generation, from hatching to release of brood 5. Our aim is to: examine a potential correlation between molecular (DNA) damage and effects observed at the individual level (survival, somatic growth and fecundity) across generations and test the suitability of DNA damage as an early indice of future trans-generational effects. As a future perspective, individual and molecular effects data will be analysed using a DEBtox model (Dynamic Energy Budget Applied to Toxicology) in order to identify the metabolic modes of action of ionizing

  18. Ecotoxicity of TiO2 to Daphnia similis under irradiation

    International Nuclear Information System (INIS)

    Graphical abstract: EC50 (mg L−1) values to TiO2 samples obtained in toxicity tests with Daphnia similis under different conditions of illumination (UV A and visible radiation) and in the dark (as standard protocols). P25: commercial sample containing 30% rutile and 70% anatase; M-S: synthesized sample containing 30% rutile and 70% anatase; Anatase-S: synthesized sample containing 100% anatase; Rutile-S: synthesized sample containing 100% rutile and P25*: commercial sample containing 100% rutile. Highlights: ► Some key physicochemical parameters of nano TiO2 explain the toxicity observed. ► Under UV A radiation, TiO2 becomes more toxic to D. similis. ► Toxicity tests of photoactive nano materials require photons as control parameter. - Abstract: Currently, there are a large number of products (sunscreen, pigments, cosmetics, plastics, toothpastes and photocatalysts) that use TiO2 nanoparticles. Due to this large production, these nanoparticles can be released into the aquatic, terrestrial and aerial environments at relative high concentration. TiO2 in natural water has the capacity to harm aquatic organisms such as the Daphnia (Cladocera) species, mainly because the photocatalytic properties of this semiconductor. However, very few toxicity tests of TiO2 nanoparticles have been conducted under irradiation. The aim of this study was to evaluate anatase and rutile TiO2 toxicity to Daphnia similis exploring their photocatalytic properties by incorporating UV A and visible radiation as a parameter in the assays. Anatase and rutile TiO2 samples at the highest concentration tested (100 mg L−1) were not toxic to D. similis, neither in the dark nor under visible light conditions. The anatase form and a mixture of anatase and rutile, when illuminated by a UV A black light with a peak emission wavelength of 360 nm, presented photo-dependent EC50 values of 56.9–7.8 mg L−1, which indicates a toxicity mechanism caused by ROS (reactive oxygen species) generation.

  19. Morphological variation and life history changes of a Daphnia hyalina population exposed to Chaoborus flavicans larvae predation (L. Candia, Northern Italy)

    OpenAIRE

    Laurence LAGORIO; Nicoletta RICCARDI; Gianluigi GIUSSANI

    2002-01-01

    The response of Daphnia populations to invertebrate predators involves morphological changes and can lead to a trade-off between growth- and reproduction-related traits. The effects of Chaoborus flavicans larvae on the Daphnia hyalina population in Lake Candia were investigated by comparing the morphometric characteristics and life history traits of the preys during one year with low predator density and one year with a ten fold higher predator density. The increase in Chaoborus density seems...

  20. An unusual type of Daphnia head shields from plankton and sediments of Himalayan lakes.

    Directory of Open Access Journals (Sweden)

    Patrizia COMOLI

    1999-02-01

    Full Text Available The paper reports the finding of a particular type of Daphnia (Ctenodaphnia, Dybowski & Grochowski 1895 head shields, found in the plankton and in the sediments of two lakes in the Khumbu Region (Nepalese Himalayas. The capsules, all of the smallest size, were characterised by the presence of a hole in the medio-dorsal region, behind the posterior median groove. The location of the hole suggests a link with the nuchal organ, which we found in the neonates of the species. The finding is important for taxonomy and provides information for discussing the current hypothesis on the biogeography of the Ctenodaphnia subgenus. Being well preserved in sediment cores, the capsules are useful tools for reconstructing past phases of active reproduction which occurred also in the past.

  1. Joint Toxicity of Two Phthalates with Waterborne Copper to Daphnia magna and Photobacterium phosphoreum.

    Science.gov (United States)

    Huang, Boyang; Li, Dinglong; Yang, Yan

    2016-09-01

    Di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) are two widely used phthalates, while Cu(II) is a common valence state of copper. They have been ubiquitously detected in the aquatic environment, but information on their joint toxicity to aquatic organisms is scarce. In this study, we evaluated the combined effects of copper and these two phthalates to Daphnia magna and Photobacterium phosphoreum by quantifying the acute toxicity expressed by the EC50 (the concentration causing 50 % of maximal effect) value. The toxicity order was DEHP + Cu(II) > DBP + Cu(II) > Cu(II) > DEHP > DBP for both test species. Antagonism effects were found in the joint toxicity of Cu(II) combined with DBP or DEHP using the toxic unit method. These findings have important implications in environmental risk assessment for phthalates in the aquatic environment in the presence of heavy metals. PMID:27385371

  2. Gravity Perception in a Cladoceran-zooplankter: Anatomy of Antennal Socket Setae of Daphnia Magna

    Science.gov (United States)

    Meyers, D. G.

    1985-01-01

    Night orientation in Daphnia magna was recently associated with setae on the basal socket of the swimming antennae. Daphnids are suspected of maintaining nocturnal equilibrium by monitoring the gravity vector through upward setal deflections caused by sinking between antennal swimming strokes. Setae appear to be hydrodynamic rheoceptors that sense the gravity vector indirectly by mechanoreceptivity to the direction and velocity of water currents. Neuroanatomical stains have revealed cell bodies at the base of the setal shafts, dendritic connections through to the distal ends of the shafts, and axonal tracts around the antennal socket connecting with an additional cell body and continuing toward the brain. These anatomical observations combined with previous scanning electron microscopy studies suggest that the setae are similar to mechanoreceptors and propreceptors used by higher crustaceans to sense water currents and gravity, and maintained balance.

  3. In vivo biodegradation of colloidal quantum dots by a freshwater invertebrate, Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Dongwook; Kim, Min Jung; Park, Chansik; Park, Jaehong [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Kyungho [Department of Environmental Health, Seoul National University, Seoul 151-742 (Korea, Republic of); Yoon, Tae Hyun, E-mail: thyoon@gmail.com [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-06-15

    Impacts of planktonic invertebrate, Daphnia magna, on the speciation of colloidal quantum dots (QD) were investigated using fluorescence spectromicroscopic technique. Well-dispersed {sup GA/TOPO}QD were prepared by forming a supramolecular assembly of hydrophobic {sup TOPO}QD with biomacromolecules (i.e., Gum Arabic, GA). Biological degradation of this nanomaterial was monitored by fluorescence spectromicroscopic methods. Our study confirmed the major uptake pathway of manufactured nanomaterials and in vivo biodegradation processes in a well-known toxicity test organism, D. magna. In addition, we also found that D. magna can induce significant deterioration of aquatic media by releasing fragments of partially degraded QD colloids. These biological processes may significantly change the predicted toxicities of nanomaterials in aquatic environments. Thus, we propose that the impacts of aquatic living organisms on the environmental fate of manufactured nanomaterials (MNs) should be carefully taken into account when assessing the risk of MNs to the environment and human health.

  4. Population developmental stage determines the recovery potential of Daphnia magna populations after fenvalerate application.

    Science.gov (United States)

    Pieters, Barry J; Liess, Matthias

    2006-10-01

    This study investigated the responses of Daphnia magna populations to pulsed exposures of the pyrethroid insecticide Fenvalerate applied during an early and a late stage of population development, and analyzed the dynamics of the subsequent recovery. A novel digital observation technique was used to describe the size and numbers of animals. High Fenvalerate concentrations caused high mortality rates during exponential population growth as well as during the food-limited stationary phase. However, recovery of populations took considerably longer in the stationary phase than in populations growing exponentially. The poor nutritional and reproductive state of food-deprived adults was indicated as the main cause of the slow recovery of populations. It is argued that populations operating at the carrying capacity of their environment are vulnerable to toxicant-induced disturbances to an extent not predictable from observations on exponentially growing populations such as are commonly used in ecotoxicology. PMID:17051815

  5. Acute and chronic toxicity of buprofezin on Daphnia magna and the recovery evaluation.

    Science.gov (United States)

    Liu, Yong; Qi, Suzhen; Zhang, Wen; Li, Xuefeng; Qiu, Lihong; Wang, Chengju

    2012-11-01

    The toxic effects of buprofezin on Daphnia magna after both chronic and acute exposures were evaluated according to OECD guidelines. A 48-h acute exposure of buprofezin resulted in daphnid immobility at an EC(50) of 0.44 mg/L. In a 14 days chronic exposure of buprofezin (0, 0.025, 0.05, 0.10 and 0.15 mg/L), the development and reproduction of daphnids were all significantly affected and the body length was more sensitive than other observed parameters. However, the adverse effects of buprofezin on parental daphnids can be passed on to their offspring and cannot be recovered in a short time. PMID:22940740

  6. Daphnia magna shows reduced infection upon secondary exposure to a pathogen.

    Science.gov (United States)

    McTaggart, Seanna J; Wilson, Philip J; Little, Tom J

    2012-12-23

    Previous pathogen exposure is an important predictor of the probability of becoming infected. This is deeply understood for vertebrate hosts, and increasingly so for invertebrate hosts. Here, we test if an initial pathogen exposure changes the infection outcome to a secondary pathogen exposure in the natural host-pathogen system Daphnia magna and Pasteuria ramosa. Hosts were initially exposed to an infective pathogen strain, a non-infective pathogen strain or a control. The same hosts underwent a second exposure, this time to an infective pathogen strain, either immediately after the initial encounter or 48 h later. We observed that an initial encounter with a pathogen always conferred protection against infection compared with controls. PMID:22875818

  7. Variation in toxicity of a current-use insecticide among resurrected Daphnia pulicaria genotypes.

    Science.gov (United States)

    Simpson, Adam M; Jeyasingh, Punidan D; Belden, Jason B

    2015-04-01

    This study examined how genotypes of Daphnia pulicaria from a single population, separated by thousands of generations of evolution in the wild, differ in their sensitivity to a novel anthropogenic stressor. These genotypes were resurrected from preserved resting eggs isolated from sediments belonging to three time periods: 2002-2008, 1967-1977, and 1301-1646 A.D. Toxicity of the organophosphate insecticide chlorpyrifos was determined through a series of acute toxicity tests. There was a significant dose-response effect in all genotypes studied. Moreover, significant variation in toxicity among genotypes within each time period was detected. Importantly, a significant effect of time period on sensitivity to chlorpyrifos was found. Analysis of the median effect concentrations (EC50s) for genotypes within each time period indicated that the 1301-1646 genotypes were 2.7 times more sensitive than the 1967-1977 genotypes. This trend may be partially explained by microevolutionary shifts in response to cultural eutrophication.

  8. Ecotoxicity of binary mixtures of Microcystis aeruginosa and insecticides to Daphnia pulex.

    Science.gov (United States)

    Asselman, J; Janssen, C R; Smagghe, G; De Schamphelaere, K A C

    2014-05-01

    In aquatic ecosystems, mixtures of chemical and natural stressors can occur which may significantly complicate risk assessment approaches. Here, we show that effects of binary combinations of four different insecticides and Microcystis aeruginosa, a toxic cyanobacteria, on Daphnia pulex exhibited distinct interaction patterns. Combinations with chlorpyrifos and tetradifon caused non-interactive effects, tebufenpyrad caused an antagonistic interaction and fenoyxcarb yielded patterns that depended on the reference model used (i.e. synergistic with independent action, additive with concentration addition). Our results demonstrate that interactive effects cannot be generalised across different insecticides, not even for those targeting the same biological pathway (i.e. tebufenpyrad and tetradifon both target oxidative phosphorylation). Also, the concentration addition reference model provided conservative predictions of effects in all investigated combinations for risk assessment. These predictions could, in absence of a full mechanistic understanding, provide a meaningful solution for managing water quality in systems impacted by both insecticides and cyanobacterial blooms.

  9. Acute toxicity evaluation of cutting fluids used in manufacturing processes to Poecilia reticulata and Daphnia magna

    Directory of Open Access Journals (Sweden)

    William Gerson Matias

    2006-09-01

    Full Text Available Grinding operations are very significant among the manufacturing processes of the metal-mechanic industry. In conventional grinding, cutting fluids are of great concern for improving productivity, but also for being hazardous to the environment. In order to contribute to the knowledge of the actual toxic effects of these products in aquatic environments, the present work assesses the toxicity potential through acute toxicity tests of three different kinds of cutting fluids, with three different usage times. The tests were carried out using the fish Poecilia reticulate and the microcrustacean Daphnia magna as test organisms. These tests made it possible to determine the Median Lethal Concentration (LC50 for the fish and the Median Effective Concentration (EC50 for the microcrustacean. The results indicate that, after storage, the toxicity potential of cutting fluids decreases. However, in the three situations investigated, the product presented a high toxicity potential, which reinforces the need of special care in its handling, usage and disposal.

