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Sample records for abalone haliotis diversicolor

  1. Identification and characterization of Vibrio harveyi associated with diseased abalone Haliotis diversicolor.

    Jiang, Qingru; Shi, Liuyang; Ke, Caihuan; You, Weiwei; Zhao, Jing

    2013-03-26

    Mass mortality of farmed small abalone Haliotis diversicolor occurred in Fujian, China, from 2009 to 2011. Among isolates obtained from moribund abalones, the dominant species AP37 exhibited the strongest virulence. After immersion challenge with 106 CFU ml-1 of AP37, abalone mortalities of 0, 53 and 67% were induced at water temperatures of 20°C, 24°C, and 28°C, respectively. Following intramuscular injection, AP37 showed a low LD50 (median lethal concentration) value of 2.9 × 102 CFU g-1 (colony forming units per gram abalone wet body weight). The LT50 (median lethal time) values were 5.2 h for 1 × 106 CFU abalone-1, 8.4 h for 1 × 105 CFU abalone-1, and 21.5 h for 1 × 104 CFU abalone-1. For further analysis of virulence, AP37 was screened for the production of extracellular factors. The results showed that various factors including presence of flagella and production of extracellular enzymes, such as lipase, phospholipase and haemolysin, could be responsible for pathogenesis. Based on its 16S rRNA gene sequence, strain AP37 showed >98.8% similarity to Vibrio harveyi, V. campbellii, V. parahaemolyticus, V. alginolyticus, V. natriegens and V. rotiferianus, so it could not be identified by this method. However, multi-locus sequence analysis (MLSA) of concatenated sequences, including the rpoD, rctB, gyrB, toxR and pyrH genes, identified strain AP37 as V. harveyi. Phenotypic characters of AP37 were identified by API 20E. In antibiotic susceptibility tests, strain AP37 exhibited susceptibility to 7 antibiotics and resistance to 13. This is the first report of a V. harveyi-related species being linked with the mass mortality of adult abalone H. diversicolor in southern China. PMID:23548363

  2. Identification and involvement of ferritin in the response to pathogen challenge in the abalone, Haliotis diversicolor.

    He, Jian; Jiang, Jingzhe; Gu, Lu; Zhao, Manman; Wang, Ruixuan; Ye, Lingtong; Yao, Tuo; Wang, Jiangyong

    2016-07-01

    Accumulating data has demonstrated that ferritin plays an important role in host defense responses against infection by pathogens in many organisms. In this study, ultracentrifugation was used to isolate ferritin from abalone, Haliotis diversicolor, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that this ferritin consisted of two subunits (designated as HdFer1 and HdFer2). There are no disulfide bonds between the HdFer1 and HdFer2 subunits; however, these subunits co-assemble to form heteropolymers. A novel ferritin subunit (HdFer2) was cloned from H. diversicolor by 5' and 3' RACE (rapid amplification of cDNA ends) approach. The full-length HdFer2 cDNA sequence consists of 878 bp with an open reading frame of 513 bp that encodes a protein that is 170 amino acids in length. Quantitative real-time PCR analysis revealed that HdFer1 and HdFer2 were transcribed in various tissues, such as the mantle, gill and hepatopancreas, with the highest levels of expression in the hepatopancreas. Following a challenge with the pathogen, Vibrio harveyi, the expression of HdFer1 and HdFer2 were markedly induced at different times. This study has identified a novel ferritin subunit in H. diversicolor which will contribute to further exploration of the role of ferritin in mollusk innate immune defense against invading pathogens. PMID:26875633

  3. Effects of tributyltin (TBT) on enzyme activity and oxidative stress in hepatopancreas and hemolymph of small abalone, Haliotis diversicolor supertexta

    Jia Xiwei; Zhang Ziping; Wang Shuhong; Lin Peng; Zou Zhihua; Huang Bangqin; Wang Yilei

    2009-01-01

    We investigated the effect of tributyltin (TBT) exposure on the concentration of malondialdehyde (MDA) and the activity levels of the superoxide dismutase (SOD), catalase (CAT), and acid and alkaline phosphatase (ACP and AKP) enzymes in the small abalone, Haliotis diversicolor supertexta. We collected samples of the hepatopancreas and hemolymph 2, 6, 24, 48, 96, and 192 h after exposure to 0.35μg (Sn)/L TBT. In the hepatopancreas, ACP activity was significantly higher in animals exposed to TBT 2, 24, and 96 h post-exposure compared with the control animals. AKP activity was also higher after 2 h, but SOD and CAT activity was unchanged. The concentration of MDA in the hemolymph was significantly higher than the control animals 2 and 6 h post-exposure. In the hemolymph of animals exposed to TBT, ACP activity was significantly lower than in the control animals 192 h post-exposure, whereas AKP activity was significantly lower 2 and 192 h post-exposure. Hemolymph SOD activity and levels of MDA were significantly lower than in the control animals 24 h after exposure but significantly higher after 96 h. Our results demonstrate that exposure to TBT cause rapid changes in ACP and AKP activity as well as altering the concentration of MDA in the hepatopancreas and hemolymph. SOD and CAT do not appear to be involved in the detoxification of TBT in the hepatopancreas of small abalone.

  4. Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

    YANG Zhihui; ZHANG Xiangjing; CAI Zhonghua

    2009-01-01

    As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP),diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP,DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of 1-1. diversicolor supertexta can be used to indicate toxicity of the PAEs.

  5. Potential mechanisms of phthalate ester embryotoxicity in the abalone Haliotis diversicolor supertexta

    The effects and associated toxicological mechanisms of five phthalate esters (PAEs) on abalone embryonic development were investigated by exposing the embryos to a range of PAEs concentrations (0.05, 0.2, 2 and 10 μg/mL). The results showed that PAEs could significantly reduce embryo hatchability, increase developmental malformations, and suppress the metamorphosis of abalone larvae. The possible toxicological mechanisms of PAEs to abalone embryos included, affecting the Na+-K+-pump and Ca2+-Mg2+-pump activities, altering the peroxidase (POD) level and the malondialdehyde (MDA) production, damaging the extraembryonic membranes structure, as well as disrupting endocrine-related genes (gpx, cyp3a, and 17β-hsd 12) expression properties. Taken together, this work showed that PAEs adversely affected the embryonic ontogeny of abalone. The abilities of PAEs affecting the osmoregulation, inducing oxidative stress, damaging embryo envelope structure, and causing physiological homeostasis disorder, are likely to be a part of the common mechanisms responsible for their embryonic toxicity. - Highlights: → PAEs affected abalone hatchability, morphogenesis and metamorphosis behavior. → The toxicity of the five PAEs to embryogenesis was ranked as DBP > DEP > DMP > DOP > DEHP. → The osmoregulation disorder and oxidative damage are the potential mechanisms. - Potential mechanisms of PAEs on abalone embryogenesis are osmoregulation disorder, oxidative damage and physiological dysfunction.

  6. Potential mechanisms of phthalate ester embryotoxicity in the abalone Haliotis diversicolor supertexta

    Zhou Jin [L-304, Life Sciences Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen University Town, Xili, Shenzhen City 518055 (China); Cai Zhonghua, E-mail: caizh@sz.tsinghua.edu.cn [L-304, Life Sciences Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen University Town, Xili, Shenzhen City 518055 (China); Key Laboratory of Aquatic-Ecology, Tianjin Agricultural University, Lishui Road 112, Tianjin 300384 (China); Xing Kezhi [Key Laboratory of Aquatic-Ecology, Tianjin Agricultural University, Lishui Road 112, Tianjin 300384 (China)

    2011-05-15

    The effects and associated toxicological mechanisms of five phthalate esters (PAEs) on abalone embryonic development were investigated by exposing the embryos to a range of PAEs concentrations (0.05, 0.2, 2 and 10 {mu}g/mL). The results showed that PAEs could significantly reduce embryo hatchability, increase developmental malformations, and suppress the metamorphosis of abalone larvae. The possible toxicological mechanisms of PAEs to abalone embryos included, affecting the Na{sup +}-K{sup +}-pump and Ca{sup 2+}-Mg{sup 2+}-pump activities, altering the peroxidase (POD) level and the malondialdehyde (MDA) production, damaging the extraembryonic membranes structure, as well as disrupting endocrine-related genes (gpx, cyp3a, and 17{beta}-hsd 12) expression properties. Taken together, this work showed that PAEs adversely affected the embryonic ontogeny of abalone. The abilities of PAEs affecting the osmoregulation, inducing oxidative stress, damaging embryo envelope structure, and causing physiological homeostasis disorder, are likely to be a part of the common mechanisms responsible for their embryonic toxicity. - Highlights: > PAEs affected abalone hatchability, morphogenesis and metamorphosis behavior. > The toxicity of the five PAEs to embryogenesis was ranked as DBP > DEP > DMP > DOP > DEHP. > The osmoregulation disorder and oxidative damage are the potential mechanisms. - Potential mechanisms of PAEs on abalone embryogenesis are osmoregulation disorder, oxidative damage and physiological dysfunction.

  7. Structural Changes and Rheological Properties of Dry Abalone Meat (Haliotis diversicolor) During the Process of Water Restoration

    2007-01-01

    Changes in tissue structure, rheological property and water content of dry abalone meat in the process of water restoration were studied. The weight and volume of dry abalone meat increased with water restoration. When observed under a light microscope, structural change in myofibrils was obvious and a distinct network was found. When water restoration time increased from 24h to 72h, the instantaneous modulus E0 and viscosity η1 increased, whereas the rupture strength and relaxation time (τ1) were reduced. There were no significant changes of rheological parameters (E0, η1, τ1, rupture strength) from 72 h to 96 h of water restoration. Therefore, the dry abalone meat was swollen enough at the time of 72 h. The rheological parameters were obviously influenced by the structural changes.

  8. Application of Novel Polymorphic Microsatellite Loci Identified in the Korean Pacific Abalone (Haliotis diversicolor supertexta (Haliotidae in the Genetic Characterization of Wild and Released Populations

    Seong Wan Hong

    2012-08-01

    Full Text Available The small abalone, Haliotis diversicolor supertexta, of the family Haliotidae, is one of the most important species of marine shellfish in eastern Asia. Over the past few decades, this species has drastically declined in Korea. Thus, hatchery-bred seeds have been released into natural coastal areas to compensate for the reduced fishery resources. However, information on the genetic background of the small abalone is scarce. In this study, 20 polymorphic microsatellite DNA markers were identified using next-generation sequencing techniques and used to compare allelic variation between wild and released abalone populations in Korea. Using high-throughput genomic sequencing, a total of 1516 (2.26%; average length of 385 bp reads containing simple sequence repeats were obtained from 86,011 raw reads. Among the 99 loci screened, 28 amplified successfully, and 20 were polymorphic. When comparing allelic variation between wild and released abalone populations, a total of 243 different alleles were observed, with 18.7 alleles per locus. High genetic diversity (mean heterozygosity = 0.81; mean allelic number = 15.5 was observed in both populations. A statistical analysis of the fixation index (FST and analysis of molecular variance (AMOVA indicated limited genetic differences between the two populations (FST = 0.002, p > 0.05. Although no significant reductions in the genetic diversity were found in the released population compared with the wild population (p > 0.05, the genetic diversity parameters revealed that the seeds released for stock abundance had a different genetic composition. These differences are likely a result of hatchery selection and inbreeding. Additionally, all the primer pair sets were effectively amplified in another congeneric species, H. diversicolor diversicolor, indicating that these primers are useful for both abalone species. These microsatellite loci

  9. Effect of hypoxia on the immune response of the abalone Haliotis diversicolor supertexta and its susceptibility to pathogen Vibrio parahaemolyticus%低氧胁迫对九孔鲍免疫防御因子的影响

    陈政强; 陈昌生; 战文斌

    2012-01-01

    为了解低氧胁迫条件下九孔鲍免疫防御因子的变化及机体抗病力变化,将九孔鲍置于不同的溶解氧环境中,观测相关免疫因子变化.结果显示,在水温为(22.1±1.3)℃,盐度为30.72±0.54,pH值为8.20±0.14的海水环境中,溶解氧含量由(7.49±0.14) mg/L下调至(2.53±0.16) mg/L后120 h内,平均体质量为(14.25±2.21)g的九孔鲍未见死亡,而每只鲍注射5.0×105 CFU副溶血弧菌后120 h内实验鲍的累计死亡率高达91.11%±7.70%,比对照组(11.11%±3.83%)累计死亡率高出80%,血淋巴抑菌清除率下降至-(3 340.47%±298.57%),显而易见,低氧胁迫使得九孔鲍拮抗副溶血弧菌感染的抵抗力显著下降.低氧(2.53±0.16)mg/L胁迫下,九孔鲍血淋巴细胞数量(THC)下降30.62%±4.87%、血淋巴细胞吞噬率下降62.77%±5.79%、呼吸爆发产生的超氧阴离子数量下降22.21%±5.89%.低氧胁迫下九孔鲍血淋巴细胞内MPO活性上升(9.63%±7.59%)~(22.90%±13.73%)、CAT活性提高(7.68%±6.83%)~(56.28%±13.96%),反映出低氧胁迫下九孔鲍体内应激反应产生的物质氧化加剧,血淋巴细胞内产生大量的活性氧自由基.溶解氧含量由(7.49±0.14) mg/L下调至(4.51±0.12) mg/L后九孔鲍已明显处于低氧胁迫和应激反应状态,120 h内的累计死亡率达到37.78%±3.85%,血淋巴抑菌率下降至883.56%±123.22%; THC、血淋巴细胞吞噬率、呼吸爆发产生的超氧阴离子O2-数量等最大降幅分别达到12.51%±6.59%、21.90%±15.84%、12.93%±5.74%; MPO活性在原有水平的-(10.61%±4.20%)~(7.13%±6.45%)之间波动,CAT活性在-(5.17%±18.08%)~(16.26%±10.85%)之间变化.%The abalone Haliotis diversicolor supertexta is the most important aquatic species in many marine farms in China. For the purpose of qualitative observation on the variation of immune defense and natural resistance of animals, the abalones were put into

  10. Australian abalone (Haliotis laevigata, H. rubra and H. conicopora) are susceptible to infection by multiple abalone herpesvirus genotypes.

    Corbeil, Serge; Williams, Lynette M; McColl, Kenneth A; Crane, Mark St J

    2016-05-01

    From 2006 to 2012, acute mortalities occurred in farmed and wild abalone (Haliotis spp.) along the coast of Victoria, Australia. The disease (abalone viral ganglioneuritis; AVG) is associated with infection by an abalone herpesvirus (AbHV). The relative pathogenicity of 5 known variants of AbHV was evaluated on abalone stocks from different states in Australia. Results indicated that all virus variants (Vic1, Tas1, Tas2, Tas3 and Tas4) cause disease and mortality in all abalone stocks tested (greenlip, blacklip and brownlip). In order to avoid further AVG outbreaks in Australian wild abalone, strict regulations on the transfer of abalone stocks must be implemented. PMID:27137068

  11. Gut microflora of abalone Haliotis discus hannai in culture changes coincident with a change in diet

    Tanaka, Reiji; Sugimura, Itsuro; SAWABE, Tomoo; Yoshimizu, Mamoru; Ezura, Yoshio

    2003-01-01

    Development of gut microflora in abalone Haliotis discus hannai cultured at two abalone farms in Japan was similar: (i) gut microflora of juvenile abalones fed on microalgae matched microflora cultured from seawater; and (ii) gut microflora changed coincident with the abalone switching food sources from microalgae to algal pellets. After abalone reached 4 months of age, the gut microflora was replaced by algal polysaccharide-degrading bacteria, which were almost entirely characterized as facu...

  12. Effects of different concentrations of benzo(a)pyrene on antioxidant enzymes in gastropod abalone,Haliotis diversicolor%不同浓度苯并(a)芘对杂色鲍抗氧化酶活性的影响

    刘洁; 林智勇; 王克坚

    2014-01-01

    为阐释不同浓度苯并(a)芘[B(a)P]对杂色鲍(Haliotis diversicolor)的毒性效应,以0.02、0.04和0.08 mg/dm33个质量浓度的B(a)P对杂色鲍进行水体暴露胁迫,7d后检测肌肉、外套膜、鳃、性腺、肾和肝胰腺的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽S-转移酶(GST)和谷胱甘肽过氧化物酶(GPx)活性及还原型谷胱甘肽(GSH)含量.结果显示:0.02 mg/dm3的B(a)P暴露对杂色鲍抗氧化系统的影响不明显,而0.04、0.08 mg/dm3的B(a)P则显著抑制了SOD、CAT和GPx酶活性以及GSH含量,同时对GST酶活性具有显著的诱导作用;实验还发现,不同组织抗氧化酶活性对B(a)P胁迫的敏感性响应存在较大差异,其中鳃、肾脏和肝胰腺的敏感性响应明显高于肌肉和外套膜.上述结果表明,苯并(a)芘暴露对杂色鲍抗氧化酶活性的影响具有明显的剂量-效应关系及组织差异性,杂色鲍的鳃、肾脏或者肝胰腺的抗氧化酶响应多环芳香烃胁迫的更敏感,可作为B(a)P污染的生物标志物.%To reveal the ecotoxicological effects of benzo(a)pyrene[B(a)P]on gastropod abalone,Haliotis diversi-color,the effects of different concentrations of B(a)P (0.02,0.04 and 0.08 mg/dm3 )were studied on antioxidant defense system of H.diversicolor.The results showed that the antioxidant enzymes activities showed little difference for the animals exposed to 0.02 mg/dm3 B(a)P compared with the control.In 0.04 mg/dm3 and 0.08 mg/dm3 groups,the activities of SOD,CAT,GPx and the contents of GSH were significant inhibited by B(a)P exposure, while the GST activities were significantly induced.The activities of antioxidant enzymes were also significantly dif-ferent among the tissues,suggesting the exist of remarkable different physiological functions and responses to B(a)P content.In summary,the antioxidant enzymes activities of exposure to

  13. Measuring abalone (Haliotis Spp.) recruitment in California to examine recruitment overfishing and recovery criteria

    Rogers-Bennett, L; Allen, B L; Davis, G E

    2004-01-01

    Abalone populations in southern California have declined dramatically since the 1950s when they supported a multispecies, commercial, and recreational fishery producing more than 3,000 t per year. Today the commercial fishery is closed statewide and the recreational fishery is closed south of San Francisco. In contrast, red abalone, Haliotis rufescens (Swainson, 1822), populations in northern California continue to sustain a 1,100 1 per year free-diving recreational fishery. We used standardi...

  14. Identifikation und Charakterisierung von Perlucin Spleißvarianten der marinen Abalone Haliotis laevigata.

    Dodenhof, Tanja

    2014-01-01

    Mother of pearl is a polymer of significance for material sciences due to its fascinating properties. A frequently investigated protein in mother of pearl from the Australian Abalone Haliotis laevigata is the protein Perlucin. Despite its importance relatively little is known about the role of Perlucin in detail in the biomineralisation of mother of pearl. After SDS-PAGE and staining with Coomassie the native protein from H. laevigata shows a heterogenic band pattern (Blank et al., 2001 [1] u...

  15. Biokinetic behavior of Tc in the red abalone, Haliotis rufescens: a reassessment

    The biokinetic behavior of /sup 95m/Tc in the red abalone, Haliotis rufescens, is reviewed in light of recent experiments on other molluscs. Additional experimentation has confirmed that, when uptake is directly from labeled seawater, abalone exhibit concentration factors in excess of 100. Bivalve molluscs under the same experimental conditions have concentration factors that do not exceed 2. However, uptake and loss kinetics cannot be described by a single compartment model as had been previously advanced. Assimilation of /sup 95m/Tc by the abalone following a single feeding of labeled macroalga, Nereocystis pyrifera, is high (approx. 45%) and loss kinetics are similar to those observed following direct uptake from seawater

  16. DIETARY PHOSPHORUS REQUIREMENT OF YOUNG ABALONE,HALIOTIS DISCUS HANNAI INO

    谭北平; 麦康森; 刘付志国

    2002-01-01

    An experiment was performed to determine the dietary phosphorus requirement of the young abalone, Haliotis discus hannai. Five semi-purified diets were formulated to provide a series of graded levels of dietary total phosphorus (0.23%-1.98) from monobasic potassium phosphate (KH2PO4). The brown alga, Laminaria japonica, was used as a control diet. Similar size abalone were distributed in a single-pass, flow-through system using a completely randomized design with six treatments and three replicates each treatment. The abalone were hand-fed to satiation with appropriate diets in excess, once daily at 17:00. The feeding trial was run for 120-d. Survival rate and soft-body to shell ratio (SB/S) were constantly maintained regardless of dietary treatment. However, the weight gain rate (WGR), daily increment in shell length (DISL), muscle RNA to DNA ratio (RNA/DNA), carcass levels of lipid and protein, soft-body alkaline phosphatase (SBAKP), and phosphorus concentrations of whole body (WB) and soft body (SB) were significantly (ANOVA, P<0.05) affected by the dietary phosphorus level. The dietary phosphorus requirements of the abalone were evaluated from the WGR, DISL, and RNA/DNA ratio respectively, by using second-order polynomial regression analysis. Based on these criteria, about 1.0%-1.2% total dietary phosphorus, i.e. 0.9%-1.1% dietary available phosphorus is recommended for the maximum growth of the abalone.

  17. Effects of Dietary Carbohydrates Sources on Lipids Compositions in Abalone, Haliotis discus hannai Ino

    WANG Weifang; MAI Kangsen; ZHANG Wenbing; XU Wei; AI Qinghui; YAO Chunfeng; LI Huitao

    2009-01-01

    A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates (dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively), all containing a carbohydrate level of 33.5%, were fed to abalone (initial shell length: 29.98 mm±0.09 mm; initial weight. 3.42 g±0.02 g) for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly (P<0.05) higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly (P<0.05)higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20:4n-6 in the foot muscles were significantly (P<0.05) lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20:4n-6 in hepatopancreas was significantly (P<0.05) lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22:6n-3 in the foot muscles were significantly (P< 0.05) lower in the abalone fed with dextrin and heat-treated wheat starch than those fed with wheat starch and potato starch.

  18. Characterization of abalone Haliotis tuberculata-Vibrio harveyi interactions in gill primary cultures.

    Pichon, Delphine; Cudennec, Benoit; Huchette, Sylvain; Djediat, Chakib; Renault, Tristan; Paillard, Christine; Auzoux-Bordenave, Stéphanie

    2013-10-01

    The decline of European abalone Haliotis tuberculata populations has been associated with various pathogens including bacteria of the genus Vibrio. Following the summer mortality outbreaks reported in France between 1998 and 2000, Vibrio harveyi strains were isolated from moribund abalones, allowing in vivo and in vitro studies on the interactions between abalone H. tuberculata and V. harveyi. This work reports the development of primary cell cultures from abalone gill tissue, a target tissue for bacterial colonisation, and their use for in vitro study of host cell-V. harveyi interactions. Gill cells originated from four-day-old explant primary cultures were successfully sub-cultured in multi-well plates and maintained in vitro for up to 24 days. Cytological parameters, cell morphology and viability were monitored over time using flow cytometry analysis and semi-quantitative assay (XTT). Then, gill cell cultures were used to investigate in vitro the interactions with V. harveyi. The effects of two bacterial strains were evaluated on gill cells: a pathogenic bacterial strain ORM4 which is responsible for abalone mortalities and LMG7890 which is a non-pathogenic strain. Cellular responses of gill cells exposed to increasing concentrations of bacteria were evaluated by measuring mitochondrial activity (XTT assay) and phenoloxidase activity, an enzyme which is strongly involved in immune response. The ability of gill cells to phagocyte GFP-tagged V. harveyi was evaluated by flow cytometry and gill cells-V. harveyi interactions were characterized using fluorescence microscopy and transmission electron microscopy. During phagocytosis process we evidenced that V. harveyi bacteria induced significant changes in gill cells metabolism and immune response. Together, the results showed that primary cell cultures from abalone gills are suitable for in vitro study of host-pathogen interactions, providing complementary assays to in vivo experiments. PMID:23756730

  19. Transcriptome characterization of the South African abalone Haliotis midae using sequencing-by-synthesis

    Roodt-Wilding Rouvay

    2011-03-01

    Full Text Available Abstract Background Worldwide, the genus Haliotis is represented by 56 extant species and several of these are commercially cultured. Among the six abalone species found in South Africa, Haliotis midae is the only aquacultured species. Despite its economic importance, genomic sequence resources for H. midae, and for abalone in general, are still scarce. Next generation sequencing technologies provide a fast and efficient tool to generate large sequence collections that can be used to characterize the transcriptome and identify expressed genes associated with economically important traits like growth and disease resistance. Results More than 25 million short reads generated by the Illumina Genome Analyzer were de novo assembled in 22,761 contigs with an average size of 260 bp. With a stringent E-value threshold of 10-10, 3,841 contigs (16.8% had a BLAST homologous match against the Genbank non-redundant (NR protein database. Most of these sequences were annotated using the gene ontology (GO and eukaryotic orthologous groups of proteins (KOG databases and assigned to various functional categories. According to annotation results, many gene families involved in immune response were identified. Thousands of simple sequence repeats (SSR and single nucleotide polymorphisms (SNP were detected. Setting stringent parameters to ensure a high probability of amplification, 420 primer pairs in 181 contigs containing SSR loci were designed. Conclusion This data represents the most comprehensive genomic resource for the South African abalone H. midae to date. The amount of assembled sequences demonstrated the utility of the Illumina sequencing technology in the transcriptome characterization of a non-model species. It allowed the development of several markers and the identification of promising candidate genes for future studies on population and functional genomics in H. midae and in other abalone species.

  20. Acute toxicity of live and decomposing green alga Ulva ( Enteromorpha) prolifera to abalone Haliotis discus hannai

    Wang, Chao; Yu, Rencheng; Zhou, Mingjiang

    2011-05-01

    From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva ( Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.

  1. In vitro culture of mantle tissue of the abalone Haliotis varia Linnaeus.

    Suja, C P; Dharmaraj, S

    2005-02-01

    The study is aimed at developing a technology for the production of in vitro pearl through tissue culture of mantle of the abalone, Haliotis varia Linnaeus, as the production of free and spherical pearls in vivo is rather difficult in abalones. In the basic study, the cell yield was intensified from the explant after 24h incubation. Among the cells liberated, the granulocytes were dominant over hyalinocytes. The size of granulocytes ranged from 3 to 16 microm and of hyalinocytes from 13 to 18 microm. Fibroblast-like cells appeared in cultures after day 2. Both granulocytes and hyalinocytes developed pseudopodial-like extensions in all directions and formed organic matrix. Granulocytes contained granules in the cytoplasm. Specific granules were responsible for nucleation of crystals. Some crystals exhibited green colour resembling mother of pearl of abalone. scanning electron microscope (SEM) study revealed the oolitic amorphous state and rhombohedral state of crystals. Its analysis through energy dispersive X-ray microanalyzer (EDS) indicated the presence of calcium. The rhombohedral crystals under polarized light showed its high birefringence (0.18) and uniaxial optically negative calcite nature with high content of calcium. A mean survival of cells was found to be 102 days in T 25 flasks and 32 days in petri dishes. Growth of cells was studied. Thirty percent of cultures were found to have contaminated during the study. The study provides basic knowledge in the development of a technology for in vitro pearl production. PMID:15695171

  2. AVAILABILITY OF PHOSPHORUS FROM SELECTED INORGANIC PHOSPHATES TO JUVENILE ABALONE,HALIOTIS DISCUS HANNAI INO

    谭北平; 麦康森; 徐玮

    2002-01-01

    The availability of phosphorus to juvenile abalone, Haliotis discus hannai from primary, secondary and tertiary calcium phosphate, primary sodium or potassium phosphate separately or in combination was determined in a 120-day feeding trial. Seven semi-purified diets were formulated to contain relativelyconstant dietary phosphorus, ranging from 0.78%-0.82%. The concentrations of dietary phosphorus were presumed to be slightly below the requirement for abalone.A brown alga, Laminaria japonica, was used as a control diet. Abalone juvenilesof similar size (average weight 1.18 g; average shell length 18.74 mm) were distributed in a single-pass, flow-through system using a completely randomized design with eight treatments and three replicates each treatment. The survival ranged from 71.1% to 81.1%, and was not significantly (P>0.05) related to dietary treatment. However, the weight gain rate (41.72%-65.02%), daily increment in shelllength (36.87-55.07 μm) and muscle RNA-DNA ratio (3.44-4.69) were significantly (P<0.05) affected by dietary treatment. Soft body alkaline phosphatase activity (10.9-19.8 U/g wet tissue) and carcass levels of lipid (7.71%-9.33%) and protein (46.68%-49.35%) were significantly (P<0.05) responsive to available phosphorus of the diets. Dietary treatment had significant effect (P<0.05) on concentrations of phosphorus in the whole body (WB) and soft body (SB). Apparent digestibility coefficients (45%-97%) of phosphorus were also significantly (P<0.05) different between dietary treatments. The results indicated that among these inorganiccompounds, primary calcium, potassium and sodium phosphates separately or in combination could be utilized effectively by juvenile abalone as dietary phosphorus sources (availability ranging from 87%-97%). However, secondary and tertiary calcium phosphates were found to be low in availability, the values being 45% and77%, respectively. ``

  3. Effects of dietary vitamin A on antioxidant responses of abalone Haliotis discus hannai Ino

    FU Jinghua; ZHANG Wenbing; MAI Kangsen; FENG Xiuni; XU Wei; LIUFU Zhiguo; TAN Beiping

    2006-01-01

    A 240 d growth experiment was conducted in a re-circulated water system to investigate the effects of dietary vitamin A on growth and antioxidant responses of abalone Haliotis discus hannai Ino. Triplicate groups of juvenile abalone [initial mass was (0.96 ± 0.02) g, shell length was (17.70 ± 0.06) mm] were fed to satiation one of three semi-purified diets containing 0, 1×103, 1×106 IU vitamin A per kilogram diet, respectively. Results showed that the daily increment in shell length (DISL) of abalone in the treatment with 1×103 IU vitamin A per kilogram diet was significantly higher than that with 0 or 1×106 IU vitamin A per kilogram supplementation (P < 0.05). Vitamin A deficiency (0 IU/kg) significantly elevated the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione reductase (GR) in the viscera of abalone (P < 0.05). In muscle, the effects of vitamin A deficiency on SOD and GPX activities were the same as those in viscera, however, the activity of GR significantly decreased (P < 0.05). Vitamin A deficiency significantly decreased the ratio of CAT to SOD (catalase/superoxide dismutase) in viscera (P < 0.05). Nevertheless, it significantly decreased the ratio of GR to GPX in muscle (P < 0.05). Compared with the supplement of 1×103 IU vitamin A per kilogram, excessive vitamin A (1×106 IU/kg) had no significant effects on the activities of CAT, SOD and glutathione-S-transferase (GST) (P > 0.05), but significantly elevated GPX and GR activities in viscera (P < 0.05). In muscle, the activities of CAT, SOD, GPX, GST and GR were significantly decreased by the excessive dietary vitamin A supplement (P < 0.05). Compared with the supplement of 1×103 IU vitamin A per kilogram, vitamin A-excessive had no significant effect on the value of ratio of CAT to SOD either in viscera or in muscle (P>0.05). The ratio of GR to GPX was significantly decreased in viscera, but significantly elevated in muscle in the vitamin A

  4. Vibrio harveyi adheres to and penetrates tissues of the European abalone Haliotis tuberculata within the first hours of contact.

    Cardinaud, Marion; Barbou, Annaïck; Capitaine, Carole; Bidault, Adeline; Dujon, Antoine Marie; Moraga, Dario; Paillard, Christine

    2014-10-01

    Vibrio harveyi is a marine bacterial pathogen responsible for episodic epidemics generally associated with massive mortalities in many marine organisms, including the European abalone Haliotis tuberculata. The aim of this study was to identify the portal of entry and the dynamics of infection of V. harveyi in the European abalone. The results indicate that the duration of contact between V. harveyi and the European abalone influences the mortality rate and precocity. Immediately after contact, the epithelial and mucosal area situated between the gills and the hypobranchial gland was colonized by V. harveyi. Real-time PCR analyses and culture quantification of a green fluorescent protein-tagged strain of V. harveyi in abalone tissues revealed a high density of bacteria adhering to and then penetrating the whole gill-hypobranchial gland tissue after 1 h of contact. V. harveyi was also detected in the hemolymph of a significant number of European abalones after 3 h of contact. In conclusion, this article shows that a TaqMan real-time PCR assay is a powerful and useful technique for the detection of a marine pathogen such as V. harveyi in mollusk tissue and for the study of its infection dynamics. Thus, we have revealed that the adhesion and then the penetration of V. harveyi in European abalone organs begin in the first hours of contact. We also hypothesize that the portal of entry of V. harveyi in the European abalone is the area situated between the gills and the hypobranchial gland. PMID:25107972

  5. Purification and characterisation of aquamarine blue pigment from the shells of abalone (Haliotis discus hannai Ino).

    Cai, Zhixing; Wu, Jiulin; Chen, Li; Guo, Wei; Li, Jianhua; Wang, Jiabin; Zhang, Qiqing

    2011-09-01

    Aquamarine blue pigment (ABP) from the shells of abalone (Haliotis discus hannai Ino) was extracted using a precipitation adsorption method and further purified via semi-preparative HPLC. The ABP with molecular weight of 582.8 was identified as a polyenic compound by NMR. The colour value of ABP was E1cm(1%)612nm=534.3. ABP can dissolve in water, ethanol, methanol, acetic acid and DMSO but was scarcely soluble in chloroform, aether, acetone, petroleum ether and cyclohexane. ABP was relatively stable between 25 and 100°C, from pH 2 to pH 12, under UV-light and indoor natural light. However, it was bleached by H2O2 and Na2SO3 and even unstable under sunlight. The stability of ABP was slightly influenced by metal ions (Ca(2+), Cu(2+), Fe(2+) and so on) and food addictives (sodium chloride, sugar, starch and so on). This is the first report on the characterisation of pigment obtained from Haliotis discus hannai Ino. PMID:25214339

  6. An AFLP genetic linkage map of pacific abalone ( Haliotis discus hannai)

    Qi, Li; Yanhong, Xu; Ruihai, Yu; Akihiro, Kijima

    2007-07-01

    A genetic linkage map of Pacific abalone ( Haliotis discus hannai) was constructed using AFLP markers based on a two-way pseudo-testeross strategy in a full-sib family. With 33 primer combinations, a total of 455 markers (225 from the female parent and 230 from the male parent) segregated in a 1:1 ratio, corresponding to DNA polymorphism: heterozygous in one parent and null in the other. The female framework map consisted of 174 markers distributed in 18 linkage groups, equivalent to the H. discus hannai haploid chromosome number, and spanning a total length of 2031.4 cM, with an average interval of 13.0 cM between adjacent markers. The male framework map consisted of 195 markers mapped on 19 linkage groups, spanning a total length of 2273.4 cM, with an average spacing of 12.9 cM between adjacent markers. The estimated coverage for the framework linkage maps was 81.2% for the female and 82.1% for the male, on the basis of two estimates of genome length. Fifty-two markers (11.4%) remained unlinked. The level of segregation distortion observed in this cross was 20.4%. These linkage maps will serve as a starting point for linkage studies in the Pacific abalone with potential application for marker-assisted selection in breeding programs.

  7. Proteomic analysis of the organic matrix of the abalone Haliotis asinina calcified shell

    Degnan Bernard M

    2010-11-01

    Full Text Available Abstract Background The formation of the molluscan shell is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell forming tissue, the mantle. This so called "calcifying matrix" is a complex mixture of proteins and glycoproteins that is assembled and occluded within the mineral phase during the calcification process. While the importance of the calcifying matrix to shell formation has long been appreciated, most of its protein components remain uncharacterised. Results Recent expressed sequence tag (EST investigations of the mantle tissue from the tropical abalone (Haliotis asinina provide an opportunity to further characterise the proteins in the shell by a proteomic approach. In this study, we have identified a total of 14 proteins from distinct calcified layers of the shell. Only two of these proteins have been previously characterised from abalone shells. Among the novel proteins are several glutamine- and methionine-rich motifs and hydrophobic glycine-, alanine- and acidic aspartate-rich domains. In addition, two of the new proteins contained Kunitz-like and WAP (whey acidic protein protease inhibitor domains. Conclusion This is one of the first comprehensive proteomic study of a molluscan shell, and should provide a platform for further characterization of matrix protein functions and interactions.

  8. Feeding preferences and the nutritional value of tropical algae for the abalone Haliotis asinina.

    Alex R Angell

    Full Text Available Understanding the feeding preferences of abalone (high-value marine herbivores is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae--or any feedstock--which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid content of algae have rarely been simultaneously investigated for abalone, and never for the emerging target species Haliotis asinina. Here we found that the tropical H. asinina had strong and consistent preferences for the red alga Hypnea pannosa and the green alga Ulva flexuosa, but no overarching relationship between protein content (sum of amino acids and preference existed. For example, preferred Hypnea and Ulva had distinctly different protein contents (12.64 vs. 2.99 g 100 g(-1 and the protein-rich Asparagopsis taxiformis (>15 g 100 g(-1 of dry weight was one of the least preferred algae. The limiting amino acid in all algae was methionine, followed by histidine or lysine. Furthermore we demonstrated that preferences can largely be removed using carrageenan as a binder for dried alga, most likely acting as a feeding attractant or stimulant. The apparent decoupling between feeding preference and algal nutritive values may be due to a trade off between nutritive values and grazing deterrence associated with physical and chemical properties.

  9. Antimicrobial peptide, hdMolluscidin, purified from the gill of the abalone, Haliotis discus.

    Seo, Jung-Kil; Go, Hye-Jin; Kim, Chan-Hee; Nam, Bo-Hye; Park, Nam Gyu

    2016-05-01

    A 4.7 kDa antimicrobial peptide was purified from the acidified gill extract of the Abalone, Haliotis discus, by cation-exchange and C18 reversed-phase high performance liquid chromatography (HPLC). Comparison of the amino acid sequences and molecular weight of this peptide with those of other known antimicrobial peptides revealed that this antimicrobial peptide have high sequence homology with that of cgMolluscidin and was designated hdMolluscidin. hdMolluscidin is composed of 46 amino acid residues containing several dibasic residue repeats like KK or K-R. hdMolluscidin showed potent antimicrobial activity against both Gram-positive bacteria including Bacillus subtilis and Staphylococcus aureus (minimal effective concentrations [MECs]; 0.8-19.0 μg/mL) and Gram-negative bacteria including Aeromonas hydrophila, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Shigella flexneri, and Vibrio parahemolyticus ([MECs]; 1.0-4.0 μg/mL) without hemolytic activity. However, hdMolluscidin did not show any significant activity against Candida albicans. The secondary structural prediction suggested that hdMolluscidin might not form an ordered or an amphipathic structure. hdMolluscidin did not show membrane permeabilization or leakage ability. The full-length hdMolluscidin cDNA contained 566-bp, including a 5'-untranslated region (UTR) of 63-bp, a 3'-UTR of 359-bp, and an open reading frame of 144-bp encoding 47 amino acids (containing Met). cDNA study of hdMolluscidin suggests that it is expressed as a mature peptide. Our results indicate that hdMolluscidin could relate to the innate immune defenses in abalone and it may not act directly on bacterial membrane. PMID:27033467

  10. Development and Characterization of Microsatellite Markers for the Pacific Abalone (Haliotis discus) via EST Database Mining

    ZHAN Aibin; BAO Zhenmin; WANG Mingling; CHANG Dan; YUAN Jian; WANG Xiaolong; HU Xiaoli; LIANG Chengzhu; HU Jingjie

    2008-01-01

    The EST database of the Pacific abalone (Haliotis discus) was mined for developing mierosatellite markers. A total of 1476 EST sequences were registered in GenBank when data mining was performed. Fifty sequences (approximately 3.4%) were found to contain one or more mierosatellites. Based on the length and GC content of the flanking regions, duster analysis and BLASTN, 13 microsatellite-containing ESTs were selected for PCR primer design. The results showed that 10 out of 13 primer pairs could amplify seorable PCR products and showed polymorphism. The number of alleles ranged from 2 to 13 and the values of Hoand He varied from 0.1222 to 0.8611 and 0.2449 to 0.9311, respectively. No significant linkage disequilibrium (LD) between any pairs of these loci was found, and 6 of 10 loci conformed to the Hardy-Weinberg equilibrium (HWE). These EST-SSRs are therefore potential tools for studies of intraspecies variation and hybrid identification.

  11. Nanoscale structure and mechanical behavior of growth lines in shell of abalone Haliotis gigantea.

    Sumitomo, Taro; Kakisawa, Hideki; Kagawa, Yutaka

    2011-04-01

    In the natural world, bottom-up hierarchical construction of complex structures results in materials with remarkable properties. A well known example is the nacre of mollusk shells, commonly called "mother of pearl", whose excellent strength and toughness has been the subject of research for many decades. A significant discovery has been the presence of periodic layers called "growth lines". These are thin distinct layers within the bulk of the shell which form periodically, with their structure affected by environmental changes. Studies of their formation and behavior offer valuable insight into the architecture of seashells. In this work, the structure and mechanical behavior of growth lines in shells of abalone Haliotis gigantea were investigated using electron microscopy and nanoindentation. Growth lines form directly out of nacre into layers of blocks and irregular particles. In comparison to nacre, they have basic structures, form rapidly, and are harder, which suggest that they serve a protective role during lifecycle transitions. This exemplifies how natural structures are able to closely control growth architecture in order to form different structures for different functions, all from the same base materials. PMID:21232604

  12. Identification of a female spawn-associated Kazal-type inhibitor from the tropical abalone Haliotis asinina.

    Wang, Tianfang; Nuurai, Parinyaporn; McDougall, Carmel; York, Patrick S; Bose, Utpal; Degnan, Bernard M; Cummins, Scott F

    2016-07-01

    Abalone (Haliotis) undergoes a period of reproductive maturation, followed by the synchronous release of gametes, called broadcast spawning. Field and laboratory studies have shown that the tropical species Haliotis asinina undergoes a two-week spawning cycle, thus providing an excellent opportunity to investigate the presence of endogenous spawning-associated peptides. In female H. asinina, we have isolated a peptide (5145 Da) whose relative abundance in hemolymph increases substantially just prior to spawning and is still detected using reverse-phase high-performance liquid chromatography chromatograms up to 1-day post-spawn. We have isolated this peptide from female hemolymph as well as samples prepared from the gravid female gonad, and demonstrated through comparative sequence analysis that it contains features characteristic of Kazal-type proteinase inhibitors (KPIs). Has-KPI is expressed specifically within the gonad of adult females. A recombinant Has-KPI was generated using a yeast expression system. The recombinant Has-KPI does not induce premature spawning of female H. asinina when administered intramuscularly. However it displays homomeric aggregations and interaction with at least one mollusc-type neuropeptide (LRDFVamide), suggesting a role for it in regulating neuropeptide endocrine communication. This research provides new understanding of a peptide that can regulate reproductive processes in female abalone, which has the potential to lead to the development of greater control over abalone spawning. The findings also highlight the need to further explore abalone reproduction to clearly define a role for novel spawning-associated peptide in sexual maturation and spawning. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27352998

  13. 杂色鲍血蓝蛋白HtH1基因第16内含子 SNP密度的分析%SNP density of hemocyanin HtH1 intron 16 in Haliotis diversicolor

    梁翠; 陈军; 游伟伟; 王德祥; 柯才焕

    2011-01-01

    Single nucleotide polymorphisms (SNP) are a new generation of genetic marker systems.EPIC was used to analyze the SNP of the hemocyanin HtH1 gene 16 intron (H1 intron 16) from 45 samples of Haliotis diversicolor.These 45 individuals came from three different wild or breeding populations in Japan, Taiwan and the Shantou Sea.There were three alleles in H1 intron 16 of the Japanese abalone (Haliotis diversicolor), which showed length polymorphism.The lengths of the three alleles were 1 900 bp, 780 bp and 440 bp.However, the H1 intron 16 of the breeding populations of Taiwan and Shantou abalone were only 1 900 bp.Sequence analysis indicated that there was a self-heterozygous SNP locus of approximately 96 bp in the Japanese abalone, but that the Taiwan and Shantou abalone contained loci of 133 bp and 153 bp, respectively.The SNP density of 13 Taiwan abalone was 31 bp, while the SNP density of 23 Shantou abalone was 21 bp.These data indicated that the existing cultured population of abalone contained rich SNP loci, and it was feasible to construct a high density genetic map using SNP markers.%单核苷酸多态性(SNPs)是继RFLP和SSR多态性标记之后的新一代遗传标记系统.本文采用EPIC的方法,分析了45个杂色鲍样品的血蓝蛋白HtH1基因第16内含子(H1 intron 16)的SNP数据.这45个个体分别来自日本、台湾和汕头3个不同海域的野生或养殖群体.日本群体的血蓝蛋白HtH1基因第16内含子呈现出长度多态性,共有3种不同长度,分别是1 900、780、440 bp,测序结果表明3个等位基因可以互相比对;而台湾和汕头杂色鲍养殖群体的均为1 900 bp.初步研究结果表明日本杂色鲍个体大约96 bp长的片段含有1个自身杂合SNP位点;台湾杂色鲍个体约133 bp含有1个自身杂合SNP位点;汕头杂色鲍个体约153 bp含有1个自身杂合SNP位点.13个台湾杂色鲍个体包含的SNP密度为约31 bp含有1个SNP;23个汕头杂色鲍个体包含的SNP密度为约 21 bp

  14. Analysis of microbiota on abalone (Haliotis discus hannai) in South Korea for improved product management.

    Lee, Min-Jung; Lee, Jin-Jae; Chung, Han Young; Choi, Sang Ho; Kim, Bong-Soo

    2016-10-01

    Abalone is a popular seafood in South Korea; however, because it contains various microorganisms, its ingestion can cause food poisoning. Therefore, analysis of the microbiota on abalone can improve understanding of outbreaks and causes of food poisoning and help to better manage seafood products. In this study, we collected a total of 40 abalones from four different regions in March and July, which are known as the maximum abalone production areas in Korea. The microbiota were analyzed using high-throughput sequencing, and bacterial loads on abalone were quantified by real-time PCR. Over 2700 species were detected in the samples, and Alpha- and Gammaproteobacteria were the predominant classes. The differences in microbiota among regions and at each sampling time were also investigated. Although Psychrobacter was the dominant genus detected on abalone in both March and July, the species compositions were different between the two sampling times. Five potential pathogens (Lactococcus garvieae, Yersinia kristensenii, Staphylococcus saprophyticus, Staphylococcus warneri, and Staphylococcus epidermidis) were detected among the abalone microbiota. In addition, we analyzed the influence of Vibrio parahaemolyticus infection on shifts in abalone microbiota during storage at different temperatures. Although the proportion of Vibrio increased over time in infected and non-infected abalone, the shifts of microbiota were more dynamic in infected abalone. These results can be used to better understand the potential of food poisoning caused by abalone consumption and manage abalone products according to the microbiota composition. PMID:27371902

  15. Actibacter haliotis sp. nov., isolated from the gut of an abalone, Haliotis discus hannai, and emended description of the genus Actibacter.

    Hyun, Dong-Wook; Kim, Joon Yong; Kim, Min-Soo; Shin, Na-Ri; Kim, Hyun Sik; Lee, June-Young; Bae, Jin-Woo

    2015-01-01

    A novel strain, designated strain W113(T), was isolated from the gut of an abalone, Haliotis discus hannai, which was collected from the northern coast of Jeju in Korea. The isolate was a Gram-staining-negative, facultatively anaerobic, non-motile, rod-shaped bacterium producing yellow-to-orange carotenoid-type pigments. 16S rRNA gene sequence analysis showed that the isolate belonged to the genus Actibacter in the family Flavobacteriaceae and it shared the highest sequence similarity with the type strain of Actibacter sediminis (98.8 % similarity). Optimal growth occurred at 25 °C, at pH 7 and with 2 % (w/v) NaCl. The major cellular fatty acids were iso-C15:0, anteiso-C15:0 and iso-C15:1 G. Menaquinone-6 was the main respiratory quinone. The polar lipids of the isolate were phosphatidylethanolamine, three unidentified amino lipids, and three unidentified lipids. The genomic DNA G+C content was 42.6 mol% and DNA-DNA hybridization values indicated that the strain shared <18 % genomic relatedness with the most closely related species. The results of the phylogenetic, phenotypic and genotypic analyses indicated that strain W113(T) represents a novel species in the genus Actibacter, for which the name Actibacter haliotis sp. nov. is proposed. The type strain is W113(T) ( = KACC 17209(T) = JCM 18868(T)). PMID:25269848

  16. Isolation and identification of lactic acid bacteria from abalone (Haliotis asinina as a potential candidate of probiotic

    YAYAN SOFYAN

    2010-01-01

    Full Text Available Sarkono, Faturrahman, Sofyan Y. 2010. Isolation and identification of lactic acid bacteria from abalone (Haliotis asinina as a potential candidate of probiotic. Nusantara Bioscience 2: 38-42. The purpose of this study was to isolate, select and characterize lactic acid bacteria (LAB from abalone as a potential candidate probiotic in abalone cultivation system. Selective isolation of LAB performed using de Man Rogosa Sharpe medium. LAB isolate that potential as probiotics was screened. Selection was based on its ability to suppress the growth of pathogenic bacteria, bacterial resistance to acidic conditions and bacterial resistance to bile salts (bile. Further characterization and identification conducted to determine the species. The results showed that two of the ten isolates potential to be developed as probiotic bacteria that have the ability to inhibit several pathogenic bacteria such as Eschericia coli, Bacillus cereus dan Staphylococus aureus, able to grow at acidic condition and bile tolerance during the incubation for 24 hour. Based on the API test kit, the both of isolate identified as members of the species Lactobacillus paracasei ssp. paracasei.

  17. Detection and Localisation of the Abalone Probiotic Vibrio midae SY9 and Its Extracellular Protease, VmproA, within the Digestive Tract of the South African Abalone, Haliotis midae

    Huddy, Robert J.; Coyne, Vernon E.

    2014-01-01

    Probiotics have been widely reported to increase the growth rate of commercially important fish and shellfish by enhancing the digestion of ingested feed through the production of extracellular enzymes such as proteases and alginases. In order to investigate this further, the objective of this study was to localise the bacterial probiont Vibrio midae SY9 and one of the extracellular proteases it produces in the digestive tract of the South African abalone Haliotis midae. This was accomplished...

  18. Development of a monoclonal antibody detection assay for species-specific identification of abalone.

    Lopata, Andreas L; Luijx, Thomas; Fenemore, Bartha; Sweijd, Neville A; Cook, Peter A

    2002-10-01

    Species identification based on biochemical and molecular techniques has a broad range of applications. These include compliance enforcement, the management and conservation of marine organisms, and commercial quality control. Abalone poaching worldwide and illegal trade in abalone products have increased mainly because of the attractive prices obtained and caused a sharp decline in stocks. Alleged poachers have been acquitted because of lack of evidence to correctly identify species. Therefore, a robust method is required that would identify tissue of abalone origin to species level. The aim of this study was to develop immunologic techniques, using monoclonal and polyclonal antibodies, to identify 10 different abalone species and subspecies from South Africa, the United States, Australia, and Japan. The combination of 3 developed monoclonal antibodies to South African abalone (Haliotis midae) enabled differentiation between most of the 10 species including the subspecies H. diversicolor supertexta and H. diversicolor diversicolor. In a novel approach, using antibodies of patients with allergy to abalone, the differentiation of additional subspecies, H. discus discus and H. discus hannai, was possible. A field-based immunoassay was developed to identify confiscated tissue of abalone origin. PMID:14961238

  19. Potential Response to Selection of HSP70 as a Component of Innate Immunity in the Abalone Haliotis rufescens

    Brokordt, Katherina B.; González, Roxana C.; Farías, William J.; Winkler, Federico M.

    2015-01-01

    Assessing components of the immune system may reflect disease resistance. In some invertebrates, heat shock proteins (HSPs) are immune effectors and have been described as potent activators of the innate immune response. Several diseases have become a threat to abalone farming worldwide; therefore, increasing disease resistance is considered to be a long-term goal for breeding programs. A trait will respond to selection only if it is determined partially by additive genetic variation. The aim of this study was to estimate the heritability (h2) and the additive genetic coefficient of variation (CVA) of HSP70 as a component of innate immunity of the abalone Haliotis rufescens, in order to assess its potential response to selection. These genetic components were estimated for the variations in the intracellular (in haemocytes) and extracellular (serum) protein levels of HSP70 in response to an immunostimulant agent in 60 full-sib families of H. rufescens. Levels of HSP70 were measured twice in the same individuals, first when they were young and again when they were pre-harvest adults, to estimate the repeatability (R), the h2 and the potential response to selection of these traits at these life stages. High HSP70 levels were observed in abalones subjected to immunostimulation in both the intracellular and extracellular haemolymph fractions. This is the first time that changes in serum levels of HSP70 have been reported in response to an immune challenge in molluscs. HSP70 levels in both fractions and at both ages showed low h2 and R, with values that were not significantly different from zero. However, HSP70 induced levels had a CVA of 13.3–16.2% in young adults and of 2.7–8.1% in pre-harvest adults. Thus, despite its low h2, HSP70 synthesis in response to an immune challenge in red abalone has the potential to evolve through selection because of its large phenotypic variation and the presence of additive genetic variance, especially in young animals. PMID

  20. Kazal-type proteinase inhibitor from disk abalone (Haliotis discus discus): molecular characterization and transcriptional response upon immune stimulation.

    Wickramaarachchi, W D Niroshana; De Zoysa, Mahanama; Whang, Ilson; Wan, Qiang; Lee, Jehee

    2013-09-01

    Proteinases and proteinase inhibitors are involved in several biological and physiological processes in all multicellular organisms. Proteinase inhibitors play a key role in regulating the activity of the respective proteinases. Among serine proteinase inhibitors, kazal-type proteinase inhibitors (KPIs) are widely found in mammals, avians, and a variety of invertebrates. In this study, we describe the identification of a kazal-type serine proteinase inhibitor (Ab-KPI) from the disk abalone, Haliotis discus discus, which is presumably involved in innate immunity. The full-length cDNA of Ab-KPI includes 600 bp nucleotides with an open reading frame (ORF) encoding a polypeptide of 143 amino acids. The deduced amino acid sequence of Ab-KPI contains a putative 17-amino acid signal peptide and two tandem kazal domains with high similarity to other kazal-type SPIs. Each kazal domain consists of reactive site (P1) residue containing a leucine (L), and a threonine (T) located in the second amino acid position after the second conserved cysteine of each domain. Temporal expression of Ab-KPI was assessed by real time quantitative PCR in hemocytes and mantle tissue following bacterial and viral hemorrhagic septicemia virus (VHSV) challenge, and tissue injury. At 6 h post-bacterial and -VHSV challenge, Ab-KPI expression in hemocytes was increased 14-fold and 4-fold, respectively, compared to control samples. The highest up-regulations upon tissue injury were shown at 9 h and 12 h in hemocytes and mantle, respectively. The transcriptional modulation of Ab-KPI following bacterial and viral challenges and tissue injury indicates that it might be involved in immune defense as well as wound healing process in abalone. PMID:23859879

  1. Genetic variation of Chinese and Japanese wild Pacific abalone (Haliotis discus hannai) measured by microsatellite DNA markers

    LI Qi; KIJIMA Akihiro

    2006-01-01

    Population differentiation and relationships among three wild populations of the Pacific abalone Haliotis discus hannai collected from coastal seas around China and Japan were estimated using microsatellite DNA analysis. The results obtained with six microsatellite loci showed a high genetic diversity for China and Japan populations. The mean number of alleles per locus ranged from 11.7 to 23.0, and the average of observed and expected heterozygosity ranged from 0.656 to 0.721, and from 0.721 to 0.793, respectively. The observed genotype frequencies at each locus were mostly in agreement with Hardy-Weinberg expectations with five exceptions. Significant differences were detected between Chinese and Japanese H. discus hannai populations [Weir and Cocker-ham's fixation index(Fst) range: 0.020~0.023; Slatkin's fixation index (Rst) range: 0.016~0.044], and no obvious difference was detected between the samples of Japanese H. discus hannai populations (Fst=0.002; Rst = 0.007). The level of differentiation among populations is further evidenced by the nNeighbor-joining tree topology on which the Japanese samples were closely clustered, and the Chinese population formed a separate cluster. These results suggest that care should be taken in future management of different populations.

  2. Marine environmental impact assessment of abalone, Haliotis discus hannai, cage farm in Wan-do, Republic of Korea

    Oh, Hyun-Taik; Jung, Rae-Hong; Cho, Yoon-Sik; Hwang, Dong-Woon; Yi, Yong-Min

    2015-12-01

    To assess the marine environmental impacts of abalone, Haliotis discus hannai, cage farms in Wan-do, we monitored the benthic environment on top of the sediment underneath cage farm stations and reference stations. We applied two methods for this assessment. One was the A- and B-investigation of the MOM system (Modeling-On fish farm-Monitoring) developed in Norway. The other was a general environmental monitoring method which is widely used. In this study, we found benthic animals in all samples that belonged to condition 1 which were based on group 1(presence of macrofauna) of the B-investigation method. The values of redox potential (group 2-pH, redox potential) in all samples were above +65 mV belonging to condition 1. Based on sensory results (group 3-gas, color, odor, thickness of deposits), five out of seven experiment samples showed condition 1 while stations 2 and 7 showed condition 2, which have been cultured for 10 years in semi-closed waters. As group 2 takes precedence over group 3, the level of the conditions for B-investigation results consequently showed condition 1 in all stations. We found that pollutants and trace metals in the sediment underneath cage farms were lower than the pollution standard. This led us to conclude that the environmental impacts of the cage farms in this study were not significant.

  3. Feeding Preferences and the Nutritional Value of Tropical Algae for the Abalone Haliotis asinina

    Alex R Angell; Igor Pirozzi; Rocky de Nys; Paul, Nicholas A.

    2012-01-01

    Understanding the feeding preferences of abalone (high-value marine herbivores) is integral to new species development in aquaculture because of the expected link between preference and performance. Performance relates directly to the nutritional value of algae--or any feedstock--which in turn is driven by the amino acid content and profile, and specifically the content of the limiting essential amino acids. However, the relationship between feeding preferences, consumption and amino acid con...

  4. Dietary ascorbic acid modulates the expression profile of stress protein genes in hepatopancreas of adult Pacific abalone Haliotis discus hannai Ino.

    Wu, Chenglong; Wang, Jia; Xu, Wei; Zhang, Wenbing; Mai, Kangsen

    2014-12-01

    This study was conducted to investigate the effects of dietary ascorbic acid (AA) on transcriptional expression patterns of antioxidant proteins, heat shock proteins (HSP) and nuclear factor kappa B (NF-κB) in the hepatopancreas of Pacific abalone Haliotis discus hannai Ino (initial average length: 84.36 ± 0.24 mm) using real-time quantitative PCR assays. L-ascorbyl-2-molyphosphate (LAMP) was added to the basal diet to formulate four experimental diets containing 0.0, 70.3, 829.8 and 4967.5 mg AA equivalent kg(-1) diets, respectively. Each diet was fed to triplicate groups of adult abalone in acrylic tanks (200 L) in a flow-through seawater system. Each tank was stocked with 15 abalone. Animals were fed once daily (17:00) to apparent satiation for 24 weeks. The results showed that the dietary AA (70.3 mg kg(-1)) could significantly up-regulate the expression levels of Cu/Zn superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), feritin (FT) and heat shock protein 26 (HSP26) in the hepatopancreas of abalone in this treatment compared to the controls. However, the expression levels of Mn-SOD, glutathione peroxidase (GPX), thioredoxin peroxidase (TPx), selenium-binding protein (SEBP), HSP70 and HSP90 were significantly down-regulated. Compared with those in the group with 70.3 mg kg(-1) dietary AA, the expression levels of CAT, GST and HSP26 were decreased in abalone fed with very high dietary AA (4967.5 mg kg(-1)). In addition, significant up-regulations of expression levels of Mn-SOD, GPX, TPx, SEBP, FT, HSP70, HSP90 and NF-κB were observed in abalone fed with apparently excessive dietary AA (829.8 and 4967.5 mg kg(-1)) as compared to those fed 70.3 mg kg(-1) dietary AA. These findings showed that dietary AA influenced the expression levels of antioxidant proteins, heat shock proteins and NF-κB in the hepatopancreas of abalone at transcriptional level. Levels of dietary AA that appeared adequate (70.3 mg kg(-1)) reduced the oxidative stress

  5. Acclimation-dependent expression of heat shock protein 70 in Pacific abalone (Haliotis discus hannai Ino) and its acute response to thermal exposure

    LI Jiaqi; HE Qingguo; SUN Hui; LIU Xiao

    2012-01-01

    Heat shock protein 70 (Hsp70) is one important member of heat shock protein (Hsp) family that is responsible for various stresses,especially thermal stress.Here we examined the response of Hsp70gene to both chronic and acute thermal exposure in Pacific abalone (Haliotis discus hannai Ino).For the chronic exposure,abalones were maintained at 8,12,20,and 30℃ for four months and their mRNA levels were measured.The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30℃-acclimated group,followed by the 8℃-acclimated group and then the 12℃- and 20℃-acclimated groups.After the long-term acclimation,gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8℃ and 38℃ for 30 min.Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure.The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups.Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions,through which they deal with the stress of thermal variations.

  6. The feasibility of bomb radiocarbon analysis to support an age-at-length relationship for red abalone, Haliotis rufescens Swainson in northern California

    Leaf, R T; Andrews, A H; Cailliet, G M; Brown, T A

    2009-01-07

    Analysis of bomb generated radiocarbon ({sup 14}C) changes in a red abalone, Haliotis rufescens Swainson shell was used to investigate age-at-length relationships derived from data from a previous multi-year, multi-site tag-recapture study. Shell carbonate was extracted from four successive growth trajectory locations in a single shell with a length of 251 mm MSL. Extraction locations were based on VBGF predictions and chosen to span the initial rise of the {sup 14}C-bomb pulse that is known to have occurred in surface ocean waters during 1958 {+-} 1 y in the northeast Pacific. The close temporal correspondence of the red abalone sample series to regional {Delta}{sup 14}C records demonstrated the utility of the technique for validating age-at-length relationships for the red abalone. The findings provided support for a mean VBGF derived age of 32 y (range 30 to 33 y) for the specimen; however, the analysis of {sup 14}C data indicated that the specimen could be older.

  7. Biochemical and immunohistochemical analyses of a GnRH-like peptide in the neural ganglia of the Pacific abalone Haliotis discus hannai (Gastropoda).

    Amano, Masafumi; Moriyama, Shunsuke; Okubo, Kataaki; Amiya, Noriko; Takahashi, Akiyoshi; Oka, Yoshitaka

    2010-08-01

    We examined whether gonadotropin-releasing hormone (GnRH)-like peptides are present in the neural ganglia of the gastropod Pacific abalone (Haliotis discus hannai) by reverse-phase high performance liquid chromatography (rpHPLC) combined with time-resolved fluoroimmunoassay (TR-FIA) analysis and by immunohistochemistry. Cerebral ganglion extracts showed a similar retention time to lamprey GnRH-II (lGnRH-II) in rpHPLC combined with TR-FIA analysis. GnRH-like-immunoreactive (ir) cell bodies (which reacted with a mouse monoclonal antibody raised against the common amino acid sequence of vertebrate GnRH) were detected in the peripheral region of the cerebral ganglion, and they were observed to send fibers into the neuropil. GnRH-like-ir fibers were also detected in the neuropil of the pedal ganglion, the visceral nerve, and the nerve originating from the pedal ganglion. Chicken GnRH-II (cGnRH-II)-like-ir fibers (which reacted with a rabbit polyclonal antibody raised against cGnRH-II) were also observed in the neuropil of the cerebral ganglion. GnRH-like-ir fibers and cGnRH-II-like-ir fibers were distinguishable in the neuropil of the cerebral ganglion by double-staining immunohistochemistry. These results suggest that multiple GnRH-like peptides exist in the neural ganglia of the Pacific abalone. PMID:20695781

  8. Molecular characterization of collagen IV evidences early transcription expression related to the immune response against bacterial infection in the red abalone (Haliotis rufescens).

    Chovar-Vera, Ornella; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2015-02-01

    Collagen IV has been described as a structural protein of the basement membrane, which as a whole forms a specialized extracellular matrix. Recent studies have indicated a possible relationship between collagen IV and the innate immune response of invertebrate organisms. The present study characterized the alpha-1 chain of collagen IV in the red abalone Haliotis rufescens (Hr-ColIV) and evaluated its association with the innate immune response against Vibrio anguillarum. To further evidence the immune response, the matrix metalloproteinase-1 (Hr-MMP-1) and C-type lectin (Hr-CLEC) genes were also assessed. The complete sequence of Hr-ColIV was composed of 6658 bp, with a 5'UTR of 154 bp, a 3'UTR of 1177 bp, and an ORF of 5327 bp that coded for 1776 amino acids. The innate immune response generated against V. anguillarum resulted in a significant increase in the transcript levels of Hr-ColIV between 3 and 6 hpi, whereas Hr-MMP-1 and Hr-CLEC had the highest transcript activity 6 and 12 hpi, respectively. The results obtained in this study propose a putative biological function for collagen IV involved in the early innate immune response of the red abalone H. rufescens. PMID:25463284

  9. Effects of waterborne Cu and Cd on anti-oxidative response, lipid peroxidation and heavy metals accumulation in abalone Haliotis discus hannai ino

    Lei, Yanju; Zhang, Wenbing; Xu, Wei; Zhang, Yanjiao; Zhou, Huihui; Mai, Kangsen

    2015-06-01

    The aim of this study was to compare the effects of waterborne copper (Cu) and cadmium (Cd) on survival, anti-oxidative response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals (initial weight: 7.49 g ± 0.01 g) were exposed to graded concentrations of waterborne Cu (0.02, 0.04, 0.06, 0.08 mg L-1) or Cd (0.025, 0.05, 0.25, 0.5 mg L-1) for 28 days, respectively. Activities of the anti-oxidative enzymes (catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST), contents of the reduced glutathione (GSH) and malondiadehyde (MDA) in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L--1 and 0.08 mg L-1 Cu caused 100% death of abalone on the 21st, 10th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopancreas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense

  10. Molluscan death effector domain (DED)-containing caspase-8 gene from disk abalone (Haliotis discus discus): molecular characterization and expression analysis.

    Lee, Youngdeuk; De Zoysa, Mahanama; Whang, Ilson; Lee, Sukkyoung; Kim, Yucheol; Oh, Chulhong; Choi, Cheol Young; Yeo, Sang-Yeob; Lee, Jehee

    2011-02-01

    The caspase family represents aspartate-specific cysteine proteases that play key roles in apoptosis and immune signaling. In this study, we cloned the first death effector domain (DED)-containing molluscan caspase-8 gene from disk abalone (Haliotis discus discus), which is named as hdCaspase-8. The full-length hdCaspase was 2855 bp, with a 1908 bp open reading frame encoding 636 amino acids. The hdCaspase-8 had 72 kDa predicted molecular mass with an estimated isoelectric point (PI) of 6.0. The hdCaspase-8 amino acid sequence contained the characteristic feature of an N-terminal two DED, a C-terminal catalytic domain and the caspase family cysteine active site ⁵¹³KPKLFFLQACQG⁵²⁴. Phylogenetic analysis results showed that hdCaspase-8 is more similar to the invertebrate Tubifex tubifex (sludge worm) caspase-8. Real-time RT-PCR results showed that hdCaspase-8 constitutively and ubiquitously expressed in all tested tissue of unchallenged disk abalone. The basal expression level of hdCaspase-8 in gill tissue was higher than all other tested tissues. The hdCaspase-8 mRNA expression in gill and hemocytes was significantly up-regulated by exposure to bacteria (Vibrio alginolyticus, Vibrio parahemolyticus and Listeria monocytogenes) and VHSV (viral hemorrhagic septicemia virus), as compared to control animals. These results suggest that hdCaspase-8 may be involved in immune response reactions in disk abalone. PMID:21130887

  11. The early stages of the immune response of the European abalone Haliotis tuberculata to a Vibrio harveyi infection.

    Cardinaud, Marion; Dheilly, Nolwenn M; Huchette, Sylvain; Moraga, Dario; Paillard, Christine

    2015-08-01

    Vibrio harveyi is a marine bacterial pathogen responsible for episodic abalone mortalities in France, Japan and Australia. In the European abalone, V. harveyi invades the circulatory system in a few hours after exposure and is lethal after 2 days of infection. In this study, we investigated the responses of European abalone immune cells over the first 24 h of infection. Results revealed an initial induction of immune gene expression including Rel/NF-kB, Mpeg and Clathrin. It is rapidly followed by a significant immuno-suppression characterized by reduced cellular hemocyte parameters, immune response gene expressions and enzymatic activities. Interestingly, Ferritin was overexpressed after 24 h of infection suggesting that abalone attempt to counter V. harveyi infection using soluble effectors. Immune function alteration was positively correlated with V. harveyi concentration. This study provides the evidence that V. harveyi has a hemolytic activity and an immuno-suppressive effect in the European abalone. PMID:25766281

  12. Innovative application of classic and newer techniques for the characterization of haemocytes in the New Zealand black-footed abalone (Haliotis iris).

    Grandiosa, Roffi; Mérien, Fabrice; Pillay, Krish; Alfaro, Andrea

    2016-01-01

    Haemocytes play an important role in innate immune responses within invertebrate organisms. However, identification and quantification of different types of haemocytes can be extremely challenging, and has led to numerous inconsistencies and misinterpretations within the literature. As a step to rectify this issue, we present a comprehensive and detailed approach to characterize haemocytes using a combination of classical (cytochemical and phagocytosis assays with optical microscopy) and novel (flow cytometry with Sysmex XN-1000 and Muse(®) Cell analyser) techniques. The Sysmex XN-1000 is an innovative fluorescent flow cytometric analyser that can effectively detect, identify and count haemocytes, while the Muse(®) Cell analyser provides accurate and rapid haemocyte cell counts and viability. To illustrate this approach, we present the first report on morphological and functional features of New Zealand black-footed abalone (Haliotis iris) haemocyte cells. Two types of haemocytes were identified in this study, including type I (monocyte-like) and type II (lymphocyte-like) cells. Granular cells, which have been reported in other molluscan species, were not detected in H. iris. Cell types were categorized based on shape, size, internal structures and function. The lymphocyte-like haemocytes were the most abundant hemocytes in the haemolymph samples, and they had large nuclei and basic cytoplasms. Monocyte-like cells generally were larger cells compared to lymphocyte-like cells, and had low nucleus-cytoplasm ratios. Monocyte-like cells showed higher phagocytic activity when encountering Zymosan A particles compared to lymphocyte-like cells. The present study provides a comprehensive and accurate new approach to identify and quantify haemocyte cells for future comparative studies on the immune system of abalone and other molluscan species. PMID:26672903

  13. Nutrient uptake efficiency of Gracilaria chilensis and Ulva lactuca in an IMTA system with the red abalone Haliotis rufescens

    Juan Macchiavello

    2014-07-01

    Full Text Available The current study examined the nutrient uptake efficiency of Ulva lactuca and Gracilaria chilensis cultivated in tanks associated with the wastewater of a land-based abalone culture. The experiments evaluated different seaweed stocking densities (1200, 1900, 2600, and 3200 g m-2 and water exchange rates (60, 80, 125, and 250 L h-1. The results show that both U. lactuca and G. chilensis were efficient in capturing and removing all of the inorganic nutrients originating from the abalone cultivation for all of the tested conditions. Furthermore, an annual experiment was performed with U. lactuca, cultivated at a stocking density of 1900 g m-2 and at a water exchanged rate of 125 L h-1, in order to evaluate seasonal changes in the nutrient uptake efficiency, productivity, and growth rate associated with the wastewater of a land-based abalone culture. The results confirmed high uptake efficiency during the entire year, equivalent to a 100% removal of the NH4, NO3, and PO4 produced by the land-based abalone culture. The growth rate and productivity of U. lactuca presented a marked seasonality, increasing from fall until summer and varying from 0.5 ± 0.2% to 2.6 ± 0.2% d-1 and 10 ± 6.1% to 73.6 ± 8.4% g m-2 d-1 for sustainable growth rate and productivity, respectively. We conclude that there is sufficient evidence that demonstrates the high possibility of changing the traditional monoculture system of abalone in Chile, to a sustainable integrated multi-trophic aquaculture system, generating positive environmental externalities, including the use of U. lactuca as a biofiltration unit.

  14. Structural characterization and expression analysis of a beta-thymosin homologue (Tβ) in disk abalone, Haliotis discus discus.

    Kasthuri, Saranya Revathy; Premachandra, H K A; Umasuthan, Navaneethaiyer; Whang, Ilson; Lee, Jehee

    2013-09-15

    Repertoires of proteins and small peptides play numerous physiological roles as hormones, antimicrobial peptides, and cellular signaling factors. The beta-thymosins are a group of small acidic peptides involved in processes such as actin sequestration, neuronal development, wound healing, tissue repair, and angiogenesis. Recent characterization of the beta thymosins as immunological regulators in invertebrates led to our identification and characterization of a beta-thymosin homologue (Tβ) from Haliotis discus discus. The cDNA possessed an ORF of 132 bp encoding a protein of 44 amino acids with a molecular mass of 4977 Da. The amino acid sequence shows high identity with another molluskan beta-thymosin and has a characteristic actin binding motif (LKKTET) and glutamyl donors. Phylogenetic analysis showed a close relationship with molluskan homologues, as well as its distinct identity and common ancestral origin. Genomic analysis revealed a 3 exon-2 intron structure similar to the other homologues. In silico promoter analysis also revealed significant transcription factor binding sites, providing evidence for the expression of this gene under different cellular conditions, including stress or pathogenic attack. Tissue distribution profiling revealed a ubiquitous presence in all the examined tissues, but with the highest expression in mantle and hemocyte. Immune challenge with lipopolysaccharide, poly I:C and Vibrio parahemolyticus induced beta-thymosin expression in gill and hemocytes, affirming an immune-related role in invertebrates. PMID:23680646

  15. Effects of abalone (Haliotis discus hannai Ino) gonad polysaccharides on cholecystokinin release in STC-1 cells and its signaling mechanism.

    Zhao, Jun; Zhou, Da-Yong; Yang, Jing-Feng; Song, Shuang; Zhang, Ting; Zhu, Ce; Song, Yan-Qing; Yu, Chen-Xu; Zhu, Bei-Wei

    2016-10-20

    Abalone gonad polysaccharide (AGP) -31, -32 and -33 prepared in this study had the molecular weight (MW) of 37.8, 32.2 and 27.5kDa, respectively. They all contained mannose, rhamnose, glucuronic acid, glucose, galactose, xylose, arabinose, and fucose, with very similar monosaccharide profile. All the three polysaccharides could significantly increase the secretion of cholecystokinin (CCK) in STC-1 cells. Among them, AGP-32 showed the strongest effect. However, the low-MW fragments of AGP-32 showed significantly lower activity than AGP-32 itself. It was also found that the inhibitors on calcium-sensing receptor (CaSR), protein kinase A (PKA), Ca(2+)⁄calmodulin-dependent protein kinase (CaMK) II, p38- mitogen-activated protein kinases (MAPK), and an intracellular calcium chelator all inhibited AGP-induced CCK secretion. To conclude, Ca(2+)/calmodulin (CaM)/CaMK, cyclic adenosine monophosphate (cAMP)/PKA and MAPK pathways are all involved in AGP-induced CCK secretion. PMID:27474567

  16. A combined telephone and creel survey of the red abalone, Haliotis rufescens (Swainson), sport fishery in California from Monterey to the Oregon border, April through November 1988

    Karpov, Konstantin A

    1991-01-01

    Combined creel and random telephone surveys were used to estimate effort, take, and return mortality for the red abalone sport fishery in central and northern California from Monterey to Del Norte counties in 1988. The 1988 telephone survey results showed most red abalone sport fishing trips were in Mendocino county (61.4%) and Sonoma county (18.1%). The 1988 red abalone sport creel was conducted at seven key study areas in Humboldt, Mendocino, and Sonoma counties where 909 divers and 625 ...

  17. Abalone farm discharges the withering syndrome pathogen into the wild

    Kevin eLafferty

    2013-12-01

    Full Text Available An intracellular bacterium Candidatus Xenohaliotis californiensis, also called Withering-Syndrome Rickettsia-Like Organism (WS-RLO, is the cause of mass mortalities that are the chief reason for endangerment of black abalone (Haliotis cracherodii. Using a real-time PCR assay, we found that a shore-based abalone farm in Santa Barbara, California, discharged WS-RLO DNA into the ocean. Several other shore-based abalone farms discharge effluent into critical habitat for black abalone in California and this might affect the recovery of wild black abalone. Existing regulatory frameworks exist that could help protect wild species from pathogens released from shore-based aquaculture.

  18. Non-selective in situ grazing of diatoms by juvenile Green Abalone (Haliotis fulgens Philippi, 1945 in the Baja California Peninsula Consumo in situ no selectivo de diatomeas por juveniles de abulón azul (Haliotis fulgens Philippi, 1945 en la Península de Baja California

    Uri Argumedo Hernández

    2010-04-01

    Full Text Available For experimental or rearing purposes, young abalones are fed benthic diatoms successfully during their early life stages without considering if the diatoms provided are found in the abalone habitat, nor if grazing selectivity exists. Our aim in this study was to gather further evidence that would indicate whether young Haliotis fulgens graze diatoms in situ selectively. Thirty-four specimens of young H. fulgens were collected in a fishing site in BCS, México on two dates. We identified the diatoms in their gut contents (144 species and determined their relative abundances. Fourteen diatoms (80% of the total abundance were considered most important and twelve were among the most important in the diet of young abalone in BCS. The diversity values (H' of the diatoms in their guts ranged from 1.05 to 4.47, depending on dominance, which reflected the structure of diatom assemblages in situ. The above observations and the low similarity measured between samples show that species richness and equitability are similar even if the species composition of diatoms ingested by young abalone differs between specimens. The results lead us to conclude that grazing of diatoms by young H. fulgens is non-selective, and that the structure of diatom assemblages is more important than the particular taxa in their diet.Durante sus etapas tempranas de vida los abulones jóvenes son alimentados exitosamente con diatomeas bentónicas sin considerar si las especies suministradas se hallan en su medio natural, o si existe algún tipo de preferencia o selectividad por ciertas diatomeas. El objetivo de este estudio fue recabar evidencias acerca de si los juveniles de Haliotis fulgens Philippi presentan un consumo selectivo de diatomeas cuando se alimentan in situ. Se recolectaron treinta y cuatro juveniles de H. fulgens en un sitio de pesca de BCS, México en dos fechas. Se disecaron y se examinaron contenidos intestinales. Se identificaron 144 taxa de diatomeas y se

  19. Impact of post-rigor high pressure processing on the physicochemical and microbial shelf-life of cultured red abalone (Haliotis rufescens).

    Hughes, Brianna H; Perkins, L Brian; Yang, Tom C; Skonberg, Denise I

    2016-03-01

    High pressure processing (HPP) of post-rigor abalone at 300MPa for 10min extended the refrigerated shelf-life to four times that of unprocessed controls. Shucked abalone meats were processed at 100 or 300MPa for 5 or 10min, and stored at 2°C for 35days. Treatments were analyzed for aerobic plate count (APC), total volatile base nitrogen (TVBN), K-value, biogenic amines, color, and texture. APC did not exceed 10(6) and TVBN levels remained below 35mg/100g for 35days for the 300MPa treatments. No biogenic amines were detected in the 300MPa treatments, but putrescine and cadaverine were detected in the control and 100MPa treatments. Color and texture were not affected by HPP or storage time. These results indicate that post-rigor processing at 300MPa for 10min can significantly increase refrigerated shelf-life of abalone without affecting chemical or physical quality characteristics important to consumers. PMID:26471583

  20. Advances in genetics and breeding in abalone:a review%鲍遗传育种研究进展

    蔡明夷; 柯才焕; 周时强; 王桂忠

    2004-01-01

    Abalones are important farming species with a high economic value. They have already been farmed for more than 50 years. As problems and new requirements rose continuously in culture industry of abalone, studies on genetic and breeding techniques are needed to improve characteristics and to gain new traits. This review concentrates on advances in genetics and breeding techniques in abalone. As for genetic studies, karyological analyses, allozyme, DNA markers and genetic diversity were reviewed. So far, karyological analyses in abalone have been performed in 12 species that can be divided into three groups according to the chromosome number. In some economically important species, loci of allozymes and. microsatellites have been isolated and applied to investigate the genetic structure of natural and hatchery populations and to identify the result of chromosome set manipulation, but the related reports are only a few yet. The resultsof investigation with DNA markers and allozymes showed that the genetic structure of natural populations presents two characteristics: excessive homozygosity and subdivision. Advances of various breeding techniques, including introduction, selection,hybridization, polyploidy, gynogenesis and gene manipulation, were reviewed in the other part. Although Haliotis discus discus, introduced from Japan, has become one of the most important culture species in China, the economic, social and environmental effects of introduction have been rarely studied. Selection is one of the most important and basic breeding techniques, but the studies on selection are only a few and preliminary, referring to the relations between genetic characteristics and the traits of growth and resistance, genetic diversity and heritability of quantitative traits, and the effect of selection. Interspecific hybridization was the first breeding program carded out in abalone. Experimental hybridization have been carded out for about 20 crosses. Heterosis,such as faster

  1. 鲍鱼内脏中天然牛磺酸的提取与检测%Extraction and determination of taurine from viscera of abalone (Haliotis discus hannai)

    章骞; 郑福来; 翁凌; 张凌晶; 曹敏杰

    2014-01-01

    目的:以皱纹盘鲍内脏为原料,优化高纯度牛磺酸的提取工艺,并建立用高压液相色谱检测牛磺酸纯度的方法。方法经水煮、乙醇抽提、蒸发浓缩、沉淀、活性炭处理、结晶等步骤,获得高纯度天然牛磺酸。用高压液相色谱检测牛磺酸纯度的方法为:色谱柱:Discovery C18;流动相:甲醇-0.05 mol/L乙酸钠缓冲液(pH 5.3)(v/v,50:50);流速:1 mL/min;检测波长:330 nm;柱温:室温。结果该提取工艺能从1 kg 鲍鱼内脏中提取得到天然牛磺酸3.07 g。采用该检测方法,牛磺酸的出峰时间为6.037 min,在1~20μg/mL浓度范围内线性关系良好(R2=0.9999),最低检出限为0.03μg/mL,最低定量限为0.12μg/mL,样品测定的平均回收率为99.44%(RSD=0.25%),方法的精密度和稳定性好(RSD<1%),用该方法检测提取得到的牛磺酸纯度为96.06%。采用红外光谱法(IR)对提取得到的鲍鱼内脏牛磺酸进一步作结构鉴定,发现它与标准品的红外特征吸收峰一致。结论获得了高纯度牛磺酸的提取工艺。本方法精密度和稳定性好,回收率高。%Objective The viscera from abalone (Haliotis discus hannai) was used as raw materials to isolate natural taurine and an HPLC method for the determination of the purity of taurine was established. Methods Natural taurine was isolated by combining methods of high temperature stewing, activated carbon treatment, ethanol extraction, concentration, precipitation and crystallization. The HPLC method for determination of the purity of taurine was performed on a Discovery C18 column eluted with a mobile phase of 50% methyl alcohol and 50% sodium acetate (pH 5.3) at flow rate of 1.0 mL/min at room tem-perature and detected by a UV detector at 330 nm. Results Taurine (3.07 g) was isolated from 1 kg ab-alone viscera by the extraction method. The retention time of taurine was at 6.037 min on HPLC and the method showed a good linearity within concentration of

  2. Preparation of hemocyanin polyclonal antibody and the identification of 35 kDa hemocyanin fragment in HaHotis diversicolor Reeve%杂色鲍血蓝蛋白多克隆抗体的制备与血蓝蛋白35kDa片段鉴定

    姜敬哲; 韩焘; 王江勇; 杨慧英; 刘金叶

    2012-01-01

    以杂色鲍(Haliotis diversicolor Reeve)为研究对象,通过密度梯度离心方法纯化得到高纯度血蓝蛋白,以其作为抗原皮下注射免疫新西兰大白兔,从而获得高效价的兔源多克隆抗血清。进一步通过ProteinA抗原亲和纯化的方法对该抗血清纯化,最终获得效价更高、检测特异性更好的血蓝蛋白多克隆抗体。应用该抗体进行Western检测发现,鲍血淋巴中存在着多样的血蓝蛋白衍生产物;进一步结合质谱技术对其中35kDa条带进行鉴定发现,其来源于血蓝蛋白I型亚基的H结构域。%Haliotis diversicolor Reeve, was taken as research material. High purity hemocyanin proteins were puri- fied from the hemolymph of abalone using CsC1 density gradient centrifugation method. By injection of the purified antigen to a rabbit, high titer polyclonal anti-serum was acquired. The anti-serum was further processed with the protein A affinity purification to produce purified antibodies. Finally, the purified polyclonal antibodies with higher titer and specificity were acquired. Further Western blotting with these antibodies, plenty of hemocyanin was found as derivates of various molecular weights in abalone hemolymph.

  3. Studies on the Antibiotic Susceptibility of Pathogens Caused Massive Death of Post Larvae of Abalone (Haliotis diversicolor supertexta)%南方九孔鲍鲍苗掉板病原菌的药敏测定

    王志; 蔡俊鹏; 杨洪志; 徐丽

    2005-01-01

    为提高鲍鱼培苗的成活率,对分离自广东汕尾一养殖场鲍苗掉板池中(包括水、藻膜和变白鲍苗)的、经回归感染试验证明为致病菌的菌株进行了鉴定和药物敏感性测定.API鉴定表明,这些致病菌株由Vibrio alginolyticus,Vibrio cholerae,Vibrio parahaemolyticus等组成,其中弧菌17株,约占总分离菌株的50%,而溶藻弧菌则为弧菌的优势菌株,有11株,约占弧菌总数的70%.药敏结果显示,绝大多数菌株对链霉素、红霉素和庆大霉素敏感;相反,四环素和新生霉素则对它们没有作用或不敏感.

  4. 九孔鲍养殖水体及消化道细菌学的研究%Bacteriological Studies in a Digestive Tract of Abalone (Haliotis diversicolor supertexta) and in the Waters

    蔡创华; 周毅频; 蔡俊鹏; 杨洪志

    2005-01-01

    2002年对汕尾健生鲍鱼养殖场养殖水体和鲍消化道中异养细菌及弧菌的数量和类群组成进行了研究.研究结果表明:养殖水体中异养细菌数量的四季变化从2.4×104~1.3×l05 cfu/ml,平均为7.6×104 cfu/ml;消化道中异养细菌数量四季变化则从1.6×107~5.4×107 cfu/g(湿重),平均为3.3×107 cfu/g.水体中弧菌数量四季变化从1.2×104~5.1×104 cfu/ml,平均为2.5×104 cfu/ml;而消化道中弧菌数量四季变化则从2.8×105~3.8×105 cfu/g,平均为3.2×105cfu/g.水体中细菌类群由Sphingomonas, Vibrio, Pasteurella, Moraxella, Pseudomonas, Aeromonas, Flavobacterium, Klebsiella, Weeksella和Alcall组成,消化道中细菌类群由Sphingomonas, Vibrio, Aeromonas, Flavobacterium, Shewanella, Sphingobacterium, Pseudomonas组成,水体和消化道弧菌种类主要为Vibrio fluvialis,Vibrio parahaemolyticus,Vibrio vulnificus,Vibrio cholerae,Vibrio minicus,Vibrio alginolyticus.并对不同养殖场水源弧菌数量也进行了比较.

  5. 不同密度的皱纹盘鲍(Haliotis discus hannai Ino)与仿刺参(Apostichopus japonicus Selenka)混养的研究%Polyculture of Juvenile Abalone(Haliotis discus hannal Ino)with Juvenile Sea Cucumber(Apostichopus japonicus Selenka)at Various Stocking Densities

    王吉桥; 杨义; 程鑫; 王年斌; 张剑诚

    2007-01-01

    在水温13.0~23.0℃、容积50L(45cm×31cm×30cm)的塑料水槽中,分别放养5、10和20个重(2.7±0.7)g的皱纹盘鲍(Haliotis discus hannai Ino),多量投喂海带,再分别混养0和5头重(1.8±0.5)g的仿刺参(Apostichopus japonicus Selenka),不投喂.153 d的饲养表明,在相同密度下,混养鲍的特殊生长率(SGR)和成活率依次比单养高16.6%、5.7%;7.1%、7.1%;1.9%、10.4%;饲料系数降低了11.7%、5.8%、2.4%.与单养池相比,混养池水中氨氮含量低而稳,溶氧量高.文中讨论了鲍与仿刺参混养的适宜比例和方式.

  6. Splice Variants of Perlucin from Haliotis laevigata Modulate the Crystallisation of CaCO3

    Dodenhof, Tanja; Dietz, Frank; Franken, Sebastian; Grunwald, Ingo; Kelm, Sørge

    2014-01-01

    Perlucin is one of the proteins of the organic matrix of nacre (mother of pearl) playing an important role in biomineralisation. This nacreous layer can be predominately found in the mollusc lineages and is most intensively studied as a compound of the shell of the marine Australian abalone Haliotis laevigata. A more detailed analysis of Perlucin will elucidate some of the still unknown processes in the complex interplay of the organic/inorganic compounds involved in the formation of nacre as...

  7. Reduced disease in black abalone following mass mortality: Phage therapy and natural selection

    Vanblaricom, Glenn R.

    2014-01-01

    Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS). Natural recovery on San Nicolas Island (SNI) of Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO) had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv) reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus) coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host–parasite relationships will better enable us to manage declining populations.

  8. Reduced disease in black abalone following mass mortality: Phage therapy and natural selection

    Carolyn S Friedman

    2014-03-01

    Full Text Available Black abalone, Haliotis cracherodii, populations along the NE Pacific ocean have declined due to the rickettsial disease withering syndrome (WS. Natural recovery on San Nicolas Island (SNI off Southern California suggested the development of resistance in island populations. Experimental challenges in one treatment demonstrated that progeny of disease-selected black abalone from SNI survived better than did those from naïve black abalone from Carmel Point (CP in mainland coastal central California. Unexpectedly, the presence of a newly observed bacteriophage infecting the WS rickettsia (WS-RLO had strong effects on the survival of infected abalone. Specifically, presence of phage-infected RLO (RLOv reduced the host response to infection, RLO infection loads, and associated mortality. These data suggest that the black abalone: WS-RLO relationship is evolving through dual host mechanisms of resistance to RLO infection in the digestive gland via tolerance to infection in the primary target tissue (the post-esophagus coupled with reduced pathogenicity of the WS-RLO by phage infection, which effectively reduces the infection load in the primary target tissue by half. Sea surface temperature patterns off southern California, associated with a recent hiatus in global-scale ocean warming, do not appear to be a sufficient explanation for survival patterns in SNI black abalone. These data highlight the potential for natural recovery of abalone populations over time and that further understanding of mechanisms governing host-parasite relationships will better enable us to manage declining populations.

  9. The complete mitochondrial genome of Haliotis laevigata (Gastropoda: Haliotidae) using MiSeq and HiSeq sequencing.

    Robinson, Nick A; Hall, Nathan E; Ross, Elizabeth M; Cooke, Ira R; Shiel, Brett P; Robinson, Andrew J; Strugnell, Jan M

    2016-01-01

    The mitochondrial genome of greenlip abalone, Haliotis laevigata, is reported. MiSeq and HiSeq sequencing of one individual was assembled to yield a single 16,545 bp contig. The sequence shares 92% identity to the H. rubra mitochondrial genome (a closely related species that hybridize with H. laevigata in the wild). The sequence will be useful for determining the maternal contribution to hybrid populations, for investigating population structure and stock-enhancement effectiveness. PMID:24660910

  10. Evaluating potential conservation conflicts between two listed species: sea otters and black abalone.

    Raimondi, Peter; Jurgens, Laura J; Tinker, M Tim

    2015-11-01

    Population consequences of endangered species interacting as predators and prey have been considered theoretically and legally, but rarely investigated in the field. We examined relationships between spatially variable populations of a predator, the California sea otter, Enhydra lutris nereis, and a prey species, the black abalone, Haliotis cracherodii. Both species are federally listed under the Endangered Species Act and co-occur along the coast of California. We compared the local abundance and habitat distribution of black abalone at 12 sites with varying densities of sea otters. All of the populations of abalone we examined were in the geographic area currently unaffected by withering disease, which has decimated populations south of the study area. Surprisingly, our findings indicate that sea otter density is positively associated with increased black abalone density. The presence of sea otters also correlated with a shift in black abalone to habitat conferring greater refuge, which could decrease illegal human harvest. These results highlight the need for a multi-species approach to conservation management of the two species, and demonstrate the importance of using field-collected data rather than simple trophic assumptions to understand relationships between jointly vulnerable predator and prey populations. PMID:27070027

  11. Gradual Ordering in Red Abalone Nacre

    Gilbert, P. U. P. A.; Metzler, Rebecca A.; Zhou, Dong; Scholl, Andreas; Doran, Andrew; Young, Anthony; Kunz, Martin; Tamura, Nobumichi; Coppersmith, Susan N.

    2008-09-03

    Red abalone (Haliotis rufescens) nacre is a layered composite biomineral that contains crystalline aragonite tablets confined by organic layers. Nacre is intensely studied because its biologically controlled microarchitecture gives rise to remarkable strength and toughness, but the mechanisms leading to its formation are not well understood. Here we present synchrotron spectromicroscopy experiments revealing that stacks of aragonite tablet crystals in nacre are misoriented with respect to each other. Quantitative measurements of crystal orientation, tablet size, and tablet stacking direction show that orientational ordering occurs not abruptly but gradually over a distance of 50 {micro}m. Several lines of evidence indicate that different crystal orientations imply different tablet growth rates during nacre formation. A theoretical model based on kinetic and gradual selection of the fastest growth rates produces results in qualitative and quantitative agreement with the experimental data and therefore demonstrates that ordering in nacre is a result of crystal growth kinetics and competition either in addition or to the exclusion of templation by acidic proteins as previously assumed. As in other natural evolving kinetic systems, selection of the fastest-growing stacks of tablets occurs gradually in space and time. These results suggest that the self-ordering of the mineral phase, which may occur completely independently of biological or organic-molecule control, is fundamental in nacre formation.

  12. Predicting the ecological carrying capacity of the Lidao artificial reef zone of Shandong Province for the sea cucumber, Apostichopus japonicus, (Selenck) and the abalone, Haliotis discus hannai, using a linear food web model%基于线性食物网模型估算荣成俚岛人工鱼礁区刺参和皱纹盘鲍的生态容纳量

    吴忠鑫; 张秀梅; 张磊; 佟飞; 刘洪军

    2013-01-01

    The Lidao reef zone is a typical artificial reef ecosystem for rare marine animal stock enhancement in the coastal sea of North China. The sea cucumber, Apostichopus japonicus (Selenck), and the abalone, Haliotis discus hannai, are the main enhancement species in the system. Based on the data of biological resources obtained from an investigation of the Lidao artificial reef zone in 2009, a balanced trophic model of the area was con-structed using the Ecopath with Ecosim software package. The effects of uncertainty of input parameters and Ecopath analysis sensitivity were explored. Trophic flow and system attributes of the Lidao artificial reef system were analyzed. The ecological carrying capacity for A. japonicus and H. discus hannai were also predicted. The model consisted of 19 functional groups, which covered the main trophic flow in the Lidao artificial reef ecosys-tem. The results showed that the pedigree index of the model was 0.51, and the input parameters having the great-est effects on the output parameters were the production/biomass ratios (P/B) of small demersal fish groups. A–50% change in the production/biomass ratios in small demersal fish groups gave a sensitivity of the biomass (B) of the same group from 100% to 136%. The total system throughput was estimated to be 10 786.680 t/(km2·a), 27% of which flowed to detritus and 17% of which is tranferred out of the ecosystem in the forms of fishing and sediment. Total net primary production was 4131.966 t/(km2·a) and the total energy transfer efficiency was 10.5%. The proportion of the total flow originating from detritus was 39%, and that from primary producers was 61%, indicating that the energy flow was dominated by grazing food chain. The ecological carrying capacity was de-fined as the level of enhancement that could be introduced without significantly changing the major trophic fluxes or structure of the food web. The ecological carrying capacities for A. japonicus and H. discus hannai were

  13. Growth of nacre in abalone: Seasonal and feeding effects

    The processes of aggregation of mineral and organic materials to the growing surfaces in red abalone (Haliotis rufescens) are analyzed. The flat pearl implantation method is used to observe the transient stages of calcium carbonate deposition, the structure of the organic interlayer, and the steady-state growth of aragonite tiles. The morphology of the organic interlayer is characterized by scanning electron microscopy. These results enable a realistic depiction of the formation of the terraced cones that comprise the principal biomineralization mechanism in this gastropod. In all cases, the growth initiated through spherulites, followed by tile formation. The transient stage with spherulitic formation was shorter at higher temperature; this is indicative of a greater activity of the animal at 21 deg. C. The growth rate in a normally fed gastropod was found to be higher compared with one provided with limited food. The effect of water temperature (seasonal) was also established, with growth proceeding faster in the summer (T ∼ 21 deg. C) than in winter (15 deg. C). The structures of the organic interlayer and of the epithelium are revealed by scanning electron microscopy.

  14. Splice variants of perlucin from Haliotis laevigata modulate the crystallisation of CaCO3.

    Dodenhof, Tanja; Dietz, Frank; Franken, Sebastian; Grunwald, Ingo; Kelm, Sørge

    2014-01-01

    Perlucin is one of the proteins of the organic matrix of nacre (mother of pearl) playing an important role in biomineralisation. This nacreous layer can be predominately found in the mollusc lineages and is most intensively studied as a compound of the shell of the marine Australian abalone Haliotis laevigata. A more detailed analysis of Perlucin will elucidate some of the still unknown processes in the complex interplay of the organic/inorganic compounds involved in the formation of nacre as a very interesting composite material not only from a life science-based point of view. Within this study we discovered three unknown Perlucin splice variants of the Australian abalone H. laevigata. The amplified cDNAs vary from 562 to 815 base pairs and the resulting translation products differ predominantly in the absence or presence of a varying number of a 10 mer peptide C-terminal repeat. The splice variants could further be confirmed by matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-ToF MS) analysis as endogenous Perlucin, purified from decalcified abalone shell. Interestingly, we observed that the different variants expressed as maltose-binding protein (MBP) fusion proteins in E. coli showed strong differences in their influence on precipitating CaCO3 and that these differences might be due to a splice variant-specific formation of large protein aggregates influenced by the number of the 10 mer peptide repeats. Our results are evidence for a more complex situation with respect to Perlucin functional regulation by demonstrating that Perlucin splice variants modulate the crystallisation of calcium carbonate. The identification of differentially behaving Perlucin variants may open a completely new perspective for the field of nacre biomineralisation. PMID:24824517

  15. Splice variants of perlucin from Haliotis laevigata modulate the crystallisation of CaCO3.

    Tanja Dodenhof

    Full Text Available Perlucin is one of the proteins of the organic matrix of nacre (mother of pearl playing an important role in biomineralisation. This nacreous layer can be predominately found in the mollusc lineages and is most intensively studied as a compound of the shell of the marine Australian abalone Haliotis laevigata. A more detailed analysis of Perlucin will elucidate some of the still unknown processes in the complex interplay of the organic/inorganic compounds involved in the formation of nacre as a very interesting composite material not only from a life science-based point of view. Within this study we discovered three unknown Perlucin splice variants of the Australian abalone H. laevigata. The amplified cDNAs vary from 562 to 815 base pairs and the resulting translation products differ predominantly in the absence or presence of a varying number of a 10 mer peptide C-terminal repeat. The splice variants could further be confirmed by matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-ToF MS analysis as endogenous Perlucin, purified from decalcified abalone shell. Interestingly, we observed that the different variants expressed as maltose-binding protein (MBP fusion proteins in E. coli showed strong differences in their influence on precipitating CaCO3 and that these differences might be due to a splice variant-specific formation of large protein aggregates influenced by the number of the 10 mer peptide repeats. Our results are evidence for a more complex situation with respect to Perlucin functional regulation by demonstrating that Perlucin splice variants modulate the crystallisation of calcium carbonate. The identification of differentially behaving Perlucin variants may open a completely new perspective for the field of nacre biomineralisation.

  16. Rheological Properties and Structural Changes in Different Sections of Boiled Abalone Meat

    GAO Xin; TANG Zhixu; ZHANG Zhaohui; Ogawa Hiroo

    2003-01-01

    Changes in tissue structures, rheological properties of cross- and vertical section boiled abalone meat were studied in relation to boiling time. The adductor muscle of abalone Haliotis discus which was removed from the shell, was boiled for 1, 2, and 3 h, respectively. Then it was cut up and separated into cross- and vertical section meat. When observed by a light microscope and a scanning electron microscope, structural changes in the myofibrils were greatest in the cross section meat compared with the vertical section meat. When boiling time was increased from 1 h to 3 h, the instantaneous modulus E0 and rupture strength of both section meat decreased gradually with increased boiling time, and no significant differences were observed between these two section meat for the same boiling time. When boiled for 1 h, the relaxation time of cross section meat was much longer than that of vertical section meat. There were no significant changes in the relaxation time of vertical section for different boiling time, but the relaxation time of cross section meat was reduced gradually with increasing boiling time. These results confirmed that the difference in rheological properties between the cross- and vertical section meat was mainly due to the denaturation level of myofibrils when heated for 1 h, as well as due to the changes in the amount of denatured proteins, and the manner in which the inner denatured protein components weve exchanged after boiling time was increased from 1 h to 3 h.

  17. Overexploitation of Abalone at Libong Island, Trang Province, Southern Thailand

    Chanyut Sudtongkong

    2012-09-01

    Full Text Available Abalone is generally known as a fishery resource of high economic value. The wild abalone from Libong Island iswidely known for its potential as a cocktail-size and high-quality broodstock for hatcheries. The high market price andexternal demand have encouraged local fisherman to catch the wild abalone without proper management, resulting in a nearextinction crisis in the abalone population in this area. The present evaluation of abalone management at Libong Island,Trang Province, Thailand, was conducted using local user perceptions. Sixteen performance indicators included effectiveness indicators, equity indicators, and sustainable indicators. These were measured to determine whether the abalonemanagement activities had achieved the set objectives in terms of better conditions for abalone cultivation and sustainability.The results revealed that the abalone population has undergone degrading and decline due to lack of proper managementmeasures in this area. The findings suggest that practical management is needed for the abalone population at Libong Island.