  10. Chronic effects of Pinus radiata and Eucalyptus globulus kraft mill effluents and phytosterols on Daphnia magna.

    Science.gov (United States)

    López, D; Chamorro, S; Silva, J; Bay-Schmith, E; Vidal, G

    2011-12-01

    Two kraft pulp mill effluents were compared in terms of their chronic toxicity to Daphnia magna. One resulted from pulping Pinus radiata and the other came from a parallel processing of Pinus radiata and Eucalyptus globulus (mixed kraft pulp mill effluent). The concentration of phytosterols found in the mixed kraft pulp mill effluent was higher than in the effluent from Pinus radiata, with values of 0.1082 and 0.02 μg/L, respectively. The phytosterols per se are responsible for 12.9% and 8.1% of the deviation from the natural shape, while the kraft pulp mill effluents account for 25.6%-27.8% of shape deviation. The role of β-sitosterol and stigmasterol is discussed in relation to endocrine disruption. PMID:21979137

  11. The forgotten cue: Daphnia bears a not yet described gravireceptive organ system

    Science.gov (United States)

    Laforsch, Christian; Fischer, Jessica; Wolfschoon Ribeiro, Bernard; Schoppmann, Kathrin; Trotter, Benjamin

    Gravity has been the only constant environmental factor in evolution of life. For plenty of pelagic organisms it is the only reliable cue for orientation in a three dimensional space especially in turbid or completely dark waters. However, there is a considerable lack of knowledge about gravisensing mechanisms in a huge variety of plankton organisms. Here we introduce a novel mechanoreceptive organ system in the model organism Daphnia functioning as a sinking receptor for the detection of the gravitational field. This organ is connected to two prominent appendages known as the postabdominal setae with so far unknown functioning. Our morphological and behavioural studies show, that the organ system is involved in gravisensing by a passive deflection mechanism not yet described in the animal kingdom. The description of this bifunctional mechanoreceptor will help to elucidate general gravity-related mechanisms valid for other organisms as well and may therefore increase our knowledge on the evolution of graviperception in aquatic ecosystems.

  12. The Neurophysiological Effects of Guarana and Ethanol Intake on Daphnia magna

    Directory of Open Access Journals (Sweden)

    Rebecca E. Kohn

    2009-01-01

    Full Text Available In recent years, the consumption of energy drinks and alcoholic beverages has become a prevalent habit, especially among younger generations. However, there is little scientific research surrounding the interaction of ethanol and the natural stimulant guarana, which is being utilized more frequently as the main caffeine source in energy drinks. This study utilized Daphnia magna (D. magna as a model organism to observe alterations in the functioning of the central nervous system when exposed to both ethanol and guarana in a series of time trials. As expected, ethanol significantly decreased the overall heart rate of the D. magna, while guarana increased it. In combination, the depressant effects of ethanol decreased the stimulating effects of guarana, as our results displayed a statistically significant reduction of heart rate. Therefore we propose that our findings indicated that the alcohol effects may be stronger than the effects of guarana.

  13. Joint Toxicity of Two Phthalates with Waterborne Copper to Daphnia magna and Photobacterium phosphoreum.

    Science.gov (United States)

    Huang, Boyang; Li, Dinglong; Yang, Yan

    2016-09-01

    Di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) are two widely used phthalates, while Cu(II) is a common valence state of copper. They have been ubiquitously detected in the aquatic environment, but information on their joint toxicity to aquatic organisms is scarce. In this study, we evaluated the combined effects of copper and these two phthalates to Daphnia magna and Photobacterium phosphoreum by quantifying the acute toxicity expressed by the EC50 (the concentration causing 50 % of maximal effect) value. The toxicity order was DEHP + Cu(II) > DBP + Cu(II) > Cu(II) > DEHP > DBP for both test species. Antagonism effects were found in the joint toxicity of Cu(II) combined with DBP or DEHP using the toxic unit method. These findings have important implications in environmental risk assessment for phthalates in the aquatic environment in the presence of heavy metals.

  14. The effects of food availability on growth and reproduction of Daphnia magna exposed to silver nanoparticles

    DEFF Research Database (Denmark)

    Mackevica, Aiga; Skjolding, Lars Michael; Gergs, A.;

    to controls, whereas concentrations above 10 μgAg/L resulted in inhibition of growth and reproduction as well as an increased mortality. The addition of higher amounts of food showed a beneficial effect on animal survival, growth and reproduction. Similar as in normal food availability treatment, animals...... time were measured by ICP-OES and the size of the particles in the medium was measured with DLS. With standard food treatment no significant effects were observed for concentrations lower than 10 μgAg/L. The animals exposed to 10 μgAg/L were slightly bigger and produced more offspring in comparison......The number of available studies on the acute effects of silver nanoparticles (AgNP) on aquatic organisms has increased dramatically in recent years, but there is still very limited information available on chronic effects. In this study, a series of Daphnia magna 21-days reproduction test (OECD 211...

  15. Daphnia as a model organism in limnology and aquatic biology: some aspects of its reproduction and development

    Directory of Open Access Journals (Sweden)

    Adam Petrusek

    2011-08-01

    Full Text Available Invertebrates comprise the overwhelming majority of all animal species - around 95% of described species, not including substantial cryptic variation. As it is an extremely diverse and heterogeneous group, research on various invertebrate taxa often follows parallel trajectories, with little interaction among experts on different groups. To promote sharing of knowledge within as well as across taxa, the International Society of Invertebrate Reproduction and Development (ISIRD was established in 1975 in Calicut, India. Since that time, the ISIRD has organised international conferences at three-year intervals where various aspects of invertebrate biology are presented and discussed, naturally with the focus on reproduction and development. Traditionally, marine invertebrate groups have been well represented at all ISIRD congresses, but freshwater invertebrates have often been relatively overlooked at these meetings. The 12th ISIRD congress took place between August 16 and 20, 2010 in Prague, the Czech Republic. Several different Czech institutions collaborated on the organisation of this meeting. As aquatic invertebrate research has a long tradition in the country, we decided to include a section dedicated to popular model organisms in aquatic ecology and evolutionary biology, the "water fleas", cladocerans of the genus Daphnia. The section entitled "Daphnia and other cladocerans as model organisms" was open to any aspects of cladoceran biology directly or indirectly related to their reproduction or development. Unfortunately, the timing of the Prague congress completely overlapped the triennial congress of the International Society of Theoretical and Applied Limnology (SIL in Cape Town, South Africa. This large meeting in a very attractive setting attracted many cladocerologists from all over the world, including Europe. Therefore, the Daphnia section of the Prague ISIRD meeting remained moderate in size, attracting 13 contributions (eight talks

  16. The effects of acclimation and rates of temperature change on critical thermal limits in Tenebrio molitor (Tenebrionidae) and Cyrtobagous salviniae (Curculionidae).

    Science.gov (United States)

    Allen, Jessica L; Clusella-Trullas, Susana; Chown, Steven L

    2012-05-01

    Critical thermal limits provide an indication of the range of temperatures across which organisms may survive, and the extent of the lability of these limits offers insights into the likely impacts of changing thermal environments on such survival. However, investigations of these limits may be affected by the circumstances under which trials are undertaken. Only a few studies have examined these effects, and typically not for beetles. This group has also not been considered in the context of the time courses of acclimation and its reversal, both of which are important for estimating the responses of species to transient temperature changes. Here we therefore examine the effects of rate of temperature change on critical thermal maxima (CT(max)) and minima (CT(min)), as well as the time course of the acclimation response and its reversal in two beetle species, Tenebrio molitor and Cyrtobagous salviniae. Increasing rates of temperature change had opposite effects on T. molitor and C. salviniae. In T. molitor, faster rates of change reduced both CT(max) (c. 2°C) and CT(min) (c. 3°C), while in C. salviniae faster rates of change increased both CT(max) (c. 6°C) and CT(min) (c. 4°C). CT(max) in T. molitor showed little response to acclimation, while the response to acclimation of CT(min) was most pronounced following exposure to 35°C (from 25°C) and was complete within 24 h. The time course of acclimation of CT(max) in C. salviniae was 2 days when exposed to 36°C (from c. 26°C), while that of CT(min) was less than 3 days when exposed to 18°C. In T. molitor, the time course of reacclimation to 25°C after treatments at 15°C and 35°C at 75% RH was longer than the time course of acclimation, and varied from 3-6 days for CT(max) and 6 days for CT(min). In C. salviniae, little change in CT(max) and CT(min) (<0.5°C) took place in all treatments suggesting that reacclimation may only occur after the 7 day period used in this study. These results indicate that both T

  17. Evolutionary factors affecting Lactate dehydrogenase A and B variation in the Daphnia pulex species complex

    Directory of Open Access Journals (Sweden)

    Cristescu Melania E

    2011-07-01

    Full Text Available Abstract Background Evidence for historical, demographic and selective factors affecting enzyme evolution can be obtained by examining nucleotide sequence variation in candidate genes such as Lactate dehydrogenase (Ldh. Two closely related Daphnia species can be distinguished by their electrophoretic Ldh genotype and habitat. Daphnia pulex populations are fixed for the S allele and inhabit temporary ponds, while D. pulicaria populations are fixed for the F allele and inhabit large stratified lakes. One locus is detected in most allozyme surveys, but genome sequencing has revealed two genes, LdhA and LdhB. Results We sequenced both Ldh genes from 70 isolates of these two species from North America to determine if the association between Ldh genotype and habitat shows evidence for selection, and to elucidate the evolutionary history of the two genes. We found that alleles in the pond-dwelling D. pulex and in the lake-dwelling D. pulicaria form distinct groups at both loci, and the substitution of Glutamine (S for Glutamic acid (F at amino acid 229 likely causes the electrophoretic mobility shift in the LDHA protein. Nucleotide diversity in both Ldh genes is much lower in D. pulicaria than in D. pulex. Moreover, the lack of spatial structuring of the variation in both genes over a wide geographic area is consistent with a recent demographic expansion of lake populations. Neutrality tests indicate that both genes are under purifying selection, but the intensity is much stronger on LdhA. Conclusions Although lake-dwelling D. pulicaria hybridizes with the other lineages in the pulex species complex, it remains distinct ecologically and genetically. This ecological divergence, coupled with the intensity of purifying selection on LdhA and the strong association between its genotype and habitat, suggests that experimental studies would be useful to determine if variation in molecular function provides evidence that LDHA variants are adaptive.

  18. Population genetics of duplicated alternatively spliced exons of the Dscam gene in Daphnia and Drosophila.

    Directory of Open Access Journals (Sweden)

    Daniela Brites

    Full Text Available In insects and crustaceans, the Down syndrome cell adhesion molecule (Dscam occurs in many different isoforms. These are produced by mutually exclusive alternative splicing of dozens of tandem duplicated exons coding for parts or whole immunoglobulin (Ig domains of the Dscam protein. This diversity plays a role in the development of the nervous system and also in the immune system. Structural analysis of the protein suggested candidate epitopes where binding to pathogens could occur. These epitopes are coded by regions of the duplicated exons and are therefore diverse within individuals. Here we apply molecular population genetics and molecular evolution analyses using Daphnia magna and several Drosophila species to investigate the potential role of natural selection in the divergence between orthologs of these duplicated exons among species, as well as between paralogous exons within species. We found no evidence for a role of positive selection in the divergence of these paralogous exons. However, the power of this test was low, and the fact that no signs of gene conversion between paralogous exons were found suggests that paralog diversity may nonetheless be maintained by selection. The analysis of orthologous exons in Drosophila and in Daphnia revealed an excess of non-synonymous polymorphisms in the epitopes putatively involved in pathogen binding. This may be a sign of balancing selection. Indeed, in Dr. melanogaster the same derived non-synonymous alleles segregate in several populations around the world. Yet other hallmarks of balancing selection were not found. Hence, we cannot rule out that the excess of non-synonymous polymorphisms is caused by segregating slightly deleterious alleles, thus potentially indicating reduced selective constraints in the putative pathogen binding epitopes of Dscam.

  19. Feeding inhibition explains effects of imidacloprid on the growth, maturation, reproduction, and survival of Daphnia magna.