  18. Responses of primary cultured haemocytes from the marine gastropod Haliotis tuberculata under 10-day exposure to cadmium chloride

    Latire, Thomas; Le Pabic, Charles; Mottin, Elmina; Mottier, Antoine; Costil, Katherine; Koueta, Noussithe; Lebel, Jean-Marc [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France); Serpentini, Antoine, E-mail: antoine.serpentini@unicaen.fr [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France)

    2012-03-15

    Among metals, cadmium, a non-essential element, is an important pollutant that is released into aquatic environments. Due to its persistence and bioaccumulation, this metal has been shown to exert immunological effects on organisms. The objective of the present study was to investigate the in vitro effects of cadmium chloride using a haemocyte primary culture from the European abalone, Haliotis tuberculata. Most studies have maintained viable haemocytes in vitro for periods ranging from several hours to several days during acute exposures. Few investigations have reported the effects of metals using longer in vitro exposures, which are more realistic with regard to mimicking environmental conditions. In this study, we exposed abalone haemocytes to concentrations from 0.5 to 50,000 {mu}g L{sup -1} of CdCl{sub 2} for 10 days. The effects of cadmium chloride were reflected in a significant decrease in the number of viable cells and morphological modifications in a concentration-dependent manner beginning at a concentration of 500 {mu}g L{sup -1} as well as in some physiological processes, such as phagocytotic activity and the number of lysosome-positive cells. In contrast, phenoloxidase (PO) activity and reactive oxygen species (ROS) production were increased beginning at a concentration of 5 {mu}g L{sup -1}, which is consistent with environmental concentrations in polluted sites. For PO activity and ROS production, maximally 9-fold and 130% inductions, respectively, were recorded under the highest dose. These results thus indicate that cadmium chloride alters immune parameters of abalone haemocytes and that the long-term (10 days) primary culture system used here represents a suitable, sensitive in vitro model for assessing cytotoxic responses.

  19. Metabolism of alkylated PAHs by Nereis diversicolor

    Malmquist, Linus Mattias Valdemar

    ’er, forvitret råolie og en af de mest væsentlige PAH metabolitter (1-pyrenkarboxylsyre), gennem enkeltstof- og blandingsforsøg med sediment eksponeringer af disse til børsteormen Nereis diversicolor. Resultaterne fra ph.d studiet viste at alkylerede PAH’er blev mere effektivt omdannet end deres usubstituerede...

  20. Underwater adhesion of abalone: The role of van der Waals and capillary forces

    The observation of the pedal foot of the red abalone Haliotis rufescens reveals the presence of micrometer-scaled setae terminating in nanometer-sized cylindrical fibrils, with some resemblance to those found on the gecko foot. Atomic force microscopy (AFM) pull-off force measurements on a single seta are compared with theoretical estimates for van der Waals attraction obtained through the Johnson-Kendall-Roberts (JKR) equation, approximately 600 nN, and show agreement. The use of the JKR equation is justified through an analysis of the shape of the fibril extremities (parabolic) as well as their diameter (∼200 nm). Measurements under varying humidity conditions indicate that additional capillary interactions play a role, since the pull-off force increases with humidity. It is proposed that both van der Waals and capillary forces play a role in the attachment mechanism of H. rufescens, effectively enabling suction to reach its theoretical limit. Bulk pull-off force measurements on entire live animals yield an average detachment stress of 115 kPa, consistent with theoretical estimates. The setae and nanoscale fibril terminations enable compliance to surfaces with a variety of roughnesses, effectively sealing the interface, in addition to providing capillary and van der Waals forces.

  1. Reprint of: Growth of nacre in abalone: Seasonal and feeding effects

    The processes of aggregation of mineral and organic materials to the growing surfaces in red abalone (Haliotis rufescens) are analyzed. The flat pearl implantation method is used to observe the transient stages of calcium carbonate deposition, the structure of the organic interlayer, and the steady-state growth of aragonite tiles. The morphology of the organic interlayer is characterized by scanning electron microscopy. These results enable a realistic depiction of the formation of the terraced cones that comprise the principal biomineralization mechanism in this gastropod. In all cases, the growth initiated through spherulites, followed by tile formation. The transient stage with spherulitic formation was shorter at higher temperature; this is indicative of a greater activity of the animal at 21 deg. C. The growth rate in a normally fed gastropod was found to be higher compared with one provided with limited food. The effect of water temperature (seasonal) was also established, with growth proceeding faster in the summer (T ∼ 21 deg. C) than in winter (15 deg. C). The structures of the organic interlayer and of the epithelium are revealed by scanning electron microscopy.

  2. Underwater adhesion of abalone: The role of van der Waals and capillary forces

    Lin, A.Y.M., E-mail: albertlin22@yahoo.com [Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093 (United States); Brunner, R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093 (United States)] [Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093 (United States); Chen, P.Y. [Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093 (United States); Talke, F.E. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093 (United States)] [Center for Magnetic Recording Research, University of California, San Diego, La Jolla, CA 92093 (United States); Meyers, M.A. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093 (United States)] [Department of Nanoengineering, University of California, San Diego, La Jolla, CA 92093 (United States)] [Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093 (United States)

    2009-08-15

    The observation of the pedal foot of the red abalone Haliotis rufescens reveals the presence of micrometer-scaled setae terminating in nanometer-sized cylindrical fibrils, with some resemblance to those found on the gecko foot. Atomic force microscopy (AFM) pull-off force measurements on a single seta are compared with theoretical estimates for van der Waals attraction obtained through the Johnson-Kendall-Roberts (JKR) equation, approximately 600 nN, and show agreement. The use of the JKR equation is justified through an analysis of the shape of the fibril extremities (parabolic) as well as their diameter ({approx}200 nm). Measurements under varying humidity conditions indicate that additional capillary interactions play a role, since the pull-off force increases with humidity. It is proposed that both van der Waals and capillary forces play a role in the attachment mechanism of H. rufescens, effectively enabling suction to reach its theoretical limit. Bulk pull-off force measurements on entire live animals yield an average detachment stress of 115 kPa, consistent with theoretical estimates. The setae and nanoscale fibril terminations enable compliance to surfaces with a variety of roughnesses, effectively sealing the interface, in addition to providing capillary and van der Waals forces.

  3. Desarrollo del ensilado del alga Gracilaria chilensis para la alimentación del abalón rojo Haliotis rufescens

    Alfonso Mardones

    2015-05-01

    Full Text Available En Chile, el principal insumo usado como alimento para abalones son las algas Gracilaria chilensis y Macrocystis pyrifera. Estas algas experimentan una notable baja de disponibilidad en otoño e invierno, lo cual trae consigo un aumento considerable de los precios, al tener que depender del abastecimiento desde áreas cada vez más alejadas de los centros de cultivo de abalones y, eventualmente, generando impactos ecológicos indirectos en sus poblaciones. El objetivo fue elaborar y evaluar un ensilado del alga G. chilensis para la alimentación de abalón rojo (Haliotis rufescens, determinando la cantidad de lixiviados generados durante el proceso, el cambio en la composición proximal del alga, la preferencia y consumo del abalón rojo de ensilado de G. chilensis. Se logró un producto ensilado de buenas características físicas, químicas y de conservación, así como una buena aceptación por parte del abalón.

  4. Accumulation of Co by abalone, 1

    The appearance of radioactive Co in the liver of abalone from sea water was examined to consider the effect of chemical forms of Co(CoCl2 and cyanocobalamin; vitamin B12) in sea water upon the metabolisms in marine organisms. Organic 57Co(cyanocobalamin) from sea water appeared in the liver of abalone combining with a constituent with a molecular weight of 4 x 104. The constituent had the activity of vitamin B12, while inorganic 60Co(CoCl2) appeared combining with three constituents with molecular weights more than or equal to 1.5 x 106, 7 x 103 and less than or equal to 1.5 x 103 which did not show the activities of vitamin B12. The effect of chemical forms of Co in sea water is significant in its accumulation by some species of marine organisms. (author)

  5. Marine reserves help preserve genetic diversity after impacts derived from climate variability: Lessons from the pink abalone in Baja California

    Adrián Munguía-Vega

    2015-07-01

    Full Text Available Genetic diversity is crucial for the adaptation of exploited species like the pink abalone (Haliotis corrugata, faced with threats from climate change, overfishing and impacts associated with aquaculture production. While marine reserves are commonly used to mitigate risks to marine populations, the duration, size, location and larval connectivity needed for a reserve to help conserve genetic resources is still poorly understood. Here, we examine the effects of fishing, reserves, and restocking on the genetic diversity of 10 populations from central Baja California, Mexico, and Southern California, USA. We demonstrate that each population shows characteristic genetic signatures according to recent management decisions. We found high allelic diversity, particularly rare alleles, a larger effective population size and a lack of a recent genetic bottleneck in pink abalones within a small (0.8 km2, recently established (5 years reserve in Baja California, compared to other fished sites after a climatic bottleneck. Higher diversity may result from the presence of older animals in the reserve. Due to its location, the reserve may also act as an important hub connecting distant populations via larval dispersal. In contrast, a population from California showed genetic isolation, loss of allelic diversity and high relatedness, consistent with the collapse of fisheries in the 1990s and their lack of recovery thereafter. In addition, a fished area in Baja California with a history of restocking for over a decade showed an increase in frequency of related individuals and high genetic differentiation from nearby sites that were consistent with the production of larvae from a few adults in the laboratory. A network of strategically placed small marine reserves that considers ocean circulation patterns could help to maintain genetic diversity and connectivity of exploited populations.

  6. Structure and reaction studies of biological organic and inorganic composite materials: Abalone shells, diatoms, and a unique birch bark

    Zaremba, Charlotte Marie

    Biopolymer/calcium carbonate composites grown on inorganic abiotic substrates implanted between the shell and the shell-secreting epithelium of live red abalones (Haliotis rufescens) results in an unusual highly (104)-oriented aggregate of microcrystalline calcite that precedes nacre deposition. Calcite of this orientation has never before been observed in nature. Also with this method, nacre deposition is found to correct for calcite surface roughness and chemically anomalous surfaces. Pole figure X-ray diffraction studies of these "flat pearls" provide comparisons of preferred orientation of the various mineral components of the abalone shell. Complete conversion of the aragonite in abalone nacre to hydroxyapatite in hydrothermal phosphate solution results in an oriented polycrystalline aggregate with ultrastructure preservation and an unexpected preferred orientation different from that of other biominerals and abiogenic CaCO3 samples subjected to this reaction. The new orientation, which increases with reaction time, may result from the organization of the organic matrix in the nacre, which directs the hydrothermal solution through the material. This orientation suggests strongly that the conversion proceeds via a dissolution-recrystallization mechanism, rather than by topotaxy, which was previously proposed. In addition to cellulose I, a highly oriented cellulose-II-like polymer was found in the bark of Prunus serrula, an exceptionally strong, tough, and extensible composite film. The cellulose II polymorph, which has not previously been found in nature, may be accordion-folded in the plane of the bark thickness and contribute to the strength and unusual behavior with plasticization of this natural film. The silica frustule of the diatom Skeletonema costatum has a surface area of 135 mm2/g and contains 1.5--2 wt % occluded organic. This organic includes a water-insoluble scaffolding. When treated with organic oxidizers, the chitin secreted by the diatom

  7. ANTIBIOTIC RESISTANT BACTERIA FROM HALIOTIS TUBERCULATA AND MYTILUS GALLOPROVINCIALIS

    F. Conte; Longo, S.; Malaspina, A.

    2009-01-01

    The antibiotic resistance (AR) of Gram negative bacteria from Haliotis tuberculata (Ht) and Mytilus galloprovincialis (Mg) was assessed. Essential differences between R profiles of Pseudomonas spp and of other strains was not observed. Strains AR from Ht and Mg was similar.

  8. Antioxidant activity of taste components from abalone viscera peptides prepared by Maillard reaction%美拉德反应制备鲍鱼脏器肽呈味基料及其抗氧化活性研究

    乔路; 周大勇; 李秀玲; 王宏海

    2011-01-01

    采用美拉德反应处理皱纹盘鲍脏器肽制备呈味基料,并通过感官评定实验及体外抗氧化实验评价了美拉德反应处理对鲍鱼脏器肽风味及抗氧化活性的影响.结果表明,鲍鱼脏器肽经美拉德反应处理后,鲜味增加,腥、苦等不良口味下降,总体风味得到显著提升.与反应前相比,美拉德反应产物的DPPH自由基清除活性增强百倍,而羟自由基清除活性及还原活性也增强数十倍.%The peptides prepared from abalone (Haliotis discus hannai Ino) viscera were treated by Maillard reaction to produce taste component. The peptides and their Maillard reaction products were tested by sensory evaluation experiment and antioxidant assay in vitro. Results showed that Maillard reaction could increase umami flavor but decrease fishy and bitter flavor, and then significantly enhance the overall taste of the abalone viscera peptides. After Maillard reaction, the DPPH radical scavenging activity was increased about a hundred fold, and the hydroxyl radical scavenging activity and the reducing capacity was increased tens of times.

  9. A national survey of marine biotoxins in wild-caught abalone in Australia.

    Malhi, Navreet; Turnbull, Alison; Tan, Jessica; Kiermeier, Andreas; Nimmagadda, Rama; McLeod, Catherine

    2014-11-01

    The first national survey of Australian wild-caught abalone was conducted between September 2012 and December 2013. The aim of the survey was to determine the presence of paralytic shellfish toxins (PSTs), amnesic shellfish toxins (ASTs), and diarrhetic shellfish toxins (DSTs) in wild-caught abalone at levels above the current Codex marine biotoxin limits during the 2013 fishing season. Abalone (n = 190) were collected from 68 abalone-fishing blocks for which the combined annual harvest accounts for 80 % of Australian production. Concurrent seawater samples were collected and enumerated for potentially toxic phytoplankton. The foot and viscera tissues of each abalone sample were analyzed separately for PSTs, ASTs, and DSTs. No samples (abalone foot or viscera) contained toxins at levels exceeding the marine biotoxin limits stipulated by Codex. The resulting prevalence estimate suggests that less than 1.6 % of the commercially caught wild abalone population in Australia were contaminated with marine biotoxins at levels above the regulatory limit during the survey period. ASTs were detected at very low (trace) levels in the foot and viscera tissue of four and three abalone samples, respectively. To our knowledge, this represents the first reported detection of domoic acid in Australian abalone. PSTs also were detected at very low levels in 17 samples of abalone foot tissue and 6 samples of abalone viscera. The association between the low levels of ASTs and PSTs detected in abalone and the presence of potential toxin-producing phytoplankton in seawater samples was weak. DSTs were not detected in any abalone despite the detection of very low levels of DST-producing phytoplankton in a small number (9 of 77) of seawater samples. The results of this survey should be useful for public health risk assessments and provide additional evidence that the prevalence of marine biotoxins in Australian wild-caught abalone is very low. PMID:25364931

  10. Contrasting patterns of population connectivity between regions in a commercially important mollusc Haliotis rubra: integrating population genetics, genomics and marine LiDAR data.

    Miller, A D; van Rooyen, A; Rašić, G; Ierodiaconou, D A; Gorfine, H K; Day, R; Wong, C; Hoffmann, A A; Weeks, A R

    2016-08-01

    Estimating contemporary genetic structure and population connectivity in marine species is challenging, often compromised by genetic markers that lack adequate sensitivity, and unstructured sampling regimes. We show how these limitations can be overcome via the integration of modern genotyping methods and sampling designs guided by LiDAR and SONAR data sets. Here we explore patterns of gene flow and local genetic structure in a commercially harvested abalone species (Haliotis rubra) from southeastern Australia, where the viability of fishing stocks is believed to be dictated by recruitment from local sources. Using a panel of microsatellite and genomewide SNP markers, we compare allele frequencies across a replicated hierarchical sampling area guided by bathymetric LiDAR imagery. Results indicate high levels of gene flow and no significant genetic structure within or between benthic reef habitats across 1400 km of coastline. These findings differ to those reported for other regions of the fishery indicating that larval supply is likely to be spatially variable, with implications for management and long-term recovery from stock depletion. The study highlights the utility of suitably designed genetic markers and spatially informed sampling strategies for gaining insights into recruitment patterns in benthic marine species, assisting in conservation planning and sustainable management of fisheries. PMID:27322873

  11. Vibrio jasicida sp. nov., a member of the Harveyi clade, isolated from marine animals (packhorse lobster, abalone and Atlantic salmon).

    Yoshizawa, Susumu; Tsuruya, Yasuhiro; Fukui, Youhei; Sawabe, Tomoo; Yokota, Akira; Kogure, Kazuhiro; Higgins, Melissa; Carson, Jeremy; Thompson, Fabiano L

    2012-08-01

    Six isolates of a facultatively anaerobic bacterium were recovered in culture from marine invertebrates and vertebrates, including packhorse lobster (Jasus verreauxi), abalone (Haliotis sp.) and Atlantic salmon (Salmo salar), between 1994 and 2002. The bacteria were Gram-negative, rod-shaped and motile by means of more than one polar flagellum, oxidase-positive, catalase-positive and able to grow in the presence of 0.5-8.0% NaCl (optimum 3.0-6.0%) and at 10-37 °C (optimum 25-30 °C). On the basis of 16S rRNA gene sequence analysis and multilocus sequence analysis (MLSA) using five loci (2443 bp; gyrB, pyrH, ftsZ, mreB and gapA), the closest phylogenetic neighbours of strain TCFB 0772(T) were the type strains of Vibrio communis (99.8 and 94.6 % similarity, respectively), Vibrio owensii (99.8 and 94.1%), Vibrio natriegens (99.4 and 88.8%), Vibrio parahaemolyticus (99.4 and 90.3%), Vibrio rotiferianus (99.2 and 94.4%), Vibrio alginolyticus (99.1 and 89.3%) and Vibrio campbellii (99.1 and 92.3%). DNA-DNA hybridization confirmed that the six isolates constitute a unique taxon that is distinct from other known species of Vibrio. In addition, this taxon can be readily differentiated phenotypically from other Vibrio species. The six isolates therefore represent a novel species, for which the name Vibrio jasicida sp. nov. is proposed; the novel species is represented by the type strain TCFB 0772(T) ( = JCM 16453(T)  = LMG 25398(T)) (DNA G+C content 45.9 mol%) and reference strains TCFB 1977 ( = JCM 16454) and TCFB 1000 ( = JCM 16455). PMID:21984666

  12. Status of abalone fishery and experiential mariculture as a resource conservation strategy in Carot, Anda, Pangasinan

    Emmanuel C. Capinpin, Jr.

    2013-01-01

    The study described the abalone f ishery in Carot, Anda, Pangasinan to develop mariculture and to reseed a part of the harvest as a resource conservation strategy. The abalone fishery of Anda is artisanal or smallscale, typif ied by f ishers gleaning or free-diving on shallow rocky areas which are the typical habitat of abalone. Low densities of 1.67 to 8 individuals per 250 m2 were observed. Local f ishers have knowledge of productive f ishing areas. Hence, cage culture of abalone in these a...

  13. Environmental Metabolism of Pyrene and 1-Methylpyrene by Nereis diversicolor

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    2011-01-01

    Mineral oils from spills contain magnitudes higher proportions of alkylated Polycyclic Aromatic Hydrocarbons (PAHs) compared to unsubstituted PAHs. Despite this, assessments of contaminations are often limited to only consider the “16 USEPA priority PAHs”, which are all unsubstituted. We studied the metabolism of 1-methylpyrene by exposure to the benthic invertebrate Nereis diversicolor in laboratory mesocosms. Analyses of worm, water and sediment extracts were performed by use of Gas Chromat...

  14. 多层抽屉式循环水幼鲍养殖系统及养殖效果%Recirculating aquaculture system with multi-layer drawer culture tanks for juvenile abalone and its effects

    吴垠; 孙建明; 柴雨; 徐长雷

    2012-01-01

    为了提高皱纹盘鲍的养殖效果,该文设计了多层抽屉式循环水养殖幼鲍系统,分析了养殖期间系统的水质指标和耗能量,及不同养殖密度下幼鲍的生长率和成活率.结果表明,该系统适宜的幼鲍养殖密度为150个,屉(70cm×40cm×10cm/屉),为流水式养鲍密度的6~9倍.试验过程中水温、溶解氧、pH值、盐度、NH4+-N和NO2--N指标均达到幼鲍生长条件,NH4+-N和NO2--N体积质量基本稳定在0.023~0.065 mg/L和0.014~0.041 mg/L范围内.试验期间总耗电量为688.88 kW·h,其中海水加热占总耗电量19.62%,相当于每天1.287 kW·h耗电量,大约是流水式养殖加热耗能的1/7.该研究表明,多层抽屉式循环水养鲍系统是一种安全、高效、节能减排的养殖模式.该系统可供选择养鲍设施时参考.%In order to improve the culture efficiency of disk abalone, Haliotis discus hannai, the recirculating aquaculture system (RAS) with multi-layer drawer abalone culture tanks (70 cm×40 cm× 10 cm per drawer) were designed. The water quality parameters, energy consumption during experiment period, as well as the growth rate and survival of juvenile abalone in different culture densities were monitored. The results showed that the culture density for 150 individuals per drawer in the recirculating systems was appropriate, which was about 6-9 times of the flow-through systems. The temperature, dissolved oxygen, pH value, salinity, NH4VN and NCV-N were all maintained within acceptable ranges for the normal growth of disk abalone. The total NH/-N and NO2-N stabilized around 0.023-0.065 mg/L and 0.014-0.041 mg/L, respectively. The power consumption per day for heating was 1.287 kW-h, where the power consumption for heating sea water accounted for 19.62% of the total power consumption (688.88 kW-h). Compared with conventional flow-through system, it was only one-seventh of energy consumption for heating sea water. The study indicates that it is a kind of

  15. Environmental Metabolism of Pyrene and 1-Methylpyrene by Nereis diversicolor

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    the metabolism of 1-methylpyrene by exposure to the benthic invertebrate Nereis diversicolor in laboratory mesocosms. Analyses of worm, water and sediment extracts were performed by use of Gas Chromatography Mass Spectrometry (GC-MS) and Ultra Performance Liquid Chromatography with UV, Fluorescence......Mineral oils from spills contain magnitudes higher proportions of alkylated Polycyclic Aromatic Hydrocarbons (PAHs) compared to unsubstituted PAHs. Despite this, assessments of contaminations are often limited to only consider the “16 USEPA priority PAHs”, which are all unsubstituted. We studied...

  16. Effects of Nereis diversicolor on the Transformation of 1-Methylpyrene and Pyrene

    Malmquist, Linus Mattias Valdemar; Christensen, Jan Henning; Selck, Henriette

    Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative...

  17. Comparison between the Nereis diversicolor and Nereis virens marine worms in the transformation of ingested hydrocarbons

    Gilbert, Franck; Desrosiers, Gaston; Hulth, Stefan; Stora, Georges

    2001-01-01

    A feeding experiment was conducted on the marine worm Nereis diversicolor to compare the fate of a hydrocarbon mixture during the gut passage in this species with the hydrocarbon breakdown process demonstrated for Nereis virens. Hydrocarbon dissolution/solubilization processes in the gut of N. diversicolor were found to have similar qualitative and quantitative importance in the hydrocarbon transformation as those observed in N. virens.

  18. Status of abalone fishery and experiential mariculture as a resource conservation strategy in Carot, Anda, Pangasinan

    Emmanuel C. Capinpin, Jr.

    2013-06-01

    Full Text Available The study described the abalone f ishery in Carot, Anda, Pangasinan to develop mariculture and to reseed a part of the harvest as a resource conservation strategy. The abalone fishery of Anda is artisanal or smallscale, typif ied by f ishers gleaning or free-diving on shallow rocky areas which are the typical habitat of abalone. Low densities of 1.67 to 8 individuals per 250 m2 were observed. Local f ishers have knowledge of productive f ishing areas. Hence, cage culture of abalone in these areas could be a viable resource conservation strategy as they serve as reproductive reserves to supply larvae for continued productivity of the f ishing grounds. Abalone mariculture following the Farmer Field School (FFS concept was explored to address both resource management and economic needs. As a resource enhancement activity, mariculture guarantees that cultured abalone are allowed to grow to maturity before harvested, while some are retained to restock a marine sanctuary. Sincemariculture makes possible the aggregation of individuals, the probability that fertilization would take place is increased. As supplemental source of livelihood, abalone is a high value commodity and its culture can help augment the income of f ishers. Small abalone (3-4 cm can be cultured further for 3-4 months to increase their size and weight. Mariculture should be done from November to May to avoid the rainy season and improve survivorship. The experiential activity was successful because it became a means for the f ishers to experienceresource management. Under the FFS, the researcher became a facilitator and mentored the cooperators in learning from their experience. The lessons sharpened the f ishers’ skills in observation, problem-solving, decision-making, and critical thinking. This enabled them to gain an appreciation of their resource.

  19. Using Local Ecological Knowledge and Environmental Education in Resource Management of Abalone in Carot, Anda, Pangasinan

    Emmanuel C. Capinpin, Jr.

    2012-06-01

    Full Text Available The objectives of the present study were to (1 determine the local ecological knowledge (LEK of abalone gatherers through interviews and mentoring, and assess the correspondence between scientific information and LEK, so that areas where local knowledge may be most useful in resource management could be identified, and (2 to empower selected gatherers/farmers with knowledge and technical skills through environmental education to help develop or build their capacity to become sustainable resource managers. The LEK of abalone fishers was determined using three complementary approaches – group interview, individual interview, and mentoring sessions. Local fishers possess a wealth of knowledge about the interactions of species gained through many years of observations, and this knowledge may be useful in guiding biologists in ecological restoration or management regimes. Additionally, the fishers’ LEK, validated by modern scientific ecological findings, could be a source of important and effective ideas in resource management. The knowledge of the abalone gatherers about important abalone fishing grounds should help in pinpointing critical areas that need to be managed. Abalone mariculture in cages should be set up in these areas to routinely create dense breeding populations which can help in enhancing recovery and in providing fishers with a source of additional income. The continued enforcement of marine protected areas and the periodic release or reseeding of abalone in sanctuaries could also be considered viable resource management options. Other recommendations for resource management based on gathered local knowledge and lessons learned from the environmental education (EE seminars are also presented.

  20. Effects of Nereis diversicolor O. F. Muller abundance on the dissolved phosphate exchange between sediment and overlying water in Palmones River estuary (southern Spain)

    Clavero, V.; Niell, F. X.; Fernandez, J. A.

    1991-08-01

    Annual variations in dissolved phosphate gradient, sediment porosity, abundance of Nereis diversicolor and phosphate flux were measured in order to determine the pattern of phosphate exchange between the sediment and overlying water in an estuarine system. N. diversicolor abundance is inversely related to the dissolved phosphate gradient while the ratio, measured flux/calculated diffusion flux, increases as does N. diversicolor abundance.

  1. Grazing effects by Nereis diversicolor on development and growth of green algal mats

    Engelsen, Anna; Pihl, Leif

    2008-08-01

    Nereis diversicolor is generally considered to be a predator and deposit feeder, but have also been found to graze on benthic algae in shallow coastal areas. In this study we investigated the grazing effects on the development and growth of green algae, Ulva spp. Algal growth was studied in an experiment including two levels of sediment thickness; 100 mm sediment including macrofauna and 5 mm sediment without macrofauna, and three treatments of varying algal biomass; sediment with propagules, sediment with low algal biomass (120 g dry weight (dwt) m - 2 ) and sediment with high algal biomass (240 g dwt m - 2 ). In the 100 mm sediment, with a natural population of macrofauna, N. diversicolor was the dominating (60% of total biomass) species. After three weeks of experimentation the result showed that N. diversicolor was able to prevent initial algal growth, affect growth capacity and also partly reduce full-grown algal mats. The weight of N. diversicolor was significantly higher for polychaetes in treatments with algae added compared to non-algal treatments. There were also indications that a rich nutrient supply per algae biomass counteracted the grazing capacity of N. diversicolor.

  2. Metabolism of pyrene by the polychaetes Nereis diversicolor and Arenicola marina.

    Christensen, Mette; Andersen, Ole; Banta, Gary T

    2002-07-01

    Absorption and elimination of [(14)C-4,5,9,10]pyrene and production of water-insoluble and water-soluble pyrene metabolites by the polychaetes Nereis diversicolor and Arenicola marina were studied. Both polychaete species were capable of rapidly accumulating and eliminating pyrene. Steady state concentrations of pyrene were established in both polychaete species within 5 days of exposure to contaminated sediments, with A. marina having 5-10 times higher bioaccumulation factors than N. diversicolor. Both water-soluble and water-insoluble metabolites were detected in tissues of N. diversicolor and A. marina. After transferring worms to uncontaminated sediment, about 50% of the body burden of parent pyrene was excreted within 1.5 days, with elimination in A. marina being faster than in N. diversicolor. The only identified water-insoluble metabolite produced by N. diversicolor was 1-hydroxypyrene. Pyrene metabolites were present in A. marina, but could not be identified. Long- and short-term absorption experiments showed an increasing production of water-soluble metabolites over time in the lugworm, which strongly suggests the presence of a PAH metabolising system in A. marina. PMID:12062152

  3. Effect of abalone farming on sediment geochemistry in the Shallow Sea near Wando, South Korea

    Kang, Jeongwon; Lee, Yeon Gyu; Jeong, Da Un; Lee, Jung Sick; Choi, Yang Ho; Shin, Yun Kyung

    2015-12-01

    Wando County has grown up to 93% of the total abalone produced in South Korea since the late 1990s; however, this production has been decreasing in recent years. The objectives of this study were to understand the potential contamination risks of abalone farming and to examine the influence of intensive abalone farming on sediment quality by analyzing grain-size composition, organic matter (total organic carbon (TOC), total nitrogen (TN), total sulfur (TS)) and heavy metal content, pH, and 210Pb geochronology. The results of organic matter analysis from surface and core sediment (length: 64 cm) showed that the area around the abalone farm had oxic marine-to-brackish conditions, but that the area directly below an abalone cage (location 7) had reductive conditions, with a C/S ratio of ~2. The average TN levels in the surface and core sediments were 0.25% and 0.29%, respectively, and this was predominantly due to the use of seaweed for feed. The low sediment pH (surface, 7.23; core, 7.04), indicates that acidification of the bottom sediment has gradually increased since the initiation of abalone farming and is likely due to the continuous accumulation of uneaten feed and feces. Heavy metal pollution was not apparent based on the examination of EF and Igeo, although the excess metal flux of Ni, Pb, Cu, Co, As, and Cd increased toward surface of the sediment core. These sediment changes may be caused by the rapid accumulation (sedimentation rate: 1.45 cm/year) of sludge discharged from the abalone farm and may be controlled by tidal currents, physiography, water depth, and tidal ranges.

  4. Oxidative stress biomarkers of the polychaete Nereis diversicolor exposed to cadmium and petroleum hydrocarbons.

    Sun, Fu-hong; Zhou, Qi-xing

    2008-05-01

    Changes in the activity of antioxidant enzymes including superoxide dismutase (SOD) and peroxidase (POD) and in the content of soluble protein (SP) in Nereis diversicolor exposed to cadmium (Cd) and petroleum hydrocarbons (PHCs) were investigated under a laboratory condition. The results indicated that SOD activity in N. diversicolor exposed to Cd and PHCs significantly (Pdiversicolor could also sensitively reflect oxidative stress induced by Cd and PHCs. Concentration combination of Cd and PHCs had significant (Pdiversicolor at single or joint exposure of Cd and PHCs. Exposure time also resulted in significant differences in POD activity (Pdiversicolor which was simultaneously exposed to Cd and PHCs, as called time-dependent effects. Compared with day 0, SOD activity in non-exposed N. diversicolor increased, possibly due to the effects of temperature. Therefore, the effects of pollutants with emphasis on abiotic parameters on the antioxidant defense system should be considered in future studies. PMID:17673290

  5. Abalone water-soluble matrix for self-healing biomineralization of tooth defects.

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53wt% the abalone water-soluble protein (AWSPro) and 2.04wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. PMID:27287112

  6. Biochemical alterations induced in Hediste diversicolor under seawater acidification conditions.

    Freitas, Rosa; Pires, Adília; Moreira, Anthony; Wrona, Frederick J; Figueira, Etelvina; Soares, Amadeu M V M

    2016-06-01

    Seawater pH is among the environmental factors controlling the performance of marine organisms, especially in calcifying marine invertebrates. However, changes in non-calcifying organisms (including polychaetes) may also occur due to pH decrease. Polychaetes are often the most abundant group of organisms in estuarine systems, representing an important ecological and economic resource. Thus, the present study aimed to evaluate the impacts of seawater acidification in the polychaete Hediste diversicolor, a species commonly used as bioindicator. For this, organisms were exposed to different pH levels (7.9, 7.6 and 7.3) during 28 days and several biochemical markers were measured. The results obtained demonstrated that pH decrease negatively affected osmotic regulation and polychaetes metabolism, with individuals under low pH (7.6 and 7.3) presenting higher carbonic anhydrase activity, lower energy reserves (protein and glycogen content) and higher metabolic rate (measured as Electron transport system activity). The increase on CA activity was associated to organisms osmoregulation capacity while the increase on ETS and decrease on energy reserves was associated to the polychaetes capacity to develop defense mechanisms (e.g. antioxidant defenses). In fact, despite having observed higher lipid peroxidation at pH 7.6, in polychaetes at the lowest tested pH (7.3) LPO levels were similar to values recorded in individuals under control pH (7.9). Such findings may result from higher antioxidant enzyme activity at the lowest tested pH, which prevented organisms from higher oxidative stress levels. Overall, our study demonstrated how polychaetes may respond to near-future ocean acidification conditions, exhibiting the capacity to develop biochemical strategies which will prevent organisms from lethal injuries. Such defense strategies will contribute for polychaetes populations maintenance and survival under predicted seawater acidification scenarios. PMID:27088614

  7. Acceleration of calcite kinetics by abalone nacre proteins

    Fu, G; Qiu, S R; Orme, C A; Morse, D E; De Yoreo, J J

    2005-06-09

    The fascinating shapes and hierarchical designs of biomineralized structures have long been an inspiration to materials scientists because of the potential they suggest for biomolecular control over synthesis of crystalline materials. One prevailing view is that mineral-associated macromolecules are responsible for initiating and stabilizing non-equilibrium crystal polymorphs and morphologies through interactions between anionic moieties and cations in solution or at mineral surfaces. Indeed, numerous studies have demonstrated that bio-organic additives can dramatically alter crystal shapes and growth-rates in vitro. However, previous molecular-scale studies revealing mechanisms of growth modification focused on small molecules such as amino acids or peptides and always observed growth inhibition. In contrast, studies using full proteins were non-quantitative and underlying sources of growth modification were ill-defined. Here we investigate interactions between proteins isolated from abalone shell nacre and growing surfaces of calcite. We find that these proteins significantly accelerate the molecular-scale kinetics and, though much larger than atomic steps, alter growth morphology through step-specific interactions that lower their free energies. We propose that these proteins act as surfactants to promote ion attachment at calcite surfaces.

  8. Cellular toxicity and bioaccumulationof silver nanoparticles in the marine polychaete, Nereis diversicolor

    cong, Yi; Banta, Gary Thomas; Selck, Henriette;

    In this study, the toxicities of commercial silver nanoparticles (Ag NPs, 20 and 80 nm) were compared with the toxicities of Ag+ ions in the marine sediment-dwelling polychaete, Nereis diversicolor, after 10 d of sediment exposure, using lysosomal membrane stability (neutral red assay), DNA damage...

  9. The effect of organic pollution on local distribution of Nereis diversicolor and Corophium volutator

    Esselink, P.; van Belkum, J.; Essink, K.

    Distribution patterns of Nereis diversicolor and Corophium volutator in the SE-Dollard, a 92 km 2 tidal flat area in the NE Netherlands are described. Body condition as well as the maximal size of juvenile worms correlated positively with elevation of the mudflat, probably caused by a better food supply on the higher mudflats. No spatial variation in size was found for C. volutator. N. diversicolor disappeared from ˜1 km 2 of the intertidal mudflats in the autumn of 1985 as a consequence of the seasonal waste discharges, whereas C. volutator disappeared from an area of ˜4 km 2. Though the discharges decreased by almost 50% from 1982 to 1985, N. diversicolor disappeared from about the same area in the 2 years. N. diversicolor is the main prey species of the avocet Recurvirostra avosetta, large flocks of which stay in the Dollard during autumn migration. Though the avocets lost ˜30% of their potential feeding area in the Dollard in the 1970s because of the high waste discharges, against only 5 to 10% in 1982 and thereafter (at significant lower discharges), the numbers of the avocets did not respond to the decrease of the discharges.

  10. Uptake pathways and subcellular fractionation of Cd in the polychaete Nereis diversicolor.

    Li, Lianzhen; Liu, Xiaoli; You, Liping; Zhang, Linbao; Zhao, Jianmin; Wu, Huifeng

    2012-01-01

    Polychaetes have often been utilized as indicator species to investigate the impacts of pollutants, such as heavy metals. The uptake of Cd by the polychaete Nereis diversicolor was determined at varying Ca concentrations and with pre-exposure to Ca ion channel blockers and metabolic inhibitors in simulated sea water over 1 week period. The supply of Ca in simulated sea water inhibited Cd uptake and increased Ca concentration in N. diversicolor after 10 μM Cd exposure. Pre-exposure to a Ca-channel blocker (Lanthanum) significantly inhibited Cd uptake, suggesting that the uptake of Cd was exerted at a Ca channel. N-ethylmaleimide, which specifically binds to sulfhydryl groups, inhibited Cd uptake at 10 μM, implying that the transport of Cd is carrier-mediated by proteins or other SH-containing compounds. Subcellular Cd distribution analysis showed that more than 60% of the total Cd associated with the cytosolic fraction. The presence of higher concentration of Ca in simulated sea water did not impact the proportional subcellular distribution of Cd in N. diversicolor. Nevertheless, the supply of Ca could significantly lower Cd concentration in cytosol and cellular debris. The present study provides evidence that Cd transport by N. diversicolor was mediated mainly through lanthanum- sensitive Ca ion channels and accumulated by SH-containing compounds. These results help to understand the uptake mechanism and subcellular distribution of Cd in polychaetes. PMID:21858512

  11. [Research advance in characteristics and mechanisms of Nereis diversicolor endurance against environmental pollution].

    Sun, Fuhong; Zhou, Qixing

    2006-03-01

    Nereis diversicolor is an ecologically keystone species of invertebrate that lives in the mud of marine-terrestrial interlaced zone. This species can accumulate a large number of toxic heavy metals such as copper, cadmium and zinc in its body, and thus, shows a high endurance against toxic heavy metals. This paper summarized the latest research advance at home and abroad in the characteristics and mechanisms of N. diversicolor endurance against heavy metals and organic contaminants. N. diversicolor could achieve its heavy metals- endurance through several eco-chemical processes, e.g., mucus secretion and contaminants excretion. The former could form a protective layer or integrate with dissolved ions of pollutants, and thus, decrease the bioavailability of pollutants, while the latter could lessen the pollutants' bio-toxicity. More researches believe that the toxic heavy metals in N. diverdicolor body are stored in non-toxic physicochemical forms, i. e., bound to metal-binding protein, such as metallothionein (MTs), metallothionein-like proteins (MTLP) and cytosolic heat-stable thiolic compounds (CHSTC), or incorporated into insoluble deposits or granules. The pivots of future researches on the ecotoxicology of N. diversicolor and its endurance mechanisms against pollutants were proposed. PMID:16724757

  12. 杂交鲍苗种“病毒性萎缩症(AbSV)”病理学研究%Studies on Pathology of “Shriveling Syndrome Associated Virus(AbSV)” in Juvenile Hybrid Abalone

    杨小强

    2013-01-01

    从福州地区患病杂交鲍苗种组织中分离到一种球形病毒用以感染健康鲍,通过对感染发病的鲍苗进行光镜和电镜观察,发现:病毒主要在消化腺嗜碱性细胞的细胞核中发生;消化腺消化细胞和嗜碱性细胞细胞核异形、染色质固缩,内质网扩张,线粒体嵴断裂、消失;消化腺小叶基膜肌纤维断裂、消失;消化道肠道具微绒毛的柱状细胞和纤毛柱状细胞发生自溶现象;足部肌细胞核浓缩,染色质固缩、边集,肌纤维断裂出现空泡.据此推测,病毒以鲍消化腺嗜碱性细胞为靶细胞,造成消化腺和胃、肠道等消化系统病变,机体因长期营养不良而萎缩,最后因全身性感染出现死亡.%Pathological analysis was done on juvenile hybrid abalone (Haliotisdiscus discus Haliotis discus hannai)artificially infected by a spherical virus isolated from the diseased ones in Fuzhou.Examination of artificially infected juvenile hybrid abalone by optical and electron microscopy showed that the virion mainly developed in nucleus of basophilic cells in digestive gland,and led to nuclear heteromorphosis,chromatin condensation,endoplasmic reticulum expansion,and mitochondria cristae breakage in digestive gland cell and basophilic cell.Meanwhile,broken digestive gland lobule basal lamina muscle fibers,autolysis and pyknosis of microvillus and cilium columnar cell in digestive gland intestinal tract were observed.In foot muscle cells,muscle fibers were broken and vesicles emerged,together with chromatin condensation and margination.These results suggested that the digestive gland basophilic cells maybe the special target cell of this virus,the infection could cause lesion in digestive gland and digestive organs such as stomach,intestines.Atrophy due to long-term malnutrition and systemic infection would finally led to death.

  13. Abalone visceral extract inhibit tumor growth and metastasis by modulating Cox-2 levels and CD8+ T cell activity

    II Kim Jae

    2010-10-01

    Full Text Available Abstract Background Abalone has long been used as a valuable food source in East Asian countries. Although the nutritional importance of abalone has been reported through in vitro and in vivo studies, there is little evidence about the potential anti-tumor effects of abalone visceral extract. The aim of the present study is to examine anti-tumor efficacy of abalone visceral extract and to elucidate its working mechanism. Methods In the present study, we used breast cancer model using BALB/c mouse-derived 4T1 mammary carcinoma and investigated the effect of abalone visceral extract on tumor development. Inhibitory effect against tumor metastasis was assessed by histopathology of lungs. Cox-2 productions by primary and secondary tumor were measured by real-time RT-PCR and immunoblotting (IB. Proliferation assay based on [3H]-thymidine incorporation and measurement of cytokines and effector molecules by RT-PCR were used to confirm tumor suppression efficacy of abalone visceral extract by modulating cytolytic CD8+ T cells. The cytotoxicity of CD8+ T cell was compared by JAM test. Results Oral administration of abalone visceral extract reduced tumor growth (tumor volume and weight and showed reduced metastasis as confirmed by decreased level of splenomegaly (spleen size and weight and histological analysis of the lung metastasis (gross analysis and histological staining. Reduced expression of Cox-2 (mRNA and protein from primary tumor and metastasized lung was also detected. In addition, treatment of abalone visceral extract increased anti-tumor activities of CD8+ T cells by increasing the proliferation capacity and their cytolytic activity. Conclusions Our results suggest that abalone visceral extract has anti-tumor effects by suppressing tumor growth and lung metastasis through decreasing Cox-2 expression level as well as promoting proliferation and cytolytic function of CD8+ T cells.

  14. Behavioural and biochemical responses of two marine invertebrates Scrobicularia plana and Hediste diversicolor to copper oxide nanoparticles

    Buffet, Pierre-Emmanuel; Tankoua, Olivia Fossi; Pan, Jin-Fen; Berhanu, Deborah; Herrenknecht, Christine; Poirier, Laurence; Amiard-Triquet, Claude; Amiard, Jean-Claude; Bérard, Jean-Baptiste; Risso, Christine; Guibbolini, Marielle; Roméo, Michèle; Reip, Paul; Valsami-Jones, Eugenia; Mouneyrac, Catherine

    2011-01-01

    Engineered nano-sized Cu oxide particles are extensively used in diverse applications. Because aquatic environments are the ultimate "sink" for all contaminants, it is expected that nanoparticles (NP) will follow the same fate. In this study, two marine invertebrates Scrobicularia plana and Hediste diversicolor were chosen as ecotoxicological models. The aim was to evaluate behavioural (burrowing kinetics, feeding rate) and biochemical (biomarkers) responses of S. plana and H. diversicolor ex...

  15. Microscale distribution of oxygen and nitrate in sediments inhabited by Nereis diversicolor; spatial patterns and estimated reaction rates

    Nielsen, O.I.; Gribsholt, B.; Kristensen, E.; Revsbeck, N.P.

    2004-01-01

    Profiles of oxygen and nitrate were measured with microsensors in sediment surrounding burrow structures of the polychaete Nereis diversicolor in a shallow mudflat in Limfjorden, Denmark. Rates and spatial distribution of reactions involving oxygen and nitrate (oxygen consumption, nitrification and nitrate reduction) in the vicinity of burrow structures and surface sediment were calculated and identified from concentration profiles. The burrow walls of the natural N. diversicolor population i...

  16. Smelling Danger – Alarm Cue Responses in the Polychaete Nereis (Hediste) diversicolor (Müller, 1776) to Potential Fish Predation

    Schaum, C. Elisa; Batty, Robert; Last, Kim S.

    2013-01-01

    The harbour ragworm, Nereis (Hediste) diversicolor is a common intertidal marine polychaete that lives in burrows from which it has to partially emerge in order to forage. In doing so, it is exposed to a variety of predators. One way in which predation risk can be minimised is through chemical detection from within the relative safety of the burrows. Using CCTV and motion capture software, we show that H. diversicolor is able to detect chemical cues associated with the presence of juvenile fl...

  17. Influence of bioturbation by the polychaete Nereis diversicolor on the structure of bacterial communities in oil contaminated coastal sediments

    Cuny, Philippe; Miralles, Gilles; Cornet-Barthaux, Véronique; Acquaviva, Monique; Stora, Georges; Grossi, Vincent; Gilbert, Franck

    2007-01-01

    Patterns of change in the structure of bacterial communities monitored by ribosomal intergenic spacer analysis (RISA) in oil contaminated sediments inhabited or not by the marine polychaete Nereis diversicolor were studied during 45 days under laboratory conditions. Results supported by principal component analysis showed a marked response of the bacterial communities to the oil contamination and to the presence of N. diversicolor. Phylogenetic affiliation of specific RISA bands showed that, ...

  18. Más sobre Abalone y algo sobre tuercas: los tetrahexos

    Rupérez, José Antonio; García, Manuel

    2012-01-01

    Comentamos los problemas planteados en anterior artículo sobre jugadas del ABALONE, describiéndolo de nuevo y presentamos el puzle de los Polihexos, fácil de construir y entretenido de resolver; útil para plantear ejercicios de combinatoria y simetrías.

  19. 酶解鲍鱼制备增味剂的研究%The flavor enhancer prepared by enzymatic abalone

    任艳艳; 李卫华

    2011-01-01

    采用Alcalase和Flavourzyme两种蛋白酶对鲍鱼蛋白进行酶解,利用鲍鱼酶解物制备得到的增味剂,经感官评定,具有显著的口感增强作用。%Alcalase and Flavourzyme were used to hydrolyze the protein of abalone.The abalone hydrolysate was prepared for flavor enhancer,which proved to have high flavor-enhance effect by sensory evaluation.

  20. Nereis diversicolor and copper contamination effect on the erosion of cohesive sediments: A flume experiment

    Fernandes, S.; Sobral, P.; Alcântara, F.

    2009-04-01

    The effect of bioturbation on the erodability of natural and manipulated copper spiked sediments (3 μmol Cu g -1 dw) was investigated using sediments collected in the Tagus estuary and Nereis diversicolor (900 ind m -2). The input of particulate matter and Cu into the water column as a result of erosion was quantified in an annular flume at 7 shear velocities (1-13 cm s -1). The biogeochemical characteristics of the sediment were analysed in depth down to 8 cm. Cu contamination elicited lower levels of eroded matter and lower shear strength profiles. Eroded matter and sediment shear strength values were higher (up to 1.7 kg m -2) in the presence of N. diversicolor, whose effect was less pronounced under contamination. Sediment erodability was not only related to hydrodynamics but was highly affected by the biogeochemical characteristics and contamination of the sediments.

  1. Uptake of /sup 55/Fe from contaminated sediments by the polychaete Nereis diversicolor

    Jennings, C.D. (Oregon Coll., Monmouth); Fowler, S.W.

    1980-01-01

    The polychaete Nereis diversicolor O.F. Mueller was exposed to marine sediments which had been contaminated with /sup 55/Fe either through the testing of nuclear devices or by the release of liquid waste effluent from a nuclear fuel reprocessing plant. The amount of /sup 55/Fe taken up reached a concentration in the worms about 6% of the concentration in both types of sediment. Bioavailability of /sup 55/Fe was shown to depend on its concentration in sediment and not on sediment type, stable iron concentration, or the source of contamination. N. diversicolor may not extract from sediment the same fraction of /sup 55/Fe as does 0.1N HCl and caution should be exercised in using such measurements to represent the bioavailable fraction.

  2. Experimental study of the retention of zinc 65 by sediment and polychaete annelids (Nereis diversicolor Muller)

    Baudin, J.P. (CEA Centre d' Etudes Nucleaires de Cadarache, 13 - Saint-Paul-les-Durance (France). Dept. de Protection)

    1981-01-01

    Zinc 65 is a radionuclide with an intermediate half-life (245 days). It is an isotope of a biological trace element which can be found in some liquid wastes released by nuclear facilities. The first part of the paper concerns zinc 65 transfer from water to sediment. This process is essentially characterised by its rapidity and intensity. After 48 hours water loses 50% of its activity and transfer reaches 100% beyond the 20th day. Zinc 65 is strongly bound to the sediment and its desorption is almost non-existent. The second part reports the results about zinc 65 contamination of Nereis diversicolor, a species which can be considered as a vehicle of recirculation for the radionuclide fixed in the sediment. This assumption is partly verified although zinc 65 accumulation by Nereis diversicolor from water is 20 times more important than from sediment.

  3. Inhibition of denitrification by hydrocarbons in marine sediments. Role of Nereis diversicolor

    Gilbert, Franck; François, Frédérique; Stora, Georges; Bertrand, Jean-Claude

    1997-01-01

    An in vitro experiment has been carried out in order to illustrate the influence of the burrowing polychaete Nereis diversicolor on denitrification in hydrocarbon-loaded sediments. After 15 and 45 days, the denitrification activity in the different contaminated or non-contaminated control (without macro-fauna) and experimental (colonized by polychaetes) sediments was compared. In control contaminated sediments, the inhibition of denitrification is solely located in the surface layer (0-2 cm)....

  4. Metal concentrations in sediment and Nereis diversicolor in two Moroccan lagoons: Khnifiss and Oualidia

    Idardare, Zaina; Chiffoleau, Jean-francois; A. Moukrim; Alla, A.; Auger, Dominique; Lefrere, L; Rozuel, Emmanuelle

    2008-01-01

    Metal concentrations were measured monthly during an annual cycle (December 2004 to January 2006) in the tissues of Nereis diversicolor ragworms and sediment from two Moroccan Atlantic coastal lagoons: Oualidia in the north, situated in a highly industrialised urban area and Khnifiss in the south, far from anthropogenic influences. Relatively high levels of Zn, Ag and Cd were found in the sediment of Oualidia lagoon, while Ni concentrations were shown to be high at Khnifiss. The significant m...

  5. Response of Nereis diversicolor population (Polychaeta, Nereididae) to the pollution impact - Authie and Seine estuaries (France)

    Gillet, P.; Mouloud, M.; Durou, C.; Deutsch, B.

    2008-01-01

    A survey within the French National Programme of Ecotoxicology was carried out in 2002, 2003 and 2004 to study the response of Nereis diversicolor populations (Polychaeta, Nereididae) to the impact of pollution in the Authie estuary (non-contaminated site) and in the Seine estuary (contaminated site). In the period studied, the density varied from 672 ind. m -2 to 3584 ind. m -2 in the Authie estuary and from 80 ind. m -2 to 920 ind. m -2 in the Seine estuary. Biomass varied from 3.94 g m -2 (dry weight) in February 2004 to 38.0 g m -2 in August 2003 in the Authie estuary and from 3.4 g m -2 in February 2002 to 0.6 g m -2 in February 2004 in the Seine estuary. Density and biomass of the populations of N. diversicolor were consistently lower in the Seine estuary than in the Authie estuary. Size frequency histograms permit the analysis of the cohorts as well as the elaboration of the growth curves. For the individuals from the Authie estuary, the relation between dry weight (DW) and length L3 (prostomium, peristomium and chaetiger 1) was DW = 4.2205 L3 2.9832. For those from the Seine estuary, the relation between dry weight and L3 was DW = 0.4697e 1.7209L3. The individuals of N. diversicolor should belong to eight cohorts in Authie estuary (two cohorts each year) instead of six cohorts for those from the Seine estuary. These differences can be attributed to the effect of pollution on the population of N. diversicolor.

  6. Bioconcentration de metaux lourds chez une annelide polychete estuarienne: Nereis diversicolor

    Septier, F.; Demuynck, S; Thomas, P; Dhainaut-courtois, N

    1991-01-01

    The concentrations of twelve heavy metals in sediments and in female Nereis diversicolor collected in the estuary of the River Aa and in the little harbour of Boulogne were investigated. Concentration variations which were sometimes considerable were found according to the site, the period of the year, the age of the animals and the cations studied. In addition, numerous intermetal correlations were detected in the nereis. Cytochemical and radioautographic studies revealed that the tegument a...

  7. The influence of Cu contamination on Nereis diversicolor bioturbation

    Fernandes, S.; Meysman, F.J.R.; Sobral, P.

    2006-01-01

    Aquatic sediments feature a two-way interaction between contaminants and benthic macrofauna. The effect of the macrofauna community on the transport of contaminants in sediment has received considerable attention. Yet, few studies have investigated the reverse effect, i.e., the influence of contaminants on bioturbation activity. To this end, we performed laboratory experiments to investigate the effect of copper contamination on sediment reworking activity of the ragworm Nereis diversicolor. ...

  8. Biotransformation of arsenate to the tetramethylarsonium ion in the marine polychaetes Nereis diversicolor and Nereis virens.

    Geiszinger, Anita E; Goessler, Walter; Francesconi, Kevin A

    2002-07-01

    Arsenic compounds in aqueous extracts of the marine polychaetes Nereis diversicolor and Nereis virens were determined by HPLC-ICP-MS. Both polychaetes contained most of their water-soluble arsenic as arsenobetaine (approximately 60%), and the tetramethylarsonium ion was also a significant arsenic constituent (approximately 20% in N. diversicolor and approximately 30% in N. virens). Trimethylarsoniopropionate and arsenosugars were present in the Nereis species as minor constituents, and traces of arsenocholine, trimethylarsine oxide, and arsenate were also detected. When N. diversicolor and N. virens were exposed in laboratory experiments to different concentrations of arsenate in seawater (10, 50, 100, 500, and 1000 microg of As L(-1)), both species accumulated arsenic in a dose-dependent manner. Atthe highest exposure level, they achieved mean arsenic concentrations (dry mass) of approximately 70 mg of As kg(-1) (N. virens) and 90 mg of As kg(-1) (N. diversicolor), which represented about a 5-fold increase when compared with the control animals. The arsenic taken up by the polychaetes was readily methylated, and the major metabolite was the tetramethylarsonium ion (up to approximately 85% of the accumulated arsenic). Two other products of arsenic methylation, methylarsonate and trimethylarsine oxide, were also produced to a small extent; however, dimethylarsinate, another likely intermediate in the formation of the tetramethylarsonium ion, could not be detected in these experiments. The remaining accumulated arsenic was present as unchanged arsenate. This is the first report of significant biomethylation of arsenic to the tetramethyl stage and provides a ready explanation for the widespread occurrence of tetramethylarsonium ion in marine animals. PMID:12144266

  9. Preliminary Data on the Bioturbation Activity of Hediste Diversicolor (Polychaeta, Nereididae) from the Loire Estuary, France

    Gillet, Patrick; Mouloud, Mohammed; Mouneyrac, Catherine; Simo, Pablo; Gilbert, Franck

    2012-01-01

    The ragworm Hediste diversicolor (O. F. Müller, 1776) plays a key role in the estuarine water-sediment interface. This scientific project comes under the framework of the International network Nereis Park Experiment gathering 27 laboratories from all over the world. The experiments were carried out concurrently in spring 2007 using a common protocol. In the Loire estuary, the samples were collected in the intertidal zone of the Saint-Nazaire Bridge. During the field experiment, we estimated t...

  10. Aquaculture growth and Fatty acid profile of Hediste diversicolor fed with three different diets

    António Santos

    2014-06-01

    Full Text Available Hediste diversicolor (O.F. Müller, 1776 or so called common ragworm, is an Annelida polychaeta is typically an inhabitant of shallow marine and brackish waters in different parts of Europe. This species has a high physiological tolerance to extreme environmental factors such as salinity, temperature and dissolved oxygen levels, which can be grown and reproduced in different types of sediment. In the field and also under laboratory conditions this worm can utilize different types of food. To improve the aquaculture of H. diversicolor we have determined the growth, survival rates and fatty acid profile of juvenile worms fed with three different diets for 2 months. This experiment was carried out with juvenile worms reared in aquaculture laboratory of Polytechnic Institute of Leiria and were fed with Aquagold (seabream dry food, moist sole (semi wet pellets for cultured sole and mackerel fillet. The temperature was maintained at 20 ± 1°C with 15 of salinity. H. diversicolor juveniles were placed in three replicates for each diet, with 30 worms per replicate. The higher growth rate was observed when the juveniles were fed with Aquagold (0,146 g d-1 for 10 individuals, and 100% survival rate was a result of moist sole diet, probably related to the immunostimulant included in this feed. The major fatty acids found in the juveniles fed with the three diets were palmitc acid (16:0, oleic acid (18:1n9; eicosapentanoic acid (20:5n3 and docosahexaenoic acid (22:6n3. Although results shown that mackerel fillet was not the diet with the higher growth rate and final weight achieved, when compared to the other two diets, but it is proved that it can be suitable for H. diversicolor aquaculture.

  11. Initial characterization of receptors for molecules that induce the settlement and metamorphosis of Haliotis rufescens larvae

    Larvae of the marine gastropod mollusc Haliotis refescens are induced to undergo metamorphosis by γ-aminobutyric acid (GABA) and stereochemically related compounds. The most potent of these inducers is (-)-β-(parachlorophenyl)-GABA (baclofen). The inductive response exhibits positive cooperatively, and is subject to both facilitation (up-regulation) and habituation (down-regulation). Facilitation is brought about by diamino acids such as L-diaminopropionic acid (L-DAPA), and is characterized by decreased Hill coefficients (n/sub H/) and concentration requirements (EC50) for inducers. Facilitation does not require the simultaneous presence of facilitating and inducing compounds, and the facilitated state is persistent. Larvae are capable of being up-regulated 2 days before they are capable of undergoing settlement and metamorphosis. Habituation can be brought about by exposure of pre-competent larvae to GABA 4 days prior to the attainment of competence; it is then slowly reversible. Larvae specifically bind tritiated (-)-baclofen in a manner that is saturable with both increasing time of exposure of larvae to, and with increasing concentration of, this compound. Specific binding can be competed for by unlabeled GABA-mimetic inducing molecules; the order of effectiveness of these molecules as competitors for specific binding correlates well with their effectiveness as inducers of metamorphosis. Facilitation of larvae by exposure to diamino acids does not alter their specific binding of tritiated (-)-baclofen. It is concluded from these findings that Haliotis larvae possess receptors for GABA-mimetic compounds

  12. Initial characterization of receptors for molecules that induce the settlement and metamorphosis of Haliotis rufescens larvae

    Trapido-Rosenthal, H.G.

    1985-01-01

    Larvae of the marine gastropod mollusc Haliotis refescens are induced to undergo metamorphosis by ..gamma..-aminobutyric acid (GABA) and stereochemically related compounds. The most potent of these inducers is (-)-..beta..-(parachlorophenyl)-GABA (baclofen). The inductive response exhibits positive cooperatively, and is subject to both facilitation (up-regulation) and habituation (down-regulation). Facilitation is brought about by diamino acids such as L-diaminopropionic acid (L-DAPA), and is characterized by decreased Hill coefficients (n/sub H/) and concentration requirements (EC/sub 50/) for inducers. Facilitation does not require the simultaneous presence of facilitating and inducing compounds, and the facilitated state is persistent. Larvae are capable of being up-regulated 2 days before they are capable of undergoing settlement and metamorphosis. Habituation can be brought about by exposure of pre-competent larvae to GABA 4 days prior to the attainment of competence; it is then slowly reversible. Larvae specifically bind tritiated (-)-baclofen in a manner that is saturable with both increasing time of exposure of larvae to, and with increasing concentration of, this compound. Specific binding can be competed for by unlabeled GABA-mimetic inducing molecules; the order of effectiveness of these molecules as competitors for specific binding correlates well with their effectiveness as inducers of metamorphosis. Facilitation of larvae by exposure to diamino acids does not alter their specific binding of tritiated (-)-baclofen. It is concluded from these findings that Haliotis larvae possess receptors for GABA-mimetic compounds.

  13. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    Coppersmith, S N; Gilbert, P. U. P. A.; Metzler, R. A.

    2009-01-01

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400-nm thick aragonite crystalline tablets confined by organic matrix sheets, with the $(001)$ crystal axes of the aragonite tablets oriented to within $\\pm$ 12 degrees from the normal to the layer planes. Recent experiments demonstrate that this orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous si...

  14. Influence of anthropogenic stress on fitness and behaviour of a key-species of estuarine ecosystems, the ragworm Nereis diversicolor

    Mouneyrac, C., E-mail: catherine.mouneyrac@uco.f [MMS, EA2160, Faculte de pharmacie, 1 rue G. Veil, BP 53508, 44035 Nantes Cedex 1 (France); Institut de Biologie et Ecologie Appliquee, CEREA, Universite Catholique de l' Ouest, 3 Place Andre Leroy, Angers, 44 rue Rabelais, 49008 Angers Cedex 01 (France); Perrein-Ettajani, H. [MMS, EA2160, Faculte de pharmacie, 1 rue G. Veil, BP 53508, 44035 Nantes Cedex 1 (France); Institut de Biologie et Ecologie Appliquee, CEREA, Universite Catholique de l' Ouest, 3 Place Andre Leroy, Angers, 44 rue Rabelais, 49008 Angers Cedex 01 (France); Amiard-Triquet, C. [CNRS, Universite de Nantes, MMS, EA2160, Faculte de pharmacie, 1 rue G. Veil, BP 53508, 44035 Nantes Cedex 1 (France)

    2010-01-15

    Fitness, (biometric measurements, reproduction) and behaviour that are ecologically relevant biomarkers in assessing the quality of estuarine sediments were studied by comparing the responses of the polychaete worm Nereis diversicolor - a key species in estuaries - along a pollution gradient. Intersite differences were shown for all the measured parameters: size-weight relationships, energy reserves as glycogen and lipids, sexual maturation patterns, total number of oocytes per female, total and relative fecundity, burrowing behaviour. The physiological and behavioural status of N. diversicolor was consistently disturbed in the larger, most contaminated estuaries (Loire and Seine, Fr.) compared to reference sites (Bay of Bourgneuf, Goyen estuary, Fr.). Many classes of potentially toxic chemicals present in these estuaries most likely contribute to these impairments but food availability may act as a confounding factor, interfering with the potential impact of contaminants. - Fitness, and behaviour in Nereis diversicolor are affected by anthropogenic pressure.

  15. Influence of anthropogenic stress on fitness and behaviour of a key-species of estuarine ecosystems, the ragworm Nereis diversicolor

    Fitness, (biometric measurements, reproduction) and behaviour that are ecologically relevant biomarkers in assessing the quality of estuarine sediments were studied by comparing the responses of the polychaete worm Nereis diversicolor - a key species in estuaries - along a pollution gradient. Intersite differences were shown for all the measured parameters: size-weight relationships, energy reserves as glycogen and lipids, sexual maturation patterns, total number of oocytes per female, total and relative fecundity, burrowing behaviour. The physiological and behavioural status of N. diversicolor was consistently disturbed in the larger, most contaminated estuaries (Loire and Seine, Fr.) compared to reference sites (Bay of Bourgneuf, Goyen estuary, Fr.). Many classes of potentially toxic chemicals present in these estuaries most likely contribute to these impairments but food availability may act as a confounding factor, interfering with the potential impact of contaminants. - Fitness, and behaviour in Nereis diversicolor are affected by anthropogenic pressure.

  16. Feeding, growth and respiration in the polychaetes Nereis diversicolor (facultative filter-feeder) and N. virens (omnivorous) - a comparative study

    M. Nielsen, A.; T. Eriksen, Niels; L. Iversen, Jens Jørgen; Riisgård, Hans Ulrik

    1995-01-01

    Nielsen, A.M., Eriksen, N.T., Iversen, J.J.L., Riisgård, H.U. (1995). Feeding, growth and respiration in the polychaetes Nereis diversicolor (facultative filter-feeder) and N. virens (omnivorous) - a comparative study. Mar. Ecol. Prog. Ser. 125: 149-158.......Nielsen, A.M., Eriksen, N.T., Iversen, J.J.L., Riisgård, H.U. (1995). Feeding, growth and respiration in the polychaetes Nereis diversicolor (facultative filter-feeder) and N. virens (omnivorous) - a comparative study. Mar. Ecol. Prog. Ser. 125: 149-158....

  17. Assessment of the influence of confounding factors (weight, salinity) on the response of biomarkers in the estuarine polychaete Nereis diversicolor.

    Kalman, J; Buffet, P E; Amiard, J C; Denis, F; Mouneyrac, C; Amiard-Triquet, C

    2010-08-01

    The influences of salinity and body size on biochemical (activities of glutathione-S-transferase, lactate dehydrogenase (LDH), acetylcholinesterase and digestive enzymes amylase and CMCase), physiological (feeding and egestion rates, energy reserves) and behavioural (burrowing speed) biomarkers were examined in the infaunal polychaete Nereis diversicolor. Only a few biomarkers were affected, including increased egestion rate and activities of CMCase and LDH at higher salinity, and higher egestion rate in larger worms. These findings reinforce the status of N. diversicolor as a robust sentinel species for estuaries which are environments that are particularly productive but also particularly at risk. PMID:20642318

  18. Influence of bioturbation by the polychaete Nereis diversicolor on the structure of bacterial communities in oil contaminated coastal sediments.

    Cuny, Philippe; Miralles, Gilles; Cornet-Barthaux, Véronique; Acquaviva, Monique; Stora, Georges; Grossi, Vincent; Gilbert, Franck

    2007-04-01

    Patterns of change in the structure of bacterial communities monitored by ribosomal intergenic spacer analysis (RISA) in oil contaminated sediments inhabited or not by the marine polychaete Nereis diversicolor were studied during 45 days under laboratory conditions. Results supported by principal component analysis showed a marked response of the bacterial communities to the oil contamination and to the presence of N. diversicolor. Phylogenetic affiliation of specific RISA bands showed that, in the contaminated sediments, the presence of the marine polychaetes favoured the development of bacteria which may play an active role in natural bioremediation processes of oil polluted environments. PMID:17254615

  19. Influences of petroleum on accumulation of copper and cadmium in the polychaete Nereis diversicolor

    SUN Fu-hong; ZHOU Qi-xing; ZHANG Qian-ru

    2006-01-01

    Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province,China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and 220 μl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220 μl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p>0.05).However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor,in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100 μl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220 μl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220 μl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive.

  20. Influences of petroleum on accumulation of copper and cadmium in the polychaete Nereis diversicolor.

    Sun, Fu-Hong; Zhou, Qi-Xing; Zhang, Qian-Ru

    2006-01-01

    Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province, China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and 220 microl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220 microl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p > 0.05). However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor, in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100 microl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220 microl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220 microl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive. PMID:20050557

  1. Factors in the distribution of intertidal, estuarine polychaetes: a field experiment with Nereis (Hediste) diversicolor and Nephtys hombergi in the Tamar at Plymouth

    Davey, J. T.; George, C. L.

    1986-05-01

    A field experiment was conducted over 10 weeks from July to mid-September, 1984, on a mudflat in the lower reaches of the Tamar Estuary at Plymouth, to test the relative importance of environmental factors and species interactions in controlling the distribution of two polychaete species. Nereis (Hediste) diversicolor from an upper shore site were transplanted into a lower shore site nearby which was characterized by the presence of Nephtys hombergi. 65-71% of N. diversicolor which were transplanted in their own sediments, with no contact with N. hombergi, survived the experimental period. The appearance of some small stages of N. diversicolor in these treatments was attributed in part to recruitment from the overlying water. N. diversicolor transplanted directly into N. hombergi-sediment survived in inverse proportion to their numbers and only the lowest densities (equivalent to 480 m -2) survived as well as those in their own sediment. Given the choice to invade the other species' sediment, more N. hombergi than N. diversicolor finally made the change, and there was some evidence that the smallest N. diversicolor suffered predation in consequence. Otherwise there was little evidence for inter-species interaction. There appeared to be some disruption of oocyte maturation of the N. diversicolor which may have been due to changes in tidal rhythm and salinity at the experimental site.

  2. Use of oil palm kernel meal as a supplement material for abalone mushroom (Pleurotus cystidiosus O.K. Miller cultivation

    Petcharat, V. and

    2004-09-01

    Full Text Available The objective of this study was to determine the optimum rate of oil palm kernel meal, for an abalone mushroom (Pleurotus cystidiosus cultivation. Different concentrations of oil palm kernel meal (5- 20% were added to pararubber sawdust and used to grow the abalone mushroom in plastic bags. Growth rate of the mycelia, number of days from watering to harvesting and yield were compared to those on 94% sawdust + 5% rice bran + 1% Ca(OH2. The results showed that 10% oil palm kernel meal was the optimum concentration for abalone mushroom cultivation. Yield on 950 g/bag of 89% sawdust + 10% oil palm kernel meal + 1% Ca(OH2 was 202.12 g/bag (B.E. = 60.79% during 120 days of havesting time. Addition of higher concentration of oil palm kernel meal (15-20% did not increase yield of the basidiocarps.

  3. Toxic effects and bioaccumulation of nano-, micron-, and ionic-Ag on the polychaete, Nereis diversicolor

    Cong, Yi; Banta, Gary Thomas; Selck, Henriette;

    2011-01-01

    ionic (AgNO3)- Ag on the sediment-dwelling polychaete, Nereis diversicolor, were compared after 10 days of sediment exposure, using survival, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, and 50 g Ag/g dry...

  4. FILTER-NET STRUCTURE AND PUMPING ACTIVITY IN THE POLYCHAETE NEREIS-DIVERSICOLOR - EFFECTS OF TEMPERATURE AND PUMP-MODELING

    Riisgård, H.U.; Vedel, A.; Boye, H.; Larsen, Poul Scheel

    1992-01-01

    Electron micrographs of the filter-net structure in the facultatively suspension-feeding polychaete Nereis diversicolor O. F. Muller showed that the net is composed of an irregular mesh-work made up of long, relatively thick filaments (up to 300 nm) interconnected with a variety of shorter and...

  5. A short-term sublethal in situ toxicity assay with Hediste diversicolor (Polychaeta) for estuarine sediments based on postexposure feeding.

    Moreira, Susana Maria; Moreira-Santos, Matilde; Guilhermino, Lúcia; Ribeiro, Rui

    2005-08-01

    This study evaluated a short-term sublethal endpoint for in situ toxicity assays for estuarine sediments, based on postexposure feeding of the polychaete Hediste (Nereis) diversicolor Müller. A method for precisely quantifying postexposure feeding rates of H. diversicolor was established under laboratory conditions using Artemia franciscana Kellog nauplii. The sensitivity of the postexposure feeding response to copper was investigated by comparing postexposure feeding rates to growth and lethality. The 48-h and 96-h median lethal concentration (LC50) of copper were 241 and 125 microg/L, respectively, whereas the 48-h median inhibitory concentration (IC50) for postexposure feeding and the 20-d IC50 for growth were 52 and 25 microg/L of copper, respectively. The influence of different exposure conditions (substrate, temperature, salinity, food availability, and light) on H. diversicolor postexposure feeding was assessed; temperature and salinity were found to influence significantly postexposure feeding. The effectiveness of the proposed in situ assay was investigated by deploying it at two reference and six contaminated Portuguese estuaries. A 48-h exposure period was followed by a 1-h postexposure feeding period. High organism recoveries (89-100%) were obtained. Postexposure feeding was depressed significantly (17-90%) at all contaminated sites relatively to reference sites. The proposed in situ assay with H. diversicolor was shown to be a potential useful tool for estuarine sediment toxicity testing. PMID:16152974

  6. Cellular internalization of silver nanoparticles in gut epithelia of the estuarine polychaete Nereis diversicolor.

    García-Alonso, Javier; Khan, Farhan R; Misra, Superb K; Turmaine, Mark; Smith, Brian D; Rainbow, Philip S; Luoma, Samuel N; Valsami-Jones, Eugenia

    2011-05-15

    Silver nanoparticles (AgNPs) are widely used which may result in environmental impacts, notably within aquatic ecosystems. As estuarine sediments are sinks for numerous pollutants, but also habitat and food for deposit feeders such as Nereis diversicolor, ingested sediments must be investigated as an important route of uptake for NPs. N. diversicolor were fed sediment spiked with either citrate capped AgNPs (30 ± 5 nm) or aqueous Ag for 10 days. Postexposure AgNPs were observed in the lumen of exposed animals, and three lines of evidence indicated direct internalization of AgNPs into the gut epithelium. With TEM, electron-dense particles resembling AgNPs were observed associated with the apical plasma membrane, in endocytotic pits and in endosomes. Energy dispersive X-ray analysis (EDX) confirmed the presence of Ag in these particles, which were absent in controls. Subcellular fractionation revealed that Ag accumulated from AgNPs was predominantly associated with inorganic granules, organelles, and the heat denatured proteins; whereas dissolved Ag was localized to the metallothionein fraction. Collectively, these results indicate separate routes of cellular internalization and differing in vivo fates of Ag delivered in dissolved and NP form. For AgNPs an endocytotic pathway appears to be a key route of cellular uptake. PMID:21517067

  7. Sediment-worm interaction: transfer of 65Zn from marine silt by the polychaete, Nereis diversicolor

    Marine polychaete worms (Nereis diversicolor) accumulated 65Zn sorbed to silty marine sediment for 5 days and were then transferred to nonradioactive sediment in the laboratory and in the sea. The mean biological half-life (T/sub B//2/) for the laboratory worms did not differ greatly from that for worms in the sea. Worms living in small flowing seawater systems containing 16 cm3 of sediment accumulated 65Zn added to each system in the form of radioactive organic detritus. Higher percentage uptake of 65Zn was from radioactive detritus particles 0.2 to 2 mm in diameter resting on the sediment surface or mixed with sediment than from finely-ground (65Zn coprecipitated from fresh water with Fe(OH)3 was accumulated by N. diversicolor when the precipitate was on the sediment surface than when the precipitate was well mixed with the sediment. These experimental results indicate that benthic organisms may take up limited amounts of heavy metals associated with bottom sediments and recycle them to benthic and pelagic food webs

  8. Distribution and production of the polychaete Nereis diversicolor in a shallow coastal lagoon in the Bay of Cádiz (SW Spain)

    Arias, Alberto M.; Drake, Pilar

    1995-01-01

    [EN] The temporal and spatial distribution and production of Nereis diversicolor in a semi-natural lagoon system were studied by taking monthly samples at 4 sites during two years. The numerical abundance and biomass, with mean annual estimates of 1886 ind.m-2 and 4.6 g AFDW. m-2 respectively for the whole studied system, showed considerable interseason and intersite variations. The lowest N. diversicolor density was recorded at the most confined lagoonal area. Seasonal patterns for the numer...

  9. Mechanism of Fluorescence and Conformational Changes of the Sarcoplasmic Calcium Binding Protein of the Sand Worm Nereis diversicolor upon Ca2+ or Mg2+ Binding

    Sillen, Alain; Verheyden, Stefan; Delfosse, Lotte; Braem, Tania; Robben, Johan; Volckaert, Guido; Engelborghs, Yves

    2003-01-01

    The calcium-binding protein isolated from the sarcoplasm of the muscles of the sand worm Nereis diversicolor has four EF-hands and three active binding sites for Ca2+ or Mg2+. Nereis diversicolor sarcoplasmic calcium-binding protein contains three tryptophan residues at positions 4, 57, and 170, respectively. The Wt protein shows a very limited fluorescence increase upon binding of Ca2+ or Mg2+. Single-tryptophan-containing mutants were produced and purified. The fluorescence titrations of th...

  10. A neurotropic herpesvirus infecting the gastropod, abalone, shares ancestry with oyster herpesvirus and a herpesvirus associated with the amphioxus genome

    Sawbridge Tim

    2010-11-01

    Full Text Available Abstract Background With the exception of the oyster herpesvirus OsHV-1, all herpesviruses characterized thus far infect only vertebrates. Some cause neurological disease in their hosts, while others replicate or become latent in neurological tissues. Recently a new herpesvirus causing ganglioneuritis in abalone, a gastropod, was discovered. Molecular analysis of new herpesviruses, such as this one and others, still to be discovered in invertebrates, will provide insight into the evolution of herpesviruses. Results We sequenced the genome of a neurotropic virus linked to a fatal ganglioneuritis devastating parts of a valuable wild abalone fishery in Australia. We show that the newly identified virus forms part of an ancient clade with its nearest relatives being a herpesvirus infecting bivalves (oyster and, unexpectedly, one we identified, from published data, apparently integrated within the genome of amphioxus, an invertebrate chordate. Predicted protein sequences from the abalone virus genome have significant similarity to several herpesvirus proteins including the DNA packaging ATPase subunit of (putative terminase and DNA polymerase. Conservation of amino acid sequences in the terminase across all herpesviruses and phylogenetic analysis using the DNA polymerase and terminase proteins demonstrate that the herpesviruses infecting the molluscs, oyster and abalone, are distantly related. The terminase and polymerase protein sequences from the putative amphioxus herpesvirus share more sequence similarity with those of the mollusc viruses than with sequences from any of the vertebrate herpesviruses analysed. Conclusions A family of mollusc herpesviruses, Malacoherpesviridae, that was based on a single virus infecting oyster can now be further established by including a distantly related herpesvirus infecting abalone, which, like many vertebrate viruses is neurotropic. The genome of Branchiostoma floridae (amphioxus provides evidence for the

  11. Ultrastructural aspects of Ellipsomyxa mugilis (Myxozoa: Ceratomyxidae) spores and developmental stages in Nereis diversicolor (Polychaeta: Nereidae).

    Rangel, Luis Filipe; Azevedo, Carlos; Casal, Graça; Santos, Maria João

    2012-06-01

    The ultrastructure of the spores and developmental stages of Ellipsomyxa mugilis in Nereis diversicolor were studied by transmission electron microscopy. The ultrastructure features and the developmental stages show many similarities with the general pattern described for other actinospores. However, several new features are definitely worth noting. For example, tetranucleated cells precede the formation of the initial pansporocyst, which preserves the 2 original enveloping cells until the end of sporogony. In the initial stages of sporogony, the future sporoplasm cell acquires the first secondary cell by an engulfment process. In the final stage of sporogony, spores are formed by a sporoplasm with 2 secondary cells and 1 somatic nucleus, and the polar capsule has a polar filament with a helicoidal arrangement possessing 7-8 coils. PMID:22263603

  12. Bioakkumulering af nanosølv og mikrosølv i Nereis diversicolor

    Knudsen, Birgitte Bendiks; Beyer, Thomas Sonne; Hansen, Louise Pigonska

    2009-01-01

    Abstrakt I dette projekt er forskellen i bioakkumulering af nanosølv og mikrosølv undersøgt hos børsteormen Nereis diversicolor. Eksponeringen foregik med nanosølvpartikler (100 nm) og mikrosølvpartikler (1000 nm) ved en koncentration på 100 µg/L. Der blev udført en vandeksponering samt en sedimenteksponering med både nanosølv såvel som mikrosølv, således at effekten af sedimentet på partiklerne kunne observeres. Forsøget viste via af AAS målinger en svag tendens til at nanosølv ved vande...

  13. The polychaete worm Nereis diversicolor increases mercury lability and methylation in intertidal mudflats.

    Sizmur, Tom; Canário, João; Edmonds, Samuel; Godfrey, Adam; O'Driscoll, Nelson J

    2013-08-01

    The polychaete worm Nereis diversicolor engineers its environment by creating oxygenated burrows in anoxic intertidal sediments. The authors carried out a laboratory microcosm experiment to test the impact of polychaete burrowing and feeding activity on the lability and methylation of mercury in sediments from the Bay of Fundy, Canada. The concentration of labile inorganic mercury and methylmercury in burrow walls was elevated compared to worm-free sediments. Mucus secretions and organic detritus in worm burrows increased labile mercury concentrations. Worms decreased sulfide concentrations, which increased Hg bioavailability to sulfate-reducing bacteria and increased methylmercury concentrations in burrow linings. Because the walls of polychaete burrows have a greater interaction with organisms, and the overlying water, the concentrations of mercury and methylmercury they contain is more toxicologically relevant to the base of a coastal food web than bulk samples. The authors recommend that researchers examining Hg in marine environments account for sediment dwelling invertebrate activity to more fully assess mercury bioavailability. PMID:23633443

  14. Immunofluorescence analysis of the internal brain anatomy of Nereis diversicolor (Polychaeta, Annelida).

    Heuer, C M; Loesel, R

    2008-03-01

    Comparative analyses of neuroanatomical characters can make valuable contributions to the inference of phylogenetic relationships. Whereas investigations in this field are numerous for arthropods, in-depth studies on other protostomes are sparse. Here, we provide a survey of the internal neuroarchitecture of the brain of the aciculate ragworm Nereis diversicolor (Polychaeta, Annelida). Descriptions are based on confocal laser scanning microscope analyses of brain sections labeled with the nuclear marker DAPI and antibodies raised against FMRF-amide, serotonin, and histamine. Autofluorescence of the nervous tissue has been utilized to further elucidate the anatomical structures of the brain. The architecture of two major brain compartments, i.e., the paired mushroom bodies and the central optic neuropil, is described in detail. The findings are compared with existent literature on polychaete neuroanatomy and on arthropod neuroanatomy, and possible phylogenetic implications are outlined. PMID:18071754

  15. From biomarkers to population responses in Nereis diversicolor: assessment of stress in estuarine ecosystems.

    Durou, Cyril; Smith, Brian D; Roméo, Michèle; Rainbow, Philip S; Mouneyrac, Catherine; Mouloud, Mohamed; Gnassia-Barelli, Mauricette; Gillet, Patrick; Deutch, Bruno; Amiard-Triquet, Claude

    2007-03-01

    Suborganismal responses to toxicants can be sensitive tools to assess marine pollution, but their ecological significance is a matter of debate. Among these biomarkers, those linked to reproduction are most probably related to populational effects. To test this hypothesis, Nereis diversicolor were collected in the multipolluted Seine estuary and the comparatively clean Authie estuary (France). Energy reserves were higher in Authie worms, suggesting a better physiological status. The number of oocytes per female was higher for the polychaetes from the Authie, but it was related to the size of animals, which was higher at this site. Densities of worms were depleted in the Seine compared to those in Authie. Demographic structure of the Seine population was also altered. The concomitant changes in energy reserves, egg production, and population structure and density suggest that the effects on biomarkers and at the population level are related. PMID:16620980

  16. A novel methodology for the determination of biomarker baseline levels in the marine polychaete Hediste diversicolor.

    Barrick, A; Châtel, A; Marion, J-M; Perrein-Ettajani, H; Bruneau, M; Mouneyrac, C

    2016-07-15

    Identifying environmental damage due to anthropogenic activities is a focal point for scientists and policy makers like those involved in the European Water Framework Directive (WFD). Many of these approaches focus on ecological endpoints for assessing environmental perturbations, which lead to policies emphasizing mitigation rather than prevention. Biomarkers provide early-warning indicators of stress but it is necessary to distinguish their natural variations from those induced by chemical stress. The global aim of this study was to establish a baseline assessment criterion (BAC) using historical data in a reference site to define toxicity thresholds. We have developed a multiple polynomial regression model (MPR) accounting the influence of salinity, temperature and size of individual on energetic reserves (glycogen and lipids) in the marine polychaete Hediste diversicolor. The model identified a complex, orthogonal relationship between confounding factors and glycogen and a linear relationship between lipids and size of individuals. PMID:27184131

  17. The effects of the polychaete Nereis diversicolor on the distribution and transplanting success of Zostera noltii

    Hughes, R. G.; Lloyd, D.; Ball, L.; Emson, D.

    2000-07-01

    Loss of saltmarsh vegetation in south-east England is a significant problem for conservation and coastal defence. The losses of vegetation began in the 1930s with the loss of intertidal Zostera marina and have continued more recently. Some preliminary trials at re-establishing Zostera in some estuaries of Essex have not been successful. This paper addresses the hypothesis that the infauna, particularly the polychaete Nereis diversicolor, may restrict natural colonisation by Zostera and reduce the success of transplanting trials. In field experiments, Z. noltii were transplanted into areas where Nereis were common, close to an established seagrass bed and into two other estuaries. The transplants protected from the effects of the polychaetes by netting had a higher survival rate, lower index of root damage and greater biomass at the end of the experiments than those that were unprotected. In laboratory experiments, Nereis reduced the survival of Z. noltii. They were observed grasping the leaves and pulling them into their burrows. These results indicate that herbivory and disturbance by N. diversicolor is responsible, at least in part, for the restriction of the distribution of Z. noltii and may have been important in limiting the success of previous transplanting experiments. A hypothesis is proposed which states that there are two stable states on the upper mud-flats. One state is dominated by plants, including Zostera spp., which prevent colonisation by burrowing infauna, and the other is dominated by infauna which prevent colonisation by plants. Managing these two states could be the key to re-establishing the early successional stages of saltmarsh development.

  18. Toxic effects and bioaccumulation of nano-, micron- and ionic-Ag in the polychaete, Nereis diversicolor.

    Cong, Yi; Banta, Gary T; Selck, Henriette; Berhanu, Deborah; Valsami-Jones, Eugenia; Forbes, Valery E

    2011-10-01

    There is increasing concern about the toxicities and potential risks, both still poorly understood, of silver nanoparticles for the aquatic environment after their eventual release via wastewater discharges. In this study, the toxicities of sediment associated nano (Nereis diversicolor, were compared after 10 days of sediment exposure, using survival, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, and 50 μg Ag/g dry weight (dw) sediment. Our results showed that Ag was able to cause DNA damage in Nereis coelomocytes, and that this effect was both concentration- and Ag form-related. There was significantly greater genotoxicity (higher tail moment and tail DNA intensities) at 25 and 50 μg/g dw in nano- and micron-Ag treatments and at 50 μg/g dw in the ionic-Ag treatment compared to the controls (0μg/g dw). The nano-Ag treatment had the greatest genotoxic effect of the three tested Ag forms, and the ionic-Ag treatment was the least genotoxic. N. diversicolor did accumulate sediment-associated Ag from all three forms. Ag body burdens at the highest exposure concentration were 8.56 ± 6.63, 6.92 ± 5.86 and 9.86 ± 4.94 μg/g dw for worms in nano-, micron- and ionic-Ag treatments, respectively, but there was no significant difference in Ag bioaccumulation among the three treatments. PMID:21831346

  19. 杂色鲍碱性磷酸酶在DMSO溶液中的活力与构象变化的研究%Effect of Dimethyl Sulfxide (DMSO) on Activity and Conformation of Alkaline Phosphatase from Haliotis diversicolor

    陈巧; 洪燕飞; 廖金花; 陈清西

    2005-01-01

    以二甲亚砜(DMSO)为效应物,研究其对杂色鲍碱性磷酸酶(ALP)活力的影响.结果表明:该酶的剩余活力随着DMSO浓度增大而迅速下降,当DMSO浓度达40%,酶活力几乎完全丧失.说明DMSO对杂色鲍ALP有明显的失活作用.导致酶活力丧失50%的DMSO浓度为17%.在较低DMSO浓度(<20%)的失活是可逆的反应过程.动力学研究表明.该酶的失活过程属于混合型.进一步测定游离酶(E)和酶底物络合物(ES)与DMSO的结合常数(K1和K1s),结果表明K1<K1s,说明底物存在对酶被DMSO的失活作用有一定的保护作用.应用荧光发射光谱研究杂色鲍ALP经DMSO微扰后的分子构象变化情况.随着DMSO浓度增大,荧光强度逐渐增强,但发射峰未发生明显变化现象,说明酶分子中的生色基团残基的微环境发生了一定的变化.

  20. An experimental study of the retention of zinc 65 by sediment and polychaete annelids (Nereis diversicolor Muller)

    Zinc 65 is a radionuclide with an intermediate half-life (245 days). It is an isotope of a biological trace element which can be found in some liquid wastes released by nuclear facilities. The first part of the paper concerns zinc 65 transfer from water to sediment. This process is essentially characterised by its rapidity and intensity. After 48 hours water loses 50% of its activity and transfer reaches 100% beyond the 20th day. Zinc 65 is strongly bound to the sediment and its desorption is almost non-existent. The second part reports the results about zinc 65 contamination of Nereis diversicolor, a species which can be considered as a vehicle of recirculation for the radionuclide fixed in the sediment. This assumption is partly verified although zinc 65 accumulation by Nereis diversicolor from water is 20 times more important than from sediment

  1. Influence of anthropogenic stress on fitness and behaviour of a key-species of estuarine ecosystems, the ragworm Nereis diversicolor.

    Mouneyrac, C; Perrein-Ettajani, H; Amiard-Triquet, C

    2010-01-01

    Fitness, (biometric measurements, reproduction) and behaviour that are ecologically relevant biomarkers in assessing the quality of estuarine sediments were studied by comparing the responses of the polychaete worm Nereis diversicolor--a key species in estuaries--along a pollution gradient. Intersite differences were shown for all the measured parameters: size-weight relationships, energy reserves as glycogen and lipids, sexual maturation patterns, total number of oocytes per female, total and relative fecundity, burrowing behaviour. The physiological and behavioural status of N. diversicolor was consistently disturbed in the larger, most contaminated estuaries (Loire and Seine, Fr.) compared to reference sites (Bay of Bourgneuf, Goyen estuary, Fr.). Many classes of potentially toxic chemicals present in these estuaries most likely contribute to these impairments but food availability may act as a confounding factor, interfering with the potential impact of contaminants. PMID:19665272

  2. The in vitro influence of the burrowing polychaete Nereis diversicolor on the fate of petroleum hydrocarbons in marine sediments

    Gilbert, Franck; Rivet, Lucien; Bertrand, Jean-Claude

    1994-01-01

    International audience The in vitro fate of the saturated hydrocarbon fraction (SF) of Arabian Light crude oil has been studied in PVC cores filled with a coastal marine sediment defaunated by sieving. Experiments were conducted in absence or presence of polychaetes Nereis diversicolor. The luminophore tracer technique was used to quantify the mixing of sediment by worms. Presence of crude oil reduced the building of burrows by polychaetes. This work demonstrates the ability of infaunal or...

  3. Croissance de juvéniles de Nereis diversicolor nourris avec des détritus d'halophytes

    Meziane, T; Retiere, C

    2002-01-01

    The comparative effect of the uptake of fresh and degraded detritus of halophytic plants, harvested from salt marches of the Mont Saint-Michel Bay (France), on the growth of a juvenile population of the annelid polychaete N. diversicolor (L.) was studied under experimental conditions in summer 1993. Fresh and degraded detritus of Spartina anglica, Halimione portulacoides and Salicornia europeae, as well as the green algae Enteromorpha sp. were distributed separately to homogenous set of juven...

  4. Characterization of specificity of bacterial community structure within the burrow environment of the marine polychaete Hediste (Nereis) diversicolor

    Pischedda, Laura; Militon, Cécile; Gilbert, Franck; Cuny, Philippe

    2011-01-01

    Bioturbation is known to stimulate microbial communities, especially in macrofaunal burrows where the abundance and activities of bacteria are increased. Until now, these microbial communities have been poorly characterized and an important ecological question remains: do burrow walls harbor similar or specific communities compared with anoxic and surface sediments? The bacterial community structure of coastal sediments inhabited by the polychaete worm Hediste diversicolor was investigated. S...

  5. Biomarkers in Nereis diversicolor (Polychaeta: Nereididae) as management tools for environmental assessment on the southwest Iberian coast

    Gomes, Tania; González-Rey, María; Rodríguez-Romero, Araceli; Trombini, Chiara; Riba, Inmaculada; Blasco, Julián; Bebianno, Maria João

    2013-01-01

    [EN] The environmental quality of the southwest Iberian coast was assessed in different areas (Ria Formosa Lagoon, Guadiana Estuary and Cádiz Bay) focusing on metal contamination (Cd, Cu, Ni, Pb and Zn) in Nereis diversicolor whole tissues. In addition, associated toxicological effects were assessed using a multibiomarker approach combining several conventional biomarkers. The set of biomarkers selected included antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase), ...

  6. Assessment of the health status of populations of the ragworm Nereis diversicolor using biomarkers at different levels of biological organisation

    Kalman, Judit; Palais, F.; Amiard, J.C.; Mouneyrac, C; Muntz, A.; Blasco, Julián; Riba, Inmaculada; Amiard-Triquet, C.

    2009-01-01

    We compared behavioural (burrowing speed), biochemical (acetylcholinesterase [AChE] inhibition, activities of digestive enzymes) and physiological (feeding and egestion rates, condition) responses in Nereis diversicolor originating from a multipolluted estuary (Loire estuary) and a relatively clean site (Bay of Bourgneuf) on 3 occasions during spring 2008. Significant inhibition of AChE and digestive enzymes (amylase and carboxymethylcellulase) activities were recorded in individuals from the...

  7. The regulation of copper stress response genes in the Polychaete Nereis diversicolor during prolonged extreme copper contamination

    McQuillan, Jonathan S.; Kille, Peter; Powell, Kate; Galloway, Tamara S.

    2014-01-01

    Polychaetes are frequented in toxicological studies, one reason being that some members occupy shallow burrows in sediments and are maximally exposed to the contaminants that accumulate within them. We have been studying one population of the polychaete Nereis (Hediste) diversicolor exhibiting inheritable tolerance to extreme copper contamination in estuarine sediment. Using transcriptome sequencing data we have identified a suite of genes with putative roles in metal detoxification and toler...

  8. Smelling danger - alarm cue responses in the polychaete Nereis (Hediste) diversicolor (Müller, 1776) to potential fish predation.

    Schaum, C Elisa; Batty, Robert; Last, Kim S

    2013-01-01

    The harbour ragworm, Nereis (Hediste) diversicolor is a common intertidal marine polychaete that lives in burrows from which it has to partially emerge in order to forage. In doing so, it is exposed to a variety of predators. One way in which predation risk can be minimised is through chemical detection from within the relative safety of the burrows. Using CCTV and motion capture software, we show that H. diversicolor is able to detect chemical cues associated with the presence of juvenile flounder (Platichthys flesus). Number of emergences, emergence duration and distance from burrow entrance are all significantly reduced during exposure to flounder conditioned seawater and flounder mucous spiked seawater above a threshold with no evidence of behavioural habituation. Mucous from bottom-dwelling juvenile plaice (Pleuronectes platessa) and pelagic adult herring (Clupea harengus) elicit similar responses, suggesting that the behavioural reactions are species independent. The data implies that H. diversicolor must have well developed chemosensory mechanisms for predator detection and is consequently able to effectively minimize risk. PMID:24155953

  9. Smelling Danger – Alarm Cue Responses in the Polychaete Nereis (Hediste) diversicolor (Müller, 1776) to Potential Fish Predation

    Schaum, C. Elisa; Batty, Robert; Last, Kim S.

    2013-01-01

    The harbour ragworm, Nereis (Hediste) diversicolor is a common intertidal marine polychaete that lives in burrows from which it has to partially emerge in order to forage. In doing so, it is exposed to a variety of predators. One way in which predation risk can be minimised is through chemical detection from within the relative safety of the burrows. Using CCTV and motion capture software, we show that H. diversicolor is able to detect chemical cues associated with the presence of juvenile flounder (Platichthys flesus). Number of emergences, emergence duration and distance from burrow entrance are all significantly reduced during exposure to flounder conditioned seawater and flounder mucous spiked seawater above a threshold with no evidence of behavioural habituation. Mucous from bottom-dwelling juvenile plaice (Pleuronectes platessa) and pelagic adult herring (Clupea harengus) elicit similar responses, suggesting that the behavioural reactions are species independent. The data implies that H. diversicolor must have well developed chemosensory mechanisms for predator detection and is consequently able to effectively minimize risk. PMID:24155953

  10. Pollution biomarkers in two estuarine invertebrates, Nereis diversicolor and Scrobicularia plana, from a Marsh ecosystem in SW Spain.

    Solé, Montserrat; Kopecka-Pilarczyk, Justyna; Blasco, Julián

    2009-04-01

    The polychaete worm Nereis diversicolor and the clam Scrobicularia plana were collected from several sites, affected by different types of contamination, in a littoral enclosure in the SW Spain (Caño Sancti-Petri and Rio San Pedro). N. diversicolor was present in 6 sampling sites whereas S. plana in 4 of them. The aim of our study was to relate several pollution biomarkers to chemical sources (metals and organic pollutants e.g. PCB, PAH) in these species, thereby confirming their adequacy as sentinels for this habitat. The biomarkers surveyed in the two invertebrates were the activities of the antioxidant enzyme catalase (CAT), the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE). Metallothionein (MT) levels were measured as a biomarker of exposure to metals. The results suggested a different response in the two sediment-dwelling organisms, the sediment-eating polychaete and the water-filtering clam, probably as a consequence of different contamination exposures. The results also suggested that samples from the "Caño Sancti-Petri" were exposed to biologically active compounds that altered some of their biochemical responses. Of all the biomarkers tested, AChE was the most sensitive one and N. diversicolor the potentially most robust sentinel in this ecosystem. In this low to moderately polluted environment, the biochemical approach better reflected temporal trends than site-related differences although it was also able to detect punctual chemical insults. PMID:19010546

  11. A neurotropic herpesvirus infecting the gastropod, abalone, shares ancestry with oyster herpesvirus and a herpesvirus associated with the amphioxus genome

    Sawbridge Tim; Wong Frank; Cocks Benjamin G; Savin Keith W; Cogan Noel; Savage David; Warner Simone

    2010-01-01

    Abstract Background With the exception of the oyster herpesvirus OsHV-1, all herpesviruses characterized thus far infect only vertebrates. Some cause neurological disease in their hosts, while others replicate or become latent in neurological tissues. Recently a new herpesvirus causing ganglioneuritis in abalone, a gastropod, was discovered. Molecular analysis of new herpesviruses, such as this one and others, still to be discovered in invertebrates, will provide insight into the evolution of...

  12. Remedial habitat creation: does Nereis diversicolor play a confounding role in the colonisation and establishment of the pioneering saltmarsh plant, Spartina anglica?

    Emmerson, M.

    2000-07-01

    Increasing concerns over global warming and expected sea level rises have led to the adoption of new coastal management strategies around the south-east coast of England. This paper explores the role played by the estuarine invertebrate Nereis diversicolor in limiting the colonisation and establishment of the invasive pioneering salt marsh plant, Spartina anglica. The biology of N. diversicolor is briefly reviewed and data from field experiments are presented demonstrating significant negative effects of worm abundance on transplanted S. anglica biomass. Laboratory-based experiments demonstrated significant negative effects of N. diversicolor abundance on the survival of S. anglica seeds transplanted to sediment cores. The importance of estuarine invertebrates in engineering the mudflat habitat may confound the foreseen ecosystem services and function provided by saltmarsh management schemes.

  13. Toxic effects and bioaccumulation of nano-, micron- and ionic-Ag in the polychaete, Nereis diversicolor

    cong, Yi; Banta, Gary Thomas; Selck, Henriette; Berhanu, Deborah; Valsami-Jones, Eugenia; Forbes, Valery E.

    There is increasing concern about the toxicities and potential risks, both still poorly understood, of silver nanoparticles for the aquatic environment after their eventual release. In this study, the toxicities of nano (< 100 nm)-, micron (2-3.5 µm)- and ionic (AgNO3)-Ag on the sediment...... cause DNA damage in Nereis coelomocytes and that this effect is both concentration- and Ag form-related. There were significantly greater genotoxity (higher tail moment and tail DNA intensities) at 25 and 50 µg/g dw in nano- and micron-Ag treated groups and at 50 µg/g dw in ionic-Ag treated group...... compared to the controls (0 µg/g dw). Nano-Ag has the greatest genotoxic effect of the three tested Ag forms and ionic-Ag is the least genotoxic, indicating different mechanisms are possibly involved to cause DNA damage by the different Ag forms. N. diversicolor did accumulate sediment-associated Ag from...

  14. Toxicity and bioaccumulation of sediment-associated silver nanoparticles in the estuarine polychaete, Nereis (Hediste) diversicolor.

    Cong, Yi; Banta, Gary T; Selck, Henriette; Berhanu, Deborah; Valsami-Jones, Eugenia; Forbes, Valery E

    2014-11-01

    In this study, the toxicities of sediment-associated silver added to sediment as commercially available silver nanoparticles (Ag NPs, 20 and 80 nm) and aqueous Ag (AgNO3) to the estuarine polychaete, Nereis (Hediste) diversicolor, were investigated for both individual and subcellular endpoints after 10 d of exposure. Both Ag NP types were characterized in parallel to the toxicity studies and found to be polydispersed and overlapping in size. Burrowing activity decreased (marginally) with increasing Ag concentration and depended on the form of Ag added to sediment. All worms accumulated Ag regardless of the form in which it was added to the sediment, and worm size (expressed as dry weight) was found to significantly affect bioaccumulation such that smaller worms accumulated more Ag per body weight than larger worms. Lysosomal membrane permeability (neutral red retention time, NRRT) and DNA damage (comet assay tail moment and tail DNA intensity %) of Nereis coelomocytes increased in a concentration-dependent manner in all three Ag treatments. Ag NP treatments were more toxic than aqueous Ag for all toxicity endpoints, even though bioaccumulation did not differ significantly among Ag forms. No significant difference in toxicity was observed between the two Ag NP treatments which was attributed to their overlap in particle size. PMID:25179147

  15. Stimulation by cadmium of myohemerythrin-like cells in the gut of the annelid Nereis diversicolor.

    Demuynck, Sylvain; Bocquet-Muchembled, Beatrice; Deloffre, Laurence; Grumiaux, Fabien; Leprêtre, Alain

    2004-03-01

    Isolated guts of Nereis diversicolor revealed the existence of a cadmium-binding protein, the MPII, belonging to the group of hemerythrins and myohemerythrins. The presence of MPII in the cells of the intestine was demonstrated by immunocytochemistry, using anti-MPII, a monoclonal antibody. In addition, using in situ hybridization and northern blotting, it was shown that MPII-cells are the site of synthesis of this molecule. Exposure of the worms to cadmium led to the cellular activation process of MPII-cells (i.e. transformation of the nucleolus, development of the endoplasmic reticulum and the Golgi apparatus), although MPII mRNA transcript levels were unchanged. Enzyme-linked immunosorbent assay (ELISA) of gut extracts revealed that MPII levels were increased after exposure to Cd, so it appears that this protein is synthesized as a response to Cd exposure without any new synthesis of mRNA. This mechanism of regulation is quite similar to that reported in the case of mammalian ferritin and may be involved in the regulation of Cd levels in this worm. PMID:14978053

  16. 1-Hydroxypyrene as a biomarker of PAH exposure in the marine polychaete Nereis diversicolor.