    Science.gov (United States)

    Agatz, Annika; Cole, Tabatha A; Preuss, Thomas G; Zimmer, Elke; Brown, Colin D

    2013-03-19

    Effects of some xenobiotics on aquatic organisms might not be caused directly by the compound but rather arise from acclimation of the organism to stress invoked by feeding inhibition during exposure. Experiments were conducted to identify effects of imidacloprid on individual performance (feeding, growth, maturation, reproduction, and survival) of Daphnia magna under surplus and reduced food availability. Concentrations inhibiting feeding by 5, 50, and 95% after one day of exposure were 0.19, 1.83, and 8.70 mg/L, respectively. Exposure with imidacloprid at ≥ 3.7 mg/L reduced growth by up to 53 ± 11% within one week. Surplus food availability after inhibition allowed recovery from this growth inhibition, whereas limited food supply eliminated the potential for recovery in growth even for exposure at 0.15 mg/L. A shift in the distribution of individual energy reserves toward reproduction rather than growth resulted in increased reproduction after exposure to concentrations ≤ 0.4 mg/L. Exposure to imidacloprid at ≥ 4.0 mg/L overwhelmed this adaptive response and reduced reproduction by up to 57%. We used the individual based Daphnia magna population model IDamP as a virtual laboratory to demonstrate that only feeding was affected by imidacloprid, and that in turn this caused the other impacts on individual performance. Consideration of end points individually would have led to a different interpretation of the effects. Thus, we demonstrate how multiple lines of evidence linked by understanding the ecology of the organism are necessary to elucidate xenobiotic impacts along the effect cascade. PMID:23425205

  20. Diversity in the reproductive modes of European Daphnia pulicaria deviates from the geographical parthenogenesis.

    Directory of Open Access Journals (Sweden)

    France Dufresne

    Full Text Available BACKGROUND: Multiple transitions to obligate parthenogenesis have occurred in the Daphnia pulex complex in North America. These newly formed asexual lineages are differentially distributed being found predominantly at high latitudes. This conforms to the rule of geographical parthenogenesis postulating prevalence of asexuals at high latitudes and altitudes. While the reproductive mode of high-latitude populations is relatively well studied, little is known about the reproduction mode in high altitudes. This study aimed to assess the reproductive mode of Daphnia pulicaria, a species of the D. pulex complex, from high altitude lakes in Europe. METHODOLOGY/PRINCIPAL FINDINGS: Variation at eight microsatellite loci revealed that D. pulicaria from the High Tatra Mountains (HTM had low genotype richness and showed excess of heterozygotes and significant deviations from Hardy-Weinberg expectations, and was thus congruent with reproduction by obligate parthenogenesis. By contrast, populations from the Pyrenees (Pyr were generally in Hardy-Weinberg equilibrium and had higher genotypic richness, suggesting that they are cyclic parthenogens. Four lakes from lowland areas (LLaP had populations with an uncertain or mixed breeding mode. All D. pulicaria had mtDNA ND5 haplotypes of the European D. pulicaria lineage. Pyr were distinct from LLaP and HTM at the ND5 gene. By contrast, HTM shared two haplotypes with LLaP and one with Pyr. Principal Coordinate Analysis of the microsatellite data revealed clear genetic differentiation into three groups. HTM isolates were intermediate to Pyr and LLaP, congruent with a hybrid origin. CONCLUSION/SIGNIFICANCE: Inferred transitions to obligate parthenogenesis have occurred only in HTM, most likely as a result of hybridizations. In contrast to North American populations, these transitions do not appear to involve meiosis suppressor genes and have not been accompanied by polyploidy. The absence of obligate parthenogenesis

  1. Meiosis genes in Daphnia pulex and the role of parthenogenesis in genome evolution

    Directory of Open Access Journals (Sweden)

    Eads Brian D

    2009-04-01

    Full Text Available Abstract Background Thousands of parthenogenetic animal species have been described and cytogenetic manifestations of this reproductive mode are well known. However, little is understood about the molecular determinants of parthenogenesis. The Daphnia pulex genome must contain the molecular machinery for different reproductive modes: sexual (both male and female meiosis and parthenogenetic (which is either cyclical or obligate. This feature makes D. pulex an ideal model to investigate the genetic basis of parthenogenesis and its consequences for gene and genome evolution. Here we describe the inventory of meiotic genes and their expression patterns during meiotic and parthenogenetic reproduction to help address whether parthenogenesis uses existing meiotic and mitotic machinery, or whether novel processes may be involved. Results We report an inventory of 130 homologs representing over 40 genes encoding proteins with diverse roles in meiotic processes in the genome of D. pulex. Many genes involved in cell cycle regulation and sister chromatid cohesion are characterized by expansions in copy number. In contrast, most genes involved in DNA replication and homologous recombination are present as single copies. Notably, RECQ2 (which suppresses homologous recombination is present in multiple copies while DMC1 is the only gene in our inventory that is absent in the Daphnia genome. Expression patterns for 44 gene copies were similar during meiosis versus parthenogenesis, although several genes displayed marked differences in expression level in germline and somatic tissues. Conclusion We propose that expansions in meiotic gene families in D. pulex may be associated with parthenogenesis. Taking into account our findings, we provide a mechanistic model of parthenogenesis, highlighting steps that must differ from meiosis including sister chromatid cohesion and kinetochore attachment.

  2. Determinación de la toxicidad aguda (cl50) del extracto de polvillo de carbón frente a larvas de artemia franciscana

    OpenAIRE

    Pacheco Gómez, Jesús David

    2011-01-01

    El carbón es una de las fuentes de energía más utilizada, su uso es globalizado y está muy ligado con el desarrollo industrial, sin embargo, es considerado como el contaminante de fuente de energía fósil más importante del mundo y su explotación está relacionada con la aparición de efectos tóxicos en diferentes organismos. El presente estudio tuvo por objetivo determinar la concentración letal media (CL50) del extracto metanólico de polvillo de carbón frente a larvas de Artemia franciscana; l...

  3. The Cytotoxicity Study of Carboxymethyl Starch (CMS) of Sago Starch (Metro xylon sago) by Brine Shrimp Lethality Test (Artemia salina nauplii)

    International Nuclear Information System (INIS)

    CMS can be produced by substitution of the hydroxyl groups with sodium monochloroacetate in the presence of strong alkali. Carboxy methylation can be performed in water as a solvent or in a water-miscible organic solvent containing a small amount of water such as ethanol, isopropanol, methanol or toluene. The use of organic solvent will preserve the final product in the granular form and the side product can be washed out easily but some of them may be having potential toxicity and carcinogenic effect. In this study, CMS was investigated the level of toxicity by using brine shrimp lethality (BSLT). Brine shrimp test method was used to screen CMS for their biological activity. The screening results showed that the LC50, of CMS is more than 100 mg/ ml dose concentration. In conclusion, CMS is not cytotoxicity to Artemia salina nauplii and BSLT method is simple, inexpensive and convenient assay for the detection of cytotoxic compound. (author)

  4. The efficiency of a new hydrodynamic cavitation pilot system on Artemia salina cysts and natural population of copepods and bacteria under controlled mesocosm conditions.

    Science.gov (United States)

    Cvetković, Martina; Grego, Mateja; Turk, Valentina

    2016-04-15

    A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential. PMID:26902683

  5. Toxic effects of Pseudanabaena tenuis (Cyanobacteria) on the cladocerans Daphnia magna and Ceriodaphnia dubia Efectos tóxicos de Pseudanabaena tenuis (Cyanobacteria) en los cladóceros Daphnia magna y Ceriodaphnia dubia

    OpenAIRE

    Roxana Olvera-Ramírez; Carla Centeno-Ramos; Fernando Martínez-Jerónimo

    2010-01-01

    Some cyanobacteria can produce toxins that affect the aquatic biota and represent a human health risk. The cyanobacterium Pseudanabaena tenuis was isolated from the Valle de Bravo dam, and cultured in the laboratory under controlled conditions. We determined the acute toxic effects and performed a chronic (consumption) test in the cladocerans Daphnia magna (a reference test organism) and Ceriodaphnia dubia (a cosmopolitan species). To determine acute toxicity, three exposure ways were assayed...

  6. Isolation of TDA-producing Phaeobacter strains from sea bass larval rearing units and their probiotic effect against pathogenic Vibrio spp. in Artemia cultures.

    Science.gov (United States)

    Grotkjær, Torben; Bentzon-Tilia, Mikkel; D'Alvise, Paul; Dourala, Nancy; Nielsen, Kristian Fog; Gram, Lone

    2016-05-01

    Fish-pathogenic Vibrio can cause large-scale crashes in marine larval rearing units and, since the use of antibiotics can result in bacterial antibiotic resistance, new strategies for disease prevention are needed. Roseobacter-clade bacteria from turbot larval rearing facilities can antagonize Vibrio anguillarum and reduce mortality in V. anguillarum-infected cod and turbot larvae. In this study, it was demonstrated that antagonistic Roseobacter-clade bacteria could be isolated from sea bass larval rearing units. In addition, it was shown that they not only antagonized V. anguillarum but also V. harveyi, which is the major bacterial pathogen in crustaceans and Mediterranean sea bass larvae cultures. Concomitantly, they significantly improved survival of V. harveyi-infected brine shrimp. 16S rRNA gene sequence homology identified the antagonists as Phaeobacter sp., and in silico DNA-DNA hybridization indicated that they could belong to a new species. The genomes contained genes involved in synthesis of the antibacterial compound tropodithietic acid (TDA), and its production was confirmed by UHPLC-TOFMS. The new Phaeobacter colonized live feed (Artemia) cultures and reduced Vibrio counts significantly, since they reached only 10(4)CFUmL(-1), as opposed to 10(8)CFUmL(-1) in non-Phaeobacter treated controls. Survival of V. anguillarum-challenged Artemia nauplii was enhanced by the presence of wild type Phaeobacter compared to challenged control cultures (89±1.0% vs 8±3.2%). In conclusion, TDA-producing Phaeobacter isolated from Mediterranean marine larviculture are promising probiotic bacteria against pathogenic Vibrio in crustacean live-feed cultures for marine fish larvae. PMID:26922490

  7. Rheoceptive mediators of graviperception in a water flea: Morphological implications of antennal-socket setae in daphnia magna

    Science.gov (United States)

    Meyers, D. G.

    1984-01-01

    Aquatic microcrustaceans of the genus Daphnia are known to orient to light during the day. At night, in the absence of visual cues, daphnids were suspected of maintaining equilibrium by monitoring the direction of gravity through their swimming antennae. Recent investigations using simulated, weightlessness conditions coupled with absence of illumination revealed hair like structures or setae on the basal, articulating socket of the antennae that, when surgically removed, resulted in disorientation. Given the simulated weightlessness or neutrally buoyant condition that eliminated sinking of the normally negatively buoyant Daphnia, it was proposed that the antennal socket setae function as rheoceptors stimulated by the upward rush of water currents during gravity induced, sinking phase of daphnid swimming movements. This rheoceptively mediated, gravity perception hypothesis is further supported by morphological investigations. Scanning electron micrographs indicate that antennal socket setae are anatomically similar to proprioceptors used by higher crustaceans to monitor gravitational direction.

  8. Local adaptation to higher temperatures reduces immigration success of genotypes from a warmer region in the water flea Daphnia

    OpenAIRE

    Van Doorslaer, Wendy; Vanoverbeke, Joost; Duvivier, Cathy; Rousseaux, Sarah; Jansen, Mieke; Jansen, Bastiaan; Feuchtmayr, Heidrun; Atkinson, David; Moss, Brian; Stoks, Robby; De Meester, Luc

    2009-01-01

    There is growing awareness that microevolutionary dynamics may alter ecological processes. Rising temperatures under global change are expected to open windows for establishment of species and genotypes from warmer regions. Yet, microevolutionary tracking of temperature change by local populations may reduce establishment success of these immigrants. We exposed a UK population of the water flea, Daphnia magna, to two temperature regimes during a 1.5-year experimental evolution trial, and subs...

  9. Clone- and age-dependent toxicity of a glyphosate commercial formulation and its active ingredient in Daphnia magna.

    OpenAIRE

    Cuhra, Marek; Traavik, Terje; Bøhn, Thomas

    2013-01-01

    Low levels of glyphosate based herbicide induced significant negative effects on the aquatic invertebrate Daphnia magna. Glyphosate herbicides such as brands of Roundup, are known to be toxic to daphnids. However, published findings on acute toxicity show significant discrepancies and variation across several orders of magnitude. To test the acute effects of both glyphosate and a commercial formulation of Roundup (hereafter Roundup), we conducted a series of exposure experiments with differen...