    Tairova, Zhanna M; Giessing, Anders M B; Hansen, Rikke; Andersen, Ole

    2009-02-01

    The possibility of using the pyrene metabolite 1-hydroxypyrene as a biomarker of polycyclic aromatic hydrocarbons (PAHs) exposure was investigated by exposure of the marine polychaete Nereis diversicolor to several PAHs in the laboratory. Animals were exposed to pyrene alone and to five different PAHs - phenanthrene, anthracene, pyrene, benzo[a]pyrene and benzo[k]flouranthene. After five days of exposure the concentrations of parent PAHs and 1-hydroxypyrene were identified using three different analytical methods, high-performance liquid chromatography with fluorescence detection (HPLC/F), synchronous fluorescence spectroscopy (SFS) and gas chromatography with mass spectrometric detection (GC/MS). The SFS measurements of 1-hydroxypyrene were validated by the more sensitive method HPLC/F. The positive correlation between total PAHs and 1-hydroxypyrene concentrations in the polychaete tissues observed in experiments, suggests the feasibility of 1-hydroxypyrene as a suitable biomarker for total PAH exposure assessment. Furthermore, the possibility of employment of the simple and rapid SFS method instead of HPLC/F for biomarker analysis has been confirmed by the positive and significant correlation between results achieved by these two analytical methods. PMID:19058843

  17. The metabolic and fitness costs associated with metal resistance in Nereis diversicolor.

    Pook, Chris; Lewis, Ceri; Galloway, Tamara

    2009-07-01

    The population of Nereis diversicolor inhabiting the upper reaches of Restronguet Creek, Cornwall, UK is highly resistant to acute zinc and copper toxicity. Here we employ bioenergetic accounting and fecundity counts to demonstrate the energetic costs associated with this phenomenon in terms of the worms' allocation of metabolic resources and reproductive output [P(r)]. Metal-resistant animals exhibited a scope for growth that was 46-62% less than that of animals from two non-resistant reference populations, corresponding to a mean metabolic cost of 1.31 mJ h(-1)mg DW(-1). The resistant population also contained 13% less lipid than animals from the reference populations and 73-81% less carbohydrates. Consequently, mass-specific fecundity was reduced in resistant animals by 39-45%, although material investment in individual gametes did not appear to vary. This demonstrates fitness costs associated with metal resistance in this ecologically important polychaete and adds to our understanding of phenotypic trade-offs associated with resistance. PMID:19285693

  18. Total mercury and methylmercury in sediments and in the polychaete Nereis diversicolor at Groot Buitenschoor (Scheldt estuary, Belgium)

    Muhaya, B.B.M.; Leermakers, M; Baeyens, W.F.J.

    1997-01-01

    Total mercury (Hg) and methylmercury (MeHg) concentrations were determined in sediments and in the polychaete worm Nereis diversicolor at 13 stations of a brackish water intertidal mudflat of the Scheldt estuary. Hg and MeHg concentrations in sediments ranged from 144 to 1192 ng g(-1) dw and from 0.8 to 6 ng g(-1) dw, respectively. Both Hg and MeHg concentrations increased with an increase of organic matter (OM) content and fine grain fraction. In contrast, Hg accumulation by N. diversicolor ...

  19. FILTER-NET STRUCTURE AND PUMPING ACTIVITY IN THE POLYCHAETE NEREIS-DIVERSICOLOR - EFFECTS OF TEMPERATURE AND PUMP-MODELING

    Riisgård, H.U.; Vedel, A.; Boye, H.; Larsen, Poul Scheel

    1992-01-01

    Electron micrographs of the filter-net structure in the facultatively suspension-feeding polychaete Nereis diversicolor O. F. Muller showed that the net is composed of an irregular mesh-work made up of long, relatively thick filaments (up to 300 nm) interconnected with a variety of shorter and thinner filaments. The thinner filaments range in diameter from 5 to >25 nm. The average size of the meshes, measured directly on the micrographs, lies between 0.5 and 1.0-mu-m, but due to shrinkage ...

  20. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    Coppersmith, S N; Gilbert, P U P A; Metzler, R A [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2009-03-27

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400 nm thick aragonite crystalline tablets confined by organic matrix sheets, with the [0 0 1] crystal axes of the aragonite tablets oriented to within {+-}12 deg. from the normal to the layer planes. Recent experiments demonstrate that greater orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous simulations of a model in which the order develops because of differential tablet growth rates (oriented tablets growing faster than misoriented ones) yield patterns of tablets that agree qualitatively and quantitatively with the experimental measurements. This paper presents an analytical treatment of this model, focusing on how the dynamical development and eventual degree of order depend on model parameters. Dynamical equations for the probability distributions governing tablet orientations are introduced whose form can be determined from symmetry considerations and for which substantial analytic progress can be made. Numerical simulations are performed to relate the parameters used in the analytic theory to those in the microscopic growth model. The analytic theory demonstrates that the dynamical mechanism is able to achieve a much higher degree of order than naive estimates would indicate.

  1. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400 nm thick aragonite crystalline tablets confined by organic matrix sheets, with the [0 0 1] crystal axes of the aragonite tablets oriented to within ±12 deg. from the normal to the layer planes. Recent experiments demonstrate that greater orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous simulations of a model in which the order develops because of differential tablet growth rates (oriented tablets growing faster than misoriented ones) yield patterns of tablets that agree qualitatively and quantitatively with the experimental measurements. This paper presents an analytical treatment of this model, focusing on how the dynamical development and eventual degree of order depend on model parameters. Dynamical equations for the probability distributions governing tablet orientations are introduced whose form can be determined from symmetry considerations and for which substantial analytic progress can be made. Numerical simulations are performed to relate the parameters used in the analytic theory to those in the microscopic growth model. The analytic theory demonstrates that the dynamical mechanism is able to achieve a much higher degree of order than naive estimates would indicate

  2. The Relationships between Rheological Properties and Structural Changes of Chilled Abalone Meat

    GAO Xin; ZHANG Zhaohui; TANG Zhixu; TASHIRO Yuri; OGAWA Hiroo

    2003-01-01

    The quantitative correlation between theological properties and structural characteristic values of chilled abalone meat was studied. Structural changes were observed, and these values were enumerated using image processing and analysis technique. Structural changes in the myofibrils and collagen fibrils were the greatest in chilling for 24 h. After chilling for 48 h, similar structures of vertical and cross sections were observed. For chilling from 0h to 72h, the instantaneous modulus E0 of the both section meat decreases gradually with time, but no significant differences were observed after chilling for 48 h.The relaxation time and viscosity of both sections attained the same values for the same chilling time, but increased gradually with increasing chilling time. Meanwhile, a negative correlation between the structural characteristic values (Dm, Am,Rvm), and rheological properties (E1,τi,η1) clearly exists. Some logarithmic expressions have been obtained for these negative correlations. These results suggest that the difference in rheological properties between the cross and vertical sections was mainly due to the structural changes of myofibrils and collagen fibrils, and rheological properties are influenced quantitatively by the structural characteristic values for chilling from 0 h to 72 h.

  3. Limited microbial degradation of pyrene metabolites from the estuarine polychaete Nereis diversicolor.

    Giessing, Anders M B; Johnsen, Anders R

    2005-12-01

    We compared microbial mineralization of [4,5,9,10-14C]pyrene and its eukaryotic [4,5,9,10-14C]pyrene metabolites in estuarine sediments. Metabolites were obtained by exposing the estuarine deposit-feeding polychaete Nereis diversicolor to sediment-associated 14C-pyrene, followed by homogenization of the worms and extraction of the pyrene-metabolites. In sediment from a pristine Danish Fjord only 2.6% of the added metabolite-label and 1.7% of the pyrene-label were mineralized to 14CO2 during 175 days incubation. Pre-exposure of the pristine sediment to unlabelled pyrene for 60 days increased the mineralization potential for 14C-pyrene substantially, as 81.2% was mineralized to 14CO2 during 95 days incubation, whereas 14C-pyrene metabolite label was unaffected by pre-exposure to pyrene. In comparison, naturally aged bunker-oil contaminated sediment did not show elevated potentials for mineralization of neither 14C-pyrene nor 14C-metabolites. Six bacterial strains of known pyrene degraders were tested for growth on crystalline 1-hydroxypyrene. 1-Hydroxypyrene is the only intermediate eucaryotic metabolite of pyrene. The results indicate that 1-hydroxypyrene was not utilized as a sole source of carbon and energy by any of them. In addition, respiration was depressed in all six strains when exposed to crystalline 1-Hydroxypyrene, demonstrating an acute toxic effect of 1-hydroxypyrene. The results presented here suggest that microbial degradation of pyrene is not enhanced by release of aqueous and polar metabolites by marine invertebrates. PMID:15922404

  4. Why do Oystercatchers Haematopus ostralegus switch from feeding on Baltic tellin Macoma balthica to feeding on the ragworm Nereis diversicolor during the breeding season?

    Bunskoeke, EJ; Ens, BJ; Hulscher, JB; DeVlas, SJ

    1996-01-01

    Oystercatchers Haematopus ostralegus breeding on the isle of Schiermonnikoog in the Dutch Wadden Sea: switched from a diet dominated by the bivalve Macoma balthica in late spring to a diet dominated by the annelid worm Nereis diversicolor in early summer. Although all Oystercatchers switched, the ti

  5. Environmental quality assessment in estuarine ecosystems: use of biometric measurements and fecundity of the ragworm Nereis diversicolor (Polychaeta, Nereididae).

    Durou, Cyril; Mouneyrac, Catherine; Amiard-Triquet, Claude

    2008-04-01

    The ability to cope with environmental stress may be expensive in terms of energy and this cost of tolerance is suspected to have negative counterparts such as reduced growth and fecundity. To date, condition indices based on biometric measurements are currently used in bivalves or fish but do not exist in endobenthic worms, despite their interest as bioindicators for the sedimentary compartment in which the major part of pollutants is stored in aquatic environments. In the present work, several biometric variables (jaw and total body length, number of segments, the length of the first three segments L3, wet or dry weight) were measured in the ragworm Nereis diversicolor originating from clean (Authie) and polluted (Seine) estuaries (France) to study size-weight relationships. The production of oocytes by females (which represent 80-90% of the population) was quantified in the same specimens. In females from the polluted site, the condition was shown to be altered and, in parallel, the production of oocytes was lower than in females from the comparatively clean site. From an operational point of view, we recommend the use of the length L3 and the wet weight. Because fecundity is mainly dependent on size and weight in N. diversicolor, biometric measurements would be useful tools for assessing the biological quality of estuarine sediments. PMID:18160093

  6. Measurement of the adenylate energy charge in Nereis diversicolor and Nephtys sp. (Polychaeta: Annelida): evaluation of the usefulness of AEC in pollution monitoring

    Verschraegen, K.; Herman, P.M.J.; Van Gansbeke, D.; Braeckman, A.

    1985-01-01

    ATP-content and adenylate energy charge (AEC) ratios were determined in two polychaete species (Nereis diversicolor and Nephtys sp.), sampled in ten stations along the heavily polluted Western Scheldt estuary (N. Belgium, S. Holland). The samples were taken between 27 December 1982 and 6 January 1983. Nereis diversicolor was also sampled in an unpolluted brackish water pond, and subjected to artificial stress by drying the organisms on filter paper. Adenine nucleotide levels were determined u...

  7. Morphology, molecular data, and development of Zschokkella mugilis (Myxosporea, Bivalvulida) in a polychaete alternate host, Nereis diversicolor.

    Rangel, Luís F; Santos, Maria J; Cech, Gábor; Székely, Csaba

    2009-06-01

    The morphology of Zschokkella mugilis Sitjà-Bobadilla and Alvarez-Pellitero, 1993 (Myxosporea, Bivalvulida) in Nereis diversicolor O. F. Müller, 1776 is described for the first time. The molecular data show that the actinospore has 100% similarity to the myxospore of Z. mugilis. Fully mature actinospores are tri-radiate, the spore body has a small process, and the sporoplasm has 2 inner daughter cells. In the polychaete, the spores of the parasite develop in groups of 8 inside pansporocysts. The schizogony phase takes place in the intestinal epithelium, while gametogony and sporogony occur in the coelom of the polychaete. Observations indicate that mature spores are released only during the polychaete reproductive season. Infection was detected only in the winter and spring. In the Aveiro estuary (Portugal), the overall prevalence of infection of the polychaete was 0.5%. PMID:18939897

  8. Toxicants accumulation rates and effects in Mytilus trossulus and Nereis diversicolor exposed separately or together to cadmium and PAHs.

    Pempkowiak, Janusz; Pazdro, Ksenia; Kopecka, Justyna; Perez, Erkuden; Sole, Montserrat

    2006-01-01

    Two invertebrates, Mytilus trossulus and Nereis diversicolor, were exposed in aquaria to cadmium (50 microg L(-1)) and a mixture of three- to six-ring PAHs (2 microg L(-1) each) for 2 weeks. Organisms of two species were reared in separate tanks or together in the same one. Concentrations of Cd, PAHs and activities of selected biomarkers: catalase (CAT), glutathione S-transferase (GST) and acetylcholinesterase (AChE) were measured within 2 weeks of exposure. When reared separately, higher accumulation rates for cadmium were measured in mussels (16.4 microg day(-1) g(-1) d.w. lipid-free tissue) than in polychaeta (0.7 microg Cd g(-1) d.w day(-1)). When co-exposed, a difference in bioaccumulation was maintained but the accumulation rate in N. diversicolor increased to 1.0 microg Cd g(-1) d.w. day(-1) and decreased to 9.6 microg Cd g(-1) d.w. day(-1) in M. trossulus. On the contrary, faster bioaccumulation rates of PAHs were seen in polychaeta than in mussels when exposed separately (19.3 vs 4.5 microg PAHs day(-1) g(-1) lipid weight) than together (12.0 vs 3.1 microg PAHs g(-1) l.w. day(-1)). Substantial changes in the bioaccumulation patterns of the different M. trossulus organs were observed when both species were reared together. Biochemical responses indicated no effect of the accumulated contaminants on AChE, enhancement of CAT in both species and depletion of GST in Mytilus. The observed differences are discussed in terms of different bioavailability of contaminants, route of uptake and detoxification mechanism, under the two modes of exposure. PMID:17000547

  9. Esterases as biomarkers in Nereis (Hediste) diversicolor exposed to temephos and Bacillus thuringiensis var. israelensis used for mosquito control in coastal wetlands of Morbihan (Brittany, France).

    Fourcy, D; Jumel, A; Heydorff, M; Lagadic, L

    2002-01-01

    Since 1998, a biomonitoring programme has been implemented to assess the potential impact of chemical mosquito control on macroinvertebrates of the coastal wetlands of Morbihan (Brittany, France). Acetylcholinesterase and carboxylesterases were used as biomarkers to assess the effects of Abate 500e (a.i. temephos) and Vectobac 12 AS (a.i. endotoxins of Bacillus thuringiensis var. israelensis, Bti) in Nereis (Hediste) diversicolor. Esterase inhibition revealed a marked impact of temephos, suggesting preferential contamination of the worms through the food. In Bti-exposed N. diversicolor, random variations of esterase activities were observed, that could not be attributed to the larvicide. However, esterases only reflected indirect physiological effects of Bti, and further investigations are needed to identify biomarkers more specific of Bti endotoxins. PMID:12408646

  10. Polycyclic aromatic hydrocarbons in Haliotis tuberculata (Linnaeus, 1758) (Mollusca, Gastropoda): Considerations on food safety and source investigation.

    Conte, Francesca; Copat, Chiara; Longo, Sabrina; Conti, Gea Oliveri; Grasso, Alfina; Arena, Giovanni; Dimartino, Angela; Brundo, Maria Violetta; Ferrante, Margherita

    2016-08-01

    Polycyclic aromatic hydrocarbons were analyzed in wild specimens of Haliotis tuberculata from three sites of the Sothern Ionian Sea. The species Ht is commonly found at these sites and has significant commercial value. Main results revealed mean values of benzo(a)pyrene higher than the threshold set by Regulation No. 835/2011/EU in all sampling sites and the sum of selected PAHs, expressed as ΣPAH4 by EC Regulation, were below the limit set by the same Regulation in ME and VSG. We found generally higher concentrations than literature finding, especially for low molecular weight PAHs, and results of diagnostic ratios highlighted both pyrolytic and petrogenic sources. The potential human health risks due consumption of Ht by local inhabitants have been assessed by exposure daily intake (EDI), target hazard quotient (THQ) and lifetime cancer risk (CR). EDI values were below the intake range reviewed by EFSA for each class of contaminant. BaP daily intake was below the value of 10 ng/Kg/day, suggested by JFCFA, and CRBaP was slightly higher than the acceptable risk level (ARL) of 1×10(-5). Conversely, target hazard quotient (THQ) resulted always below 1, thus the risk to develop chronic systemic effects due naphthalene, acenaphthene, fluorene, anthracene, fluoranthene and pyrene was low. PMID:27235950

  11. Effects of population density on the sediment mixing induced by the gallery-diffusor Hediste (Nereis) diversicolor O.F. Müller, 1776

    Duport, Eric; Stora, Georges; Tremblay, Pierre; Gilbert, Franck

    2006-01-01

    The aim of this work was to quantify the intensity of sediment mixing induced by the gallery-diffusor (functional bioturbation group) Hediste diversicolor as a function of density, using particles tracers (luminophores). In order to assess the impact of density on sediment reworking, a 1-D model was used to obtain sediment reworking coefficients such as Db (biodiffusion-like) and r (biotransport). Densities used in this experiment corresponded to population densities observed in the sampling ...

  12. Response of Nereis diversicolor (Polychaeta, Nereidae) populations to reduced wastewater discharge in the polluted estuary of Oued Souss, Bay of Agadir, Morocco

    Ait Alla, A.; Gillet, P.; Deutsch, B.; Moukrim, A.; Bergayou, H.

    2006-12-01

    Field investigations on the population dynamics of Nereis diversicolor were carried out from January 2002 to December 2003 in the estuary of Oued Souss (southwestern Morocco) to determine the changes caused by setting up of a domestic and industrial wastewater purification plant (M'zar) before and after by the end of wastewater discharges in November 2002 on the structure of the ecosystem. Samples of N. diversicolor were collected monthly in the intertidal zone at low tide before (during 2002) and after (during 2003) the end of wastewater discharges. Separation of cohorts using the Algorithm EM method (McLachlan, G.J., Krishnan, T., 1997. The EM algorithm and extensions. Wiley Series in Probability and Statistics. Wiley, New York, 274 pp.) allowed determination of the growth rate (mm day -1) by cohort and the annual production. The data showed significant differences between populations of Nereis diversicolor before and after the end of wastewater discharges. During the wastewater discharge period (2002), the population had a mean annual density of 1992 ind m -2, a mean annual biomass of 75.52 g DW m -2 and an annual secondary production of 141.3 g DW m -2 with a P/ B ratio of 1.87. After the end of discharges (2003), density, biomass and secondary production decreased significantly. The annual averages for these parameters were 740 ind m -2, 14.16 g DW m -2 and 23.83 g DW m -2, respectively, with a P/ B ratio of 1.68. The important decrease observed in density, biomass and secondary production of Nereis diversicolor may be attributed (a) to the environmental changes observed after the end of wastewater discharges in the estuary of Oued Souss, namely the increase of salinity and the decrease of organic matter content, and (b) to the migration of this species towards other areas.

  13. Assessment of heavy metal contamination in Hediste diversicolor (O.F. Müller, 1776), Mugil cephalus (Linnaeus, 1758), and surface sediments of Bafa Lake (Eastern Aegean).

    Aydin-Onen, S; Kucuksezgin, F; Kocak, F; Açik, S

    2015-06-01

    In the present study, the bioaccumulation of six heavy metals (Cd, Cr, Cu, Hg, Pb, and Zn) in Hediste (Nereis) diversicolor (O.F. Müller, 1776) and also in the muscle and liver of Mugil cephalus (Linnaeus, 1758) collected from seven stations in the Bafa Lake was investigated. Sediment samples were also collected in each site to assess heavy metal levels and to provide additional information on pollution of the lake. The mean concentrations of heavy metals in sediment, H. diversicolor, and muscle and liver of the fish were found to be in the magnitude of Cr>Pb>Zn>Cu>Cd>Hg, Zn>Cu>Cr>Pb>Hg>Cd, Zn>Cu>Pb>Cr >Hg>Cd, and Cu>Zn>Cr>Cd>Pb>Hg, respectively. Hg, Cu, and Zn in H. diversicolor and Hg and Zn in muscle and also Hg, Cd, Cu, and Zn in liver of fish accumulated in a higher degree than in sediment. There was no clear relationship between metal concentrations in sediments, polychaetes, and fish, except Cr. According to international criteria and Turkish regulations, Pb and Zn values in edible muscle of the fish collected from stations S6 and S5 exceeded the food safety limits, respectively. The results of this study suggest that these sentinel species can be considered as good anthropogenic biological indicators for heavy metal pollution along the Bafa Lake. PMID:25567060

  14. Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model.

    Kalman, J; Smith, B D; Riba, I; Blasco, J; Rainbow, P S

    2010-06-01

    Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration. PMID:20137808

  15. Genotoxic and oxidative responses in coelomocytes of Eisenia fetida and Hediste diversicolor exposed to lipid-coated CdSe/ZnS quantum dots and CdCl2.

    Saez, Gladys; Aye, Mélanie; De Meo, Michel; Aimé, Ahissan; Bestel, Isabelle; Barthélémy, Philippe; Di Giorgio, Carole

    2015-07-01

    The emerging of Quantum Dots utilization in industrial or medicinal fields involved a potentially increase of these nanoparticles in environment. In this work, the genotoxic (comet assay) and oxidative effects (SOD activity, TBARS) of functionalized-QDs and cadmium chloride were investigated on Hediste diversicolor and Eisenia fetida coelomocytes. Results demonstrated that functionalized-QDs (QDNs) and cadmium chloride induced DNA damages through different mechanisms that depended on the nano- or ionic nature of Cd. The minimal genotoxic concentrations for H. diversicolor (<0.001ng/g for QDNs and CdCl2 ) were lower than for E. fetida (between 0.01 and 0.1 ng/g for QDNs, and between 0.001 and 0.01 ng/g for CdCl2 ). These results showed that H. diversicolor was more sensitive than E. fetida. The two contaminants had a low impact on the oxidative stress markers. PMID:24500942

  16. Characterization of specificity of bacterial community structure within the burrow environment of the marine polychaete Hediste (Nereis) diversicolor.

    Pischedda, Laura; Militon, Cécile; Gilbert, Franck; Cuny, Philippe

    2011-12-01

    Bioturbation is known to stimulate microbial communities, especially in macrofaunal burrows where the abundance and activities of bacteria are increased. Until now, these microbial communities have been poorly characterized and an important ecological question remains: do burrow walls harbor similar or specific communities compared with anoxic and surface sediments? The bacterial community structure of coastal sediments inhabited by the polychaete worm Hediste diversicolor was investigated. Surface, burrow wall and anoxic sediments were collected at the Carteau beach (Gulf of Fos, Mediterranean Sea). Bacterial diversity was determined by analyzing small subunit ribosomal RNA (16S rRNA) sequences from three clone libraries (168, 179 and 129 sequences for the surface, burrow wall and anoxic sediments, respectively). Libraries revealed 306 different operational taxonomic units (OTUs) belonging to at least 15 bacterial phyla. Bioinformatic analyses and comparisons between the three clone libraries showed that the burrow walls harbored a specific bacterial community structure which differed from the surface and anoxic environments. More similarities were nevertheless found with the surface assemblage. Inside the burrow walls, the bacterial community was characterized by high biodiversity, which probably results from the biogeochemical heterogeneity of the burrow system. PMID:21946148

  17. The regulation of copper stress response genes in the polychaete Nereis diversicolor during prolonged extreme copper contamination.

    McQuillan, Jonathan S; Kille, Peter; Powell, Kate; Galloway, Tamara S

    2014-11-18

    Polychaetes are frequented in toxicological studies, one reason being that some members occupy shallow burrows in sediments and are maximally exposed to the contaminants that accumulate within them. We have been studying one population of the polychaete Nereis (Hediste) diversicolor exhibiting inheritable tolerance to extreme copper contamination in estuarine sediment. Using transcriptome sequencing data we have identified a suite of genes with putative roles in metal detoxification and tolerance, and measured their regulation. Copper tolerant individuals display significantly different gene expression profiles compared to animals from a nearby population living without remarkable copper levels. Gene transcripts encoding principle copper homeostasis proteins including membrane copper ion transporters, copper ion chaperones and putative metallothionein-like proteins were significantly more abundant in tolerant animals occupying contaminated sediment. In contrast, those encoding antioxidants and cellular repair pathways were unchanged. Nontolerant animals living in contaminated sediment showed no difference in copper homeostasis-related gene expression but did have significantly elevated levels of mRNAs encoding Glutathione Peroxidase enzymes. This study represents the first use of functional genomics to investigate the copper tolerance trait in this species and provides insight into the mechanism used by these individuals to survive and flourish in conditions which are lethal to their conspecifics. PMID:25337783

  18. Tolerance to metals and assessment of energy reserves in the polychaete Nereis diversicolor in clean and contaminated estuaries.

    Durou, C; Mouneyrac, C; Amiard-Triquet, C

    2005-02-01

    Estuaries are subject to anthropogenic activities. Because the intrasedimentary worm Nereis diversicolor has ecological characteristics and bioindicator abilities, its use was pertinent in investigating the concepts and cost of tolerance to heavy metals (Cd, Cu, Zn). In this context, two approaches were carried out, performing toxicity tests and estimating energy reserves (glycogen and lipids), in populations originating from a contaminated site (Seine estuary) compared with those from a clean site (Authie estuary). Mean lethal times (LT(50)s) of organisms exposed to zinc from the Seine estuary were higher than those from the Authie estuary, but not of organisms exposed to Cd or Cu. The influence of animal weight and salinity on the sensitivity of worms also was studied. The biggest worms were more tolerant to zinc than the smallest ones, and worms survived longer at a reduced salinity (15 per thousand). Concentrations of glycogen and lipids in each sampling season were higher in specimens from the Authie estuary than in worms from the Seine estuary. No influence of salinity on glycogen and lipid levels was observed. Glycogen concentrations were not influenced by the weight of specimens, whereas lipid concentrations were significantly and positively correlated with weight. In conclusion, worms from the Seine estuary exhibited tolerance to Zn, and the depletion of energy reserves observed in this population could be interpreted as a cost of tolerance. PMID:15712333

  19. Linking steroid hormone levels to sexual maturity index and energy reserves in Nereis diversicolor from clean and polluted estuaries.

    Durou, C; Mouneyrac, C

    2007-01-01

    The objective of this work was to compare seasonal variations of reproduction physiology of the ragworm Nereis diversicolor --a key species in estuarine ecosystems--originating from a clean (Authie) and multi-polluted (Seine) estuaries. A particular attention was carried out in female worms, on relationships between sexual maturity stages, energy reserves (glycogen and lipids) and steroid hormone levels (progesterone, 17beta-estradiol, and testosterone). Sexual maturity index (SMI), energy reserves and steroid hormones are clearly influenced by season in worms from both sites. Depleted steroid hormone levels were depicted in specimens exhibiting high sexual maturity stage and energy reserves. Intersite analysis has revealed all over the sampling period:--a sexual precocity in worms from Seine,--glycogen concentrations generally higher in worms from Authie,--no clear tendency for lipids,--no differences in steroid hormone levels. Sexual precocity and lower glycogen levels in Seine could be explained by a specific strategy above all devoted to reproduction in these worms. Chemical stress could be a possible explanation of these observations. PMID:16959253

  20. [Toxic effects of petroleum hydrocarbons and copper on polychaete Nereis diversicolor and on its antioxidant enzyme systems].

    Sun, Fu-hong; Zhou, Qi-xing; Zhang, Qian-ru

    2006-07-01

    Under the condition of the laboratory simulation, the toxic effects of petroleum hydrocarbons and various concentrations of copper (Cu2+) on the polychaete Nereis diversicolor and on its antioxidant enzyme defense systems were examined. The results indicate that both petroleum hydrocarbons and CU2+ have high toxicity to the polychaete. After a 3-day exposure to petroleum hydrocarbons and Cu2+, the value of LD50 was 117.5 microL x L(-1) and 864.0 microg x L(-1), respectively. The activities of peroxidase (POD) and superoxide dismutase (SOD) were influenced significantly through a 5-day exposure to single pollution of Cu2+. The activity of POD was inhibited at first and then enhanced gradually; on the contrary, the activity of SOD showed a tendency of induction firstly and then inhibition. After exposed to petroleum hydrocarbons at the concentration of the value of LD50 for 5 days, POD activity of the polychaete was not significantly induced, and the activity of SOD was lower than that of control. A 5-day exposure to the joint-pollution of petroleum hydrocarbons and Cu2+ could bring out a decrease in the activities of POD and SOD firstly and then an increase. The changes in the activity of SOD can better reflect the toxic effects of pollutants on the polychaete. PMID:16881321

  1. Monitoring pollution in Tunisian coasts using a scale of classification based on biochemical markers in worms Nereis (Hediste) diversicolor.

    Bouraoui, Zied; Banni, Mohamed; Chouba, Lassad; Ghedira, Jihen; Clerandeau, Cristelle; Jebali, Jamel; Narbonne, Jean Francois; Boussetta, Hamadi

    2010-05-01

    This paper aims to assess the marine environment quality along the Tunisian coasts using a statistical approach based on biomarkers response in the polychaete worms Nereis (Hediste) diversicolor. Worms were collected from six sites: Bizerta Lagoon, Gargour, Nakta, Mahres, Skhira and from Teboulba considered as a reference site. The biomarkers selected in this work were (1) the activities of cytochrome P450-dependent NADPH cytochrome c reductase (NADPH red) as phase I enzyme, (2) glutathione S-transferase as phase II enzyme and (3) the acetylcholinesterase activity as neurotoxicity marker. Oxidative stress was evaluated using catalase activity and malondialdehyde accumulation. For each biomarker, a discriminatory factor was calculated and a response index was allocated. For each site, a multi-marker pollution index was calculated as the sum of the response index of each of the five more discriminating biomarkers. The results show differences between sites compared with the reference samples. The multi-marker approach confirms that worms from Bizerta and Mahress have been submitted to highly polluted environment. Mahress shows the highest multi-marker pollution index, indicating a highly contamination status. PMID:19404756

  2. Expression and evolution studies of ets genes in a primitive coelomate, the polychaete annelid, Hediste (Nereis) diversicolor.

    Bocquet-Muchembled, Béatrice; Leroux, Régine; Chotteau-Lelièvre, Anne; Vergoten, Gérard; Fontaine, François

    2002-08-01

    The Ets family includes numerous proteins with a highly conserved DNA-binding domain of 85 amino acids named the ETS domain. Phylogenetic analyses from ETS domains revealed that this family could be divided into 13 groups, among them are ETS and ERG. The ets genes are present in the Metazoan kingdom and we have previously characterized the Nd ets and Nd erg genes in the polychaete annelid Hediste diversicolor. Here, we isolated a fragment encoding the ETS domain from Nd Ets, by genomic library screening. By Northern blot analysis, we showed that this gene was transcribed as one major mRNA of 2.6 kb and one minor mRNA of 3.2 kb. By in situ hybridization, we observed that Nd ets was expressed in the intestine and oocytes and that Nd erg was expressed in cellular clumps present in the coelomic cavity, in an area of proliferating cells situated between the last metamere and the pygidium. Finally, we showed that Nd erg shared the expression pattern of Nd ets in oocytes. Molecular modeling studies have revealed that the spatial structure of ETS domain of Nd Ets and Nd Erg was conserved, in comparison to the murine Ets-1 and human Fli-1 proteins, respectively. PMID:12128055

  3. 鲍鱼养殖饲料选择决策研究%Research on choice of abalone aquaculture feed

    马德好; 王雅琴; 高华; 李道亮

    2013-01-01

    Feed is an important material foundation for the development of aquaculture, but feed cost reaches about 50% of total costs. Therefore, the economic benefits of aquaculture depend largely on whether feed choice is reasonable. The aim of this study is to investigate how to choose the abalone feed to reduce feeding cost. This article uses Excell2007 and develops a feeding selection decision system based on the simplex method algorithm for linear program-ming to make sure that feed cost is the lowest under the premise of meeting the required nutri-tional elements for the growth of abalone. Data shows, these two methods can effectively reduce the cost of feed. And using computer for solving linear programming problem is effective means to find the optimal solution.%饲料是发展水产养殖业的重要物质基础,饲料费用在养殖成本中所占比例达到50%左右。因此,水产养殖经济效益的好坏在很大程度上取决于饲料选择是否合理。研究旨在探讨如何选择鲍鱼饲料才能降低投喂成本。文章利用Excel 2007以及基于单纯形法求解线性规划算法研发的饲料投喂选择决策系统,实现了在满足鲍鱼生长所需的营养元素前提下饲料投入成本的最低。数据证明,两种方式均能有效地降低饲料成本。运用计算机求解线性规划问题是寻求最优解的有效手段。

  4. Contrasting effects of the polychaetes Marenzelleria viridis and Nereis diversicolor on benthic metabolism and solute transport in sandy coastal sediment

    Kristensen, Erik; Hansen, Tanja; Delfosse, Matthieu; Banta, Gary Thomas; Quintana, Cintia O.

    2011-01-01

    sediment. Sulfate reduction after 1 mo, on the other hand, was more than twice as high in sediment inhabited by M. viridis alone than in any other treatment, even when combined with N. diversicolor. Denitrification estimated from benthic TCO2 release, porewater reaction stoichiometry and nutrient fluxes...... was largely unaffected by the presence of fauna. Accordingly, the partitioning of reaction pathways after 1 mo revealed that M. viridis stimulated sulfate reduction at the expense of aerobic respiration. Most of the oxygen uptake in M. viridis sediment was apparently due to enhanced oxidation...

  5. Bioaccumulation and oxidative stress responses measured in the estuarine ragworm (Nereis diversicolor) exposed to dissolved, nano-and bulk-sized silver

    Cozzari, Margherita; Elia, Antonia Concetta; Pacini, Nicole;

    2015-01-01

    The impact of Ag NPs on sediment-dwelling organisms has received relatively little attention, particularly in linking bioaccumulation to oxidative injury. The polychaete Nereis diversicolor was exposed to sediments spiked with dissolved Ag (added as AgNO3), Ag NPs (63 ± 27 nm) and larger bulk Ag...... bulk Ag particles, changes in antioxidant markers (glutathione, SOD, CAT, GPx, SeGPx, GST and GR) occurred without significant Ag accumulation. Differences in biomarker profiles between the three Ag forms suggest that the mechanism of oxidative stress caused by particulate Ag is distinct from that of...

  6. Feeding ecology of Nereis diversicolor (O.F. Müller) (Annelida, Polychaeta) on estuarine and lagoon environments in the southwest coast of Portugal

    Pedro Fidalgo e Costa; Oliveira, Rui Filipe; Fonseca, Luís Cancela da

    2006-01-01

    A ecologia alimentar de Nereis diversicolor (O.F. Müller, 1776) (Annelida: Polychaeta) foi estudada num período de 14 meses em três sistemas estuarino-lagunares da costa Sudoeste de Portugal (Odeceixe, Aljezur e Carrapateira). A análise do conteúdo digestivo revelou uma variação da dieta de acordo com os locais estudados, época do ano e com o tamanho dos indivíduos. Não houve diferenças nos conteúdos de machos e fêmeas. Foram encontrados em todas as estações amostradas um total...

  7. Uptake of curium (244Cm) by five benthic marine species (Arenicola marina, Cerastoderma edule, Corophium volutator, Nereis diversicolor and Scrobicularia plana): comparison with americium and plutonium

    Curium (244Cm) uptake from contaminated sea water was studied in five benthic marine species: two bivalve molluscs (Scrobicularia plana and Cerastoderma edule), two polychaete annelids (Arenicola marina and Nereis diversicolor) and one amphidpod crustacean (Corophium volutator). The concentrations in the whole organisms relative to the concentration in the sea water (concentration factors) were: 700 for the amphipods (after 11 d of accumulation), 140 for the cockles (after 28 d), 80 for the scrobicularia (after 23d) and approx. 30 for the two annelids (after > 20 d). All species except S. plana accumulated americium and curium similarly; S. plana accumulated similar amounts of curium and plutonium. (author)

  8. Phytoplankton reduction in near-bottom water caused by filter-feeding Nereis diversicolor - Implications for worm growth and population grazing impact

    Larsen, Poul Scheel; Riisgård, H.U.; Poulsen, L

    1996-01-01

    Studies of vertical profiles of phytoplankton in the field combined with laboratory experiments demonstrated that reduction in phytoplankton concentrations in the near-bottom water layer, 5 to 10 cm in thickness on calm days, may play a significant role for the filter-feeding polychaete Nereis diversicolor in realizing its grazing capacity (estimated at 13.8 m3 m-2 d-1 in the shallow bay of Kertinge Nor, Denmark, in July 1994). Field-growth experiments were performed with worms transferred to...

  9. Uptake of curium (/sup 244/Cm) by five benthic marine species (Arenicola marina, Cerastoderma edule, Corophium volutator, Nereis diversicolor and Scrobicularia plana): comparison with americium and plutonium

    Miramand, P.; Germain, P.; Arzur, J.C.

    1987-01-01

    Curium (/sup 244/Cm) uptake from contaminated sea water was studied in five benthic marine species: two bivalve molluscs (Scrobicularia plana and Cerastoderma edule), two polychaete annelids (Arenicola marina and Nereis diversicolor) and one amphidpod crustacean (Corophium volutator). The concentrations in the whole organisms relative to the concentration in the sea water (concentration factors) were: 700 for the amphipods (after 11 d of accumulation), 140 for the cockles (after 28 d), 80 for the scrobicularia (after 23d) and approx. 30 for the two annelids (after > 20 d). All species except S. plana accumulated americium and curium similarly; S. plana accumulated similar amounts of curium and plutonium.

  10. Bio-ecologia e produção do poliqueta Nereis diversicolor O.F. Müller - recurso zoológico de ambientes costeiros

    Pedro Fidalgo e Costa

    2001-01-01

    A presente dissertação teve como objectivo investigar alguns aspectos da biologia e ecologia do poliqueta Nereis diversicolor na costa Sudoeste de Portugal, nomeadamente nas ribeiras de Odeceixe, Aljezur e Carrapateira, durante o período de Abril de 1993 até Maio de 1994, bem como a tentativa de produção deste recurso em pequena escala e em condições controladas. Esta espécie de poliqueta muito comum e frequentemente dominante em substratos móveis de ambientes estuarinos, apresentou alguma...

  11. In situ relationship between energy reserves and steroid hormone levels in Nereis diversicolor (O.F. Müller) from clean and contaminated sites.

    Mouneyrac, C; Pellerin, J; Moukrim, A; Ait Alla, A; Durou, C; Viault, N

    2006-10-01

    The aim of this study was to investigate, in situ, the temporal effects of urban effluent discharge on energy reserves and steroid hormone levels in the intrasedimentary worm Nereis diversicolor. Results have shown no differences in energy reserves (glycogen, lipids) in organisms originating from a contaminated site (Oued Souss) and a comparatively clean site (Oualidia). Both sites are located on the Moroccan Atlantic coast. In contrast, steroid hormone (progesterone, testosterone, and 17beta-estradiol) levels were significantly decreased in animals from Oued Souss. The differences in the responses suggest that organisms from the polluted site have been exposed to endocrine disruptors. PMID:16157376

  12. Mechanism of fluorescence and conformational changes of the sarcoplasmic calcium binding protein of the sand worm Nereis diversicolor upon Ca2+ or Mg2+ binding.

    Sillen, Alain; Verheyden, Stefan; Delfosse, Lotte; Braem, Tania; Robben, Johan; Volckaert, Guido; Engelborghs, Yves

    2003-09-01

    The calcium-binding protein isolated from the sarcoplasm of the muscles of the sand worm Nereis diversicolor has four EF-hands and three active binding sites for Ca(2+) or Mg(2+). Nereis diversicolor sarcoplasmic calcium-binding protein contains three tryptophan residues at positions 4, 57, and 170, respectively. The Wt protein shows a very limited fluorescence increase upon binding of Ca(2+) or Mg(2+). Single-tryptophan-containing mutants were produced and purified. The fluorescence titrations of these mutants show a limited decrease of the affinity for calcium, but no alterations of the cooperativity. Upon adding calcium, Trp170 shows a strong fluorescence increase, Trp57 an extensive fluorescence decrease, and Trp4 shows no fluorescence change. Therefore mutant W4F/W170F is ideally suited to analyze the fluorescence titrations and to study the binding mechanism. Mutations of the calcium ligands at the z-position in the three binding sites show no effect at site I and a total loss of cooperativity at sites III and IV. The quenching of Trp57 upon calcium binding is dependent on the presence of arginine R25, but this residue is not just a simple dynamic quencher. The role of the salt bridge R25-D58 is also investigated. PMID:12944301

  13. Biomonitoring in a clean and a multi-contaminated estuary based on biomarkers and chemical analyses in the endobenthic worm Nereis diversicolor

    Durou, Cyril [CNRS, Universite de Nantes, Pole Mer et Littoral, SMAB, 2 rue de la Houssiniere, BP 92208, F-44322 Nantes Cedex 3 (France) and Institut de Biologie et Ecologie Appliquees, CEREA, Universite Catholique de l' Ouest, 44 rue Rabelais, 49008 Angers Cedex 01 (France)]. E-mail: cyril.durou@uco.fr; Poirier, Laurence [CNRS, Universite de Nantes, Pole Mer et Littoral, SMAB, 2 rue de la Houssiniere, BP 92208, F-44322 Nantes Cedex 3 (France); Amiard, Jean-Claude [CNRS, Universite de Nantes, Pole Mer et Littoral, SMAB, 2 rue de la Houssiniere, BP 92208, F-44322 Nantes Cedex 3 (France); Budzinski, Helene [CNRS UMR 5472, LPTC, Universite de Bordeaux I, 33405 Talence (France); Gnassia-Barelli, Mauricette [UMR INRA UNSA 1112 ROSE, Faculte des Sciences, BP 71, 06108 Nice Cedex 2 (France); Lemenach, Karyn [CNRS UMR 5472, LPTC, Universite de Bordeaux I, 33405 Talence (France); Peluhet, Laurent [CNRS UMR 5472, LPTC, Universite de Bordeaux I, 33405 Talence (France); Mouneyrac, Catherine [CNRS, Universite de Nantes, Pole Mer et Littoral, SMAB, 2 rue de la Houssiniere, BP 92208, F-44322 Nantes Cedex 3 (France); Institut de Biologie et Ecologie Appliquees, CEREA, Universite Catholique de l' Ouest, 44 rue Rabelais, 49008 Angers Cedex 01 (France); Romeo, Michele [UMR INRA UNSA 1112 ROSE, Faculte des Sciences, BP 71, 06108 Nice Cedex 2 (France); Amiard-Triquet, Claude [CNRS, Universite de Nantes, Pole Mer et Littoral, SMAB, 2 rue de la Houssiniere, BP 92208, F-44322 Nantes Cedex 3 (France)

    2007-07-15

    Relationships between biochemical and physiological biomarkers (acetylcholinesterase [AChE], catalase, and glutathione S-transferase [GST] activities, thiobarbituric acid reactive substances, glycogen, lipids and proteins) and accumulated concentrations of contaminants (polychlorinated biphenyls [PCBs], polycyclic aromatic hydrocarbons and metals) were examined in the keystone species Nereis diversicolor. The chemical analyses of worms and sediments allowed the designation of the Seine estuary and the Authie estuary as a polluted and relatively clean site respectively. Worms from the Seine estuary exhibited higher GST and lower AChE activities. Generally, larger worms had higher concentrations of energy reserves. Principal component analyses clearly highlighted intersite differences: in the first plan, GST activities and chemical concentrations were inversely related to concentrations of energy reserves; in the second one, PCB concentrations and AChE activity were inversely related. Depleted levels of energy reserves could be a consequence of combating toxicants and might predict effects at higher levels of biological organization. The use of GST and AChE activities and energy reserve concentrations as biomarkers is validated in the field in this keystone species. - The use of N. diversicolor as a biomonitor of environmental quality via the measurement of biomarkers and accumulated concentrations of contaminants is validated in the field.

  14. Bioaccumulation, subcellular distribution and toxicity of sediment-associated copper in the ragworm Nereis diversicolor: The relative importance of aqueous copper, copper oxide nanoparticles and microparticles.

    Thit, Amalie; Banta, Gary T; Selck, Henriette

    2015-07-01

    The sediment-dwelling ragworm, Nereis diversicolor was exposed to sediment spiked with aqueous Cu (CuAq, CuCl2), CuO nanoparticles (CuONP) or CuO microparticles (CuOMicro) at 150 μg Cu g(-1) dw sediment for 10d. Exposures to CuAq and CuOMicro caused mortality (62.5 and 37.5%, respectively), whereas mean burrowing time increased during exposure to CuAq and CuONP from 0.12 h (controls) to 19.3 and 12.2 h, respectively. All Cu treatments bioaccumulated, especially CuAq (up to 4 times more than the other treatments). Cu was roughly equally distributed among the five subcellular fractions in controls and worms exposed to CuONP or CuOMicro. In contrast, ≈50% of accumulated Cu in CuAq exposed worms was found in metal rich granules and significantly more Cu was present in heat-denatured proteins and organelles than in worms exposed to CuOMicro or in controls. Our results suggest that Cu form affects its bioaccumulation and subsequent toxicity and detoxification in a polychaete like N. diversicolor. PMID:25800937

  15. Biomonitoring in a clean and a multi-contaminated estuary based on biomarkers and chemical analyses in the endobenthic worm Nereis diversicolor

    Relationships between biochemical and physiological biomarkers (acetylcholinesterase [AChE], catalase, and glutathione S-transferase [GST] activities, thiobarbituric acid reactive substances, glycogen, lipids and proteins) and accumulated concentrations of contaminants (polychlorinated biphenyls [PCBs], polycyclic aromatic hydrocarbons and metals) were examined in the keystone species Nereis diversicolor. The chemical analyses of worms and sediments allowed the designation of the Seine estuary and the Authie estuary as a polluted and relatively clean site respectively. Worms from the Seine estuary exhibited higher GST and lower AChE activities. Generally, larger worms had higher concentrations of energy reserves. Principal component analyses clearly highlighted intersite differences: in the first plan, GST activities and chemical concentrations were inversely related to concentrations of energy reserves; in the second one, PCB concentrations and AChE activity were inversely related. Depleted levels of energy reserves could be a consequence of combating toxicants and might predict effects at higher levels of biological organization. The use of GST and AChE activities and energy reserve concentrations as biomarkers is validated in the field in this keystone species. - The use of N. diversicolor as a biomonitor of environmental quality via the measurement of biomarkers and accumulated concentrations of contaminants is validated in the field

  16. Trophic transfer of trace metals from the polychaete worm Nereis diversicolor to the polychaete N. virens and the decapod crustacean Palaemonetes varians

    Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

    2006-01-01

    Diet is an important exposure route for the uptake of trace metals by aquatic invertebrates, with trace metal trophic transfer depending on 2 stages - assimilation and subsequent accumulation by the predator. This study investigated the trophic transfer of trace metals from the sediment-dwelling polychaete worm Nereis diversicolor from metal-rich estuarine sediments in southwestern UK to 2 predators - another polychaete N. virens (Cu, Zn, Pb, Cd, Fe) and the decapod crustacean Palaemonetes varians (Cu, Zn, Pb, Cd, Fe, Ag, As, Mn). N. virens showed net accumulation of Cu, Zn, Pb and Cd from the prey; accumulation increased with increasing prey concentration, but a coefficient of trophic transfer decreased with increasing prey concentration, probably because a higher proportion of accumulated metal in the prey is bound in less trophically available (insoluble) detoxified forms. The trace metal accumulation patterns of P. varians apparently restricted significant net accumulation of metals from the diet of N. diversicolor to just Cd. There was significant mortality of the decapods fed on the diets of metal-rich worms. Metal-rich invertebrates that have accumulated metals from the rich historical store in the sediments of particular SW England estuaries can potentially pass these metals along food chains, with accumulation and total food chain transfer depending on the metal assimilation efficiencies and accumulation patterns of the animal at each trophic level. This trophic transfer may be significant enough to have ecotoxicological effects. ?? Inter-Research 2006.

  17. Biomarker responses to pollution in two invertebrate species: Scrobicularia plana and Nereis diversicolor from the Cádiz bay (SW Spain).

    Pérez, Erkuden; Blasco, Julian; Solé, Montserrat

    2004-01-01

    The clam Scrobicularia plana and the polychaete worm Nereis diversicolor were collected in several sites from a littoral enclosure in SW Spain. The aim of our study was to relate various biomarker responses in these species to a pollution gradient caused by untreated domestic discharges and to verify the adequacy of the selected species as sentinels in this habitat. The biomarkers selected were the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX) and DT-diaphorase (DT-D). In addition, the activities of cytochrome P450-dependent ethoxyresorufin O-deethylase (EROD) activity, the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE) were measured. Metallothionein levels were selected as biomarkers of heavy metals exposure in both species. The results suggest a different response in the water filtering organism (clam) and the sediment eater (polychaete), probably as a consequent of different pollution exposure and that samples from the "Caño Sancti-Petri" were exposed to biologically active compounds that altered some of their biochemical responses. AChE was the most sensitive biomarker in both species and N. diversicolor proved to be a more robust sentinel in this ecosystem. PMID:15178044

  18. Bioaccumulation and oxidative stress responses measured in the estuarine ragworm (Nereis diversicolor) exposed to dissolved, nano- and bulk-sized silver

    The impact of Ag NPs on sediment-dwelling organisms has received relatively little attention, particularly in linking bioaccumulation to oxidative injury. The polychaete Nereis diversicolor was exposed to sediments spiked with dissolved Ag (added as AgNO3), Ag NPs (63 ± 27 nm) and larger bulk Ag particles (202 ± 56 μm), for up to 11 days at sublethal concentrations (nominally 2.5, 5, 10 μg Ag g−1 sediment (dw)). There were concentration- and time-dependent differences in the accumulation of the three Ag forms, but all three forms elicited an oxidative stress response. In the cases of Ag NPs and bulk Ag particles, changes in antioxidant markers (glutathione, SOD, CAT, GPx, SeGPx, GST and GR) occurred without significant Ag accumulation. Differences in biomarker profiles between the three Ag forms suggest that the mechanism of oxidative stress caused by particulate Ag is distinct from that of dissolved Ag. - Highlights: • N. diversicolor exposed to dissolved, nano and bulk Ag via spiked sediments. • Concentration- and time-dependent differences in the accumulation patterns. • All three forms elicited an oxidative stress response. • Antioxidant markers changed without significant accumulation for particulate Ag. • Biomarker profile resulting from particulate Ag exposure different to dissolved Ag. - Exposure to different Ag forms leads to distinct oxidative stress biomarker profiles. Particulate Ag activates the oxidative stress response differently to dissolved Ag

  19. Progress Research on the Molecular Mechanism of Abalone Larvae Metamorphosis%鲍幼虫变态分子机制的研究进展

    王国栋; 张丽莉; 王艺磊

    2012-01-01

    The metamorphosis of molluscs larvae is an important biological question.Abalone is one of an ideal model for mollusc metamorphosis and even marine invertebrates because abalone larvae are lecithotrophic(non-feeding),have more rapid metamorphosis than insect and batrachia.Early studies discovered that some material could induce abalone larvae metamorphosis,by pharmacology and electrophysiology.Furthermore,some signal pathways of metamorphosis were developed.However,there is little knowledge of molecular mechanism regulating abalone larvae metamorphosis.Some different expressive genes were found by different display RT-PCR(DDRT-PCR) and gene microarray.Moreover,the metamorphosis is decided and influenced by numerous genes and signals.The traditional method has low efficiency and gets few differential expression genes.Furthermore,the number of EST(expressed sequence tag)is an important limit to the traditional method.So the molecular network and mechanism of metamorphosis have not been established.There is little knowledge of the cellular process.The transcriptome analysis of metamorphosis can acquire a large number of differential expression genes,contribute to building interaction network of differential expression genes,and is a new orientation of the study on molecular mechanism of metamorphosis.In addition,it is another problem to confirm and annotate these different expressed genes.Gene interference may be a solution.This paper summarizes the advances on metamorphosis of abalone larvae and its molecular mechanism.%综述了鲍幼虫变态及其分子机制的研究进展.鲍因其幼虫营卵黄营养,且同昆虫和蛙类相比,鲍幼虫变态速度快、存在提早发育(‘anticipatory’developmental program)现象,是研究贝类乃至海洋无脊椎动物变态现象的理想模式.早期研究采用药理学和电生理学方法发现了GABA等能够诱导鲍变态的物质,并且提出了变态过程信号通路,但调

  20. Effects of the polychaetes Arenicola marina and Nereis diversicolor on microbial pyrene mineralization

    Timmermann, Karen; Banta, Gary T.; Johnsen, Anders R.;

    2008-01-01

    mineralization potential in bulk (reduced and presumably anoxic) sediment was significantly lower than for surface and burrow sediments. However, when the bulk sediments were oxidized, mineralization rates increased rapidly. Collectively, these data indicate that oxygen availability controlled pyrene......The effects of 2 polychaetes, Nereis diversicolor and Arenicola marina, on the microbial mineralization of the organic contaminant pyrene, a polycyclic aromatic hydrocarbon (PAH), were followed over 44 d. We also examined whether the effect of the polychaetes was caused by enhanced oxygen supply......, altered pyrene bioavailability and/or a changed abundance or activity of pyrenedegrading bacteria. The presence of polychaetes enhanced microbial pyrene mineralization by 180 to 200% compared with defaunated sediment. Collectively, the replicates of the different treatments showed that mineralization...