  10. Sequence Conservation and Sexually Dimorphic Expression of the Ftz-F1 Gene in the Crustacean Daphnia magna

    OpenAIRE

    Nur Syafiqah Mohamad Ishak; Yasuhiko Kato; Tomoaki Matsuura; Hajime Watanabe

    2016-01-01

    Identifying the genes required for environmental sex determination is important for understanding the evolution of diverse sex determination mechanisms in animals. Orthologs of Drosophila orphan receptor Fushi tarazu factor-1 (Ftz-F1) are known to function in genetic sex determination. In contrast, their roles in environmental sex determination remain unknown. In this study, we have cloned and characterized the Ftz-F1 ortholog in the branchiopod crustacean Daphnia magna, which produces males ...

  11. Nano-TiO{sub 2} enhances the toxicity of copper in natural water to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Fan Wenhong, E-mail: fanwh@buaa.edu.cn [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Cui Minming [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Liu Hong; Wang Chuan [Research Center for Green Chemistry and Engineering, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Shi Zhiwei; Tan Cheng; Yang Xiuping [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2011-03-15

    The acute toxicity of engineered nanoparticles (NPs) in aquatic environments at high concentrations has been well-established. This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna by increasing the copper bioaccumulation. Specifically, at 2 mg L{sup -1} nano-TiO{sub 2}, the (LC{sub 50}) of Cu{sup 2+} concentration observed to kill half the population, decreased from 111 {mu}g L{sup -1} to 42 {mu}g L{sup -1}. Correspondingly, the level of metallothionein decreased from 135 {mu}g g{sup -1} wet weight to 99 {mu}g g{sup -1} wet weight at a Cu{sup 2+} level of 100 {mu}g L{sup -1}. The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the animals, thereby causing toxic injury. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification by metallothioneins. - Research highlights: > This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. > The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the Daphnia magna, thereby causing toxic injury. > The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein. - The nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein.

  12. Chronic toxicity of hydrogen peroxide to Daphnia magna in a continuous exposure, flow-through test system

    Science.gov (United States)

    Meinertz, J.R.; Greseth, Shari L.; Gaikowski, M.P.; Schmidt, L.J.

    2008-01-01

    A flow-through, continuous exposure test system was developed to expose Daphnia magna to an unstable compound. 35% Perox-Aid?? is a specially formulated hydrogen peroxide (a highly oxidative chemical) product approved for use in U.S. aquaculture and therefore has the potential to be released from aquaculture facilities and pose a risk to aquatic invertebrates. The study objective was to assess the effects of 35% Perox-Aid?? on an aquatic invertebrate by evaluating the survival, growth, production, and gender ratio of progeny from a representative aquatic invertebrate continuously exposed to 35% Perox-Aid??. The study design consisted of 6 treatment groups (10 test chambers each) with target hydrogen peroxide concentrations of 0.0, 0.32, 0.63, 1.25, 2.5, and 5.0??mg L- 1. The study was initiated with hydrogen peroxide for 21??days. Hydrogen peroxide concentrations ??? 1.25??mg L- 1 had no significant effect on Daphnia time to death compared to controls and no significant effect on the time to first brood production and the number of broods produced. Concentrations ??? 0.63??mg L- 1 had no significant effect on the total number of young produced. Concentrations ??? 0.32??mg L- 1 had a negative effect on Daphnia growth. Hydrogen peroxide had no significant effect on the gender ratio of young produced. All second generation Daphnia were female. A continuous discharge of hydrogen peroxide into aquatic ecosystems is not likely to affect cladocerans if the concentration is maintained at ??? 0.63??mg L- 1 for less than 21??days.

  13. The Time- and Age-dependent Effects of the Juvenile Hormone Analog Pesticide, Pyriproxyfen on Daphnia magna Reproduction

    OpenAIRE

    Ginjupalli, Gautam K.; Baldwin, William S.

    2013-01-01

    Pyriproxyfen is an insecticidal juvenile hormone analog that perturbs insect and tick development. Pyriproxyfen also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects. In this study, we investigate the impacts of pyriproxyfen on Daphnia magna reproduction using a series of male production screening assays. These assays demonstrate that p...

  14. Development and evaluation of new behavioral indexes for a biological early warning system using Daphnia magna

    OpenAIRE

    T. Y. Jeong; Jeon, J. H.; Kim, S. D.

    2013-01-01

    New behavioral indexes including combined index (CI), distribution index (DI), toxic index (TI), and altitude index (AI) for a biological early warning system (BEWS) were developed and evaluated using Daphnia magna in this study. The sensitivity and stability of each index were compared to evaluate the performance of the indexes through a real-time exposure test with a synthetic copper solution. The applicability of the CI to the field sample was evaluated through an effluent exposure test. T...

  15. Morphology and ecology of Daphnia middendorffiana, Fisher 1851 (Crustacea, Daphniidae from four new populations in the Alps

    Directory of Open Access Journals (Sweden)

    Rocco TIBERTI

    2011-08-01

    Full Text Available Daphnia middendorffiana has an arctic, circumpolar distribution, with some isolated southerly populations restricted to mountainous areas, including the Alps. In this paper, new records of Daphnia middendorffiana on the Alps are reported. The species was regularly recorded in several samples collected from 2006 to 2009 in four high altitude lakes in the Gran Paradiso National Park (GPNP during the ice free period. This is the third finding for the Alps and the described populations are the largest. Chemical and morphometric features of the lakes are provided, the morphology of the Daphnia middendorffiana from GPNP is described as well as some aspects concerning its ecology. The studied lakes are small, oligotrophic (total phosphorus ranged from 0 to 7 μg L-1 and well preserved from acidification risk (pH ranged from 6.45 to 8.14. D. middendorffiana is the largest zooplanktonic crustacean inhabiting the Alpine lakes in GPNP reaching 3.43 mm in length; the morphological analysis noted some differences within the studied populations; however there is a clear resemblance to the only Alpine population previously described (from Central Alps, Bognanco Valley, Lake Campo IV and to the arctic populations. D. middendorffiana in GPNP lives at low density levels, reaching higher densities in late August and early September. No males have been found during the sample campaign confirming its ability to produce asexual viable diapauses eggs. This study confirms the attitude of this species for cold and oligotrophic waters and increases the current knowledge on the geographical distribution, morphology and ecology of this species in Alpine environments. The finding of D. middendordorffiana in the GPNP poses interesting issues concerning the phylogeography of Alpine Daphnia middendorffiana, as well as raising need for conservation efforts aimed at keeping the populations safe from several global and local threats, such as climate warming and the ecological

  16. Propriedade inseticida dos óleos essenciais de Piper hispidinervum C. DC.; Piper aduncum L. e Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum sobre Tenebrio molitor L., 1758 Insecticidal properties of essential oils of Piper hispidinervum C. DC.; Piper aduncum L. and Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum against Tenebrio molitor L., 1758

    Directory of Open Access Journals (Sweden)

    Murilo Fazolin

    2007-02-01

    Full Text Available Óleos essenciais das piperáceas Piper aduncum L., Piper hispidinervum C. DC. e da bignoniácea Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum foram avaliados para o controle de larvas de Tenebrio molitor L., 1758. Para a avaliação do efeito por contato em superfície contaminada, foram utilizados papéis-filtro impregnados com diferentes quantidades dos óleos essenciais. Para a avaliação do efeito tópico foram aplicados 5 mL de soluções com diferentes concentrações dos óleos sobre larvas de quinto instar do inseto. A taxa de mortalidade foi a variável utilizada para avaliar os experimentos. Todos os óleos essenciais apresentaram efeito inseticida sobre larvas de T. molitor, sendo que as respostas variaram em função da concentração utilizada, assim como do método de exposição do inseto. A toxicidade dos óleos essenciais foi elevada apresentando os seguintes valores de CL50: 0,045; 0,033 e 1,515 mL de óleo cm-2 para exposição por contato (papel filtro aos óleos de P. hispidinervum,P. aduncum e T. nocturnum, respectivamente. Para a aplicação tópica, os valores da DL50 foram de: 0,000025; 0,009 e 0,000015 mL de óleo mg de inseto -1 para os óleos essenciais de P. hispidinervum,P. aduncum e T. nocturnum, respectivamente. Resultados promissores para o emprego desses óleos essenciais como inseticidas foram obtidos utilizando-se concentrações acima de 3,0% (v v-1 para P. hispidinervum e 2,5% (v v-1 para P. aduncum e T. nocturnum.Essential oils from Piper aduncum L., Piper hispidinervum C. DC. (Piperaceae and Tanaecium nocturnum (Barb. Rodr. Bur.& K. Shum (Bignoniaceae were tested against Tenebrio molitor L., 1758 larvaes. Filter paper with different amounts of oils were employed for contact toxicity effects study. For topical effect study, aliquots of 5 mL of oils at different concentrations were applied on larvaes of the fifth instar. Mortality rate was used to evaluate the assays. All essential oils possessed

  17. Can the teleconnection indices explain the interannual variability of Daphnia phenology ? A case study in Lake Iseo, northern Italy.

    Science.gov (United States)

    Beluzzi, Stefano; Leoni, Barbara; Salmaso, Nico; Manca, Marina

    2013-04-01

    In the last years, increasing interest has been shown on the impact of inter-annual climate variability on zooplankton. Several teleconnection indices have been successfully applied in order to explain inter-annual variations in zooplankton and phytoplankton seasonal dynamics. During the winter months (December-February), the East Atlantic pattern (EADJF) and the Eastern Mediterranean Pattern (EMPDJF) showed a clear relationship with the variables directly connected with the winter climate and limnological variables in the large lakes south of the Alps. A recent study carried out in the lakes Maggiore and Garda confirmed that the impact of the winter large scale atmospheric patterns was detectable also on the phenology of Daphnia populations. We extended the same approach to zooplankton of Lake Iseo, the fourth largest and deepest italian lake, with costant characteristic of meso-eutrophy during last decades. We analysed data from 1998 to 2012, focusing on population dynamics of Daphnia sp., the most important larger filter feeder in this lake. The results showed a link between the interannual climate fluctuations and the development of Daphnia. Our observations are consistent with the patterns obtained in the lakes Maggiore and Garda. Overall, the results confirm that these indices may help to detect and predict the effect of the impact of climate change on populations and freshwater ecosystems.

  18. Acute and Chronic Toxicity of Soluble Fractions of Industrial Solid Wastes on Daphnia magna and Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Letícia Flohr

    2012-01-01

    Full Text Available Industrial wastes may produce leachates that can contaminate the aquatic ecosystem. Toxicity testing in acute and chronic levels is essential to assess environmental risks from the soluble fractions of these wastes, since only chemical analysis may not be adequate to classify the hazard of an industrial waste. In this study, ten samples of solid wastes from textile, metal-mechanic, and pulp and paper industries were analyzed by acute and chronic toxicity tests with Daphnia magna and Vibrio fischeri. A metal-mechanic waste (sample MM3 induced the highest toxicity level to Daphnia magna(CE50,48 h=2.21%. A textile waste induced the highest toxicity level to Vibrio fischeri (sample TX2, CE50,30 min=12.08%. All samples of pulp and paper wastes, and a textile waste (sample TX2 induced chronic effects on reproduction, length, and longevity of Daphnia magna. These results could serve as an alert about the environmental risks of an inadequate waste classification method.

  19. Acute and Chronic Toxicity of Soluble Fractions of Industrial Solid Wastes on Daphnia magna and Vibrio fischeri

    Science.gov (United States)

    Flohr, Letícia; de Castilhos Júnior, Armando Borges; Matias, William Gerson

    2012-01-01

    Industrial wastes may produce leachates that can contaminate the aquatic ecosystem. Toxicity testing in acute and chronic levels is essential to assess environmental risks from the soluble fractions of these wastes, since only chemical analysis may not be adequate to classify the hazard of an industrial waste. In this study, ten samples of solid wastes from textile, metal-mechanic, and pulp and paper industries were analyzed by acute and chronic toxicity tests with Daphnia magna and Vibrio fischeri. A metal-mechanic waste (sample MM3) induced the highest toxicity level to Daphnia magna(CE50,48 h = 2.21%). A textile waste induced the highest toxicity level to Vibrio fischeri (sample TX2, CE50,30 min = 12.08%). All samples of pulp and paper wastes, and a textile waste (sample TX2) induced chronic effects on reproduction, length, and longevity of Daphnia magna. These results could serve as an alert about the environmental risks of an inadequate waste classification method. PMID:22619632

  20. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS).

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J

    2016-06-27

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon.

  1. Characterization of genome-wide SNPs for the water flea Daphnia pulicaria generated by genotyping-by-sequencing (GBS)

    Science.gov (United States)

    Muñoz, Joaquín; Chaturvedi, Anurag; De Meester, Luc; Weider, Lawrence J.