  1. Bioaccumulation and oxidative stress responses measured in the estuarine ragworm (Nereis diversicolor) exposed to dissolved, nano- and bulk-sized silver.

    Cozzari, Margherita; Elia, Antonia Concetta; Pacini, Nicole; Smith, Brian D; Boyle, David; Rainbow, Philip S; Khan, Farhan R

    2015-03-01

    The impact of Ag NPs on sediment-dwelling organisms has received relatively little attention, particularly in linking bioaccumulation to oxidative injury. The polychaete Nereis diversicolor was exposed to sediments spiked with dissolved Ag (added as AgNO3), Ag NPs (63 ± 27 nm) and larger bulk Ag particles (202 ± 56 μm), for up to 11 days at sublethal concentrations (nominally 2.5, 5, 10 μg Ag g(-1) sediment (dw)). There were concentration- and time-dependent differences in the accumulation of the three Ag forms, but all three forms elicited an oxidative stress response. In the cases of Ag NPs and bulk Ag particles, changes in antioxidant markers (glutathione, SOD, CAT, GPx, SeGPx, GST and GR) occurred without significant Ag accumulation. Differences in biomarker profiles between the three Ag forms suggest that the mechanism of oxidative stress caused by particulate Ag is distinct from that of dissolved Ag. PMID:25549865

  2. A statistical study of environmental factors controlling concentrations of heavy metals in the burrowing bivalve Scrobicularia plana and the polychaete Nereis diversicolor

    Luoma, Samuel N.; Bryan, G. W.

    1982-07-01

    Multiple regression analyses indicate that the most important factors controlling Ag, Cd, Co, Cu, Pb and Zn concentrations in the estuarine bivalve Scrobicularia plana and the polychaete Nereis diversicolor are the concentrations of these metals in surface sediments and the partitioning of sediment-bound metals between different sediment constituents. Extraction of the sediments with 1-N HCl provides more information about the bioavailability of the metals than do extractions with five other techniques. Biologically available Cd and Co in solution contribute significantly to Cd and Co concentrations in both Scrobicularia and Nereis. Concentrations of Ag in Scrobicularia are reduced where Cu concentrations in sediments are high. An unexplained increase in concentrations of Cu in Scrobicularia at specific stations in six estuaries suggests that under certain very anoxic conditions the availability of copper may be exceptionally high.

  3. The use of enzymatic biomarkers in two marine invertebrates Nereis diversicolor and Patella vulgata for the biomonitoring of Tangier's bay (Morocco).

    Douhri, Hikmat; Sayah, Fouad

    2009-02-01

    The fast increase of anthropogenic activities has led to a continual influx of xenobiotics into the marine ecosystems. Quantifying biochemical parameters in marine invertebrates makes possible the evaluation of pollutants' damaging effect. In fact, to examine the health state of Tangier's bay, we focused on the study of catalase, esterase, acetylcholinesterase and alpha-amylase activities as biomarkers in two species of marine invertebrates Nereis diversicolor (Polychaeta, Nereidae) and Patella vulgata (Mollusca, Prosobranchia), collected from different sites along the Mediterranean coastline of Tangier. Our results showed that these biochemical parameters are disturbed following the level of decreasing environmental quality, and for this reason they are promising in the biomonitoring studies of the Moroccan marine environment. PMID:18786724

  4. Hedistin: A novel antimicrobial peptide containing bromotryptophan constitutively expressed in the NK cells-like of the marine annelid, Nereis diversicolor.

    Tasiemski, Aurélie; Schikorski, David; Le Marrec-Croq, Françoise; Pontoire-Van Camp, Christelle; Boidin-Wichlacz, Céline; Sautière, Pierre-Eric

    2007-01-01

    A novel antimicrobial peptide, named hedistin was identified from the coelomocytes of Nereis diversicolor. Hedistin shows no obvious similarities with other known peptides and constitutes the first antimicrobial peptide containing bromotryptophans demonstrated in annelids. cDNA and mass spectrometry analysis revealed that, upon bacteria challenge, this peptide is secreted following processing of a precursor containing a signal peptide and prosequences. Hedistin was shown to possess an activity against a large spectrum of bacteria including the methicillin resistant Staphylococcus aureus and Vibrio alginolyticus. The gene was demonstrated to be constitutively and exclusively expressed in circulating NK cells like known to play an important role in the immunity of the sand worm. These data contrast with those observed in another annelid, the leech, in which genes coding for antimicrobial peptides are upregulated in a specific tissue and peptides are rapidly released into the hemolymph after septic injury. PMID:17210178

  5. Bioaccumulation, subcellular distribution and toxicity of sediment-associated copper in the ragworm Nereis diversicolor: The relative importance of aqueous copper, copper oxide nanoparticles and microparticles

    The sediment-dwelling ragworm, Nereis diversicolor was exposed to sediment spiked with aqueous Cu (CuAq, CuCl2), CuO nanoparticles (CuONP) or CuO microparticles (CuOMicro) at 150 μg Cu g−1 dw sediment for 10d. Exposures to CuAq and CuOMicro caused mortality (62.5 and 37.5%, respectively), whereas mean burrowing time increased during exposure to CuAq and CuONP from 0.12 h (controls) to 19.3 and 12.2 h, respectively. All Cu treatments bioaccumulated, especially CuAq (up to 4 times more than the other treatments). Cu was roughly equally distributed among the five subcellular fractions in controls and worms exposed to CuONP or CuOMicro. In contrast, ≈50% of accumulated Cu in CuAq exposed worms was found in metal rich granules and significantly more Cu was present in heat-denatured proteins and organelles than in worms exposed to CuOMicro or in controls. Our results suggest that Cu form affects its bioaccumulation and subsequent toxicity and detoxification in a polychaete like N. diversicolor. - Highlights: • CuAq exposure resulted in Cu body burden up to 4 times higher than CuONP and CuOMicro. • CuAq was the most toxic (62.5% mortality) of the treatments tested. • Subcellular Cu distribution after CuAq exposure differed significantly from control. • Cu in CuAq exposed worms was mainly found in metal rich granules (≈50%). - CuAq was more bioavailable and toxic, and showed a different subcellular distribution compared to the particulate forms tested (CuONP and CuOMicro)

  6. 莆田南日岛鲍鱼养殖区环境变化评价%Environment Change Evaluation in Abalone Cultivation Area at Nanri Island of Putian

    金媛娟

    2012-01-01

    根据2009-2011年13个站位的监测数据,采用富营养化评价法和内梅罗综合污染指数法对鲍鱼养殖区进行了三年的纵向数据对比,得出该区环境正在日趋恶化,通过2011年鲍鱼区、藻类区及码头区监测数据的横向对比,发现藻类养殖的开展,对鲍鱼区的海洋环境有所改善,但由于布局的不科学不合理,未能够完全发挥藻类对环境的修复作用,甚至于可能给鲍鱼造成一定时间段的不良影响。因此提出建议:应合理规划藻类区和鲍鱼区的产业布局。%According to the monitoring data of thirteen stations from2009 to 2011, this paper makes three years longitudinal data contrast for the abalone cultivation area based on the eutrophication evaluation and Nemerow pollution index. The result indicates that the environment of thearea becomes worsen. Moreover, the monitoring data compared among abalone areas, alga areas and wharfareas in 2011 shows that the development of alga cultivation makes some improvement for the marine environment of abalone areas. However, because of the unscientific and unreasonable distribution, the effects of algas on environment are notfully satisfied. Conversely, it may have harm effect onabalones for some time. So it is suggest that the industrial layout of alga areas and abalone areas should be planned reasonably.

  7. Influence of copper oxide nanoparticle shape on bioaccumulation, cellular internalization and effects in the estuarine sediment-dwelling polychaete, Nereis diversicolor.

    Thit, Amalie; Dybowska, Agnieszka; Købler, Carsten; Kennaway, Gabrielle; Selck, Henriette

    2015-10-01

    CuO nanoparticles (NPs) released into the aquatic environment will likely accumulate in the sediment. Here we synthesized and characterized CuO NPs with different shapes and thus sizes: spheres, rods and spindles. Nereis diversicolor were exposed for 10 days to control sediment or sediment spiked with CuO NPs or aqueous Cu (Cu-Aq, CuCl2) at 7, 70 and 140 μg Cu g(-1) dw sediment. Cu from all Cu treatments accumulated in worms in a concentration-dependent manner. Only Cu-Aq decreased burrowing, suggesting that worms avoid Cu when added to sediment as Cu-Aq, but not CuO NPs. Transmission Electron Microscopy of gut sections indicated limited presence of CuO NP-like objects in the gut lumen, but evidence on whether accumulated Cu from CuO NP exposure was internalized as particles was not conclusive. Overall, bioavailability and avoidance was not influenced by particle shape or size, whereas Cu form (Cu-Aq vs particulate) and exposure concentration had significant impact. PMID:26149327

  8. Influence of copper oxide nanoparticle shape on bioaccumulation, cellular internalization and effects in the estuarine sediment-dwelling polychaete, Nereis diversicolor

    Thit, Amalie; Dybowska, Agnieszka; Købler, Carsten;

    2015-01-01

    CuO nanoparticles (NPs) released into the aquatic environment will likely accumulate in the sediment. Here we synthesized and characterized CuO NPs with different shapes and thus sizes: spheres, rods and spindles. Nereis diversicolor were exposed for 10 days to control sediment or sediment spiked...... with CuO NPs or aqueous Cu (Cu-Aq, CuCl2) at 7, 70 and 140 μg Cu g-1 dw sediment. Cu from all Cu treatments accumulated in worms in a concentration-dependent manner. Only Cu-Aq decreased burrowing, suggesting that worms avoid Cu when added to sediment as Cu-Aq, but not CuO NPs. Transmission Electron...... Microscopy of gut sections indicated limited presence of CuO NP-like objects in the gut lumen, but evidence on whether accumulated Cu from CuO NP exposure was internalized as particles was not conclusive. Overall, bioavailability and avoidance was not influenced by particle shape or size, whereas Cu form (Cu...

  9. In vivo measurements of the internal pH of Hediste (Nereis) diversicolor (Annelida, Polychaeta) exposed to ambient sulphidic conditions using pH microelectrodes

    Sommer, Stefan; Jahn, Andreas; Funke, Friederike; Brenke, Nils

    The effect of different ambient sulphide concentrations on the internal pH regime of Hediste (Nereis) diversicolor was studied under in vivo conditions using liquid membrane pH microelectrodes, a method which is new to marine sciences. As a case study, the hypothesis was tested whether organisms exposed to ambient sulphidic conditions are able to lower their internal pH which, in effect, would reduce sulphide influx into the animals and thus could represent an effective detoxification mechanism. It was shown that a significant lowering of the internal pH occurred within only 20min after adding sulphide. This pH lowering appeared to be dependent on the external sulphide concentration of the ambient medium and showed a saturation beyond a threshold level of about 130μM. It is discussed whether this sulphide-induced pH drop is an active regulatory mechanism and acts as an effective protection mechanism against sulphide during short-term exposures.

  10. Effects of Nereis diversicolor on the transformation of 1-methylpyrene and pyrene: transformation efficiency and identification of phase I and II products.

    Malmquist, Linus M V; Christensen, Jan H; Selck, Henriette

    2013-05-21

    Transformation of nonsubstituted and alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) by the benthic invertebrate Nereis diversicolor was compared in this study. Pyrene and 1-methylpyrene were used as model compounds for nonsubstituted and alkyl-substituted PAHs, respectively. Qualitative and quantitative analyses of metabolites and parent compounds in worm tissue, water, and sediment were performed. Transformation of 1-methylpyrene generated the benzylic hydroxylated phase I product, 1-pyrenecarboxylic acid that comprised 90% of the total metabolites of 1-methylpyrene, and was mainly found in water extracts. We tentatively identified 1-methylpyrene glucuronides and 1-carbonylpyrene glycine as phase II metabolites not previously reported in literature. Pyrene was biotransformed to 1-hydroxypyrene, pyrene-1-sulfate, pyrene-1-glucuronide, and pyrene glucoside sulfate, with pyrene-1-glucuronide as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C₁-C₄-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation of sediment-associated 1-methylpyrene may result in a high exposure of water-living organisms to metabolites of alkyl-substituted PAHs, whose toxicities are unknown. This study demonstrates the need to consider fate and effects of substituted PAHs and their metabolites in risk assessments. PMID:23611659

  11. Restriction of Spartina anglica (C.E. Hubbard) marsh development by the infaunal polychaete Nereis diversicolor (O.F. Müller)

    Paramor, O. A. L.; Hughes, R. G.

    2007-01-01

    Spartina anglica has been planted around the coast of SE England, and throughout the world, to help stabilise sediments and reduce wave erosion of sea defences. Recently the areas of S. anglica have declined on this coast, contributing to the overall loss of saltmarsh area, in contrast to the north and west coasts of the UK where expanding S. anglica marshes have had to be controlled to maintain mudflat feeding areas for birds. Field experiments were established in two old coastal realignment areas in the Blythe Estuary (Suffolk) and on open mudflats in the Blackwater Estuary (Essex), in which surface deposit feeding by Nereis diversicolor was prevented by laying porous mats on the mudflat surface. These mats promoted sediment deposition and quickly became buried. S. anglica colonised these infauna exclusion areas by growth of rhizomes from adjacent plants, to a significantly higher degree than in control areas. In one of the Blythe sites this occurred when the adjacent S. anglica marsh was retreating. These results support the conclusions of Paramor and Hughes (2004, 2005), that the infauna are responsible for much of the loss of saltmarsh in SE England, and that managed coastal realignment will not necessarily lead to saltmarsh creation. The experiments point to an alternative means of managing saltmarsh creation and sediment accretion on existing mudflats, with consequent benefits for coastal defence and conservation.

  12. Sediment-worm interactions: transfer of 65Zn, 109Cd and sup(110m)Ag from marine sediment by Nereis diversicolor

    Radiotracer experiments to understand the role of benthic worms in transferring 65Zn, 109Cd and sup(110m)Ag from marine sediments to marine food webs are described. Sediments were made radioactive by adding 30 to 50μCi of the appropriate high specific activity isotope to 500 ml of sea water and mixing with 100 cm3 of sediment. The 65Zn and 109Cd were added as chlorides and the sup(110m)Ag was added as nitrate. Relative accumulation from radioactive sediments and the loss rates of the metals from N. diversicolor were determined at different time intervals. Radioactive worms were transferred to fresh sediments and were periodically radioanalysed. It was observed that simple ingestion of subsurface radioactive sediments is a less effective route of Zn transfer to the worm than by deposit feeding at the sediment-water interface. Cadmium appears to be much less tightly bound to marine sediment than zinc. Worms which accumulated sup(110m)Ag from sediment during a 20 day exposure lost it at a faster rate than 65Zn accumulated during a 5 day exposure

  13. Ecology of the polychaete Nereis diversicolor in the Canal de Mira (Ria de Aveiro, Portugal): Population dynamics, production and oogenic cycle

    Abrantes, António; Pinto, Fátima; Moreira, Maria Helena

    1999-07-01

    The population of Nereis diversicolor O.F. Müller was studied in 1993 and 1994 at three intertidal areas along the estuarine gradient in the Canal de Mira (Ria de Aveiro). The population dynamics, secondary production and growth were followed for the 2-year period, whereas in the second year, a study on the oogenic cycle was also carried out. For the population dynamics and production studies, core samples were collected monthly at each site, and for the study of the oogenic cycle, medium size and large individuals were sampled from the sediment. Mean annual densities were higher (573-718 ind.m -2) at a station located in the middle zone of the channel, followed by the outer (190-275 ind.m -2) and the innermost (43-94 ind.m -2) stations. A cohort analysis by `Bhatta' software enabled the separation of the cohorts present at each date, and two cohorts were followed from recruitment to extinction. The secondary production ranged from 15.9 to 74.2 g ash free dry weight.m -2.year -1 and the P/ overlineBratio from 4.4 to 7.9. The average body growth rate varied between 0.16 and 0.20 mm.d -1 for worms longer than 2 cm. Two recruitment seasons were detected each year. Two spawning periods were also observed, one in the spring and the other in early autumn.

  14. Intersite variations of a battery of biomarkers at different levels of biological organisation in the estuarine endobenthic worm Nereis diversicolor (Polychaeta, Nereididae).

    Fossi Tankoua, O; Buffet, P E; Amiard, J C; Amiard-Triquet, C; Méléder, V; Gillet, P; Mouneyrac, C; Berthet, B

    2012-06-15

    The ragworm Nereis diversicolor has been proposed as a sentinel species for the assessment of estuarine sediment quality. The aim of this study was to test the responsiveness of the worms using a battery of biomarkers in specimens from a moderately contaminated site (Loire estuary, Fr.) and a comparatively cleaner site (Bay of Bourgneuf, Fr.) as a reference site. Ragworms were collected on 7 occasions from April 2008 to October 2009 for the determination of biochemical (GST, AChE, digestive enzymes), physiological (energy reserves (glycogen, lipids and proteins), relationship between length and weight), and behavioural (feeding and burrowing) biomarkers. The biomarker responses were tentatively interpreted in terms of the concept of cascading events potentially responsible for local depletion/extinction of populations submitted to chemical stress. Impairments of AChE and amylase activities, feeding rate, energy reserve concentrations (glycogen and lipids), and the relationship between length and weight showed up differences between the reference site and the Loire estuary despite the latter being far from the most contaminated estuary in France or internationally. However, no links could be established in the Loire estuary ragworms between effects at infra-individual and individual levels, nor with worm population density, even though a small oil spill had occurred in the Loire estuary only one month before the beginning of sampling. PMID:22417766

  15. 1-Hydroxypyrene glucuronide as the major aqueous pyrene metabolite in tissue and gut fluid from the marine deposit-feeding polychaete Nereis diversicolor.

    Giessing, Anders M B; Mayer, Lawrence M; Forbes, Thomas L

    2003-05-01

    Both 1-hydroxypyrene and 1-hydroxypyrene glucuronide are identified as the primary phase I and phase II metabolites of the four-ringed polycyclic aromatic hydrocarbon (PAH) pyrene in the marine deposit-feeding polychaete Nereis diversicolor. Identification of pyrene and primary metabolites was performed using high-pressure liquid chromatography (HPLC) with diode-array detection and fluorescence detection (HPLC/DAD/F) and an ion-trap mass spectrometer for positive identification of 1-hydroxypyrene glucuronide. Besides 1-hydroxypyrene and 1-hydroxypyrene glucuronide, the HPLC/F trace of tissue samples from pyrene-exposed worms showed three additional low-intensity peaks that may be related to pyrene metabolism based on similar excitation/emission wavelengths. The peaks were all too low in intensity to be positively identified. Of the total PAH in tissue, 1-hydroxypyrene glucuronide, 1-hydroxypyrene, and pyrene constituted 73%, 2%, and 25% respectively. Gut elimination of metabolic products is supported by the identification of 1-hydroxypyrene and 1-hydroxypyrene glucuronide in both gut fluid and defecation water. Being the only phase I metabolite of pyrene, 1-hydroxypyrene becomes a useful marker for PAH exposure, and it may serve as a valuable model compound for assessing species-specific PAH metabolic capabilities. PMID:12729221

  16. Biomonitoring in a clean and a multi-contaminated estuary based on biomarkers and chemical analyses in the endobenthic worm Nereis diversicolor.

    Durou, Cyril; Poirier, Laurence; Amiard, Jean-Claude; Budzinski, Hélène; Gnassia-Barelli, Mauricette; Lemenach, Karyn; Peluhet, Laurent; Mouneyrac, Catherine; Roméo, Michèle; Amiard-Triquet, Claude

    2007-07-01

    Relationships between biochemical and physiological biomarkers (acetylcholinesterase [AChE], catalase, and glutathione S-transferase [GST] activities, thiobarbituric acid reactive substances, glycogen, lipids and proteins) and accumulated concentrations of contaminants (polychlorinated biphenyls [PCBs], polycyclic aromatic hydrocarbons and metals) were examined in the keystone species Nereis diversicolor. The chemical analyses of worms and sediments allowed the designation of the Seine estuary and the Authie estuary as a polluted and relatively clean site respectively. Worms from the Seine estuary exhibited higher GST and lower AChE activities. Generally, larger worms had higher concentrations of energy reserves. Principal component analyses clearly highlighted intersite differences: in the first plan, GST activities and chemical concentrations were inversely related to concentrations of energy reserves; in the second one, PCB concentrations and AChE activity were inversely related. Depleted levels of energy reserves could be a consequence of combating toxicants and might predict effects at higher levels of biological organization. The use of GST and AChE activities and energy reserve concentrations as biomarkers is validated in the field in this keystone species. PMID:17289233

  17. Isolation and identification of a novel polysaccharide-peptide complex with antioxidant, anti-proliferative and hypoglycaemic activities from the abalone mushroom.

    Li, Ning; Li, Le; Fang, Jin Cen; Wong, Jack Ho; Ng, Tzi Bun; Jiang, Yun; Wang, Chang Rong; Zhang, Ni Ye; Wen, Ting Yi; Qu, Li Yuan; Lv, Peng Yun; Zhao, Ruili; Shi, Bin; Wang, Yin Ping; Wang, Xiao Ying; Liu, Fang

    2012-06-01

    A novel antioxidant polysaccharide-peptide complex LB-1b from the fruiting bodies of the edible abalone mushroom (Pleurotus abalonus) was purified and identified. The structural characteristic of LB-1b was identified by FTIR (Fourier-transform IR), 13C NMR and 1H NMR spectroscopy. LB-1b is a polysaccharide-peptide complex that contains glucose, rhamnose, glucuronic acid and galactose in the molar ratio of 22.4:1:1.7:1.6 and the N-terminal sequence of its peptide moiety has also been determined. The N-terminal amino acid sequence of LB-1b, IPKERKEFQQAQHLK, showed some resemblance to antioxidant enzymes. LB-1b exhibited high antioxidant activity in erythrocyte haemolysis in vitro and the anti-proliferative activity towards hepatoma HepG2 cells and breast cancer MCF7 cells with an IC50 of 24 and 14 μM respectively. LB-1b also demonstrated hypoglycaemic activity in drug-induced diabetic mice and anti-HIV-1 RT (reverse transcriptase) with an IC50 value of 12.5 μM. PMID:21810081

  18. Identification of 1-hydroxypyrene glucuronide in tissue of marine polychaete Nereis diversicolor by liquid chromatography/ion trap multiple mass spectrometry.

    Giessing, Anders M B; Lund, Torben

    2002-01-01

    1-Hydroxypyrene glucuronide is identified as the single major aqueous metabolite of the tetracyclic aromatic hydrocarbon pyrene, in tissue from a deposit-feeding marine polychaete, Nereis diversicolor. Identification was performed using an ion trap mass spectrometer fitted with an atmospheric pressure chemical ionization (APCI) probe and connected to a high-performance liquid chromatography/diode array detector (HPLC/DAD) system. Besides 1-hydroxypyrene, the 339-nm UV trace of tissue samples from pyrene-exposed worms showed only one dominant peak that could be related to pyrene metabolism. Negative APCI-MS of this supposed 1- hydroxypyrene conjugate gave a characteristic signal at m/z 429 corresponding to the molecular ion of 1-hydroxypyrene glucuronide plus eluent adducts ([M - H + 2H(2)O](-)). Fragmentation pathways were studied by isolating the abundant ion at m/z 429 in the ion trap and performing multiple mass spectrometric experiments (MS(n)). The fragmentations observed were consistent with the proposed identification. Two low intensity LC peaks that could be related to pyrene metabolism by their DAD absorption spectra were also present in the 339-nm UV chromatogram of tissue samples. However, these peaks could not be identified by their mass spectra in negative ion mode due to ion suppression by very abundant co-eluting impurities. The present method shows that LC/MS(n) is a fast and useful analytical tool for identification of aqueous polycyclic aromatic hydrocarbon biotransformation products in samples from relatively small marine invertebrates with limited sample preparation. PMID:12203242

  19. A comparison of acute and chronic toxicity tests used to examine the temporal stability of a gradient in copper tolerance of Hediste diversicolor from the Fal estuary, Cornwall, UK.

    Burlinson, F C; Lawrence, A J

    2007-01-01

    The aim of this study was to use two different toxicity tests to verify the existence of a gradient in tolerance along Rostronguet Creek. Hediste diversicolor was collected from five populations in the Fal estuary previously shown to vary in copper tolerance. Exposure to 4 mgL(-1) of copper in an acute assay demonstrated that Mylor Creek worms were sensitive (LT(50) 86 h) and the tolerance of Rostronguet Creek worms increased moving upstream from the mouth of the creek (LT(50)s 100-258 h). There was no significant difference in tolerance between Mylor worms and worms from the mouth of Rostronguet Creek. This is in agreement with a previous study [Grant, A., Hateley, J.G., Jones, N.V., 1989. Mapping the ecological impact of heavy metals on the estuarine polychaete Nereis diversicolor using inherited metal tolerance. Marine Pollution Bulletin 20, 235-238] and demonstrates temporal stability of the gradient. Copper tolerance was also measured using a chronic toxicity test run for 90 d using step-wise increases in challenge concentration. A significant difference in tolerance was shown between populations from Mylor Creek and those at the mouth of Rostronguet Creek, which has not been reported previously. Experimental protocol was therefore an important factor in detecting population variation in tolerance. PMID:17113608

  20. Fate of isotopically labeled zinc oxide nanoparticles in sediment and effects on two endobenthic species, the clam Scrobicularia plana and the ragworm Hediste diversicolor.

    Buffet, Pierre-Emmanuel; Amiard-Triquet, Claude; Dybowska, Agnieszka; Risso-de Faverney, Christine; Guibbolini, Marielle; Valsami-Jones, Eugénia; Mouneyrac, Catherine

    2012-10-01

    Although it is reported that metal and metal oxide nanoparticles, which are among the most rapidly commercialized materials, can cause toxicity to organisms, their fate in the environment and toxicity to marine organisms are not well understood. In this study, we used a stable isotope labelling approach to trace the fate of nanoparticles (NPs) in sediments and also investigated bio-uptake in two estuarine intra-sedimentary invertebrates Scrobicularia plana and Nereis diversicolor. We selected exposure to 3 mg kg(-1) sediment ZnO NPs since this level is a realistic prediction of the environmental concentration in sediments. 67ZnO NPs (DLS: 21-34 nm, positively charged: 31.3 mV) suspensions were synthesised in diethylene glycol (DEG). We explored the fate of 67ZnO NPs in sediment, 67Zn bioaccumulation and the biochemical (biomarkers of defence and damage) and behavioural (burrowing kinetics and feeding rates) biomarkers in both species to 67ZnO NPs and DEG on its own during a 16 d laboratory exposure. After exposure, 67Zn concentrations in sediment showed higher levels in the upper section (1cm: 2.59 mg kg(-1)) decreasing progressively (2 cm: 1.63 mg kg(-1), 3 cm: 0.90 mg kg(-1), 4 cm: 0.67 mg kg(-1)) to a minimum value at the bottom (5 cm: 0.31 mg kg(-1)). 67Zn bioaccumulation was observed in both organisms exposed to 67ZnO NPs in DEG but no major inter-species differences were found. At the biochemical level, 67ZnO NPs exposure significantly induced increased glutathione-S-transferase activity in worms and catalase activity in clams whereas superoxide dismutase activity and thiobarbituric acid reactive substance levels were not affected in any species. Exposure to DEG on its own leads to a significant increase of metallothionein-like protein levels in clams compared with those exposed to 67ZnO NPs or controls. Burrowing behaviour as well as feeding rate were significantly impaired in both species exposed to 67ZnO NPs. Concerning exposure to DEG on its own

  1. Hierarchical super-structure identified by polarized light microscopy, electron microscopy and nanoindentation: Implications for the limits of biological control over the growth mode of abalone sea shells

    Schneider Andreas S

    2012-09-01

    Full Text Available Abstract Background Mollusc shells are commonly investigated using high-resolution imaging techniques based on cryo-fixation. Less detailed information is available regarding the light-optical properties. Sea shells of Haliotis pulcherina were embedded for polishing in defined orientations in order to investigate the interface between prismatic calcite and nacreous aragonite by standard materialographic methods. A polished thin section of the interface was prepared with a defined thickness of 60 μm for quantitative birefringence analysis using polarized light and LC-PolScope microscopy. Scanning electron microscopy images were obtained for comparison. In order to study structural-mechanical relationships, nanoindentation experiments were performed. Results Incident light microscopy revealed a super-structure in semi-transparent regions of the polished cross-section under a defined angle. This super-structure is not visible in transmitted birefringence analysis due to the blurred polarization of small nacre platelets and numerous organic interfaces. The relative orientation and homogeneity of calcite prisms was directly identified, some of them with their optical axes exactly normal to the imaging plane. Co-oriented "prism colonies" were identified by polarized light analyses. The nacreous super-structure was also visualized by secondary electron imaging under defined angles. The domains of the super-structure were interpreted to consist of crystallographically aligned platelet stacks. Nanoindentation experiments showed that mechanical properties changed with the same periodicity as the domain size. Conclusions In this study, we have demonstrated that insights into the growth mechanisms of nacre can be obtained by conventional light-optical methods. For example, we observed super-structures formed by co-oriented nacre platelets as previously identified using X-ray Photo-electron Emission Microscopy (X-PEEM [Gilbert et al., Journal of the

  2. The effect of sewage pollution on the feeding behaviour and diet of Hediste (Nereis diversicolor (O.F. Müller, 1776)) in three estuaries in south-east England, with implications for saltmarsh erosion.

    Aberson, M J R; Bolam, S G; Hughes, R G

    2016-04-15

    Stable isotope analyses of the abundant infaunal polychaete Hediste diversicolor, recognised as an indicator of sewage pollution, support the hypothesis that nutrient enrichment promotes surface deposit feeding, over suspension feeding and predation. At sewage-polluted sites in three estuaries in SE England Hediste mainly consumed microphytobenthos, sediment organic matter and filamentous macroalgae Ulva spp. At cleaner sites Hediste relied more on suspension feeding and consumption of Spartina anglica. There were no consistent differences in Hediste densities between the polluted and cleaner sites, probably because of increased densities at the cleaner sites too, facilitated by the planting of Spartina and nitrogen enrichment there too, including from agricultural run-off. Increased nutrient enrichment and the artificial availability of Spartina have probably increased densities of, and deposit-feeding by, Hediste in the past half-century and contributed indirectly to saltmarsh losses, since deposit-feeding by Hediste has been implicated in recent saltmarsh erosion in SE England. PMID:26902686

  3. 不同密度的皱纹盘鲍(Haliotis discus hannai Ino)与仿刺参(Apostichopus japonicus Selenka)混养的研究

    王吉桥; 杨义; 程鑫; 王年斌; 张剑诚

    2007-01-01

    在水温13.0-23.0℃、容积50L(45cm×31cm×30cm)的塑料水槽中,分别放养5、10和20个重(2.7±0.7)g的皱纹盘鲍(Haliotis discushannai Ino),多量投喂海带,再分别混养0和5头重(1.8±0.5)g的仿刺参(Apostichopus japonicus Selenka),不投喂。153d的饲养表明,在相同密度下,混养鲍的特殊生长率(SGR)和成活率依次比单养高16.6%、5.7%;7.1%、7.1%;1.9%、10.4%;饲料系数降低了11.7%、5.8%、2.4%。与单养池相比,混养池水中氨氮含量低而稳,溶氧量高。文中讨论了鲍与仿刺参混养的适宜比例和方式。

  4. Cellular energy allocation in Hediste (Nereis) diversicolor

    2006-01-01

    Abstract Perfluorinated alkylated substances (PFAS) are persistent compounds with many uses, for example impregnation of fabrics and leather and as fire-retardants. Recently, it has focused on these compounds, because of their wide environmental distribution and the lack of knowledge about their behaviour in the environment. Since they have been detected in the Nordic marine environment, two PFAS were chosen as test compounds. Tributyltin (TBT) has been used in anti-fouling paints since th...

  5. Assessment of the local environmental impact of abalone suspended longline culture-Application of the MOM system in Sungo Bay%筏式养鲍对沉积环境压力的评价——MOM-B监测系统模型在桑沟湾的应用

    张继红; 任黎华; 吴桃; 张明亮; 王巍; 方建光

    2011-01-01

    于2010年5月、7月、8月和10月对桑沟湾筏式养鲍区的沉积环境进行现场调查,采用娜威海洋研究所建立的鱼类养殖环境监测系统模型(Modelling-Ongrowing fish farms-Monitoring,MOM system),应用MOM-B着重对鲍养殖区的沉积环境状况进行监测和评价,由生物、化学和感官指标组组成.生物指标组的结果显示,各站位都有大型底栖动物,鲍养殖区处于1,2或者3等级.根据化学指标组(pH值和氧化还原电位Eh)和感官指标组(颜色、气味、气泡、粘稠度等)的监测结果进行了进一步的评价,结果显示,各站位的pH>7.0,为弱碱性,沉积物都无气泡产生,无臭味或硫化氢气味.鲍养殖区的沉积环境状况整体良好,5月和7月为1级,8月和10月为2级.虽然鲍养殖区目前的沉积环境状况较好,但需要注意的是8月和10月Eh<0,沉积环境已经处于还原状态,可能与鲍养殖压力有关.%Sediment environmental parameters were investigated in abalone long-line culture area of Sungo Bay in May, July, August and October, 2010.Impact of abalone long-line culture on the sediment environment was assessed by the method of Norway MOM system ( Modelling-Ongrowing fish farms-Monitoring).Faunal investigation results showed animals larger than 1 mm in the sediment is present, environmental condition was not unacceptable.Chemical investigation and sensory investigation results showed pH of each station was greater than 7.0, no gas bubbles and without H2S smell.Totally, the sediment environment was well, of condition 1 in May and July, condition 2 in August and October.Current situation is good, but it should be pay more attention that, the redox potential values were negative in August and October, the sedimentary environment was in reductive state, which stress may related of abalone long-line culture.

  6. 一株高产琼胶酶菌株MA-B22的分子鉴定与产酶条件优化%Isolation and identification of a bacterium MA-B22 producing agarase and the optimal cultivation of enzyme production

    卢斌; 柯才焕; 杨明; 康康; 赵晶

    2009-01-01

    琼胶酶在多糖降解应用中的作用日益重要,而从海洋微生物中筛选琼胶酶高产菌株成为一个重要途径.本研究从养殖的杂色鲍体内分离到一株高产琼胶酶的菌株MA-B22.该菌为革兰氏阴性菌,经16S rRNA序列鉴定表明,与Tamlana agarivorans sp.nov.具有99%同源性,因此初步定为Tamlana sp..在2216E培养基中该菌株在培养时间60 h,温度25℃,起始pH为6.0条件下产酶活性最高.基于上述培养条件,通过单因素和正交实验确定了培养基的最佳基本组成:氮源为牛肉膏(其最适浓度为6.0‰),碳源为琼脂(其最适浓度为2.5‰),配制培养基的人工海水的最适盐度为25.经培养条件优化后,该菌胞外琼胶酶活力可达1021.79 U/mL,较优化前提高8.82倍.实验首次对Tamlana sp.属的琼胶酶活性进行确定并优化其产酶条件,为构建琼胶酶高产工程菌株提供了基础,并可能为今后鲍养殖提供潜在的益生菌.%Agarase plays a key role in degrading many complex polysaccharides. The screening of agar-degrading bacteria from marine environment and organisms becomes an important means. A gram-negative bacterial strain, MA-B22 with high agarase activity was isolated from small abalone Haliotis diversicolor. By 16S rRNA analysis, this strain has 99% homology to Tamlana agarivorans sp. Nov. , it was named Tamlana sp. In this report. Under 2216E medium, the optimal temperature, pH value and culture time are 25℃, 6.0 and 60h respectively. With one-factor-at-a-time method and orthogonal designed experiment, the optimal compositions of the ferment medium were confirmed. It contained 2.5‰ agar, 6.0‰ beef extract based on the salinity of 25. The highest enzyme activity of agarase was detected by DNS method at 1021.79 U/mL, which is 8.82 times higher than before. MA-B22 demonstrated high-performance characteristics of enzyme production. This is the first report on the agar-degrading Tamlana sp. And optimal cultivation to

  7. The hyperparasite of the rickettsiales-like prokaryote, Candidatus Xenohaliotis californiensis has morphological characteristics of a Siphoviridae (Caudovirales).

    Cruz-Flores, Roberto; Cáceres-Martínez, Jorge

    2016-01-01

    Transmission electron microscopy analysis (TEM) of the rickettsiales-like prokaryote, Candidatus Xenohaliotis californiensis (CXc), pathogen of Haliotis spp. from the West Coast of North America, were found to be infected by a bacteriophage hyperparasite previously described in red abalone from California. The hyperparasite has an icosahedrical-like capsid with a narrow long flexible tail, this morphological characteristic tentatively place this virus in the Family Siphoviridae from the order Caudovirales. TEM images also showed the bacteriophage in different stages of assembly in the cytoplasm of CXc, demonstrating its lytic cycle. PMID:26585301

  8. Effects of offshore oil and gas development activities in southern California on larval settlement

    A series of in situ field experiments were conducted to determine effects of oil and gas drilling activities on the settlement of marine larvae in the deep ocean (180 m). The study sites were a series of three drilling rigs and three reference sites between Pt. Arguello and Pt. Conception in California. Experiments were carried out in both pre-drilling and drilling phases to test the effects of drilling activities (e.g. drilling, drilling mud release, and produced water discharges) on the ability of red abalone (Haliotis rufescens) larvae to settle using an in situ experiment. Their in situ experiment involved reciprocal transplants of settling plates that were ''filmed'' with bacteria from each site. After filming in the field at each of two heights, plates were mounted into chambers, covered with mesh and placed onto recoverable larval arrays for deployment in the field. Before deployment the authors injected approximately 300 competent red abalone larvae into each chamber. One larval array was deployed at each site for three days and each array contained plates filmed at all sites. In addition sterile plates (no surface filming) were included at each site. Upon recovery the number of settled abalone larvae were counted. Therefore, the experiment tested location-related (drilling sites versus reference), waterborne, and height effects on settlement in both the pre-drilling and drilling phases. Their results show that red abalone served as a sensitive indicator for in situ studies of larval settlement. The authors found significantly higher numbers of abalone settling onto plates that were filmed versus those that were not. The authors also found significantly lower settlement rates between the pre-drilling and drilling periods

  9. Cryo-EM structure of isomeric molluscan hemocyanin triggered by viral infection.

    Hongtao Zhu

    Full Text Available Hemocyanins (Hcs of arthropods and mollusks function not only as oxygen transporters, but also as phenoloxidases (POs. In invertebrates, PO is an important component in the innate immune cascade, where it functions as the initiator of melanin synthesis, a pigment involved in encapsulating and killing of pathogenic microbes. Although structures of Hc from several species of invertebrates have been reported, the structural basis for how PO activity is triggered by structural changes of Hc in vivo remains poorly understood. Here, we report a 6.8 Å cryo-electron microscopy (cryo-EM structure of the isomeric form of hemocyanin, which was isolated from Abalone Shriveling syndrome-associated Virus (AbSV infected abalone (Halitotis diversicolor, and build a pseudoatomic model of isomeric H. diversicolor hemocyanin 1 (HdH1. Our results show that, compared with native form of HdH1, the architecture of isomeric HdH1 turns into a more relaxed form. The interactions between certain functional units (FUs present in the native form of Hc either decreased or were totally abolished in the isomeric form of Hc. As a result of that, native state Hc switches to its isomeric form, enabling it to play its role in innate immune responses against invading pathogens.

  10. Concentration of radioactive cobalt by seaweeds in the food chain

    On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link of food chain in the sea. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer expts. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26 through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (auth.)

  11. Concentration of radioactive cobalt by seaweeds in the food chain

    On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link in the food chain. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer experiments. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26% through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (author)

  12. Sublethal Toxic Effects of Water Pollution on Red Abalone

    Tjeerdema, Ronald

    2002-01-01

    Though difficult to quantify, chemicals in agricultural and urban runoff are contributing to population declines of commercially valuable marine species. Although these pollutants may not be immediately lethal to marine organisms, they can impair key biological processes, hindering reproduction and causing early death.

  13. One-dimensional photonic bandgap structure in abalone shell

    LI Bo; ZHOU Ji; LI Longtu; LI Qi; HAN Shuo; HAO Zhibiao

    2005-01-01

    @@ Photonic bandgap (PBG) materials are periodic com- posites of dielectric materials in which electromagnetic waves of certain frequency range cannot propagate in any or a special direction. Recently, there has been great inter- est in synthetic PBG materials due to their ability in ma- nipulation of photons. Since 500 million years ago, the natural world has been exploiting photonic structures for specific biological purposes[1]. Different types of biologi- cal PBG materials have been discovered in recent years, such as the one-dimension PBG structure in the sea mouse Aphrodita[2], and the fruits Elaeocarpus[3,4]; two-dimension PBG structure in the male peacock Pavo muticus feathers[5], Indonesian male Papilio palinurus butterfly[6], Thaumantis diores butterfly[7] and the male Ancyluris meliboeus Fabricius butterflies[8]; and three-dimension PBG structure in the weevil Pachyrhynchus argus[9].

  14. Dicty_cDB: SSC652 [Dicty_cDB

    Full Text Available 60 (AT... 229 4e-59 EU244369_1( EU244369 |pid:none) Haliotis diversicolor clone HDr4CJ... 229 4e-59 CR380951...3Q.Seq.d/ 394 e-109 own update 2002.12.12 Homology vs DNA Score E Sequences producing significant alignments... breaker fruit, TIGR Lycopersicon esculentum cDNA clone cLEG10K8, mRNA sequence. 52 1e-14 3 BE342564 |BE3425...A20O8, mRNA sequence. 52 1e-14 3 dna update 2003. 7.30 Homology vs Protein Score E Sequences producing signific...ISALLSDPNPDDPLVPDIANLFK TDKNRFESNAREWTRKYAQ*fftnr*gnpkkkiffgerlnf*nkq*kfcykskkk Homology vs CSM-cDNA Score E Sequences producing si

  15. Dicty_cDB: Contig-U12391-1 [Dicty_cDB

    Full Text Available BC097212 |pid:none) Danio rerio zgc:114162, mRNA (cDNA... 56 2e-06 ( Q02605 ) RecName: Full=Chaperone prote...623 |pid:none) Gallus gallus mRNA for hypothetica... 61 1e-07 DQ144980_1( DQ144980 |pid:none) Symbiodinium s...is thaliana BAC TM021B04.... 59 5e-07 EU244371_1( EU244371 |pid:none) Haliotis diversicolor clone HDr4CJ... ...m... 57 1e-06 CP001047_221( CP001047 |pid:none) Mycoplasma arthritidis 158L3-1, ... 57 1e-06 (B5...6 S42091( S42091 ) Tid(56) protein - fruit fly (Drosophila melanogas... 55 7e-06 AB292574_1( AB292574 |pid:none) Mycobacterium per

  16. Dicty_cDB: Contig-U06890-1 [Dicty_cDB

    Full Text Available mos... 37 0.17 DQ144988_1( DQ144988 |pid:none) Symbiodinium sp. C3 ubiquitin conj... 37 0.17 AB026055_1( AB026055 |pid:none) Nico...2 ) 214PbH05 Pb MBN #21 Plasmodium berghei genomic 3'... 48 0.28 1 ( DE144715 ) Bombyx mori genomic DNA, Fos...U244369_1( EU244369 |pid:none) Haliotis diversicolor clone HDr4CJ... 39 0.074 FJ4....63 FN392322_448( FN392322 |pid:none) Pichia pastoris GS115 chromosome... 35 0.63 BC155782_1( BC155782 |pid:none) Danio rerio...047863_1( BC047863 |pid:none) Danio rerio zgc:56340, mRNA (cDNA ... 33 2.4 AM448784_1( AM448784 |pid:none) Vitis vinifera co

  17. New toughening concepts for ceramic composites from rigid natural materials.

    Mayer, George

    2011-07-01

    The mechanisms underlying the toughening in rigid natural composites exhibited by the concentric cylindrical composites of spicules of hexactinellid sponges, and by the nacre (brick-and-mortar) structure of mollusks such as Haliotis rufescens (red abalone), as well as the crossed-lamellar structure of Strombus gigas (queen conch) show commonalities in the manner in which toughening takes place. It is proposed that crack diversion, a new kind of crack bridging, resulting in retardation of delamination, creation of new surface areas, and other energy-dissipating mechanisms occur in both natural systems. However, these are generally different from the toughening mechanisms that are utilized for other classes of structural materials. Complementary to those mechanisms found in rigid natural ceramic/organic composites, special architectures and thin viscoelastic organic layers have been found to play controlling roles in energy dissipation in these structures. PMID:21565715

  18. The inventory of mollusc species and its potent on seagrass bed in Kei Kecil Islands, Southeast Moluccas

    AGUS KUSNADI

    2008-10-01

    Full Text Available Inventory of mollusk species and its potential on sea grass bed in Kei Kecil islands, Southeast Moluccas have been conducted by using quadrate-transect line method. The study was carried out in February-August 2007. There were 103 species of mollusk observed, 80 species belong to gastropods and 23 belong to bivalves. From the total species, 72 of them were reported as the potential species and the others still unknown. Most of potential group was used as food resources (55 species and other species were potential as decoration, souvenir, ornament, and accessories (31 species. Some species were potential for building material, knife tool, barter tool and bioactive compounds. The top shells (Trochus niloticus, the giant clams (Tridacna spp. and Hippopus hippopus and the abalone (Haliotis spp. were the major trading commodities for shellfish fisheries.

  19. Viscoelastic response of anisotropic biological membranes. Part II: Constitutive models

    Lubarda Vlado A.

    2014-01-01

    Full Text Available In Part I of this series [7] we described the structure of the biopolymer interlayers found in the shell of the mollusk Haliotis rufescens (the red abalone. There we described how the layers can be viewed as a viscoelastic composite reinforced by a network of chitin fibrils arranged in an often nearly unidirectional architecture. Mechanical testing documented the response to tensile testing of layers removed via demineralization. Herein in Part II we describe a general viscoelastic constitutive model for such layers that may be both transversely isotropic or orthotropic as would follow from the network of nearly aligned chitin fibrils described by Bezares et al. in Part I [7]. Part III of this series will be concerned with applying the models to more fully describing the response of these types of biological membranes to mechanical loading.

  20. Variations of 210Po and 210Pb in various marine organisms from Western English Channel: contribution of 210Po to the radiation dose

    Measurements of 210Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg-1 (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg-1 (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. 210Po/210Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 103 and 5.0 x 103) and for molluscs, with highest CFs (>105) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to 210Po received by the marine organisms (0.05 μG h-1 for macroalgae, between 0.70 and 1.5 μG h-1 for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 μSv y-1)

  1. Variations of {sup 210}Po and {sup 210}Pb in various marine organisms from Western English Channel: contribution of {sup 210}Po to the radiation dose

    Connan, O. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)], E-mail: olivier.connan@irsn.fr; Germain, P.; Solier, L.; Gouret, G. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire de Radioecologie de Cherbourg-Octeville, IRSN/DEI/SECRE/LRC, Rue Max Pol Fouchet, 50130 Cherbourg-Octeville (France)

    2007-10-15

    Measurements of {sup 210}Po were carried out in various marine matrices (mussels, oysters, seaweed, fish, and abalones) and in seawater at several points along the French coast, over a period of 2 years (2003-2005). These measurements contribute to a better knowledge of this element, since few recent data exist for the French coast. Marked seasonal variations have been revealed in some species and there are differences according to the way of life of these species. Activities in mussels (Mytilus edulis) and oysters (Crassostrea gigas) are similar and varying between 90 and 600 Bq kg{sup -1} (d.w.). Activities in macroalgae (Fucus serratus) are lowest, between 4 and 16 Bq kg{sup -1} (d.w.). In oyster, abalone (Haliotis tuberculata) and fish (Solea solea, Sparus sp.), the strongest activities are measured in the digestive glands, the gills and the gonads. {sup 210}Po/{sup 210}Pb ratios in all cases have values of more than one for all species. From a significant number of measurements, CFs were calculated for seaweed (between 4.6 x 10{sup 3} and 5.0 x 10{sup 3}) and for molluscs, with highest CFs (>10{sup 5}) found for the digestive gland and gills of the oysters, the digestive gland of the abalones and the liver of fish. Finally, the activities measured have made it possible to estimate the internal dose from chronic exposure due to {sup 210}Po received by the marine organisms (0.05 {mu}G h{sup -1} for macroalgae, between 0.70 and 1.5 {mu}G h{sup -1} for mussels and oyster), and the contribution of seafood to the dose received by humans (46-129 {mu}Sv y{sup -1})

  2. ЭКОЛОГИЧЕСКИЕ ОСОБЕННОСТИ И МНОГОЛЕТНЯЯ ДИНАМИКА РАСПРЕДЕЛЕНИЯ БИОМАССЫ И ЧИСЛЕННОСТИ МНОГОЩЕТИНКОВОГО ЧЕРВЯ NEREIS DIVERSICOLOR O. F MULLER У ДАГЕСТАНСКОГО ПРИБРЕЖЬЯ СРЕДНЕГО КАСПИЯ

    Исрапов, Исрап; Абдулмеджидов, Ахмед; Гаписова, Умаган

    2013-01-01

    В статье представлены данные о многолетних изменениях распределения биомассы и численности многощетинкового червя Nereis diversicolor O. F Muller и показаны ее экологические особенности у дагестанского прибрежья Среднего Каспия.

  3. Environ: E00356 [KEGG MEDICUS

    Full Text Available E00356 Haliotis shell ... Crude drug Calcium carbonate [CPD:C08129], Organic compound, Magnesium, Ir ... Haliotis gigantea [TAX:37743] Haliotidae Haliotis shell ... Compound(Haliotis discus): Calcium carbonate, Orga ... rugs [BR:br08305] Animals Mollusks E00356 Haliotis shell ...

  4. The role of MAPK signaling in patterning and establishing axial symmetry in the gastropod Haliotis asinina

    Koop, Demian; Richards, Gemma S; Wanninger, Andreas;

    2007-01-01

    Gastropods are members of the Spiralia, a diverse group of invertebrates that share a common early developmental program, which includes spiral cleavage and a larval trochophore stage. The spiral cleavage program results in the division of the embryo into four quadrants. Specification of the dorsal...

  5. 1-Hydroxypyrene as a biomarker of PAH exposure in the marine polychaete Nereis diversicolor

    Tairova, Zhanna; Giessing, Anders; Hansen, Rikke;

    2009-01-01

    /F), synchronous fluorescence spectroscopy (SFS) and gas chromatography with mass spectrometric detection (GC/MS). The 5FS measurements of 1-hydroxypyrene were validated by the more sensitive method HPLC/F. The positive correlation between total PAHs and 1-hydroxypyrene concentrations in the polychaete tissues...... observed in experiments, suggests the feasibility of 1-hydroxypyrene as a suitable biomarker for total PAH exposure assessment. Furthermore, the possibility of employment of the simple and rapid SFS method instead of HPLC/F for biomarker analysis has been confirmed by the positive and significant...... PAHs phenanthrene, anthracene, pyrene, benzo[a]pyrene and benzo[k]flouranthene. After five days of exposure the concentrations of parent PAHs and 1-hydroxypyrene were identified using three different analytical methods, high-performance liquid chromatography with fluorescence detection (HPLC...

  6. Toxicity and bioaccumulation of sediment-associated silvernanoparticles in the estuarine polychaete, Nereis (Hediste) diversicolor

    Cong, Yi; Banta, Gary Thomas; Selck, Henriette;

    2014-01-01

    damage (comet assay tail moment and tail DNA intensity %) of Nereis coelomocytes increased in a concentration-dependent manner in all three Ag treatments. Ag NP treatments were more toxic than aqueous Ag for all toxicity endpoints, even though bioaccumulation did not differ significantly among Ag forms...

  7. Phylogeography of the Sponge Suberites diversicolor in Indonesia: insights into the evolution of marine lake populations

    Becking, L.E.; Erpenbeck, D.; Peijnenburg, K.T.C.A.; Voogd, de N.J.

    2013-01-01

    The existence of multiple independently derived populations in landlocked marine lakes provides an opportunity for fundamental research into the role of isolation in population divergence and speciation in marine taxa. Marine lakes are landlocked water bodies that maintain a marine character through

  8. Effects of Nereis diversicolor on the transformation of 1-Methylpyrene and Pyrene

    Malmquist, Linus Mattias Valdemar; Christensen, Jan H.; Selck, Henriette

    2013-01-01

    -glucuronide as the most prominent metabolite. Transformation of 1-methylpyrene (21% transformed) was more than 3 times as efficient as pyrene transformation (5.6% transformed). Because crude oils contain larger amounts of C1−C4-substituted PAHs than nonsubstituted PAHs, the rapid and efficient transformation...... of sediment-associated 1-methylpyrene may result in a high exposure of water-living organisms to metabolites of alkyl-substituted PAHs, whose toxicities are unknown. This study demonstrates the need to consider fate and effects of substituted PAHs and their metabolites in risk assessments....

  9. Isolasi Dan Identifikasi Senyawa Steroid/Triterpenoid Dari Sponge Suberites diversicolor Becking & Lim

    Siahaan, Dewi Fransiska

    2015-01-01

    Indonesian seas are part Indopasifik region which is one of the centers of diversity of marine life in the world. One example is amarine sponge. Sponge is a source of compounds of natural materials such as terpenoid, steroid and alkaloid. Compounds steroid/triterpenoid used as oral contraceptives, antiinflammatory, antidiabetic, skin disorders and liver damage. The purpose of this study was to determine the characteristics of crude drug, isolating the compounds steroid/triterpenoid of sponge ...

  10. Indirect control of the intracellular nitrate pool of intertidal sediment by the polychaete Hediste diversicolor

    Heisterkamp, Ines Maria; Kamp, Anja; Schramm, Angela T.; de Beer, Dirk; Stief, Peter

    2012-01-01

    In an intertidal flat of the German Wadden Sea, a large sedimentary pool of intracel- lular nitrate was discovered that by far exceeded the pool of nitrate that was freely dissolved in the porewater. Intracellular nitrate was even present deep in anoxic sediment layers where it might be used for ...

  11. Marenzelleria viridis vs. Nereis diversicolor: Their Effects on the Nutreint Cycling in Danish Coastal Ecosystems

    Calderon, Ernesto; Essinger, Alexandria; Lassen, Mette; Niclasen, Laura; Stenz, Marta

    2013-01-01

    The effect of the invasive species Marenzeleria viridis and the native species Nereis dirvesicolor in the sediment nutrient dynamics was studied over the period of one month and a half. The two species were studied in a laboratory experiment separately and in combination to observe the effects on sediment metabolism (O2 uptake), and nutrient release; nitrogen (NH4+ and NO3) and phosphorous (PO43-). A 2x2, with 4 replicates design was established with 4 treatments; (1) Control, (2) Marenzeller...

  12. Polycyclic Aromatic Acids Are Primary Metabolites of Alkyl-PAHs-A Case Study with Nereis diversicolor.

    Malmquist, Linus M V; Selck, Henriette; Jørgensen, Kåre B; Christensen, Jan H

    2015-05-01

    Although concentrations of alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) in oil-contaminated sediments are higher than those of unsubstituted PAHs, only little attention has been given to metabolism and ecotoxicity of alkyl-PAHs. In this study we demonstrated that metabolism of alkyl-PAHs primarily forms polycyclic aromatic acids (PAAs). We generalize this to other alkyl-PAHs, based on literature and the present study of the metabolism of 1-methylphenanthrene, 3,6-dimethylphenanthrene, and 1-, 2-, 3-, and 6-methylchrysene related to their unsubstituted parent PAHs. Also, we observed that body burdens and production of PAAs was related to the position of the methyl group, showing the same isomer specific preferences as for microbial degradation of alkyl-PAHs. We detected a high production of PAAs, and larger metabolism of alkyl-PAHs than their unsubstituted parent PAHs. We therefore propose that carboxylic acid metabolites of alkyl-PAHs have the potential of constituting a new class of contaminants in marine waters that needs attention in relation to ecological risk assessments. PMID:25827176

  13. Black abalone habitat suitability model for Channel Islands National Marine Sanctuary Biogeographic Assessment

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries (ONMS) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the public,...

  14. Red abalone habitat suitability model for Channel Islands National Marine Sanctuary Biogeographic Assessment

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Sanctuary Program (NMSP) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the public,...

  15. White abalone habitat suitability model for Channel Islands National Marine Sanctuary Biogeographic Assessment

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Sanctuary Program (NMSP) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the public,...

  16. Comparative Studies on the Molecular Genetic Diversities among Haliotis discus hannai,H.discus discus and Their Hybrids

    Wan Junfen(万俊芬); Bao Zhenmin; Zhang Quanqi; Wang Xiaolong

    2004-01-01

    The hybrid (H. discus hannai♀× H. discus discus♂) shows strong heterosis in both growth and survival rates during aquaculture. In order to better understand the genetic basis of heterosis, AFLP markers are adopted to compare the genetic diversities of the two parents and their hybrids. Six primer combinations reveal 552 loci, among which 88 loci show significant difference between the two parent populations (P<0.01). Analysis of molecular variance (AMOVA) indicates the genetic variance between them is significantly different (P<0.001). Thus there should be genetic basis of heterosis for their hybrids. In contrast to parents, more loci with lower frequency are amplified in hybrids than those in parents, whereas the loci with 0% and 100% frequency are less in hybrids than those in parents. Moreover, the genetic diversities of hybrids increase since the similarity indexes are lower and heterozygosities are higher in hybrids than those in parents. In addition, the genetic distances between reciprocal F1s and H. discus discus are both smaller than those between reciprocal F1s H. discus hannai.

  17. 1-hydroxypyrene as a biomarker of PAH exposure in the marine invertebrates N. diversicolor

    Tairova, Zhanna; Giessing, Anders; Hansen, Rikke;

    develop such a biomarker, we quantified 1-hydroxypyrene and total PAH content in invertebrate tissues and studied the correlation between total PAHs and 1-hydroxypyrene concentrations. The total PAH content was measured by Gas Chromatography with Mass Spectrometry detection (GC/MS) and HPLC/F. The 1...... exposure assessment. Furthermore, the possibility of employment of the simple and rapid SFS method instead of HPLC/F for biomarker analysis has been confirmed by the positive and significant correlation between results achieved by these two analytical methods. Keywords: Sediment, PAH, Polychaetes...... serve as useful screening tools for preliminary stages of environmental risk assessment of PAH-contaminated sediment. Pyrene is one of the predominant pyrogenic PAHs and analysis of its metabolites provides an extra dimension to the environmental risk assessment of ecosystems with regard to PAH exposure...

  18. Polycyclic aromatic acids are primary metabolites of alkyl-PAHs - a case study with Nereis diversicolor

    Malmquist, Linus Mattias Valdemar; Selck, Henriette; Jørgensen, Kåre Bredeli; Christensen, Jan H.

    2015-01-01

    Although concentrations of alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) in oil-contaminated sediments are higher than those of unsubstituted PAHs, only little attention has been given to metabolism and ecotoxicity of alkyl-PAHs. In this study we demonstrated that metabolism of alkyl......-PAHs primarily forms polycyclic aromatic acids (PAAs). We generalize this to other alkyl-PAHs, based on literature and the present study of the metabolism of 1-methylphenanthrene, 3,6-dimethylphenanthrene, and 1-, 2-, 3-, and 6-methylchrysene related to their unsubstituted parent PAHs. Also, we observed that...

  19. Toxic effects and bioaccumulation of nano-, micron- and aqueous-Ag in the estuarine polychaete, Nereis (Hediste) diversicolor

    cong, Yi

    concern about the fate and potential risks of nanosilver for the aquatic environment after its eventual release via wastewater discharges. In this thesis, dispersion and stability tests of commercially available nano (water vs....... filtered natural seawater) were firstly performed with the purpose to investigate the behavior of Ag particles in aqueous environments. A sediment exposure pathway was selected for the following toxicity experiments (I and II) as both Ag particles tended to precipitate in the water phase over time. Due...... diameter and zeta potential was only carried out on nano-Ag in stock suspension (deionized water). However, we observed a clear difference of particle sizes between the manufacturer’s information and what we measured for both nano- and micron-Ag samples. In toxicity experiment I, toxic effects of sediment...

  20. Gamma-aminobutyric acid and 5-hydroxytryptamine in the nervous system of an annelid worm (Nereis diversicolor)

    Autoradiographic techniques have been employed to define the cellular elements involved in the elaboration of gamma-aminobutyric acid (GABA) and 5-hydroxytryptamine (5-HT) in the nervous system of Nereis. This procedure is described. Results concerning the distribution of 5-HT and GABA in Nereis are still incomplete. Nevertheless, as a result of these initial autoradiographic data, it seems possible to postulate an effect of 5-HT and GABA in the neuropil and in the peripheral nerves. 5-HT would also act in certain endplates located in the pharynx of Nereis, for instance. This monoamine, however, probably does not act the level of the infracerebral complex

  1. Spermatogenesis in Nereis diversicolor O.F. Mueller (Annelid Polychete) morphologic and autoradiographic study of nuclear evolution

    The evolution of nuclear structure was related to DNA and RNA syntheses, visualized by high resolution autoradiography. In spermatogonia, the nucleus shows chromatin clumps, irregular in shape and size. At this stage, 3H-uridine and 3H-thymidine incorporation is very low. In premeiotic interphase spermatocytes, a typical nuclear evolution is found. During the G1 period, chromatin strands constitute a regular reticulum. Autoradiography performed at this stage indicates a huge increase in RNA synthesis. During the S period, chromatin undergoes extensive dispersion. The G2 period seems to be marked by nucleolar regression and decrease in RNA synthesis. The possible relation between increase of RNA synthesis at premeiotic interphase and the differentiation of meiotic cells is discussed

  2. 78 FR 69033 - Endangered and Threatened Wildlife; 90-Day Finding on Petitions To List the Pinto Abalone as...

    2013-11-18

    ...; (2) food, water, air, light, minerals, or other nutritional or physiological requirements; (3) cover..., delisting, and reclassifying a species under the ESA (61 FR 4722; February 7, 1996). A species, subspecies... and for locomotion. The epipodium (the circular fringe of skin around the foot) and tentacles...

  3. Effects of Element Chelates Supplementation on Growth and Energy Transformation in Fish and Shellfish%复合螯合微量元素添加剂对鱼、贝生长及能量转化的影响

    赵元凤; 吕景才; 刘靖

    2001-01-01

    Inorganic salts and amino-acid chelates of some elements were added to Tilapia nilotica、common carp (Cyprinus carpio) and abalone (Haliotis discus hannai Ino) diets and the effect of the supplementation on growth and energy transformation were investigated. The results indicated that supplementation of element chelates of amino acids significantly increased weight gain of experimental fish compared with inorganic salt supplementation. Average specially designated growth rate of two experiment groups with two levels of supplementation of element chelates of amino acids increased by 89.25% and 79.61% in Tilapia nilotica; by 36.45% and 64.49% in abalone compared with corresponding control groups and increased by 55.00% in common carp when diet was supplemented with element chelates compared with when diet was supplemented with inorganic salts.%在罗非鱼、鲤鱼、皱纹盘鲍饲料中,分别添加氨基酸螯合盐添加剂和无机盐添加剂对罗非鱼、鲤鱼、皱纹盘鲍进行了对比喂养试验。结果表明:氨基酸螯合盐较无机盐具有显著促生长作用。添加螯合盐的2个试验组罗非鱼的平均特定生长率分别比无机盐对照组提高89.25%、79.61%;鲤鱼螯合盐试验组比对照组平均特定生长率提高55.00%;添加螯合盐的2个试验组皱纹盘鲍的平均特定生长率分别比对照组提高36.45%和64.49% 。

  4. Toughening mechanisms in laminated composites: A biomimetic study in mollusk shells

    Kamat, Shekhar Shripad

    2000-10-01

    Mollusk shells can be described as structural biocomposite materials composed of a mineral (aragonite) and a continuous, albeit minor, organic (protein) component. The conch shell, Strombus Gigas, has intermediate strength and high fracture toughness. The high fracture toughness is a result of enhanced energy dissipation during crack propagation due to delamination, crack bridging, frictional sliding etc. A theoretical and experimental study was conducted on the crack bridging mechanisms operative in the shell. Four-point bend tests were conducted. Acoustic emission and post-mortem dye penetrants were used to characterize the crack propagation, together with conventional fractography. A two layer composite configuration is seen in the shells, with the tough and weak layers having a toughness ratio of ˜4 (Ktough = 2.2MPam1/2). This toughness ratio is a requisite for multiple cracking in the weak layer. A theoretical shear lag analysis of the crack bridging phenomena in the tough layer is shown to lead to a bridging law for the crack wake of the form of p = betau1/2 (p is the bridging traction for a crack opening u, with beta, being a constant of proportionality). Finite element analysis yielded a value of beta = 630 Nmm-5/2 and ucritical = 5 mum for the bridging law parameters. In a nonlinear fracture mechanics phenomenology, these values are relevant material parameters, rather than a critical stress intensity factor. The work of fracture for unnotched specimens is three orders of magnitude higher than mineral aragonite, and is demonstrated numerically incorporating the toughening mechanisms in the shell. Similar structural adaptations have been observed and studied in the red abalone shell, haliotis rufescens and the spines of the sea urchin, Heterocentrotus trigonarius. The toughening mechanisms seen in these shells give insight into structural design needs of brittle matrix composites (BMC) as well as conventional structural ceramics.

  5. Biogeochemical studies of technetium in marine and estuarine ecosystems. Progress report, 1 July 1979-30 June 1980

    Progress is reported in research dealing with the biogeochemical behavior of technetium in marine and estuarine ecosystems. Studies were planned to elaborate the biokinetic behavior of Tc as TcO4- in selected marine and estuarine organisms and to determine the affinity of TcO4- for different marine sediments under oxygenated conditions. It is concluded that concentration factors for TcO4- in bivalve molluscs (oysters and mussels) do not exceed 2 when calculated for whole animals and when uptake is directly from water. Direct uptake from water by limpets (archeogastropod) are very much lower than have been reported for red abalone (archeogastropod). Whole body concentration factors for TcO4- in the plaice, Pleuronectes platessa, where uptake is directly from labeled seawater, do not exceed 10 at equilibrium. Both the lobster, Homarus gammaris and the polychaete, Nereis diversicolor appear to concentrate Tc efficiently from water labelled intially with TcO4-. Both plaice and rays (Raja clavata) fed /sup 95m/Tc labeled Nereis show an initial rapid loss of the isotope for approximately five days. Thereafter, loss is much reduced. Shrimp (Palaemon elegans), Cragnon sp.) and Crab (Cancer pagurus) show concentration factors similar to plaice (C.F. is less than 10). Isopods, however, have concentration factors of only 3 following four weeks exposure to labeled seawater. Uptake of TcO4- by phytoplankton is extremely low, which precludes experiments in which TcO4- labeled phytoplankton can be fed to either bivalve molluscs or microzooplankton. Sediment distribution coefficients for TcO4- are essentially zero and are independent of sediment type in well oxygenated seawater. Experiments to date have shown that it is not possible to make generalizations concerning the bioavailability of TcO4- to marine organisms

  6. Biogeochemical studies of technetium in marine and estuarine ecosystems. Progress report, 1 July 1979-30 June 1980

    Beasley, T. M.

    1980-01-01

    Progress is reported in research dealing with the biogeochemical behavior of technetium in marine and estuarine ecosystems. Studies were planned to elaborate the biokinetic behavior of Tc as TcO/sub 4//sup -/ in selected marine and estuarine organisms and to determine the affinity of TcO/sub 4//sup -/ for different marine sediments under oxygenated conditions. It is concluded that concentration factors for TcO/sub 4//sup -/ in bivalve molluscs (oysters and mussels) do not exceed 2 when calculated for whole animals and when uptake is directly from water. Direct uptake from water by limpets (archeogastropod) are very much lower than have been reported for red abalone (archeogastropod). Whole body concentration factors for TcO/sub 4//sup -/ in the plaice, Pleuronectes platessa, where uptake is directly from labeled seawater, do not exceed 10 at equilibrium. Both the lobster, Homarus gammaris and the polychaete, Nereis diversicolor appear to concentrate Tc efficiently from water labelled intially with TcO/sub 4//sup -/. Both plaice and rays (Raja clavata) fed /sup 95m/Tc labeled Nereis show an initial rapid loss of the isotope for approximately five days. Thereafter, loss is much reduced. Shrimp (Palaemon elegans), Cragnon sp.) and Crab (Cancer pagurus) show concentration factors similar to plaice (C.F. is less than 10). Isopods, however, have concentration factors of only 3 following four weeks exposure to labeled seawater. Uptake of TcO/sub 4//sup -/ by phytoplankton is extremely low, which precludes experiments in which TcO/sub 4//sup -/ labeled phytoplankton can be fed to either bivalve molluscs or microzooplankton. Sediment distribution coefficients for TcO/sub 4//sup -/ are essentially zero and are independent of sediment type in well oxygenated seawater. Experiments to date have shown that it is not possible to make generalizations concerning the bioavailability of TcO/sub 4//sup -/ to marine organisms.

  7. Risks of Cadmium Nanoparticles on Estuarine Organisms : Ecotoxicological Effects of Engineered Cadmium Nanoparticles through Biochemical and Behavioral Responses in Two Marine Invertebrates, Nereis diversicolor and Scrobicularia plana

    Wu, Pianpian

    2012-01-01

    There is an increasing concern over the safety of engineered nanoparticles (ENPs) to humans and the environment. It is important that the environmental risks of these particles to be tested under research and regulatory schemes, e.g. Nano Risks to the environment & Human Health (NanoReTox) under Seventh Framework Programme (FP7) in EU. Due to their unique properties and the fact that their detection and characterization in complex matrices is challenging, classic analytical methods and te...

  8. Bioaccumulation, subcellular distribution and toxicity of sediment-associated copper in the ragworm Nereis diversicolor: The relative importance of aqueous copper, copper oxide nanoparticles and microparticles

    Thit, Amalie; Banta, Gary Thomas; Selck, Henriette

    2015-01-01

    and worms exposed to CuONP or CuOMicro. In contrast, ≈50% of accumulated Cu in CuAq exposed worms was found in metal rich granules and significantly more Cu was present in heat-denatured proteins and organelles than in worms exposed to CuOMicro or in controls. Our results suggest that Cu form affects...... mean burrowing time increased during exposure to CuAq and CuONP from 0.12 h (controls) to 19.3 and 12.2 h, respectively. All Cu treatments bioaccumulated, especially CuAq (up to 4 times more than the other treatments). Cu was roughly equally distributed among the five subcellular fractions in controls...

  9. Phytoplankton reduction in near-bottom water caused by filter-feeding Nereis diversicolor - Implications for worm growth and population grazing impact

    Larsen, Poul Scheel; Riisgård, H. U.; Poulsen, L.

    1996-01-01

    Studies of vertical profiles of phytoplankton in the field combined with laboratory experiments demonstrated that reduction in phytoplankton concentrations in the near-bottom water layer, 5 to 10 cm in thickness on calm days, may play a significant role for the filter-feeding polychaete Nereis...

  10. Characterization of benthic types in the lower Medway estuary, Kent. [Nereis diversicolor; Polydora ciliata; Spiophanes bombyx; Hydrobia ulvae; Peloacolex benedeni; Capitella capitatus; Heteromastus filiformis; Caulleriella zetlandica

    Wharfe, J.R.

    1976-09-01

    A number of sediment parameters, including particle size and redox potential profiles, were measured during an ecological study of the benthic invertebrate macrofauna of the lower Medway estuary, Kent. The results proved more meaningful in characterizing the sediment habitats of the benthic invertebrate fauna than did measurements on the overlying water.

  11. Poliploidia en moluscos de importancia comercial (almeja catarina Argopecten ventricosus Sowerby ii, 1842; almeja mano de leon Nodipecten subnodosus Sowerby 1835; y abulón rojo Haliotis rufescens Swainson 1822)

    Maldonado, R.

    2003-01-01

    La poliploidía ha sido una de las biotecnologías más empleadas en la ultima década para el mejoramiento genético de moluscos bivalvos por ser una de las mejores alternativas a corto plazo para incrementar la producción. Los organismos triploides presentan tres juegos completos de cromosomas homólogos que afectan la sinapsis, lo cual da como resultado una esterilidad parcial o total, la cual teóricamente repercute favorablemente en el crecimiento. Sin embargo, la inducción a la triploidía pres...

  12. 40 CFR Appendix A to Part 132 - Great Lakes Water Quality Initiative Methodologies for Development of Aquatic Life Criteria and...

    2010-07-01

    ... flowing out. F. Data must be rejected if obtained using: 1. Brine shrimp, because they usually only occur..., lobsters, crabs, shrimp and abalones be the 96-hour EC50 based on the percentage of organisms with..., mussels, oysters and scallops), sea urchins, lobsters, crabs, shrimp and abalones be the 96-hour...

  13. 75 FR 59899 - Endangered and Threatened Wildlife and Plants: Proposed Rulemaking To Designate Critical Habitat...

    2010-09-28

    ... area (Geiger 2003, State Water Resources Control Board 1979, J. Sones pers. comm.), black abalone were...-water discharge, agricultural pesticide application and irrigation, construction and operation of tidal... recovery, including: waste-water discharge, agricultural pesticide application and irrigation,...

  14. 78 FR 50107 - Notice of Intent To Repatriate Cultural Items: University of Colorado Museum of Natural History...

    2013-08-16

    ... four inlays, three of which are turquoise and a fourth abalone. These inlays are located at the wider... grayish-white mirage/aragonite stone. Both ends of the cylinder are bordered with an inlay of...

  15. Effect of temperature on biogeochemistry of marine organic-enriched systems: implications in a global warming scenario

    Sanz-Lázaro, Carlos; Valdemarsen, Thomas; Marín, Arnaldo; Holmer, Marianne

    2011-01-01

    Coastal biogeochemical cycles are expected to be affected by global warming. By means of a mesocosm experiment, the effect of increased water temperature on the biogeochemical cycles of coastal sediments affected by organic-matter enrichment was tested, focusing on the carbon, sulfur, and iron cycles. Nereis diversicolor was used as a model species to simulate macrofaunal bioirrigation activity in natural sediments. Although bioirrigation rates of N. diversicolor were not temperature dependen...

  16. Macrobenthos recruitment success in a tidal flat: feeding trait dependent effects of disturbance history

    Van Colen, C.; Montserrat, F.; Vincx, M.; Herman, P.M.J.; Ysebaert, T.J.; Degraer, S.

    2010-01-01

    Juvenile growth rate and production of the bivalves Macoma balthica and Cerastoderma edule and the polychaeteNereis diversicolor were investigated on two contrasting tidal flat sediments that represented different recovery stages following disturbance. Juvenile M. balthica and N. diversicolor grew faster and yielded a higher production in the early succession community where fresh microalgal food supply was higher and physical stress was lower in comparison with the mature community, while C....

  17. Fishing the future. A snapshot of the Chilean TURFs through the lens of fishers and key stakeholders‟ perceptions

    Ueyonahara, Jorge

    2012-01-01

    Overfishing is not an exclusive topic of big fishing industry. Overfishing by small-scale fishers is also happening. The Territorial Use of Rights – TURFs was implemented in Chile to protect the Chilean abalone from overfishing. Through the implementation of the TURFs Chilean abalone are no longer threatened by overfishing. The challenge to protect the resource thus seems to be solved. However, while some problems are solved others persist or new ones arise. The thesis explores the discourses...

  18. Concentrations of 239,240Pu and 241Am of marine products in coastal waters of Ibaraki

    More than 200 samples of marine products have been collected and analyzed for plutonium and almost 100 samples for americium around Hitachi, Tokai and Oarai in the pacific coast of Ibaraki prefecture. The data have shown that the concentration factor (CF) values for plutonium were 330 for bivalve, 770 for abalone (muscle) and 610 for brown algae. For americium, the CF was calculated as 2400 for bivalve, 1000 for abalone (muscle) and 420 for brown algae. (author)

  19. Bioavailability of a natural lead-contaminated invertebrate diet to zebrafish.

    Boyle, David; Amlund, Heidi; Lundebye, Anne-Katrine; Hogstrand, Christer; Bury, Nic R

    2010-03-01

    Dietary metals are increasingly recognized as key determinants of total metal burdens in fish, yet their ecotoxicological significance remains unclear. In this study, a pairwise experimental design was used to assess reproductive performance of zebrafish (Danio rerio) fed diets supplemented with a natural Pb-enriched polychaete, Nereis diversicolor. Zebrafish were fed 1% flake food (dry wt diet/wet wt fish/d), 1% brine shrimp, and 1% N. diversicolor collected from either Gannel estuary, Cornwall, United Kingdom (UK), an estuary with legacy Pb contamination, or Blackwater estuary, Essex, UK, a reference site with low background metal concentrations, for 63 d. Mean daily dietary doses of Pb were 0.417 and 0.1 mg/kg/d (dry wt feed:wet wt fish) for fish fed N. diversicolor from Gannel and Blackwater estuaries, respectively. With the exception of Ag, which was higher for fish fed N. diversicolor from Gannel estuary, there were no differences in daily dietary exposures to other metals (As, Cd, Cu, Fe, and Zn) between treatment groups. Fish fed Pb-enriched Gannel N. diversicolor exhibited no significant impairment to incidence of spawning, numbers of eggs per breeding pair or hatch rate of embryos compared with pre-exposure levels, when N. diversicolor was omitted from the dietary regimen. Nevertheless, metal analysis revealed significant increases in whole-body Pb burdens of male fish fed polychaetes from Gannel estuary, Ag in female fish fed Gannel worms, and Ag and Cd in male fish fed the Blackwater worms. These data demonstrate that Pb naturally incorporated in N. diversicolor is bioavailable to fish, and fish exhibit sex-dependent dietary metal accumulation patterns, but after 63 d of the experimental feeding regimen, reproductive performance was unaffected. PMID:20821498

  20. Short Communication: Growth of seaweed Eucheuma cottonii in multi trophic sea farming systems at Gerupuk Bay, Central Lombok, Indonesia

    SUKIMAN

    2014-05-01

    Full Text Available Sukiman, Faturrahman, Rohyani IS, Ahyadi H. 2014. Growth of seaweed Eucheuma cottonii in multi trophic sea farming systems at Gerupuk Bay, Central Lombok, Indonesia. Nusantara Bioscience 6: 82-85. Eucheuma cottonii is a seaweed commodity that has a high economic value because it contains compounds used as raw materials for industries. Various methods of seaweed farming have been developed, one of which is a system of cultivation Multi Trophic Sea Farming. This study aimed to analyze the growth of E. cottonii by observing the production of biomass in four trophic combinations in the system Multi Trophic Sea Farming. The study was conducted in the area of the marine aquaculture Gerupuk bay, Central Lombok, Indonesia. Experiments were performed on four plots cages with trophic combination treatment as follows: K1 (E. cottonii-lobster-abalone, K2 (E. cottonii-abalone-red carp, K3 (E. cottonii-abalone-grouper, and K4 (E. cottonii-abalone-pomfret fish. Seedling of E. cottonii weighing 50 g was tied to a rope and placed at a depth of 5 cm, 50 cm, 100 cm and 150 cm. Measurement of biomass production was done every ten days until the thirtieth day. The highest biomass production of E. cottonii was obtained in K3 trophic combination (E. cottonii-abalone-grouper fish with a depth of seedlings of 5 cm. The combination of K3 trophic is recommended for cultivation of seaweed in the MTSF system.

  1. Dicty_cDB: VSI551 [Dicty_cDB

    Full Text Available nacchii Cu/Zn supero... 195 2e-48 AY449747_1( AY449747 |pid:none) Haliotis diversic...EC... 196 1e-48 ( P10791 ) RecName: Full=Superoxide dismutase [Cu-Zn]; EC... 196 1e-48 AY736280_1( AY736280 |pid:none) Trematomus ber

  2. Dicty_cDB: Contig-U03408-1 [Dicty_cDB

    Full Text Available ec... 40 0.095 2 ( EF634883 ) Pristionchus pauli small subunit ribosomal protei... 42 0.25 2 ( EH361767 ) NP...Haliotis discus discus ribosomal p... 46 4e-04 EF634883_1( EF634883 |pid:none) Pristionchus pauli small subu

  3. Bacterial extracellular polymeric substances (EPS): A carrier of heavy metals in the marine food-chain

    Bhaskar, P.V.; Bhosle, N.B.

    benthic polychaete Hediste diversicolor. On an average, 29% of the ingested EPS was absorbed into tissues and 49% of the EPS was respired. It was apparent that the animals used the EPS as a source of energy and nutrition. The labile nature of the bacterial...

  4. Oxygen dynamics and porewater transport in sediments inhabited by the invasive polychaete Marenzelleria viridis

    Jovanovic, Zeljko; Larsen, Morten; Quintana, Cintia Organo;

    2014-01-01

    The polychaete Marenzelleria viridis is an invasive species and often replaces the native Nereis diversicolor. This shift leads to more reduced conditions and changes in the biogeochemical function of the sediments. By combining imaging techniques for O2 (planar optodes) and irrigation patterns...

  5. Biomixing generated by benthic filterfeeders: A diffusion model for near-bottom phytoplankton depletion

    Scheel Larsen, Poul; Riisgård, H.U.

    1997-01-01

    polychaete Nereis diversicolor and the ascidian Ciona intestinalis, respectively. The model is based on sinks located at inhalant openings and Fick's law with an effective diffusivity that decreases with distance above the bottom due to the biomixing generated by exhalant and inhalant feeding currents. For N...

  6. Macrobenthic community response to the Marenzelleria viridis (Polychaeta) invasion of a Danish estuary

    Delefosse, Matthieu; Banta, Gary; Canal Vergés, Paula;

    2012-01-01

    investigate its effect on the native benthic community with focus on the two common polychaetes, Nereis (Hediste) diversicolor and Arenicola marina. M. viridis colonized Odense Fjord rapidly and within 3 years it had spread to about 50% of the estuary. The population development of M. viridis in Odense Fjord...

  7. Macrobenthic community response to the Marenzelleria viridis (Polychaeta) invasion of a Danish estuary

    Delefosse, Matthieu; Banta, Gary Thomas; Canal Vergés, Paula;

    2012-01-01

    with focus on the 2 common polychaetes, Nereis (Hediste) diversicolor and Arenicola marina. Marenzelleria viridis colonized Odense Fjord rapidly, and within 3 yr it had spread to ~50% of the estuary. The population development of M. viridis in Odense Fjord followed the ‘boom-bust’ pattern that is...

  8. Benthic Macro Invertebrate Fauna and Physico-chemical Parameters in Okpoka Creek Sediments, Niger Delta, Nigeria

    J.F.N. Abowei

    2009-01-01

    The benthic macro invertebrate fauna and physico-chemical parameters in Okpoka creek sedimentswas studied for a period of one year. A total of nineteen (19) species(Ophidonais serpentina, Arenicola marina,Eunice harassi, Marphysa sanguinea, Capitella capitata, Notomastus latrella, Notomastus tenuis, Glyceracapitata, Glycera convoluta, Nereis diversicolor, Nereis pelagica, Nereis virens, Nephthys hombergi,Nototropis swamidami, Cliberanus cooci, Iphinoe tripanosa, Chironomus ablabiesmia, Tellin...

  9. Udbredelsen af den invasive børsteorm, Marenzelleria viridis, langs danske kyster – tegn på økologiske konsekvenser?

    Banta, Gary Thomas; Christoffersen, Kenn

    andre søskendearter, da sidstnævnte fortrækker enten lavere salinitet eller lavere temperatur end typisk for de danske kyster. Der blev observerede nogle svage negative sammenhæng mellem Marenzelleria viridis og de naturligt forekommende arter, såsom Hediste (Nereis) diversicolor, Corophium spp. og...

  10. Polychaete burrows harbour distinct microbial communities in oil-contaminated coastal sediments.

    Taylor, Joe D; Cunliffe, Michael

    2015-08-01

    Previous studies have shown that the bioturbating polychaete Hediste (Nereis) diversicolor can affect the composition of bacterial communities in oil-contaminated sediments, but have not considered diversity specifically within bioturbator burrows or the impact on microbial eukaryotes. We tested the hypothesis that H. diversicolor burrows harbour different eukaryotic and bacterial communities compared with un-bioturbated sediment, and that bioturbation stimulates oil degradation. Oil-contaminated sediment was incubated with or without H. diversicolor for 30 days, after which sediment un-affected by H. diversicolor and burrow DNA/RNA samples were analysed using quantitative reverse transcription PCR (Q-RT-PCR) and high-throughput sequencing. Fungi dominated both burrow and un-bioturbated sediment sequence libraries; however, there was significant enrichment of bacterivorous protists and nematodes in the burrows. There were also significant differences between the bacterial communities in burrows compared with un-bioturbated sediment. Increased activity and relative abundance of aerobic hydrocarbon-degrading bacteria in the burrows coincided with the significant reduction in hydrocarbon concentration in the bioturbated sediment. This study represents the first detailed assessment of the effect of bioturbation on total microbial communities in oil-contaminated sediments. In addition, it further shows that bioturbation is a significant factor in determining microbial diversity within polluted sediments and plays an important role in stimulating bioremediation. PMID:25858418

  11. Species-specific elimination of polychlorinated biphenyls in estuarine animals and its impact on residue patterns.

    Goerke, H; Weber, K

    2001-03-01

    Elimination kinetics of tetra-, penta- and hexachlorobiphenyls (IUPAC Nos. 44, 52, 87, 95, 101, 153) were investigated by laboratory experiments in three species of different phyla: Nereis diversicolor (Polychaeta), Palaemon longirostris (Crustacea) and Platichthys flesus (Pisces). Half-lives were species-specific and structure-dependent. Palaemon longirostris eliminated all components fastest. N. diversicolor was faster than Platichthys flesus except for components 95 and 153. Contrary to the fish species, the two invertebrates contained significant amounts of polar transformation products of No. 52, which had been applied as 14C labelled. Therefore, the faster elimination by Palaemon longirostris and N. diversicolor was assumed to be generally due to increased biotransformation. Elimination was in accordance with polychlorinated biphenyl (PCB) residue patterns obtained from field samples of the species. Congeners with vicinal H atoms in m,p positions were under-represented in Palaemon longirostris and so were congeners with > or = 7 Cl in N. diversicolor, while the PCB residue pattern in Platichthys flesus was similar to that of Clophen A60. By comparing percentages of the experimental congeners in sigma PCB and their elimination half-lives in the three species, it was revealed that residue patterns were also influenced by species-dependent uptake, e.g. feeding habits. Extractable organic matter-based sigma PCB levels increased with trophic levels of the three species. PMID:11468813

  12. Natural arsenic contaminated diets perturb reproduction in fish.

    Boyle, David; Brix, Kevin V; Amlund, Heidi; Lundebye, Anne-Katrine; Hogstrand, Christer; Bury, Nic R

    2008-07-15

    The toxicological effect of natural diets elevated in metals on reproduction in fish is poorly understood. The reproductive output of zebrafish fed the polychaete Nereis diversicolor collected from a metal-impacted estuary, Restronguet Creek, Cornwall, UK, was compared to fish fed N. diversicolor collected from a nonmetal impacted estuary, Blackwater, Essex, UK. Fish fed the metal laden N. diversicolorfor 68 days showed reduced reproductive output, characterized by reduced cumulative egg production (47%), cumulative number of spawns (30%), as well as reduced average number of eggs produced per spawn and % hatch rate. The mRNA transcript levels of the egg-yolk protein vitellogenin was also reduced 1.5 fold in the livers of female fish fed metal-laden N. diversicolor. No difference was seen between the lipid, protein, or moisture content of the two diets and no difference in growth was seen between the two fish populations. The Restronguet Creek polychaetes have elevated arsenic, cadmium, copper, zinc, lead, and silver body burdens, but the only element found to accumulate in the tissues of zebrafish fed this diet was As. The As in these N. diversicolor was found to be predominantly potentially toxic inorganic As species, 58% of total As content, which is unusual for aquatic organisms where arsenic is typically biotransformed into less toxic organoarsenical compounds. These results demonstrate that reproduction in fish is a sensitive target of exposure to a natural diet contaminated with As and this exposure route could be of significance to the health of fish populations. PMID:18754393

  13. Odors influencing foraging behavior of the California spiny lobster, Panulirus interruptus, and other decapod crustacea

    Zimmer-Faust, R.K.; Case, J.F.

    1982-01-01

    Trapping experiments were conducted in the More Mesa coastal area of Santa Barbara, California, 4 km east of the U.C. Santa Barbara campus. Live intact and injured prey and excised tissues were placed in traps, in containers allowing odor release but preventing contacts with entering animals. Individuals of six prey species failed to attract lobsters when alive and intact, but some became attractive once injured. Excised tissues were the most effective baits. Abalone and mackerel muscle were attractive to lobsters but relatively nonattractive to crabs, while angel shark muscle was attractive to crabs but not to lobsters. Shrimp cephalothoraces were repellant to lobsters. Naturally occurring attractant and repellent tissues are thus identified and chemosensory abilities of lobsters and sympatric crabs are demonstrated to differ. Abalone muscle increased in attractivity following 1-2 days field exposure. Molecular weights of stimulants released by both weathered and fresh abalone were < 10,000 daltons with evidence suggesting that the 1000-10,000 dalton fraction may contribute significantly to attraction. Concentrations of total primary amines released from abalone muscle failed to differ from background levels, following an initial three (0-3h) period. Primary amines thus appear not to contribute directly to captures of lobsters, since animals were usually caught greater than or equal to 7 h after baits were positioned. Amino acids were the dominant contributors to present measurements of total primary amines, suggesting that these molecules may not direct lobster foraging behavior in the present experiments. 41 references, 4 figures, 8 tables.

  14. 'Põhjala saared' Tartus

    1999-01-01

    Eesti Rahva Muuseumi näitusemajas avatakse 12. veebr. fotonäitus 'Põhjala saared'. Fotograafid Göte Ask Gotlandilt, Abalon Hansen Fääri saartelt ja Andy Horner Ahvenamaalt. Lisaks Tartu kunstikooli õpilaste fotod Eesti väikesaartest.

  15. Impact of oil on bacterial community structure in bioturbated sediments.

    Magalie Stauffert

    Full Text Available Oil spills threaten coastlines where biological processes supply essential ecosystem services. Therefore, it is crucial to understand how oil influences the microbial communities in sediments that play key roles in ecosystem functioning. Ecosystems such as sediments are characterized by intensive bioturbation due to burrowing macrofauna that may modify the microbial metabolisms. It is thus essential to consider the bioturbation when determining the impact of oil on microbial communities. In this study, an experimental laboratory device maintaining pristine collected mudflat sediments in microcosms closer to true environmental conditions--with tidal cycles and natural seawater--was used to simulate an oil spill under bioturbation conditions. Different conditions were applied to the microcosms including an addition of: standardized oil (Blend Arabian Light crude oil, 25.6 mg.g⁻¹ wet sediment, the common burrowing organism Hediste (Nereis diversicolor and both the oil and H. diversicolor. The addition of H. diversicolor and its associated bioturbation did not affect the removal of petroleum hydrocarbons. After 270 days, 60% of hydrocarbons had been removed in all microcosms irrespective of the H. diversicolor addition. However, 16S-rRNA gene and 16S-cDNA T-RFLP and RT-PCR-amplicon libraries analysis showed an effect of the condition on the bacterial community structure, composition, and dynamics, supported by PerMANOVA analysis. The 16S-cDNA libraries from microcosms where H. diversicolor was added (oiled and un-oiled showed a marked dominance of sequences related to Gammaproteobacteria. However, in the oiled-library sequences associated to Deltaproteobacteria and Bacteroidetes were also highly represented. The 16S-cDNA libraries from oiled-microcosms (with and without H. diversicolor addition revealed two distinct microbial communities characterized by different phylotypes associated to known hydrocarbonoclastic bacteria and dominated by

  16. Impact of oil on bacterial community structure in bioturbated sediments.

    Stauffert, Magalie; Cravo-Laureau, Cristiana; Jézéquel, Ronan; Barantal, Sandra; Cuny, Philippe; Gilbert, Franck; Cagnon, Christine; Militon, Cécile; Amouroux, David; Mahdaoui, Fatima; Bouyssiere, Brice; Stora, Georges; Merlin, François-Xavier; Duran, Robert

    2013-01-01

    Oil spills threaten coastlines where biological processes supply essential ecosystem services. Therefore, it is crucial to understand how oil influences the microbial communities in sediments that play key roles in ecosystem functioning. Ecosystems such as sediments are characterized by intensive bioturbation due to burrowing macrofauna that may modify the microbial metabolisms. It is thus essential to consider the bioturbation when determining the impact of oil on microbial communities. In this study, an experimental laboratory device maintaining pristine collected mudflat sediments in microcosms closer to true environmental conditions--with tidal cycles and natural seawater--was used to simulate an oil spill under bioturbation conditions. Different conditions were applied to the microcosms including an addition of: standardized oil (Blend Arabian Light crude oil, 25.6 mg.g⁻¹ wet sediment), the common burrowing organism Hediste (Nereis) diversicolor and both the oil and H. diversicolor. The addition of H. diversicolor and its associated bioturbation did not affect the removal of petroleum hydrocarbons. After 270 days, 60% of hydrocarbons had been removed in all microcosms irrespective of the H. diversicolor addition. However, 16S-rRNA gene and 16S-cDNA T-RFLP and RT-PCR-amplicon libraries analysis showed an effect of the condition on the bacterial community structure, composition, and dynamics, supported by PerMANOVA analysis. The 16S-cDNA libraries from microcosms where H. diversicolor was added (oiled and un-oiled) showed a marked dominance of sequences related to Gammaproteobacteria. However, in the oiled-library sequences associated to Deltaproteobacteria and Bacteroidetes were also highly represented. The 16S-cDNA libraries from oiled-microcosms (with and without H. diversicolor addition) revealed two distinct microbial communities characterized by different phylotypes associated to known hydrocarbonoclastic bacteria and dominated by Gammaproteobacteria

  17. Lectins with Potential for Anti-Cancer Therapy

    Tammy Yau; Xiuli Dan; Charlene Cheuk Wing Ng; Tzi Bun Ng

    2015-01-01

    This article reviews lectins of animal and plant origin that induce apoptosis and autophagy of cancer cells and hence possess the potential of being developed into anticancer drugs. Apoptosis-inducing lectins encompass galectins, C-type lectins, annexins, Haliotis discus discus lectin, Polygonatum odoratum lectin, mistletoe lectin, and concanavalin A, fucose-binding Dicentrarchus labrax lectin, and Strongylocentrotus purpuratus lectin, Polygonatum odoratum lectin, and mistletoe lectin, Polygo...

  18. Lectins with Potential for Anti-Cancer Therapy

    Tammy Yau

    2015-02-01

    Full Text Available This article reviews lectins of animal and plant origin that induce apoptosis and autophagy of cancer cells and hence possess the potential of being developed into anticancer drugs. Apoptosis-inducing lectins encompass galectins, C-type lectins, annexins, Haliotis discus discus lectin, Polygonatum odoratum lectin, mistletoe lectin, and concanavalin A, fucose-binding Dicentrarchus labrax lectin, and Strongylocentrotus purpuratus lectin, Polygonatum odoratum lectin, and mistletoe lectin, Polygonatum odoratum lectin, autophagy inducing lectins include annexins and Polygonatum odoratum lectin.

  19. Ecological implications of changes in polychaetes population in a shallow Danish estuary

    Delefosse, Matthieu

    increased sulfate reduction rates in the sediment and created more reduced conditions than N. diversicolor. This was probably caused by the different ventilation and irrigation mechanisms of the 2 species (MS6). M. viridis deep burrow ventilation irrigates the sediment along the wall of the blind...... presented in this thesis evaluates the effect of population change in size and distribution of 3 polychaete species in a shallow Danish estuary - Odense Fjord: the 2 ecologically important Arenicola marina and Nereis diversicolor and the non-native species Marenzelleria viridis. We focus on the effect of...... the dynamic of the polychaete population on sediment biogeochemistry and the seagrass Zostera marina. In MS1, the results obtained from different survey indicate that M. viridis was first recorded in 2002 in this estuary and is now present in about 50% of the estuary. The loss of seagrass habitat in...

  20. Studies on the isolation and culture of protoplasts from Kappaphycus alvarezii

    ZHANG Si; LIU Cui; JIN Yuemei; CHI Shan; TANG Xianming; CHEN Fuxiao; FANG Xu; LIU Tao

    2014-01-01

    In this study, protoplasts were successfully isolated from Kappaphycus alvarezii using snail enzymes, aba-lone enzymes and cellulase. The optimum enzymic ratio was fixed to be 20%of abalone enzyme, 12%of cellulase and the osmotic stabilizer was 2.0 mol/L glucose. The optimum enzymic hydrolysis conditions were found to be dark enzymolysis at 30°C continuing for 4.0 h. The resultant density and yield of protoplasts achieved 32.60×104 mL-1, 65.20×104 g-1 tissue for Kappaphycus alvarezii. Finally, under the temperature of 20°C, light intensity of 1 500-2 000 lx and photoperiod of 12 h/d, two developmental pathways were investi-gated:(1) callus-like cell mass and regenerated plantlet occurred on protoplast;(2) young shoots and callus-like cell mass occurred in tissue blocks after enzymolysis.

  1. New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

    Kulkarni, Kantimati G.; Panchang, Rajani

    2015-01-01

    Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time rep...

  2. Uptake of plutonium from seawater and sediment by a marine polychaete worm

    The results of the uptake of plutonium 239 from sediment by a marine polychaete worm Nereis diversicolor is reported in the present paper. A comparison is made of the relative importance of two possible uptake pathways, sediment and seawater by which this worm may obtain its plutonium body-burden. Under the laboratory conditions used for the comparison of those two routes it would appear that Nereis obtained greater than 98% of its body activity from seawater. (auth.)

  3. Nedbryting av DDT i sedimenter og bioakkumulering i sedimentlevende dyr. (Metabolization of DDT in sediments and bioaccumulation in sediment dwelling organisms)

    Skei, J.; Andersen, L

    1996-01-01

    DDT og nedbrytningsproduktene DDD og DDE ble påvist i bunnsedimenter fra Gullaugbukta i Drammensfjorden og fra Lierelva. I oksiske sedimenter dominerte DDE som er den stabileste og mest giftige komponenten. I anoksiske sedimenter dominerte DDD. Eksperimentelt arbeid med de forurensede sedimentene for å studere opptak av DDT, DDD og DDE i børstemark (Nereis diversicolor) og nettsnegl (Nassarius reticulatus) ble utført ved NIVAs marine forskningsstasjon Solbergstrand. Resultatene viste at det e...

  4. Effect of macrofauna, oxygen exchange and particle reworking on iron and manganese sediment biogeochemistry: a laboratory experiment

    I. Ferro; Nugteren, P.; Middelburg, J. J.; Herman, P.M.J.; Heip, C. H. R.

    2003-01-01

    The impact of bioturbation on iron and manganese cycling in marine sediments was studied in laboratory experiments in which faunal effects which combine in the field (particle mixing and oxygen exchange) were studied separately. Particle mixing and sediment aeration both enhance metal oxide reduction rates as reflected in pore-water and solid phase profiles, and in sediment-water exchange fluxes. We also studied the effect of Nereis diversicolor on iron and manganese biogeochemistry. The pres...

  5. Marenzelleria viridis (Verril, 1873) (Polychaeta: Spionidae) : a new record from the Ems Estuary (The Netherlands / Federal Republic of Germany)

    Essink, K.; Kleef, H.L.

    1988-01-01

    A new record of the North American spionid polychaete Marenzelleria viridis (Verril, 1873) is reported from the Ems Estuary. The species was first found in 1983. From 1983 to 1986 densities increased to a few thousands per m2 while densities of another polychaete, Nereis diversicolor decreased. Juveniles showed peak densities of c. 19000 m2 in muddy sediments. Adults preferred sandy sediments. In Europe M. viridis was recorded recently also in other estuaries: Tay and Forth (Scotland), Weser ...

  6. Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete : inter-population variability and a generalised predictive model

    Kalman, J.; Smith, B. D.; Riba, I; Blasco, J.; Rainbow, P.S.

    2010-01-01

    Abstract Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirm...

  7. Bioavailability of metals in weight materials for drilling muds

    Schaanning, M.; Ruus, A.; Bakke, T.; Hylland, K; Olsgard, F.

    2002-01-01

    Bioaccumulation of metals from various weight materials used in drilling muds was determined after 28 days exposure of polychaetes (Nereis diversicolor) and gastropodes (Hinia (Nassarius) reticulata) to spiked sediments. The test was performed in a standard experimental set-up at Solbergstrand Marine Research Station and showed significantly higher concentrations of barium, titanium, lead, mercury and copper in organisms exposed to various test substances than in organisms exposed to non-spik...

  8. Destabilization of cohesive intertidal sediments by infauna

    De Deckere, E.M.G.T.; Tolhurst, T. J.; de Brouwer, J.F.C.