    2016-01-01

    The keystone aquatic herbivore Daphnia has been studied for more than 150 years in the context of evolution, ecology and ecotoxicology. Although it is rapidly becoming an emergent model for environmental and population genomics, there have been limited genome-wide level studies in natural populations. We report a unique resource of novel Single Nucleotide Polymorphic (SNP) markers for Daphnia pulicaria using the reduction in genomic complexity with the restriction enzymes approach, genotyping-by-sequencing. Using the genome of D. pulex as a reference, SNPs were scored for 53 clones from five natural populations that varied in lake trophic status. Our analyses resulted in 32,313 highly confident and bi-allelic SNP markers. 1,364 outlier SNPs were mapped on the annotated D. pulex genome, which identified 2,335 genes, including 565 within functional genes. Out of 885 EuKaryotic Orthologous Groups that we found from outlier SNPs, 294 were involved in three metabolic and four regulatory pathways. Bayesian-clustering analyses showed two distinct population clusters representing the possible combined effects of geography and lake trophic status. Our results provide an invaluable tool for future population genomics surveys in Daphnia targeting informative regions related to physiological processes that can be linked to the ecology of this emerging eco-responsive taxon. PMID:27346179

  2. Daphnia longicephala neuropeptides: morphological description of crustacean cardioactive peptide (CCAP) and periviscerokinins in the Ctenodaphnia central nervous system.

    Science.gov (United States)

    Weiss, Linda C; Laforsch, Christian; Ioannidou, Ioanna; Herbert, Zsofia; Tollrian, Ralph

    2014-10-01

    The publication of the Daphnia genome has driven research in this ecologically relevant model organism in many directions. However, information on this organism's physiology and the relevant controlling factors is limited. In this regard, especially neuropeptides are important biochemical regulators that control a variety of cellular processes, which in combination influence physiological conditions and allow the adaptation of the internal physiological state to external conditions. Thus, neuropeptides are prime in understanding an organism's physiology. We here aimed to detect and describe the distribution of evolutionary conserved neuropeptides including the crustacean cardioactive peptide (CCAP) and peptides of the family periviscerokinins (PVKs) in the central nervous system and the periphery of the Daphnia longicephala head region. We were able to identify a large pair of CCAP immunoreactive cells within central nervous system. In addition, in the periphery we found CCAP immunoreactive cells in the epidermis of the head with processes indicating cuticular secretion. Furthermore, we were able to identify and describe a complex neuronal circuit of PVK neuropeptides in the central nervous system. The data obtained in this study will provide important background information for future investigations aiming to unravel the cellular, neuronal and physiological pathways in a highly adaptive organism such as Daphnia.

  3. Copy number variation of ribosomal DNA and Pokey transposons in natural populations of Daphnia

    Directory of Open Access Journals (Sweden)

    Eagle Shannon HC

    2012-03-01

    Full Text Available Abstract Background Despite their ubiquity and high diversity in eukaryotic genomes, DNA transposons are rarely encountered in ribosomal DNA (rDNA. In contrast, R-elements, a diverse group of non-LTR retrotransposons, specifically target rDNA. Pokey is a DNA transposon that targets a specific rDNA site, but also occurs in many other genomic locations, unlike R-elements. However, unlike most DNA transposons, Pokey has been a stable component of Daphnia genomes for over 100 million years. Here we use qPCR to estimate the number of 18S and 28S ribosomal RNA genes and Pokey elements in rDNA (rPokey, as well as other genomic locations (gPokey in two species of Daphnia. Our goals are to estimate the correlation between (1 the number of 18S and 28S rRNA genes, (2 the number of 28S genes and rPokey, and (3 the number of rPokey and gPokey. In addition, we ask whether Pokey number and distribution in both genomic compartments are affected by differences in life history between D. pulex and D. pulicaria. Results We found differences in 18S and 28S gene number within isolates that are too large to be explained by experimental variation. In general, Pokey number within isolates is modest (Pokey. There is no correlation between the number of rRNA genes and rPokey, or between rPokey and gPokey. However, we identified three isolates with unusually high numbers of both rPokey and gPokey, which we infer is a consequence of recent transposition. We also detected other rDNA insertions (rInserts that could be degraded Pokey elements, R- elements or the divergent PokeyB lineage recently detected in the Daphnia genome sequence. Unlike rPokey, rInserts are positively correlated with rRNA genes, suggesting that they are amplified by the same mechanisms that amplify rDNA units even though rPokey is not. Overall, Pokey frequency and distribution are similar in D. pulex and D. pulicaria suggesting that differences in life history have no impact on Pokey. Conclusions The

  4. Commentary on effects of anthropogenic and natural organic chemicals on development, swimming behavior, and reproduction of Daphnia, a key member of aquatic ecosystems.

    Science.gov (United States)

    Dodson, S I; Hanazato, T

    1995-05-01

    Because of their trophodynamic role, small invertebrates are often critical components of ecosystems. An especially important group of freshwater invertebrates is the water fleas of the genus Daphnia. These animals are often the dominant herbivores in lakes and ponds. They play a key role in determining water clarity (by grazing on algae) and they are an important part of the diet of fish. Natural chemical signals (kairomones) produced by predators affect the development, life history strategy, and behavior of zooplankton. Laboratory studies of anthropogenic chemicals that have biological activity (xenobiotics), such as the insecticide carbaryl, have demonstrated effects of concentrations in the 1 to 5 ppb range on Daphnia development, growth rate, and swimming behavior in our laboratory experiments. Low concentrations of carbaryl inhibit growth and reproduction and delay maturation, whereas survivorship was not effected. These sublethal exposures to carbaryl reduced Daphnia population growth rate (productivity) by about 15% (at 5 ppb), enough to have significant ecological effects on the rest of the lake community. The insecticide carbaryl showed synergistic interactions with natural chemicals associated with predators (kairomones) that modify Daphnia development and life history characteristic. In addition, there were complex synergisms between carbaryl, the predator odors, and oxygen concentration (low oxygen concentration can be either a natural environmental stress or an anthropogenic stress). Daphnia produce males facultatively, usually in late fall; at other times, reproduction is asexual.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7556027

  5. Toxic effect of cyanobacterial blooms on the grazing activity of Daphnia magna Straus

    Directory of Open Access Journals (Sweden)

    Maria £otocka

    2001-12-01

    Full Text Available The investigations aimed to determine the impact of cyanobacteria Microcystis aeruginosa (Kütz. Kütz. and Aphanizomenon flos-aquae (L. Ralfs ex Bornet et Flah., both toxic algae, on the grazing intensity of Daphnia magna Straus. In order to determine the parameter permitting the quantitative determination of the grazing intensity of herbivorous organisms, methods based on the following techniques were applied: microscopy, to determine the degree of gut fullness; spectrophotometry, to determine the levels of chlorophyll a and its degradation products in the food composition; high-performance liquid chromatography (HPLC to determine the content of exogenous and endogenous carotenoids. Each of these methods confirmed that the tested algae species inhibited grazing intensity in D. magna Straus. The most obvious effects were obtained when M. aeruginosa (Kütz. Kütz. was used as food. With these cyanobacteria, the gut fullness indicator did not exceed 58%, and the chlorophyll a content in the digestive system of the tested D. magna was three times lower than that in the control organisms. It seems that the defensive reaction of organisms was a reversible process. However, the possibility of a long-term, sublethal influence of cyanobacteria on the physiology and internal processes of this species cannot be ruled out.

  6. Titanium dioxide nanoparticles increase sensitivity in the next generation of the water flea Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Mirco Bundschuh

    Full Text Available The nanoparticle industry is expected to become a trillion dollar business in the near future. Therefore, the unintentional introduction of nanoparticles into the environment is increasingly likely. However, currently applied risk-assessment practices require further adaptation to accommodate the intrinsic nature of engineered nanoparticles. Combining a chronic flow-through exposure system with subsequent acute toxicity tests for the standard test organism Daphnia magna, we found that juvenile offspring of adults that were previously exposed to titanium dioxide nanoparticles exhibit a significantly increased sensitivity to titanium dioxide nanoparticles compared with the offspring of unexposed adults, as displayed by lower 96 h-EC(50 values. This observation is particularly remarkable because adults exhibited no differences among treatments in terms of typically assessed endpoints, such as sensitivity, number of offspring, or energy reserves. Hence, the present study suggests that ecotoxicological research requires further development to include the assessment of the environmental risks of nanoparticles for the next and hence not directly exposed generation, which is currently not included in standard test protocols.

  7. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water.

  8. Combined Effect of Ethanol and Acetaminophen on the Central Nervous System of Daphnia magna

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    Brigid Bleaken

    2010-01-01

    Full Text Available The combined consumption of acetaminophen (APAP and ethanol (EtOH has been an issue with clinical implications. Previous findings regarding the simultaneous consumption of APAP and EtOH have reported harmful effects on the liver and stomach; however, little is known about the effects on the central nervous system (CNS. We hypothesized that EtOH and APAP will have a synergistic effect on the CNS of Daphnia magna (D. magna, causing a pronounced decrease in heart rate at a toxic dose of EtOH. To better understand the effects of the combined consumption of EtOH and APAP on the CNS, the heart rates of D. magna were measured under a dissection microscope after exposure to EtOH, APAP, or a combined EtOH-APAP solution. Interestingly, the average heart rates of D. magna exposed to the EtOH-APAP solution and D. magna exposed only to APAP were approximately the same. Although our results did not support our original hypothesis, the data demonstrated that APAP exerted a dominant effect over EtOH. APAP and EtOH are known to have inhibitory effects on the CNS. Therefore, these findings suggest that APAP and EtOH may compete against each other on similar pathways to be the substance that exerts an inhibitory effect in the CNS.

  9. Immune genes undergo more adaptive evolution than non-immune system genes in Daphnia pulex

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    McTaggart Seanna J

    2012-05-01

    Full Text Available Abstract Background Understanding which parts of the genome have been most influenced by adaptive evolution remains an unsolved puzzle. Some evidence suggests that selection has the greatest impact on regions of the genome that interact with other evolving genomes, including loci that are involved in host-parasite co-evolutionary processes. In this study, we used a population genetic approach to test this hypothesis by comparing DNA sequences of 30 putative immune system genes in the crustacean Daphnia pulex with 24 non-immune system genes. Results In support of the hypothesis, results from a multilocus extension of the McDonald-Kreitman (MK test indicate that immune system genes as a class have experienced more adaptive evolution than non-immune system genes. However, not all immune system genes show evidence of adaptive evolution. Additionally, we apply single locus MK tests and calculate population genetic parameters at all loci in order to characterize the mode of selection (directional versus balancing in the genes that show the greatest deviation from neutral evolution. Conclusions Our data are consistent with the hypothesis that immune system genes undergo more adaptive evolution than non-immune system genes, possibly as a result of host-parasite arms races. The results of these analyses highlight several candidate loci undergoing adaptive evolution that could be targeted in future studies.

  10. Hazard assessment for a pharmaceutical mixture detected in the upper Tennessee River using Daphnia magna

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    D. Wolfe

    2015-01-01

    Full Text Available Widespread use of pharmaceuticals has resulted in mixture concentrations ranging from mg/L in effluent to µg/L concentrations in surface water. In a 2008 study, 13 pharmaceuticals, ranging in amounts from 0.0028 to 0.1757 µg/l, were identified in the Tennessee River, USA and its tributaries. In order to address the need for risk assessment of environmentally relevant pharmaceutical mixtures, Daphnia magna 21-d life cycle tests were performed on a mixture of 11 of the 13 pharmaceuticals as well as on the individual components of the mixture. Mixture exposures were based on the same initial ratios of individual compounds, up to 1000x the initial mixture concentrations.  The endpoints of mortality, time to first brood, size, and fecundity were the assessed.  The LOEC of the 11- pharmaceutical mixture was determined to be 100x greater than the measured mixture concentration detected in the Tennessee River, with the NOEC being 75x that of the measured mixture.  Single concentrations of pharmaceuticals within the mixture up to the 100x LOEC were not statistically different from control for any of the assessed endpoints.  Thus, no single pharmaceutical was deemed predominately responsible for the mixture toxicity at the concentrations tested. While mixtures of pharmaceuticals are common in many systems, based on the findings of the present study, they may not pose a significant acute or chronic hazard to aquatic invertebrates at current concentrations.

  11. Growth Retardation and Altered Isotope Composition As Delayed Effects of PCB Exposure in Daphnia magna.

    Science.gov (United States)

    Ek, Caroline; Gerdes, Zandra; Garbaras, Andrius; Adolfsson-Erici, Margaretha; Gorokhova, Elena

    2016-08-01

    Trophic magnification factor (TMF) analysis employs stable isotope signatures to derive biomagnification potential for environmental contaminants. This approach relies on species δ(15)N values aligning with their trophic position (TP). This, however, may not always be true, because toxic exposure can alter growth and isotope allocation patterns. Here, effects of PCB exposure (mixture of PCB18, PCB40, PCB128, and PCB209) on δ(15)N and δ(13)C as well as processes driving these effects were explored using the cladoceran Daphnia magna. A two-part experiment assessed effects of toxic exposure during and after exposure; juvenile daphnids were exposed during 3 days (accumulation phase) and then allowed to depurate for 4 days (depuration phase). No effects on survival, growth, carbon and nitrogen content, and stable isotope composition were observed after the accumulation phase, whereas significant changes were detected in adults after the depuration phase. In particular, a significantly lower nitrogen content and a growth inhibition were observed, with a concomitant increase in δ(15)N (+0.1 ‰) and decrease in δ(13)C (-0.1 ‰). Although of low magnitude, these changes followed the predicted direction indicating that sublethal effects of contaminant exposure can lead to overestimation of TP and hence underestimated TMF. PMID:27367056

  12. Effects of Microcystis aeruginosa on life history of water flea Daphnia magna

    Science.gov (United States)

    Liu, Liping; Li, Kang; Chen, Taoying; Dai, Xilin; Jiang, Min; Diana, James S.

    2011-07-01

    Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic microcystins and deteriorating water quality. In this study, microcystins (MCs) in Microcystis aeruginosa, and Daphnia magna exposed to M. aeruginosa, were analyzed by HPLC-MS, and the effects of M. aeruginosa on D. magna were investigated. When D. magna was exposed to M. aeruginosa for more than 2 h, Microcystin-LR (MC-LR) was detected. When exposed to 1.5 × 106, 3 × 106, 0.75 × 107, and 1.5 × 107 cell/mL of M. aeruginosa for 96 h, average survival of D. magna for treatments were 23.33%, 33.33%, 13.33%, 16.67%, respectively, which were significantly lower than the average 100% survival in the control group ( P < 0.05). The adverse effects of M. aeruginosa on body length, time for the first brood, brood numbers, gross fecundity, lifespan, and population growth of D. magna were density-dependent. These results suggest that the occurrence of M. aeruginosa blooms could strongly inhibit the population growth of D. magna through depression of survival, individual growth and gross fecundity. In the most serious situations, M. aeruginosa blooms could undermine the food web by eliminating filter-feeding zooplankton, which would destroy the ecological balance of aquaculture water bodies.

  13. Toxicity Thresholds for Diclofenac, Acetaminophen and Ibuprofen in the Water Flea Daphnia magna.

    Science.gov (United States)

    Du, Juan; Mei, Cheng-Fang; Ying, Guang-Guo; Xu, Mei-Ying

    2016-07-01

    Non-steroid anti-inflammatory drugs (NSAIDs) have been frequently detected in aquatic ecosystem and posed a huge risk to non-target organisms. The aim of this study was to evaluate the toxic effects of three typical NSAIDs, diclofenac (DFC), acetaminophen (APAP) and ibuprofen (IBP), toward the water flea Daphnia magna. All three NSAIDs showed remarkable time-dependent and concentration-dependent effects on D. magna, with DFC the highest and APAP the lowest toxic. Survival, growth and reproduction data of D. magna from all bioassays were used to determine the LC10 and LC50 (10 % lethal and median lethal concentrations) values of NSAIDs, as well as the EC10 and EC50 (10 % effect and median effect concentrations) values. Concentrations for the lethal and sublethal toxicity endpoints were mainly in the low ppm-range, of which reproduction was the most sensitive one, indicating that non-target organisms might be adversely affected by relevant ambient low-level concentrations of NSAIDs after long-time exposures. PMID:27098253

  14. Daphnia magna transcriptome by RNA-Seq across 12 environmental stressors

    Science.gov (United States)

    Orsini, Luisa; Gilbert, Donald; Podicheti, Ram; Jansen, Mieke; Brown, James B.; Solari, Omid Shams; Spanier, Katina I.; Colbourne, John K.; Rush, Douglas; Decaestecker, Ellen; Asselman, Jana; De Schamphelaere, Karel A.C.; Ebert, Dieter; Haag, Christoph R.; Kvist, Jouni; Laforsch, Christian; Petrusek, Adam; Beckerman, Andrew P.; Little, Tom J.; Chaturvedi, Anurag; Pfrender, Michael E.; De Meester, Luc; Frilander, Mikko J.

    2016-01-01

    The full exploration of gene-environment interactions requires model organisms with well-characterized ecological interactions in their natural environment, manipulability in the laboratory and genomic tools. The waterflea Daphnia magna is an established ecological and toxicological model species, central to the food webs of freshwater lentic habitats and sentinel for water quality. Its tractability and cyclic parthenogenetic life-cycle are ideal to investigate links between genes and the environment. Capitalizing on this unique model system, the STRESSFLEA consortium generated a comprehensive RNA-Seq data set by exposing two inbred genotypes of D. magna and a recombinant cross of these genotypes to a range of environmental perturbations. Gene models were constructed from the transcriptome data and mapped onto the draft genome of D. magna using EvidentialGene. The transcriptome data generated here, together with the available draft genome sequence of D. magna and a high-density genetic map will be a key asset for future investigations in environmental genomics. PMID:27164179

  15. Two-generational effects of contaminants in Daphnia magna: Effects of offspring quality.

    Science.gov (United States)

    Campos, Bruno; Jordão, Rita; Rivetti, Claudia; Lemos, M F L; Soares, A M V M; Tauler, Roma; Barata, Carlos

    2016-06-01

    The authors set up a protocol to perform a 2-generational ring test using the existing guidelines for the Daphnia magna reproduction test. It is well known in ecology that size and quality of offspring vary across the first clutches in D. magna and that certain chemicals affect offspring quality. Therefore, the origin of the second generation is an important factor to consider. Two-generational effects across first, second, and third clutches were evaluated using 4-nonylphenol; those across first and third clutches were evaluated using tributyltin, and those across the third clutch were evaluated using piperonyl butoxide. The compound showing the greatest aggravation of toxic effects between the parental and second generations was piperonyl butoxide, followed by 4-nonylphenol, whereas intergenerational effects of tributyltin varied across experiments. The studied chemicals affected the quantity and quality of the offspring produced by exposed females of the parental generation, those effects being greater in third-clutch neonates. Therefore, when third-clutch offspring were further exposed, they turned out to be more sensitive than the parental generation. The results are in line with those obtained in multigenerational studies using mammalian tests, which showed that, in many cases, effects on the second generation can be predicted by evaluating the quality of the offspring produced. Environ Toxicol Chem 2016;35:1470-1477. © 2015 SETAC. PMID:26505489

  16. Classification of solid industrial waste based on ecotoxicology tests using Daphnia magna: an alternative

    Directory of Open Access Journals (Sweden)

    William Gerson Matias

    2005-11-01

    Full Text Available The adequate treatment and final disposal of solid industrial wastes depends on their classification into class I or II. This classification is proposed by NBR 10.004; however, it is complex and time-consuming. With a view to facilitating this classification, the use of assays with Daphnia magna is proposed. These assays make possible the identification of toxic chemicals in the leach, which denotes the presence of one of the characteristics described by NBR 10.004, the toxicity, which is a sufficient argument to put the waste into class I. Ecotoxicological tests were carried out with ten samples of solid wastes of frequent production and, on the basis of the results from EC(I50/48h of those samples in comparison with the official classification of NBR 10.004, limits were established for the classification of wastes into class I or II. A coincidence in the classification of 50% of the analyzed samples was observed. In cases in which there is no coherence between the methods, the method proposed in this work classifies the waste into class I. These data are preliminary, but they reveal that the classification system proposed here is promising because of its quickness and economic viability.

  17. Population dynamics in Daphnia magna as modified by chronic tetradifon stress.

    Science.gov (United States)

    Villarroel, M J; Ferrando, M D; Sancho, E; Andreu, E

    2000-03-01

    Two Daphnia magna offsprings (animals from the first and third brood) whose parentals (F0-generation) were exposed during 21 days to different tetradifon (4-chlorophenyl 2,4,5-trichlophenyl sulfone) concentrations, were transferred to a pesticide free medium during 21 days (recovery period). The algae Nannochloris oculata (5 x 10(5) cells/mL) was used as food. In this recovery study, survival, growth and reproduction (mean total young per female, mean brood size, onset of reproduction and mean number broods per female) were assessed as individual parameters and the intrinsic rate of natural increase (r) as population parameter, for F1 generation (1st and 3rd broods). Reproduction was still reduced in F1 (1st and 3rd broods) generation daphnids from parentals (F0) exposed to 0.18 mg/L tetradifon and higher concentrations even after 21 days in clean water. However, survival was not significantly different (p > 0.05) in those F1 offsprings from parentals pre-exposed to the acaricide. Growth was still reduced in F1 daphnids from parentals pre-exposed to 0.10-0.44 mg/L tetradifon. The intrinsic rate of natural increase (r) was still affected in F1 generation daphnids, specially in those from the third brood. Therefore, F1 generation D. magna offsprings from a parental generation (F0) previously exposed to the acaricide tetradifon were not able to recuperate completely when a recovery period of 21 days was allowed. PMID:10736770

  18. Postexposure feeding depression: a new toxicity endpoint for use in laboratory studies with Daphnia magna.

    Science.gov (United States)

    McWilliam, Ruth A; Baird, Donald J

    2002-06-01

    In situ bioassays with daphnids currently employ lethality as an endpoint, and although sublethal responses (reproduction and feeding rate) can be measured in the field, such endpoints pose major practical challenges. Previous studies have indicated that Daphnia magna exposed to toxic substances can exhibit delayed recovery in feeding behavior (postexposure feeding depression). This simple, robust response has the potential to be an ecologically relevant and potentially diagnostic endpoint. This study developed and tested the use of postexposure feeding depression as a toxicity endpoint in the laboratory environment. First, replicate numbers were manipulated to produce statistically reliable results. Second, postexposure feeding depression in D. magna was studied under laboratory conditions, by employing toxic substances with differing modes of action. Although most substances caused feeding inhibition during direct exposure, not all substances produced postexposure feeding depression. However, the use of lethality as a supplementary endpoint provided an alternative measure when no feeding depression was apparent after exposure. In combination, these endpoints offer a potentially more sensitive, ecologically relevant alternative to the use of lethality alone for in situ bioassay studies. PMID:12069303

  19. An integrated model describing the toxic responses of Daphnia magna to pulsed exposures of three metals.

    Science.gov (United States)

    Hoang, Tham C; Tomasso, Joseph R; Klaine, Stephen J

    2007-01-01

    Some toxicology research in which toxicant exposures are continual (pulsed) rather than continuous have been reported. A number of toxicity models have been developed for pulsed and continuous exposures. Most of these models were developed based on one- or two-compartment, first-order toxicokinetics and were calibrated with organic compounds. In the present study, the relationship between mortality (after 21 d) of Daphnia magna in response to pulsed and continuous exposures to Cu, Zn, and Se was used to develop a model that integrated the effects of single and multiple pulsed metal exposures based on first-order uptake and depuration kinetics. Mortality was a function of exposure concentration, duration, and recovery time between exposures. The model was successfully validated using an independent data set. It is applicable to risk assessment and, potentially, may be incorporated with other models (e.g., the biotic ligand model) to predict the toxicity of pulsed metal exposures under a range of environmental conditions. PMID:17269470

  20. Acute and chronic effects of pulse exposure of Daphnia magna to dimethoate and pirimicarb.

    Science.gov (United States)

    Andersen, Tobias Henrik; Tjørnhøj, Rikke; Wollenberger, Leah; Slothuus, Tina; Baun, Anders

    2006-05-01

    Short-term (Daphnia magna exposed to pulses of 0.5 to 8 h in duration. During a 21-d postexposure observation period, the following parameters were monitored: Mortality, mobility, day for first offspring, animal size, weight of offspring and adults, and number of offspring produced. In general, animals exposed to a single pulse of dimethoate or pirimicarb regained mobility after 24 to 48 h in clean media. Animals exposed to repeated pulses of dimethoate did not recover mobility during a 48-h postexposure observation period, and mortality was significantly increased. Animals exposed to two pulses of pirimicarb showed less recovery of mobility compared with those exposed to one pulse. Exposure of D. magna to 30 mg/L of dimethoate or 100 microg/L of pirimicarb for 2 to 6 h resulted in a significant reduction in the number of offspring and in the average weight of offspring. The average body length was reduced after pulse exposure to 30 mg/L of dimethoate for 3 h or 70 microg/L of pirimicarb for 4 h, and these exposure concentrations caused a delay in the day for first offspring at exposure durations of 2 to 6 h. The most important new findings in the present study are that short-term (<4 h) pulse exposure of neonates to acetylcholinesterase-inhibiting pesticides caused reproductive damage in D. magna and that repeated-pulse exposure significantly increased mortality in animals that apparently had recovered after a single-pulse exposure. PMID:16704047

  1. Transgenerational effects of two antidepressants (sertraline and venlafaxine) on Daphnia magna life history traits.

    Science.gov (United States)

    Minguez, Laëtitia; Ballandonne, Céline; Rakotomalala, Christiane; Dubreule, Christelle; Kientz-Bouchart, Valérie; Halm-Lemeille, Marie-Pierre

    2015-01-20

    The low levels of antidepressants detected in surface waters currently raise concern about their potential long-term risks to nontarget aquatic organisms. We investigated the transgenerational effects of sertraline, a selective serotonin reuptake inhibitor, and venlafaxine, a serotonin-norepinephrine reuptake inhibitor, on the life traits of Daphnia magna over two generations under environmentally realistic concentrations. We also studied the reversibility of the effect using recovery experiments. We assessed daphnid survival, growth, and reproduction over 21 days and evidenced detectable effects of the antidepressants. Sertraline increased the F0-daphnid fecundity whereas it decreased the offspring number of F1-daphnids. Transfer to clean medium caused negative effects on the offspring of daphnids exposed to 0.3 μg L(–1), but improved the fecundity of offspring of daphnids exposed to 100 μg L(–1). Venlafaxine exposure decreased the offspring number of F0-daphnids and resulted in drug tolerance in the F1 generation. Sertraline, unlike venlafaxine, may turn out to be a true environmental threat due to its accumulation in algae and the physiological weakness observed over generations. These effects across generations point out to the need to perform multigeneration tests to assess the environmental risk of pharmaceuticals in nontarget organisms. PMID:25506746

  2. Daphnia magna feeding behavior after exposure to tetradifon and recovery from intoxication.

    Science.gov (United States)

    Villarroel, M J; Ferrando, M D; Sancho, E; Andreu, E

    1999-09-01

    The feeding behavior of the cladocera Daphnia magna subjected to a short-term exposure to the acaricide tetradifon (4-chlorophenyl 2,4, 5-trichlorophenyl sulfone) was studied. The experiments were performed using the unicellular algae Nannochloris oculata at a density of 5x10(5) cells/ml as food for the organisms. In a first experiment, three generations (F0, F1, and F3) of the daphnids were exposed to sublethal levels of tetradifon (0.1, 0.18, 0.22, and 0.44 mg/l) and the effect of the toxicant on filtration and ingestion rates was determined. Rates of filtration and ingestion of D. magna declined in the three generations studied with increasing toxicant concentrations; however, toxicant effect was greater in daphnids from generations F1 and F3 than in those from the parental generation F0. A second experiment was conducted in order to evaluate whether animals of a first (1) or third (F3) generation coming from parental daphnids (F0) previously exposed to those pesticide concentrations exhibited any alteration in feeding behavior when transferred to clean water (recovery period). The results indicated that the feeding rates of D. magna generations F1 and F3 were still affected during the recovery period but to a less degree. The effective tetradifon concentrations D. magna at which feeding rates were reduced to 50% that of controls (EC(50)) were also calculated. PMID:10499987

  3. Effects of an organophosphate on Daphnia magna at suborganismal and organismal levels: implications for population dynamics.

    Science.gov (United States)

    Duquesne, Sabine

    2006-10-01

    The effects and recovery of 24 h pulse exposure to paraoxon-methyl on Daphnia magna were recorded for various endpoints to study the propagation of effects through various biological levels of organization. Above a threshold concentration (2.2 microgL(-1)), all selected endpoints were affected. Thus, effects at the suborganismal level (e.g., the biomarker response: transient inhibition of cholinesterase (ChE) activity) were accompanied by effects at the organismal (survival, reduction in reproductive performance, decrease in body size) and population (reduced population growth rate) levels. At intermediate and sublethal concentrations, exposure induced a transient ChE inhibition that was also accompanied by effects at the organismal level and that exerted long-term effects on population dynamics. At lower concentrations, although ChE activity was affected, there was no propagation of effects to higher biological levels. This study shows that effects of pulse exposure to organophosphates propagate from the suborganismal level toward the population level and demonstrates the significance of transient ChE inhibition on population dynamics. PMID:16545452

  4. Reproduction recovery of the crustacean Daphnia magna after chronic exposure to ibuprofen.

    Science.gov (United States)

    Hayashi, Yuya; Heckmann, Lars-Henrik; Callaghan, Amanda; Sibly, Richard M

    2008-05-01

    In mammals, the pharmaceutical ibuprofen (IB), a non-steroidal anti-inflammatory drug, primarily functions by reversibly inhibiting the cyclooxygenase (COX) pathway in the synthesis of eicosanoids (e.g. prostaglandins). Previous studies suggest that IB may act in a similar manner to interrupt production of eicosanoids reducing reproduction in the model crustacean Daphnia magna. On this basis withdrawal of IB should lead to the recovery of D. magna reproduction. Here we test whether the effect of IB is reversible in D. magna, as it is in mammals, by observing reproduction recovery following chronic exposure. D. magna (5-days old) were exposed to a range of IB concentrations (0, 20, 40 and 80 mg l(-1)) for 10 days followed by a 10 day recovery period in uncontaminated water. During the exposure period, individuals exposed to higher concentrations produced significantly fewer offspring. Thereafter, IB-stressed individuals produced offspring faster during recovery, having similar average population growth rates (PGR) (1.15-1.28) to controls by the end of the test. It appears that maternal daphnids are susceptible to IB during egg maturation. This is the first recorded recovery of reproduction in aquatic invertebrates that suffered reproductive inhibition during chronic exposure to a chemical stressor. Our results suggest a possible theory behind the compensatory fecundity that we referred to as 'catch-up reproduction'. PMID:18214676

  5. Biochemical, metabolic, and behavioural responses and recovery of Daphnia magna after exposure to an organophosphate.

    Science.gov (United States)

    Duquesne, Sabine; Küster, Eberhard

    2010-03-01

    The responses of various suborganismal and organismal endpoints of Daphnia magna to pulse exposure to sublethal levels of the organophosphate paraoxon-methyl were compared. The changes and recovery of biochemical, metabolic, and behavioural variables, as well as physiological responses, were observed. The cholinesterase (ChE), filtration, and swimming activities were all affected in a concentration-dependent manner, and these effects reached significance at concentrations of 1.0, 1.5, and 0.7 microg L(-1), respectively. The levels of these variables recovered significantly after detoxification for 24h in clean medium. ChE and swimming activities were affected significantly by lower concentrations of paraoxon-methyl than filtration activity, which had the same threshold as the physiological responses ((15)N abundance and body size). This study showed that among the parameters studied, swimming activity was the most sensitive, whereas changes in filtration activity had the most significant physiological consequences, and were therefore important in terms of effects propagation to the population level. PMID:20031215

  6. Bioaccumulation and oxidative stress in Daphnia magna exposed to arsenite and arsenate.

    Science.gov (United States)

    Fan, Wenhong; Ren, Jinqian; Li, Xiaomin; Wei, Chaoyang; Xue, Feng; Zhang, Nan

    2015-11-01

    Arsenic pollution and its toxicity to aquatic organisms have attracted worldwide attention. The bioavailability and toxicity of arsenic are highly related to its speciation. The present study investigated the differences in bioaccumulation and oxidative stress responses in an aquatic organism, Daphnia magna, induced by 2 inorganic arsenic species (As(III) and As(V)). The bioaccumulation of arsenic, Na(+) /K(+) -adenosine triphosphatase (ATPase) activity, reactive oxygen species (ROS) content, total superoxide dismutase (SOD) activity, total antioxidative capability, and malondialdehyde content in D. magna were determined after exposure to 500 µg/L of arsenite and arsenate for 48 h. The results showed that the oxidative stress and antioxidative process in D. magna exposed to arsenite and arsenate could be divided into 3 phases, which were antioxidative response, oxidation inhibition, and antioxidative recovery. In addition, differences in bioaccumulation, Na(+) /K(+) -ATPase activity, and total SOD activity were also found in D. magna exposed to As(III) and As(V). These differences might have been the result of the high affinity of As(III) with sulfhydryl groups in enzymes and the structural similarity of As(V) to phosphate. Therefore, arsenate could be taken up by organisms through phosphate transporters, could substitute for phosphate in biochemical reactions, and could lead to a change in the bioaccumulation of arsenic and activity of enzymes. These characteristics were the possible reasons for the different toxicity mechanisms in the oxidative stress process of arsenite and arsenate. PMID:26084717

  7. Effect of pulse frequency and interval on the toxicity of chlorpyrifos to Daphnia magna.

    Science.gov (United States)

    Naddy, R B; Klaine, S J

    2001-11-01

    Due to the episodic nature in which organisms are exposed to non-point source pollutants, it is necessary to understand how they are affected by pulsed concentrations of contaminants. This is essential, as standard toxicity tests may not adequately simulate exposure scenarios for short-lived hydrophobic compounds, such as chlorpyrifos (CPF), a broad-spectrum organophosphate insecticide. Studies were conducted with 7-day old Daphnia magna for 7 days to evaluate the effect of pulse frequency and interval among multiple CPF exposures. Daphnids were exposed to a total exposure of either 12 h at 0.5 microg/l or 6 h at 1.0 microg/l nominal CPF, respectively, in all studies. For interval studies, D. magna were exposed to two pulses of CPF at each concentration, with 0-96-h intervals between pulses. For frequency studies, D. magna were exposed to each CPF concentration altering the pulse scheme by decreasing the exposure duration but increasing the number of pulses, keeping the total exposure time the same. The pulse interval between multiple pulses in these experiments was 24 h. Our results suggest that D. magna can withstand an acutely lethal CPF exposure provided that there is adequate time for recovery between exposures. PMID:11680745

  8. Predicting the toxicity of permethrin to Daphnia magna in water using SPME fibers.

    Science.gov (United States)

    Harwood, Amanda D; Bunch, Aubrey R; Flickinger, Dallas L; You, Jing; Lydy, Michael J

    2012-04-01

    Multiple factors can influence bioavailability, which can make predictions of toxicity in natural systems difficult. The current study examined the potential use of solid-phase microextraction fibers as a matrix-independent approach to predict the toxicity of permethrin to Daphnia magna across various water sources, including a laboratory reconstituted water, two natural waters, and a modified natural water. Water source strongly affected the toxicity of permethrin as well as the concentration-response relationships. Although permethrin concentrations in the water were predictive of toxicity to D. magna for individual water sources, there was no relationship between permethrin concentrations among water sources and mortality. This indicated that compositional differences among water sources can greatly influence toxicity, suggesting that benchmarks established using reconstituted water may be overly conservative for some natural waters. In addition, although permethrin tissue residues were predictive of mortality for individual waters, the correlation among waters was not as clear. Finally, both 48-h and equilibrium-based SPME fiber concentrations adequately predicted toxicity independent of water properties. This demonstrated that bioavailability-based estimates provided a more accurate prediction of toxicity than water concentrations and that SPME fibers could be used in environmental monitoring as a rapid and accurate means of predicting toxicity in natural waters. PMID:22037820

  9. Analysis of the swimming velocity of cadmium-stressed Daphnia magna

    International Nuclear Information System (INIS)

    The swimming velocity of the waterflea Daphnia magna is dependent on its body size. Therefore, environmental factors like toxic stress that influence growth also influence swimming velocity. An experiment was set up to test whether exposure to cadmium would reduce only growth, with a concomitant decrease in velocity, or whether it would reduce velocity below the swimming velocity of similarly-sized control animals. Daphnids were exposed for 10 days to free cadmium ion concentrations ranging from 1x10-8 to 1x10-7 M Cd2+, and body size and swimming velocity were measured every 2 days. The results showed that cadmium decreased both growth and velocity, i.e. exposed daphnids swam slower than similarly-sized control daphnids. Swimming velocity provided no indication of successful acclimation in any cadmium treatment. Food consumption and assimilation were reduced by exposure to cadmium. This reduced food intake may have, at least partially, caused the decreased growth rates. However, since reduced food intake does not affect swimming velocity, the reduced swimming velocity must be attributed to toxic effects of cadmium, other than those on food intake. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water. PMID:22197265

  11. Effect of an Aspartame-Ethanol Mixture on Daphnia magna Cardiac Activity

    Directory of Open Access Journals (Sweden)

    Rebecca Kohn

    2009-01-01

    Full Text Available Aspartame in conjunction with alcohol has been shown to increase the blood alcohol level in humans faster than alcohol and sucrose (Wu et al., 2006. To determine the potential effects of various mixtures of ethanol and aspartame on the nervous system, the heart rate of Daphnia magna (D.magna, water flea was measured in deionized water (control, ethanol, aspartame, and five different mixtures of ethanol and aspartame. The heart rate was chosen as a representative measure since it is controlled by the nervous system and the heart rate of D.magna can easily be measured. The results were statistically evaluated by student’s t-test. A significant increase in heart rate was observed for all mixed assays compared to both control and ethanol, but not to aspartame. The data suggests that the aspartame and alcohol mixture have a greater effect on D. magna heart rate than water or ethanol, but not aspartame alone. We propose that alcohol in combination with aspartame has potentially detrimental consequences for the nervous system.

  12. Neuroanatomy of the optic ganglia and central brain of the water flea Daphnia magna (Crustacea, Cladocera).

    Science.gov (United States)

    Kress, Timm; Harzsch, Steffen; Dircksen, Heinrich

    2016-03-01

    We reveal the neuroanatomy of the optic ganglia and central brain in the water flea Daphnia magna by use of classical neuroanatomical techniques such as semi-thin sectioning and neuronal backfilling, as well as immunohistochemical markers for synapsins, various neuropeptides and the neurotransmitter histamine. We provide structural details of distinct neuropiles, tracts and commissures, many of which were previously undescribed. We analyse morphological details of most neuron types, which allow for unravelling the connectivities between various substructural parts of the optic ganglia and the central brain and of ascending and descending connections with the ventral nerve cord. We identify 5 allatostatin-A-like, 13 FMRFamide-like and 5 tachykinin-like neuropeptidergic neuron types and 6 histamine-immunoreactive neuron types. In addition, novel aspects of several known pigment-dispersing hormone-immunoreactive neurons are re-examined. We analyse primary and putative secondary olfactory pathways and neuronal elements of the water flea central complex, which displays both insect- and decapod crustacean-like features, such as the protocerebral bridge, central body and lateral accessory lobes. Phylogenetic aspects based upon structural comparisons are discussed as well as functional implications envisaging more specific future analyses of ecotoxicological and endocrine disrupting environmental chemicals. PMID:26391274

  13. Acute toxicity bioassays using Daphnia magna Straus (Cladocera, Daphniidae maintained in a modified culture medium

    Directory of Open Access Journals (Sweden)

    Mónica Núñez

    2013-05-01

    Full Text Available Daphnia magna is a test organism used in ecotoxicological assays of freshwater; however, traditional culture systems for this organism could result expensive, for that the aim of this research was to developed a new economic culture medium. With this purpose, 10 strains of D. magna were isolated, their population development was evaluated by total count of organisms and pregnant females using 3 different culture media: (A alfalfa juice, (B solved yeast and (C a mixture of alfalfa juice plus solved yeast. Successful development of 4 strains was observed in the A medium, but the same strains failed to survive in the B and the C media. The 24h and 48h EC50 average values in acute ecotoxicological assays with potassium dicromate were 0,4045 mg/L ± 0,0389 and 0,1857 mg/L ± 0,0072 respectively. Also, acute ecotoxicological assays with these 4 strains were performed using potassium cyanide, which is a toxic reactive frequently used in mining operations. In this case 24h EC50 value was 1,5388 mg/L ± 0,1146 and 48h EC50 values were 0,6359 mg/L ± 0,0516. 48h EC50 values were lower than the cyanide permissible effluent values established by the Energy and Mining Authority.

  14. A comparative study on toxicity identification of industrial effluents using Daphnia magna.

    Science.gov (United States)

    Yi, Xianliang; Kim, Eunhee; Jo, Hun-Je; Han, Taejun; Jung, Jinho

    2011-09-01

    In this study, acute toxicity monitoring and toxicity identification evaluation procedures were applied to identify causative toxicants in industrial effluents. Effluents from a metal plating factory and a rubber products factory were acutely toxic toward Daphnia magna and the toxicity varied over different sampling events (2.9-5.9 and 1.7-7.6 TU, respectively). For the rubber products effluent, it was confirmed that zinc (5.65-13.18 mg L(-1)) was found to be a major cause of toxicity, which is likely originated from zinc 2-mercaptobenzothiazole and zinc diethyldithiocarbamate used as vulcanization accelerators. For the metal plating effluent, it appeared that the presence of high concentrations of Cl(-) and SO(4)(2-) (8,539-11,400 and 3,588-4,850 mg L(-1), respectively) caused the observed toxicity. These toxicants likely originated from sodium bisulfate (NaHSO(3)) and sodium hypochlorite (NaOCl) used as reducing and oxidizing agents. Though copper was found to be present in levels much higher than the EC(50) (50% effective concentration) value, this was not attributable to the toxicity of metal plating effluent likely due to complexation with dissolved organic matter. PMID:21761172

  15. Effect of pH on the toxicity and bioconcentration of sulfadiazine on Daphnia magna

    DEFF Research Database (Denmark)

    Anskjær, Gitte Gotholdt; Rendal, Cecilie; Kusk, Kresten Ole

    2013-01-01

    The antimicrobial sulfonamide sulfadiazine has in the last decades been detected in environmental water bodies, both surface and ground water. Since pH in the environment may vary considerably, this study examined the toxicity of the amphoter sulfadiazine towards Daphnia magna at pH levels of 6.......0, 7.5 and 8.5, thus taking the impact of speciation into consideration, contrary to earlier eco-toxicity studies conducted at standard conditions. Toxicity tests were performed using the standard ISO 6341 test procedure modified to accommodate the three pH levels and the toxicity was expressed as EC50....... After 48h the EC50 was determined to be 27.2, 188 and 310mgL−1 at pH 6.0, 7.5 and 8.5, respectively, thus demonstrating a significant effect of pH on the toxicity of sulfadiazine. Furthermore, the bioconcentration factor (dry weight) was determined to be 50 and 36 at pH 6.0 and 8.5, respectively...

  16. Development and evaluation of new behavioral indexes for a biological early warning system using Daphnia magna

    Directory of Open Access Journals (Sweden)

    T. Y. Jeong

    2013-03-01

    Full Text Available New behavioral indexes including combined index (CI, distribution index (DI, toxic index (TI, and altitude index (AI for a biological early warning system (BEWS were developed and evaluated using Daphnia magna in this study. The sensitivity and stability of each index were compared to evaluate the performance of the indexes through a real-time exposure test with a synthetic copper solution. The applicability of the CI to the field sample was evaluated through an effluent exposure test. The proportional relationship between toxicity level and magnitude of response was much lower in the effluent due to the complexity of water than in the copper solution. The results showed that the CI was most sensitive among the three indexes, while the DI was confirmed as the most useful index among the individual indexes. The combined index (CI shows not only sensitivity but also stability in normal conditions below the statistically significant threshold (p p > 0.01. The CI improved performance of the BEWS in terms of sensitivity and stability, and it was confirmed as the higher correlation coefficient between the magnitude of the index and the toxicity level of the water sample.

  17. Assessment of the effects of the carbamazepine on the endogenous endocrine system of Daphnia magna.

    Science.gov (United States)

    Oropesa, A L; Floro, A M; Palma, P

    2016-09-01

    In the present study, the endocrine activity of the antiepileptic pharmaceutical carbamazepine (CBZ) in the crustacean Daphnia magna was assessed. To assess the hormonal activity of the drug, we exposed maternal daphnids and embryos to environmental relevant concentrations of CBZ (ranging from 10 to 200 μg/L) and to mixtures of CBZ with fenoxycarb (FEN; 1 μg/L). Chronic exposure to CBZ significantly decreased the reproductive output and the number of molts of D. magna at 200 μg/L. This compound induced the production of male offspring (12 ± 1.7 %), in a non-concentration-dependent manner, acting as a weak juvenile hormone analog. Results showed that this substance, at tested concentrations, did not antagonize the juvenoid action of FEN. Further, CBZ has shown to be toxic to daphnid embryos through maternal exposure interfering with their normal gastrulation and organogenesis stages but not producing direct embryo toxicity. These findings suggest that CBZ could act as an endocrine disruptor in D. magna as it decreases the reproductive output, interferes with sex determination, and causes development abnormality in offspring. Therefore, CBZ could directly affect the population sustainability.

  18. EFFECT OF A BIODEGRADABLE DETERGENT IN WATER ON DAPHNIA MAGNA REPRODUCTION

    Directory of Open Access Journals (Sweden)

    Castiglioni, M

    2010-01-01

    Full Text Available The aquatic ecosystems near to urban zone have a constant risk by several physical and chemical factors relative to human activities. This provokes synergic effects on aquatic organisms, being the domestic sewage an important factor to assess, highlighting the detergents. The cladocerans Daphnia magna, there is not originate in the Neotropical region, is a specie more used in ecotoxicological assays in the world by its easy culture and short life cycle. The aim of the work is observe as affect the commercial detergent on D. magna and their reproductive fitness. This was realized with chronic assays of isolated and grouped individuals using three sublethal concentrations of anionic detergent, previously the C was determined. The assays lasted 21 days, daily the 50 neonates were registered. These were counted and measured. In the chronic assays, the isolated individuals produced 262 embryos in the control group, being alike to two lower concentrations. The neonates were more abundant in the higher concentration than in lower and control ones. In the grouped animal experience, the increase in the egg number was progressive to detergent concentration. In this study, the detergent could be induced a production of more abundant and viable offspring. This could be associated with that the detergent permit an effective use of trophic resource and bioavailability of energy to reproduction, when the detergent discharge breaks down the particles or algal cells offered as food.

  19. Daphnia magna negatively affected by chronic exposure to purified Cry-toxins.

    Science.gov (United States)

    Bøhn, Thomas; Rover, Carina Macagnan; Semenchuk, Philipp Robert

    2016-05-01

    Cry-toxin genes originating from Bacillus thuringiensis are inserted into genetically modified (GM) plants, often called Bt-plants, to provide insect resistance to pests. Significant amounts of Bt-plant residues, and thus Cry-toxins, will be shed to soil and aquatic environments. We exposed Daphnia magna to purified Cry1Ab and Cry2Aa toxins for the full life-span of the animals. We used single toxins in different doses and combinations of toxins and Roundup(®), another potential stressor on the rise in agricultural ecosystems. Animals exposed to 4.5 mg/L (ppm) of Cry1Ab, Cry2Aa and the combination of both showed markedly higher mortality, smaller body size and very low juvenile production compared to controls. Animals exposed to 0.75 mg/L also showed a tendency towards increased mortality but with increased early fecundity compared to the controls. Roundup(®) stimulated animals to strong early reproductive output at the cost of later rapid mortality. We conclude that i) purified Cry-toxins in high concentrations are toxic to D. magna, indicating alternative modes-of-action for these Cry-toxins; ii) Cry-toxins act in combination, indicating that 'stacked events' may have stronger effects on non-target organisms; iii) further studies need to be done on combinatorial effects of multiple Cry-toxins and herbicides that co-occur in the environment. PMID:26993955

  20. Acute toxicity of butachlor and atrazine to freshwater green alga Scenedesmus obliquus and cladoceran Daphnia carinata.

    Science.gov (United States)

    He, Hongzhi; Yu, Jing; Chen, Guikui; Li, Wenyang; He, Jinbo; Li, Huashou

    2012-06-01

    Both single and joint toxicity of atrazine and butachlor to freshwater green alga Scenedesmus obliquus and cladoceran Daphnia carinata isolated from South China were investigated in the present study. The 96 h-EC(50) values of atrazine and butachlor to S. obliquus were 0.0147 and 2.31 mg L(-1), while the 48 h-LC(50) values to D. carinata were 60.6 and 3.40 mg L(-1), respectively. These results suggest that atrazine could be highly toxic to S. obliquus and slightly toxic to D. carinata, while butachlor exhibits moderate toxicity to both organisms. The additive indexes of atrazine and butachlor mixtures were -2.68 (-3.02 to -2.32) to S. obliquus and 0.054 (-0.025 to 0.238) to D. carinata, respectively. Therefore, the joint action of two herbicides was significant antagonism to S. obliquus, while significant synergism was not shown to D. carinata. Moreover, significant linear correlation between the natural logarithm of herbicide concentrations and growth rates of alga S. obliquus was observed. Taken together, it is the first study reporting the toxicity endpoints for mixture of atrazine and butachlor against S. obliquus and D. carinata isolated from south China. The present results would be helpful to provide data to assess the ecological risk of both herbicides to aquatic organisms.