    2001-01-01

    Bioturbation activity was reduced in four plots on an intertidal mudflat in the Humber estuary (UK) during 4 days, by spraying the sediment with an insecticide, namely vydate. Macrofaunal, especially Nereis diversicolor and oligochaeta, and meiofaunal densities decreased, while the diatom biomass did not change. This resulted in a 300% increase in sediment stability, caused by a reduction in bioturbation and grazing pressure and a decrease in the water content.

  9. Imaging Oxygen Distribution in Marine Sediments. The Importance of Bioturbation and Sediment Heterogeneity

    Pischedda, Laura; Poggiale, Jean-Christophe; Cuny, Philippe; Gilbert, Franck

    2008-01-01

    The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns:the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was qu...

  10. Latent capacities for gametogenic cycling in the semelparous invertebrate Nereis.

    Golding, D W; Yuwono, E

    1994-01-01

    Most nereid polychaetes are strictly semelparous, a single episode of reproduction being invariably followed by death. Endocrine manipulation in Nereis diversicolor by the regular implantation of cerebral ganglia from immature donors unveils characteristics associated with a capacity to engage in repeated gametogenic cycling. Such manipulation permits full maturation of the gametes but blocks spawning. Gamete resorption then leads on to another bout of gametogenesis and a new cohort of gamete...

  11. Bioaccumulation surveillance in Milford Haven Waterway

    Langston, W.J.; O'Hara, S.; Pope, N.D.; Davey, M; Shortridge, E.; IMAMURA, M; Harino, H.; Kim, A.; Vane, C.

    2012-01-01

    Biomonitoring of contaminants (metals, organotins, PAHs, PCBs) was carried out along the Milford Haven Waterway (MHW) and at a reference site in the Tywi Estuary during 2007-2008. The species used as bioindicators encompass a variety of uptake routes - Fucus vesiculosus (dissolved contaminants); Littorina littorea (grazer); Mytilus edulis and Cerastoderma edule (suspension feeders); and Nereis diversicolor (omnivore which often reflects contaminants in sediment). Differences...

  12. Destabilization of Cohesive Intertidal Sediments by Infauna

    de Deckere, E. M. G. T.; Tolhurst, T. J.; de Brouwer, J. F. C.

    2001-11-01

    Bioturbation activity was reduced in four plots on an intertidal mudflat in the Humber estuary (UK) during 4 days, by spraying the sediment with an insecticide, namely vydate. Macrofaunal, especially Nereis diversicolor and oligochaeta, and meiofaunal densities decreased, while the diatom biomass did not change. This resulted in a 300% increase in sediment stability, caused by a reduction in bioturbation and grazing pressure and a decrease in the water content.

  13. Bioavailability of heavy metals in drilling muds

    Schaanning, M.; Ruus, A.; Bakke, T.; Hylland, Ketil; Olsgard, Frode

    2002-01-01

    Experimental work on uptake of metals from sediments spiked with barite, ilmenite and hematite were performed using the ragworm Nereis diversicolor and the netted dog whelk Hinia (Nassarius) reticulata as test organisms. The present report also provides a brief review of recent litterature on biological effects of metals in drill cuttings, including relevant results from the UKOOA Drill Cuttings Initiative - an international research programme completed in December 2001. The review suggest lo...

  14. Regiospecific synthesis of disubstituted phenanthrenes

    Böhme, Thomas

    2014-01-01

    As the Norwegian oil fields mature, the wells produce more water. This produced water containing a diverse mixture of dissolved PAHs is eventually released to the environment. A major part of these discharges are alkylated PAHs, but due to lack of pure compounds the e↵ect of alkylated PAHs have been scarcely studied. Studies on the metabolism of monomethylated phenanthrenes by the benthic invertebrate Nereis diversicolor gave di↵erent product distributions depending on the posi...

  15. Role of biotic interactions on seasonal migrations of the macrozoobenthos living in the upper tidal-flat of the Mont-Saint-Michel bay, France

    Meziane, T; Retiere, C

    2001-01-01

    On the tidal flat of the western part of the Mont-Saint-Michel bay, the macrozoobenthos of the upper flat is characterised by an assemblage of the Macoma balthica community. The dominant species are M. balthica, Nereis diversicolor and Corophium volutator. A field monitoring during a 1-year period along a four-stations transect perpendicularly to the shore showed that biotic interactions affected the local distributions of these species. This was particularly obvious from late spring to late ...

  16. Trophic relationships in the community of the upper Tagus estuary (Portugal): A preliminary approach

    Moreira, F.; Assis, C. A.; Almeida, P. R.; Costa, J. L.; Costa, M. J.

    1992-06-01

    The diet of 25 invertebrate and fish species occurring in the upper Tagus estuary are compared. Multivariate methods are used to define trophic groups and identify key prey species, fundamental links in the understanding of the estuarine food web. Four trophic groups are described: microalgae, macroinfauna, mysid and fish and decapod eaters. It was found that the food web of this area heavily relies on the polychaete Nereis diversicolor and the crustacean Crangon crangon.

  17. Behaviour and speciation of mercury in the Scheldt estuary (water sediments and benthic organisms)

    Baeyens, W.F.J.; Meuleman, C.; Muhaya, B.; Leermakers, M

    1998-01-01

    Surface waters, sediments and the polychaete Nereis diversicolor were sampled in the Scheldt Estuary between 1990 and 1994. In surface waters particulate Hg (Hgp) concentrations ranged from 350-1610 ng g-¹. They are essentially controlled by physical mixing of polluted fluvial particulates with relatively unpolluted marine particulates, but unaffected by seasonal changes. Dissolved Hg species, on the other hand, show large seasonal variations essentially controlled by the redox conditions in ...

  18. Diopatra neapolitana (Polychaeta: Onuphidae) as a Second Intermediate Host of Gymnophallus choledochus (Digenea: Gymnophallidae) in the Aveiro Estuary (Portugal): Distribution Within the Host and Histopathology

    Rangel, LF; Santos, MJ

    2009-01-01

    This is the first host record of Gymnophallus choledochus metacercariae infecting the polychaete Diopatra neapolitana in the Aveiro estuary (Portugal). The metacercariae were round unencysted, and their morphology is similar to that presented by metacercariae harbored by Nereis diversicolor and Cerastoderma edule, although they are larger in size. In D. neapolitana, the prevalence and mean intensity of the infection was very high, at 100% and 202 +/- 139 metacercariae per host, respectively, ...

  19. Feeding habits of young predatory fishes in marsh creeks situated along the salinity gradient of the Schelde estuary, Belgium and The Netherlands

    Hampel, H.; Cattrijsse, A.; Elliott, M.

    2005-01-01

    Fish and macrobenthos were sampled in four different marshes along the salinity gradient of the Schelde estuary, Belgium/Netherlands, to investigate the importance of marsh creeks as foraging grounds for the dominant, larger fish species. The total density and biomass of all the main macrobenthic taxa (Corophium volutator, Nereis diversicolor, Oligochaeta, Macoma baltica and Heteromastus fliliformis) were measured. The feeding habits of the larger predatory fishes (Platichthys flesus, Dicentr...

  20. Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

    Kristensen, Erik; Neto, João Magalhães; Lundkvist, Morten; Frederiksen, Lars; Pardal, Miguel Ângelo; Valdemarsen, Thomas; Flindt, Mogens Rene

    2013-01-01

    The impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (uc) a...

  1. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations

    Moreira, Susana M; Moreira-Santos, Matilde; Guilhermino, Lúcia; Ribeiro, Rui

    2006-01-01

    This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Müller as food source, was first developed. The sensitivity of the postexposure feeding response was verified b...

  2. Biodiversity of Vibrios

    Fabiano L. Thompson; Iida, Tetsuya; Swings, Jean

    2004-01-01

    Vibrios are ubiquitous and abundant in the aquatic environment. A high abundance of vibrios is also detected in tissues and/or organs of various marine algae and animals, e.g., abalones, bivalves, corals, fish, shrimp, sponges, squid, and zooplankton. Vibrios harbour a wealth of diverse genomes as revealed by different genomic techniques including amplified fragment length polymorphism, multilocus sequence typing, repetetive extragenic palindrome PCR, ribotyping, and whole-genome sequencing. ...

  3. ROS-Dependent Mitochondria Molecular Mechanisms Underlying Antitumor Activity of Pleurotus abalonus Acidic Polysaccharides in Human Breast Cancer MCF-7 Cells

    Shi, Xiaolong; ZHAO Yan; Jiao, Yadong; Shi, Tengrui; Yang, Xingbin

    2013-01-01

    Background A greater reduction in cancer risk associated with mushroom diet rich in fungus polysaccharides is generally accepted. Meanwhile, edible Pleurotus abalonus as a member of Abalone mushroom family is a popular nutritional supplement that purportedly prevents cancer occurrence. However, these anecdotal claims are supported by limited studies describing tumor-inhibitory responses to the promising polysaccharides, and the molecular mechanisms underlying these properties have not yet bee...

  4. Selection in the Rapid Evolution of Gamete Recognition Proteins in Marine Invertebrates

    Vacquier, Victor D.; Swanson, Willie J.

    2011-01-01

    Animal fertilization is governed by the interaction (binding) of proteins on the surfaces of sperm and egg. In many examples presented herein, fertilization proteins evolve rapidly and show the signature of positive selection (adaptive evolution). This review describes the molecular evolution of fertilization proteins in sea urchins, abalone, and oysters, animals with external fertilization that broadcast their gametes into seawater. Theories regarding the selective forces responsible for the...

  5. From Seascapes of Extinction to Seascapes of Confidence : Territorial Use Rights in Fisheries in Chile: El Quisco and Puerto Oscuro

    Gallardo Fernández, Gloria L.

    2008-01-01

    In Chile, the indiscriminate harvest for export of the edible shellfish, Concholepas concholepas or false abalone, propelled by a neo-liberal market economy during the 1970s, almost led to the extinction of the species, thereby threatening the dependant small-scale artisan fishers’ survival as well as the ecosystem. To reverse this, fishers’ organizations in Chile have adopted the state created regulatory measure, Management and Exploitation Areas for Benthic Resources (MEABR; locally known a...

  6. The History, Present Condition, and Future of the Molluscan Fisheries of North and Central America and Europe: Volume 2, Pacific Coast and Supplemental Topics

    MacKenzie, Jr., Clyde L.; Burrell, Jr. , Victor G.; Rosenfield, Aaron; Hobart, Willis L.

    1997-01-01

    Over 100 molluscan species are landed in Mexico. About 30% are harvested on the Pacific coast and 70% on the Atlantic coast. Clams, scallops, and squid predominate on the Pacific coast (abalone, limpets, and mussels are landed there exclusively). Conchs and oysters predominate on the Atlantic coast. In 1988, some 95,000 metric tons (t) of mollusks were landed, with a value of $33 million. Mollusks were used extensively in prehispanic Mexico as food, tools, and jewelry. Their use as food an...

  7. Oil palm empty fruit bunch as media for mushroom cultivation

    The mushroom strains Pleurotus sajor caju(grey oyster mushroom), Pleurotus flavellatus((pink oyster mushroom), Pleurotus cystidiosus(abalone mushroom) and Auricularia polytricha (black jelly mushroom) grow satisfactorily on the EFB media treated with lime. Based on their Biological Efficiency (BE) or yield, the strain Pleurotus sajor caju was selected for further investigation. The BE of the Pleurotus sajor caju was 73.8 %. The lime treatment, aeration and four weeks incubation period was necessary for fruiting

  8. Development of chloroplast simple sequence repeats (cpSSRs) for the intraspecific study of Gracilaria tenuistipitata (Gracilariales, Rhodophyta) from different populations

    Song, Sze-Looi; Lim, Phaik-Eem; Phang, Siew-Moi; Lee, Weng-Wah; Hong, Dang Diem; Prathep, Anchana

    2014-01-01

    Background Gracilaria tenuistipitata is an agarophyte with substantial economic potential because of its high growth rate and tolerance to a wide range of environment factors. This red seaweed is intensively cultured in China for the production of agar and fodder for abalone. Microsatellite markers were developed from the chloroplast genome of G. tenuistipitata var. liui to differentiate G. tenuistipitata obtained from six different localities: four from Peninsular Malaysia, one from Thailand...

  9. A Study of the Impact of a Pipeline Construction on Estuarine Benthic Invertebrate Communities

    Lewis, L. J.; Davenport, J.; Kelly, T. C.

    2002-08-01

    The effects of a pipeline construction on benthic invertebrates were investigated using a Before/After impact protocol at Clonakilty Bay, West Cork, Ireland. Benthic invertebrates were sampled once before the excavation and at one, two, three and six months after the completion of the work. Analysis was designed to compare natural variation over time within control sites with the variation that occurred in the disturbed site from before to after construction. Invertebrate samples were dominated by Hediste diversicolor, Scrobicularia plana and Tubifex spp. An impact was obvious in the construction site in that no live invertebrates were found at one month after disturbance, but there followed a gradual recolonization by Hediste diversicolor. Scrobicularia plana failed to recolonize the impacted area during the study. At six months after the disturbance there was no significant difference in the mean number of total individuals (of all species) per core sample amongst all study sites, but the apparent ' recovery ' in the impacted area was due to two taxa only, namely Hediste diversicolor and Tubifex spp. The process of recovery of the benthic community within the impacted area is thus dependent on the species within the surrounding area. Their respective life cycle characteristics and mobilities will have been major factors in determining recovery.

  10. The influence of four macrozoobenthic species on the abundance of the amphipod Corophium volutator on tidal flats of the Wadden Sea

    Flach, E. C.

    On the tidal flats of the Wadden Sea, a zonation pattern can be found with Corophium volutator and Nereis diversicolor as the dominating species of the upper intertidal zone and Arenicola marina and Cerastoderma edule as the dominating species of the lower zone. As C. volutator can live under a great variety of physical conditions, its restriction to higher areas might result from biotic interactions. This was investigated by field experiments on a tidal flat in the westernmost part of the Wadden Sea. Within large depopulated areas, small plots were recolonized with different densities of N. diversicolor, A. marina, C. edule and Macoma balthica and the subsequent settlement and dynamics of C. volutator were studied. In addition, A. marina and/or C. edule were added to or removed from small plots within a natural benthic community. Neither the presence of M. balthica not that of N. diversicolor significantly affected the abundance of C. volutator. A strongly negative effect was found of C. edule when present in high densities, whereas A. marina negatively affected C. volutator abundance already at relatively low densities. Local removals of A. marina and C. edule from their own zone resulted in increases of Corophium numbers at these locations and local additions of these species within the Corophium zone resulted in decreases of Corophium numbers at these locations. It is suggested that the major species to restrict C. volutator effectively to the upper tidal zone is A. marina.

  11. Dietary toxicity of field-contaminated invertebrates to marine fish: effects of metal doses and subcellular metal distribution.

    Dang, Fei; Rainbow, Philip S; Wang, Wen-Xiong

    2012-09-15

    There is growing awareness of the toxicological effects of metal-contaminated invertebrate diets on the health of fish populations in metal-contaminated habitats, yet the mechanisms underlying metal bioaccumulation and toxicity are complex. In the present study, marine fish Terapon jurbua terepon were fed a commercial diet supplemented with specimens of the polychaete Nereis diversicolor or the clam Scrobicularia plana, collected from four metal-impacted estuaries (Tavy, Restronguet Creek, West Looe, Gannel) in southwest England, as environmentally realistic metal sources. A comparative toxicological evaluation of both invertebrates showed that fish fed S. plana for 21 d exhibited evident mortality compared to those fed N. diversicolor. Furthermore, a spatial effect on mortality was observed. Differences in metal doses rather than subcellular metal distributions between N. diversicolor and S. plana appeared to be the cause of such different mortalities. Partial least squares regression was used to evaluate the statistical relationship between multiple-metal doses and fish mortality, revealing that Pb, Fe, Cd and Zn in field-collected invertebrates co-varied most strongly with the observed mortality. This study provides a step toward exploring the underlying mechanism of dietary toxicity and identifying the potential causality in complex metal mixture exposures in the field. PMID:22579710

  12. [Bioturbation of macrobenthos on estuarine sediment].

    Qin, Xue-Bo; Sun, Hong-Wen; Wu, Ji-Zhou; Wang, Ruo-Nan; Sun, Tie-Heng

    2010-02-01

    By using microcosm tracer technique, the bioturbation of macrobenthos Helice tientsinensis, Nereis diversicolor, Bullacta exarata, and Cyclina sinensis on the sediment in Beitang Estuary of Tianjin, China was quantitatively studied. The bioturbation of test macrobenthos had obvious effects on the distribution of the sediment, and the effects differed with the macrobenthos. The disturbed intensity (diffusion coefficient, 10(-3) cm2 x d(-1)) of surface sediment under the effects of the macrobenthos was in order of N. diversicolor (2.95) > H. tientsinensis (1.00) > C. sinensis ( 0.78) > B. exarata. (0.35) > control (0.05), and that of deep sediment was H. tientsinensis (3.10) > N. diversicolor (2.33) > C. sinensis (0.28) > B. exarata (0.15) > control (0.05), which was mainly due to that the macrobenthos were belonged to different functional groups. There was a significant relationship between the bio-volume of test macrobentos and the diffusion coefficient of surface sediment (P < 0.05), suggesting that the bio-volume of macrobenthos could be used as an indicator to predict their bioturbation capacity on esturaine sediment. PMID:20462020

  13. Architecture of Columnar Nacre, and Implications for Its Formation Mechanism

    We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers

  14. Biomixing generated by benthic filter feeders: a diffusion model for near-bottom phytoplankton depletion

    Larsena, Poul S.; Riisgård, Hans Ulrik

    1997-05-01

    Transient concentration distributions of flagellate cells ( Rhodomonas sp.) previously measured by Riisgård and co-workers in laboratory experiments have been examined to develop a diffusion model for the process of phytoplankton depletion in stagnant seawater above populations of benthic filter feeders, the polychaete Nereis diversicolor and the ascidian Ciona intestinalis, respectively. The model is based on sinks located at inhalant openings and Fick's law with an effective diffusivity that decreases with distance above the bottom due to the biomixing generated by exhalant and inhalant feeding currents. For N. diversicolor, having inhalant and exhalant openings flush with the sediment surface and a moderate exhalant jet velocity of ˜0.01 m s -1, concentration boundary layer growth is retarded and limited by the low values of diffusivity prevailing at heights greater >˜0.05 m above the bottom. For C. intestinalis, having inhalant and exhalant openings situated ˜0.05-0.1 m above the bottom and a higher and inclined exhalant jet velocity of ˜0.1-0.2 m s -1, the concentration distributions show a nearly uniform depletion over a layer reaching a thickness of 0.2-0.3 m above the bottom due to high biomixing in this layer. Numerical predictions of concentration distributions reproduce essential features of experiments, and suggest near-bottom values of effective diffusivity of 0.3 x 10 -6 and 150 x 10 -6 m 2 s -1, for N. diversicolor and C. intestinalis, respectively. It is suggested that the latter value is so large that the induced mixing should be accounted for in modelling benthic concentration boundary layers under flow conditions.

  15. Bioakkumulering av miljøgifter fra marine sediment - etablering av et test-system. (Bioaccumulation of sediment-bound contaminants - establishment of a test-system)

    Hylland, K.

    1996-01-01

    Det har blitt etablert et oppsett for testing av biotilgjengeligheten av miljøgifter i marine sedimenter. Test-systemet kan brukes til testing av sediment innhentet fra felt og sediment innblandet en ønsket miljøgift eller blanding av miljøgifter. Test-organismer i oppsettet er børstemarken Nereis diversicolor og nettsnegl Hinia (Nassarius) reticulata. Dette er sentrale arter i økosystemet, de er lette å samle i store antall og det er mulig å holde begge i akvariesystemer over lengre tid. All...

  16. Survival and bioturbation effects of common marine macrofauna in coastal soils newly flooded with seawater

    Valdemarsen, Thomas Bruun; Quintana, Cintia Organo; Thorsen, Sandra Walløe; Kristensen, Erik

    Low-lying coastal soils are at risk of being permanently flooded due to global sea level rise, but how will these areas develop as habitat for marine species? We conducted an experiment to evaluate the habitat quality of flooded soils for common marine polychaetes (Marenzelleria viridis, Nereis...... diversicolor and Scoloplos armiger). Soil cores were collected at Gyldensteen Beach (Northern Fyn, Denmark), where a 200 ha area is designated for flooding as part of a nature restoration project. Soils cores were experimentally flooded for 1 month before adding polychaetes. We measured the effect of...

  17. Does the introduced polychaete Alitta succinea establish in the Caspian Sea?

    Ghasemi, Amir Faraz; Taheri, Mehrshad; Jam, Armin

    2013-12-01

    Members of the polychaete family Nereididae do not occur naturally in the Caspian Sea but are documented intentional human introductions that commenced in 1939. However, the identity of the species involved has been uncertain; material has been identified as both Alitta succinea and Hediste diversicolor. In this study, we confirm the presence of both species in the Caspian Sea. We discuss the distribution of both species, based on tolerance to physical factors, especially salinity. Although establishment of this partially predatory Nereidid, as a food reservoir could facilitate the recreation of commercially exploited fish stock, the consequences for native benthic communities are unclear and may be subject to unforeseen negative impacts.

  18. Effect of experimental crude oil contamination on abundance, mortality and resettlement of representative mud flat organisms in the mesohaline area of the elbe estuary

    Van Bernem, K. H.

    After repeated experimental contamination with small doses of the crude oils Arabian light, Kuwait crude and Iranian light on a silty mud flat in the Elbe estuary, neither an increased mortality nor emigration was found in Macoma balthica or Nereis diversicolor. Oligochaetes increased in abundance. The entire population of Corophium volutator tried to leave the contaminated sediment. Most specimens came into contact with the oil coating of the sediment and were killed. Twelve weeks after the beginning of the contaminations the original community structure had reestablished. Different effects between the 3 crude oils tested were not significant.

  19. Physiological response to a metal-contaminated invertebrate diet in zebrafish: importance of metal speciation and regulation of metal transport pathways.

    Boyle, David; Hogstrand, Christer; Bury, Nicolas R

    2011-09-01

    Dietary metal uptake in fish is determined by metal bioavailability in prey and the metal requirements of the fish. In this study zebrafish were fed the intertidal polychaete worm Nereis diversicolor (3% wet weight day(-1)) collected from Ag, Cd and Cu-impacted Restronguet Creek (RC) or a reference site, Blackwater estuary (BW), for 21 days. On days 0, 7, 14 and 21 fish were fed a single meal of RC or BW N. diversicolor labeled with (110m)Ag or (109)Cd for measurements of metal assimilation efficiency (AE). Zebrafish intestines were also taken for mRNA expression analysis of copper transporter 1 (ctr1), divalent metal transporter 1 (dmt1) and metallothionein 2 (mt2). No significant difference was observed in the AE of (109)Cd in metal naïve fish at day 0 between RC and BW worms, 11.8±2.1 and 15.3±2.8%, respectively. However, AE of (110m)Ag was significantly greater in fish fed worms from BW compared to RC, 5±1.2% and 1.6±0.5%, respectively at day 0. Fractionation analysis of radiolabeled metal partitioned in N. diversicolor from RC revealed a greater proportion of Ag (40±1.1%) in a fraction containing protein and organelle bound metal, associated with high trophic availability, compared to BW polychaetes (24±2.5%). Lower AE of (110m)Ag from RC polychaetes is therefore unlikely due to speciation of (110m)Ag in N. diversicolor from RC, but to the high concentration of Cu, a potential Ag antagonist. Exposure to RC polychaetes significantly increased the AE of (110m)Ag (6.2±1%), but not (109)Cd, from RC worms, after 21 days. AE of (110m)Ag and (109)Cd was unaffected by pre-exposure to BW. Elevated concentration of intestinal Cu and increased expression of ctr1, dmt1 and mt2 after 14 days exposure in fish fed worms from RC suggest altered Cu handling strategy of these fish which may increase AE of Ag via shared Ag and Cu transport pathways. These data suggest metal exposure history of invertebrates may affect metal bioavailability to fish, and fish may alter

  20. A step toward the prediction of the fluorescence lifetimes of tryptophan residues in proteins based on structural and spectral data.

    Sillen, A.; Díaz, J. F.; Engelborghs, Y.

    2000-01-01

    A method is presented that allows the calculation of the lifetimes of tryptophan residues on the basis of spectral and structural data. It is applied to two different proteins. The calcium binding protein from the sarcoplasm of the muscles of the sand worm Nereis diversicolor (NSCP) changes its conformation upon binding of Ca2+ or Mg2+. NSCP contains three tryptophan residues at position 4, 57, and 170, respectively. The fluorescence lifetimes of W57 are investigated in a mutant in which W4 a...

  1. Bioaccumulation surveillance in Milford Haven Waterway.

    Langston, W J; O'Hara, S; Pope, N D; Davey, M; Shortridge, E; Imamura, M; Harino, H; Kim, A; Vane, C H

    2012-01-01

    Biomonitoring of contaminants (metals, organotins, polyaromatic hydrocarbons (PAHs), PCBs) was undertaken in Milford Haven Waterway (MHW) and a reference site in the Tywi Estuary (St Ishmael/Ferryside) during 2007-2008. Bioindicator species encompassed various uptake routes-Fucus vesiculosus (dissolved contaminants); Littorina littorea (grazer); Mytilus edulis and Cerastoderma edule (suspension feeders); and Hediste (=Nereis) diversicolor (sediments). Differences in feeding and habitat preference have subtle implications for bioaccumulation trends though, with few exceptions, contaminant burdens in MHW were higher than the Tywi reference site, reflecting inputs. Elevated metal concentrations were observed at some MHW sites, whilst As and Se (molluscs and seaweed) were consistently at the higher end of the UK range. However, for most metals, distributions in MH biota were not exceptional. Several metal-species combinations indicated increases in bioavailability upstream, which may reflect the influence of geogenic/land-based sources-perhaps enhanced by lower salinity. TBT levels in MH mussels were below OSPAR toxicity thresholds and in the Tywi were close to zero. Phenyltins were not accumulated appreciably in M. edulis, whereas some H. diversicolor populations appear subjected to localized (historical) sources. PAHs in H. diversicolor were distributed evenly across most of MHW, although acenaphthene, fluoranthene, pyrene, benzo(a)anthracene and chrysene were highest at one site near the mouth; naphthalenes in H. diversicolor were enriched in the mid-upper Haven (a pattern seen in M. edulis for most PAHs). Whilst PAH (and PCB) concentrations in MH mussels were mostly above reference and OSPAR backgrounds, they are unlikely to exceed ecotoxicological thresholds. Bivalve Condition indices (CI) were highest at the Tywi reference site and at the seaward end of MH, decreasing upstream-giving rise to several significant (negative) relationships between CI and body burdens

  2. Makroinfaunal biodiversitet og mikrobiel olienedbrydning

    Ibdah, Sana; Buck, Sine; Prehn, Jonas; Enggaard, Mattias

    2006-01-01

    Gennem opstilling af enkelt-, dobbelt- og trippelartssammensætninger af henholdsvis Arinicola marina, Nereis diversicolor og Cerastoderma edule undersøger projektet sammenhængen mellem biodiversitet af bioturberende infauna og mikrobiel nedbrydning samt fjernelse for alkaner og methylphenantrener (MP) i sedimentet ved en nominel koncentration på 700 ppm råolie. Forsøget forløb over 4 uger. Ud fra ekstraktioner af sedimentet i 3 dybder ved forsøgets afslutning, hvorfra udvalgte oliekompone...

  3. Ecological consequence of the introduction of the polychaete Marenzelleria cf. viridis into a shallow-water biotope of the northern Baltic Sea

    Kotta, Jonne; Orav, Helen; Sandberg-Kilpi, Eva

    2001-12-01

    Effects of the North American polychaete Marenzelleria cf. viridis on a simple shallow-water benthic community of the northern Baltic Sea were studied in a field experiment combining natural densities of dominating macrofaunal species. The presence of M. cf. viridis increased benthic production (chlorophyll a) and reduced the survival of the native polychaete Nereis diversicolor. Adult Macoma balthica caused a significant mortality on M. cf. viridis whereas adult Cerastoderma glaucum had no effect on M. cf. viridis. We suggest that the competitive interactions between M. cf. viridis and M. balthica are a possible key factor determining the distribution pattern of M. cf. viridis in the Baltic Sea.

  4. Determination and localization of oil components in living benthic organisms by fluorescence microscopy

    Zeeck, E.

    1980-03-01

    Microspectrofluorometric measurements are made to determine uptake and distribution of oil in marine organisms after exposure to crude oil. Equipment combining fluorescence microscopy with spectral analysis of the fluorescence emission is described. After contamination with oil, the intestine content of Lumbricillus lineatus, Nereis diversicolor and Anaitides mucosa shows a fluorescence emission at long wavelengths with a maximum at about 550 nm; this is in contrast to the fluorescence emission of these organisms without oil contamination. There is evidence that aromatic hydrocarbons are metabolized in the intestine of the worms studied.

  5. Bioeconomics of a Marine Disease

    Conrad, Jon M.; Daniel Rondeau

    2014-01-01

    We study the economic impact of the viral disease AVG, its stochastic transmission across abalone reefs in southern Australia, and the optimal management response as AVG approaches an uninfected reef. Using conservative estimates of the virulence and mortality rates associated with the disease, we find it optimal to maintain the pre-AVG steady-state biomass on reef j until AVG has reached reef j - 1. The size of the optimal harvest when AVG has reached reef j - 1 is significant, ranging from ...

  6. Bioinspired Design of Building Materials for Blast and Ballistic Protection

    Yu-Yan Sun

    2016-01-01

    Full Text Available Nacre in abalone shell exhibits high toughness despite the brittle nature of its major constituent (i.e., aragonite. Its specific structure is a major contributor to the energy absorption capacity of nacre. This paper reviews the mechanisms behind the performance of nacre under shear, uniaxial tension, compression, and bending conditions. The remarkable combination of stiffness and toughness on nacre can motivate the development of bioinspired building materials for impact resistance applications, and the possible toughness designs of cement-based and clay-based composite materials with a layered and staggered structure were discussed.

  7. Spectral confocal reflection microscopy using a white light source

    Booth, M.; Juškaitis, R.; Wilson, T.

    2008-08-01

    We present a reflection confocal microscope incorporating a white light supercontinuum source and spectral detection. The microscope provides images resolved spatially in three-dimensions, in addition to spectral resolution covering the wavelength range 450-650nm. Images and reflection spectra of artificial and natural specimens are presented, showing features that are not normally revealed in conventional microscopes or confocal microscopes using discrete line lasers. The specimens include thin film structures on semiconductor chips, iridescent structures in Papilio blumei butterfly scales, nacre from abalone shells and opal gemstones. Quantitative size and refractive index measurements of transparent beads are derived from spectral interference bands.

  8. Stable isotopes reveal habitat-related diet shifts in facultative deposit-feeders

    Rossi, Francesca; Baeta, Alexandra; Marques, João C.

    2015-01-01

    Seagrass patches interspersed in a sediment matrix may vary environmental conditions and affect feeding habits of consumers and food-web structure. This paper investigates diet shifts between bare sediments and a Zostera noltei (Hornemann, 1832) meadow for three facultative deposit-feeding macrofaunal consumers, notably the bivalve Scrobicularia plana (da Costa, 1778), the polychaete Hediste diversicolor (O.T. Müller, 1776), and the gastropod Hydrobia ulvae (Pennant, 1778). In July 2008, one eelgrass meadow and two bare sediment locations were chosen in the Mondego estuary (40° 08″ N, 8° 50‧ W, Portugal) and sampled for stable isotope signatures (δ13C and δ15N) of macrofauna consumers and some of their potential basal food sources, such as sedimentary organic matter (SOM), microphytobenthos (MPB), seagrass shoots, leaves and seaweeds laying on the surface sediment. The δ15N of H. diversicolor was 3‰ higher in the eelgrass meadow than in bare sediment, indicating a change of trophic position, whereas the Bayesian stable-isotope mixing model showed that S. plana assimilated more macroalgal detritus than microphytobenthos in the eelgrass bed. Such habitat-related diet shifts have the potential to change structure and spatial dynamics of benthic food webs.

  9. Interaction of nemertines and their prey on tidal flats

    Thiel, Martin; Reise, Karsten

    Two common nemertines of the European Wadden Sea, Lineus viridis and Amphiporus lactifloreus, occur preferentially in clusters of mussels, spread over sedimentary flats in the upper intertidal near the island of Sylt. The heteronemertine L. viridis preys mainly on the polychaete Nereis diversicolor. The hoplonemertine A. lactifloreus feeds almost exclusively on the amphipod Gammarus locusta. Abundance of both predators and their respective prey in the field showed inverse relationships. Experimentally increased numbers of L. viridis in clusters of mussels caused a gradual decrease of nereid abundance in the sediment underneath over a period of 1 month, suggesting that losses of individuals were caused by prey capture. Experimentally increased numbers of A. lactifloreus were followed by an escape response of gammarids from clusters of mussels within 2 d. In aquaria, both prey species exhibited prolonged swimming activity when their respective predators lurked at the bottom. We conclude that escape behaviour in N. diversicolor may be only effective during its migrant phases, while G. locusta is permanently on the alert to avoid encounters with its predator. This refuging behaviour in response to endobenthic predators has strong implications on prey distribution, while the actual consumption of prey may be relatively modest. Enclosure experiments in the field and in aquaria lead to overestimates of prey capture when refuging behaviour is not accounted for.

  10. Effect of temperature on biogeochemistry of marine organic-enriched systems: implications in a global warming scenario.

    Sanz-Lázaro, Carlos; Valdemarsen, Thomas; Marín, Arnaldo; Holmer, Marianne

    2011-10-01

    Coastal biogeochemical cycles are expected to be affected by global warming. By means of a mesocosm experiment, the effect of increased water temperature on the biogeochemical cycles of coastal sediments affected by organic-matter enrichment was tested, focusing on the carbon, sulfur, and iron cycles. Nereis diversicolor was used as a model species to simulate macrofaunal bioirrigation activity in natural sediments. Although bioirrigation rates of N. diversicolor were not temperature dependent, temperature did have a major effect on the sediment metabolism. Under organic-enrichment conditions, the increase in sediment metabolism was greater than expected and occurred through the enhancement of anaerobic metabolic pathway rates, mainly sulfate reduction. There was a twofold increase in sediment metabolism and the accumulation of reduced sulfur. The increase in the benthic metabolism was maintained by the supply of electron acceptors through bioirrigation and as a result of the availability of iron in the sediment. As long as the sediment buffering capacity toward sulfides is not surpassed, an increase in temperature might promote the recovery of organic-enriched sediments by decreasing the time for mineralization of excess organic matter. PMID:22073651

  11. Evaluation of protein extraction protocols for 2DE in marine ecotoxicoproteomics.

    Wu, Huifeng; Ji, Chenglong; Wei, Lei; Zhao, Jianmin

    2013-11-01

    In ecotoxicoproteomics, an accurate and reproducible extraction of proteins is a critical step for 2DE analysis and further protein identification using MS. The criteria for the assessment of protein extraction quality include protein yield, protein spots resolved in a 2DE gel, matched protein spots in replicate gels, reproducibility, and compatibility with MS. In this work, we evaluated three protein extraction systems, straightforward lysis buffer, trichloroacetic acid-acetone, and TRIzol reagent with some modifications, for the protein extraction from three animal species including mussel Mytilus galloprovincialis, flounder Paralichthys olivaceus, and polychaete Nereis diversicolor used in marine ecotoxicology. Our results indicated that these methods could extract significantly different protein profiles. The method using TRIzol reagent resulted in the most matched protein spots resolved in four replicate 2DE gels and highest reproducibilities for the gill of M. galloprovincialis and liver of P. olivaceus. However, a modified trichloroacetic acid-acetone solvent system was best for the whole soft tissue of N. diversicolor. This work provides the fundamental information of the extraction quality of protein extraction protocols from different marine animals, which may facilitate the selection of a suitable protein extraction protocol for ecotoxicoproteomics. PMID:24106175

  12. Comparative investigation on the potential use of Wadden Sea organisms of different trophic levels for trend monitoring of selected heavy metals and polychlorinated biphenyls. Short version; Vergleichende Untersuchungen ueber die Eignung von Wattorganismen unterschiedlicher Trophiestufen zum Trendmonitoring ausgewaehlter Schwermetalle und polychlorierter Biphenyle. Kurzfassung

    Lorch, D.; Thiel, H.; Kaiser, M.; Lade, J.; Marencic, H.

    1992-03-01

    From September 1986 to March 1989 sediments and organisms were sampled 17 times near Rantum on the North Frisian Island of Sylt. Sediments, Littorina littorea, Macoma baltica, Mytilus edulis, Nereis diversicolor, Arenicola marina, Spartina anglica, Zostera marina and microphytobenthos were characterized and analysed for heavy metals and chlorinated hydrocarbons. To evaluate the possible potential of the different organisms in trend monitoring, a catalogue of criteria was compiled and the data evaluated accordingly. Macoma baltica was found to best satisfy the prerequisites and, to a lesser extent, Zostera marina. It is concluded, that in a long term trend monitoring effort, both organisms should be considered. A first comparison of Sylt and an area in the East Frisian Wadden Sea has been undertaken. (orig.). [Deutsch] Von September 1986 bis Maerz 1989 wurden bei Rantum auf Sylt 17 Beprobungen durchgefuehrt und dabei Sediment und folgende Organismen entnommen: Littorina littorea, Macoma baltica, Mytilus edulis, Nereis diversicolor, Arenicola marina, Spartina anglica, Zostera marina und Mikrophytobenthos. Die Schwermetall- und Chlorkohlenwasserstoff-Konzentrationen sowie sedimentologische und biologische Parameter wurden ermittelt.Anhand vorhandener und neu entwickelter Kriterienkataloge konnten Macoma baltica und Zostera marina als geeignete Organismen fuer ein langfristiges Trendmonitoring Programm ermittelt werden. Erste Vergleiche mit Standorten im Ostfriesischen Watt wurden durchgefuehrt. (orig.).

  13. Metals in sediments and benthic organisms in the Mersey estuary

    Langston, W. J.

    1986-08-01

    Concentrations of twelve metals were determined in sediments, seaweed ( Fucus vesiculosus), winkles ( Littorina littorea), polychaetes ( Nereis diversicolor), suspension feeding bivalves ( Mytilus edulis, Cerastoderma edule) and deposit feeding bivalves ( Macoma balthica, Scrobicularia plana) collected from the Mersey estuary between April 1980 and June 1984. Sediments and organisms in the Mersey are moderately contaminated with most of the metals measured, but mercury concentrations are consistently higher than in other United Kingdom estuaries. Comparisons with other sites in the North West of England indicate that mercury residues in organisms, though primarily dependent on sediment concentrations, are also influenced by complexation with particulate organic matter which reduces the availability of mercury. The biological availability of arsenic in Mersey sediments is similarly influenced by complexation with iron oxyhydroxides. Nereis diversicolor and Macoma balthica are the most suitable indicator species in terms of abundance and widespread distribution along the estuary, and, for the majority of metals, tissue concentrations increase upstream, reflecting corresponding gradients in sediment contamination. However mid-estuarine peaks for tin, chromium copper and nickel in Nereis indicate more localised inputs to the estuary. Correlations between lead in sediments and organisms are poor; it is suggested that hydrophilic alkyl lead compounds may be the predominant biologically available forms. Progressive reductions in mercury contamination in sediments and mercury and lead in organisms have occurred in recent years, which coincide with efforts to reduce inputs of these metals to teh Mersey estuary.

  14. Gene structure and molecular phylogeny of the linker chains from the giant annelid hexagonal bilayer hemoglobins.

    Chabasse, Christine; Bailly, Xavier; Sanchez, Sophie; Rousselot, Morgane; Zal, Franck

    2006-09-01

    Giant extracellular hexagonal bilayer hemoglobin (HBL-Hb), found only in annelids, is an approximately 3500-kDa heteropolymeric structure involved in oxygen transport. The HBL-Hbs are comprised of globin and linker chains, the latter being required for the assembly of the quaternary structure. The linker chains, varying in size from 225 to 283 amino acids, have a conserved cysteine-rich domain within their N-terminal moiety that is homologous to the cysteine-rich modules constituting the ligand binding domain of the low-density lipoprotein receptor (LDLR) protein family found in many metazoans. We have investigated the gene structure of linkers from Arenicola marina, Alvinella pompejana, Nereis diversicolor, Lumbricus terrestris, and Riftia pachyptila. We found, contrary to the results obtained earlier with linker genes from N. diversicolor and L. terrestris, that in all of the foregoing cases, the linker LDL-A module is flanked by two phase 1 introns, as in the human LDLR gene, with two more introns in the 3' side whose positions varied with the species. In addition, we obtained 13 linker cDNAs that have been determined experimentally or found in the EST database LumbriBASE. A molecular phylogenetic analysis of the linker primary sequences demonstrated that they cluster into two distinct families of linker proteins. We propose that the common gene ancestor to annelid linker genes exhibited a four-intron and five-exon structure and gave rise to the two families subsequent to a duplication event. PMID:16838215

  15. Food supply for waders (Aves: Charadrii) in an estuarine area in the Bay of Cádiz (SW Iberian Peninsula)

    Masero, José A.; Pérez-González, Maite; Basadre, Marta; Otero-Saavedra, Mónica

    1999-07-01

    We studied the composition, density, size distribution and biomass of the food supply for waders in an estuarine area in the Bay of Cádiz (SW Iberian Peninsula), in winter (January-February) and in the pre-migratory period (late March). The estuarine area comprises an intertidal mudflat and an adjacent salina or salt-pan. On the intertidal mudflat, the biomass was 53 and 37 g AFDW .m -2in winter and the pre-migratory period, respectively. The main food source on mudflat was the polychaete Nereis diversicolor (44-54 % of the total biomass). On the other hand, the biomass in the salina was comparatively very poor, ranging from 0.008 to 0.079 g AFDW .m -2in winter and ranging from 0.011 to 0.09 g AFDW in late March. The main source of food in the salina was the crustacean Artemia. The total biomass on the mudflat during the pre-migratory period was 1.4 times lower than in February. This depletion could be caused by wader predation, mainly by Nereis diversicolor consumption. Although the potential food on the mudflats could allow high intertidal densities of waders, the availability of high tide foraging areas in the salina seems to contribute to the maintenance of these high intertidal densities.

  16. Bone indentation recovery time correlates with bond reforming time

    Thompson, James B.; Kindt, Johannes H.; Drake, Barney; Hansma, Helen G.; Morse, Daniel E.; Hansma, Paul K.

    2001-12-01

    Despite centuries of work, dating back to Galileo, the molecular basis of bone's toughness and strength remains largely a mystery. A great deal is known about bone microsctructure and the microcracks that are precursors to its fracture, but little is known about the basic mechanism for dissipating the energy of an impact to keep the bone from fracturing. Bone is a nanocomposite of hydroxyapatite crystals and an organic matrix. Because rigid crystals such as the hydroxyapatite crystals cannot dissipate much energy, the organic matrix, which is mainly collagen, must be involved. A reduction in the number of collagen cross links has been associated with reduced bone strength and collagen is molecularly elongated (`pulled') when bovine tendon is strained. Using an atomic force microscope, a molecular mechanistic origin for the remarkable toughness of another biocomposite material, abalone nacre, has been found. Here we report that bone, like abalone nacre, contains polymers with `sacrificial bonds' that both protect the polymer backbone and dissipate energy. The time needed for these sacrificial bonds to reform after pulling correlates with the time needed for bone to recover its toughness as measured by atomic force microscope indentation testing. We suggest that the sacrificial bonds found within or between collagen molecules may be partially responsible for the toughness of bone.

  17. Characterization of Biochemical Composition for Different Types of Spent Mushroom Substrate in Malaysia

    A preliminary study was conducted to identify the amount and changes of biochemical composition of different types of Malaysian spent mushroom substrate (SMS) before and after several cycle of mushroom cultivation. The characterization of SMS involved the analysis of crude protein, carbohydrate, fat, lignin and ash for selected mushrooms namely as white oyster (Pleuratos oestrous), grey oyster (Pleuratos sajor-caju), abalone (Pleuratos cystidiosus), ganoderma (Ganoderma lucidium) and black jelly (Auricularia polytricha). Overall trend showed that there were increment for crude protein and fat, whereas carbohydrate and lignin showed reduction in the content. Significant results were showed on protein increment where ganoderma attained the highest value, 36.6 g, followed by black jelly, white oyster, grey oyster and abalone. Contradictory, lowest carbohydrate reduction was observed in ganoderma at 70.42 g and the most was in black jelly. Increment in fat and reduction in lignin was almost similar for each SMS. There was an increment in the ash percentage resulted from sterilization process. Clearly cultivation by mushroom had changed biochemical value especially in increasing the protein content that might be useful in protein required industry such as animal feeding. (author)

  18. Dicty_cDB: Contig-U15359-1 [Dicty_cDB

    Full Text Available 00450_519( CP000450 |pid:none) Nitrosomonas eutropha C91, compl... 60 3e-07 CP000300_1111( CP000300 |pid:none) Methanococco...1H2 sequ... 48 0.91 1 ( DQ191761 ) Monosiga ovata Hoglet (hoglet) mRNA, complete cds. 48 0.91 1 ( AY013583 ) Haliotis kamtschatkana...lyphosphate kinase (PP... 48 0.91 1 ( AE014298 ) Drosophila melanogaster chromosome X, comp...9 CP000713_1310( CP000713 |pid:none) Psychrobacter sp. PRwf-1, compl... 66 3e-09 CP000099_988( CP000099 |pid:none) Methanosarcina...ne) Erwinia tasmaniensis strain ET1... 64 1e-08 CP000744_77( CP000744 |pid:none) Pseudomonas aeruginosa PA7, comp

  19. Alternative splicing produces transcripts coding for alpha and beta chains of a hetero-dimeric phosphagen kinase.

    Ellington, W Ross; Yamashita, Daisuke; Suzuki, Tomohiko

    2004-06-01

    Glycocyamine kinase (GK) catalyzes the reversible phosphorylation of glycocyamine (guanidinoacetate), a reaction central to cellular energy homeostasis in certain animals. GK is a member of the phosphagen kinase enzyme family and appears to have evolved from creatine kinase (CK) early in the evolution of multi-cellular animals. Prior work has shown that GK from the polychaete Neanthes (Nereis) diversicolor exits as a hetero-dimer in vivo and that the two polypeptide chains (termed alpha and beta) are coded for by unique transcripts. In the present study, we demonstrate that the GK from a congener Nereis virens is also hetero-dimeric and is coded for by alpha and beta transcripts, which are virtually identical to the corresponding forms in N. diversicolor. The GK gene from N. diversicolor was amplified by PCR. Sequencing of the PCR products showed that the alpha and beta chains are the result of alternative splicing of the GK primary mRNA transcript. These results also strongly suggest that this gene underwent an early tandem exon duplication event. Full-length cDNAs for N. virens GKalpha and GKbeta were individually ligated into expression vectors and the resulting constructs used to transform Escherichia coli expression hosts. Regardless of expression conditions, minimal GK activity was observed in both GKalpha and GKbeta constructs. Inclusion bodies for both were harvested, unfolded in urea and alpha chains, beta chains and mixtures of alpha and beta chains were refolded by sequential dialysis. Only modest amounts of GK activity were observed when alpha and beta were refolded individually. In contrast, when refolded the alpha and beta mixture yielded highly active hetero-dimers, as validated by size exclusion chromatography, electrophoresis and mass spectrometry, with a specific activity comparable to that of natural GK. The above evidence suggests that there is a preference for hetero-dimer formation in the GKs from these two polychaetes. The evolution of the

  20. Comparative study of plutonium and americium bioaccumulation from two marine sediments contaminated in the natural environment

    Plutonium and americium sediment-animal transfer was studied under controlled laboratory conditions by exposure of the benthic polychaete Nereis diversicolor (O. F. Mueller) to marine sediments contaminated by a nuclear bomb accident (near Thule, Greenland) and nuclear weapons testing (Enewetak Atoll). In both sediment regimes, the bioavailability of plutonium and 241Am was low, with specific activity in the tissues 241Am occurred and 241Am uptake from the Thule sediment was enhanced compared to that from lagoon sediments of Enewetak Atoll. Autoradiography studies indicated the presence of hot particles of plutonium in the sediments. The results highlight the importance of purging animals of their gut contents in order to obtain accurate estimates of transuranic transfer from ingested sediments into tissue. It is further suggested that enhanced transuranic uptake by some benthic species could arise from ingestion of highly activity particles and organic-rich detritus present in the sediments. (author)

  1. Chemical monitoring in the Dutch Wadden Sea by means of benthic invertebrates and fish

    Essink, Karel

    1989-09-01

    In monitoring, it is of utmost importance to carefully define the purpose, the sampling strategy, as well as the analytical chemical and statistical requirements. Surveys are appropriate for describing the geographical variation in environmental contaminant levels. Repeated surveys and recurrentdata collection at permanent locations provide means of detecting temporal trends. Results are presented here of surveys on pollution by trace metals, polychlorinated biphenyls and organochlorine pesticides in the Ems Estuary and Dutch Wadden Sea using Mytilus edulis, Mya arenaria, Arenicoia marina, Nereis diversicolor and Crangon crangon as test organisms. Trends towards decreasing pollution by mercury are illustrated by monitoring data on Mytilus edulis and Zoarces viviparus. It is stressed that the results of chemical monitoring in organisms may be interpreted only in termser the biological effects on the basis of relevant toxicological knowledge and/or additional bio-assays.

  2. Seasonal and annual changes in the macrozoobenthic populations of the Gulf of Gdańsk with respect to hypoxia and hydrogen sulphide

    Urszula Janas

    2004-03-01

    Full Text Available This study was designed to investigate seasonal and annual changes in the benthic macrofauna in relation to changes in hydrogen sulphide concentration in the sediment and the oxygen content in the water column. Data were collected over a three-year period from 1994 to 1997. The benthic macrofauna inhabiting the sediments of the Gulf of Gdansk, in which H2S is permanently present, consists mostly of species with a high tolerance to oxygen deficiency and the presence of H2S. These species are: Macoma balthica, Harmothoe sarsi, Nereis diversicolor, Saduria entomon and Halicryptus spinulosus, as well as Pontoporeia femorata and Corophium volutator, which are more sensitive to these factors. In 1996-1997 a decline in the abundance of almost all benthic species, and especially of the bivalve M. balthica at all the stations was observed in comparison to 1994-1995.

  3. Uptake and distribution of heavy metals in annelidae, with particular regard to limnic tubificides (oligochaeta). Aufnahme und Verteilung von Schwermetallen in Anneliden, unter besonderer Beruecksichtigung limnischer Tubificiden (Oligochaeta)

    Back, H.G.

    1985-01-01

    The uptake and distribution of Pb, Cd, and Zn were investigated in Tubifex tubifex and Limnodrilus udekemianus (oligochaeta). Further, comparative laboratory and field experiments were made in marine vertebrates. The toxic heavy metals lead and cadmium were preferably taken up by respiratory epithels, e.g. the epidermis of the back end of the tubificides or the gills of Arenica marina (polychaeta). In Nereis diversicolor (polychaeta), the parapodia in which most of the gas exchange takes place were the preferred regions of metal uptake, both in laboratory and field experiments. In limnic tubificides, zinc inhibited the Cd uptake and promoted the Pb uptake. The AAS data and electron microscope data suggest three different uptake mechanisms for Pb (pinocytosis), Cd (facilitated diffusion), and Zn (uptake via an ATP-splitting process).

  4. Entre nécessité, volonté et réalité. Le ramassage des vers marins en baie de Sallenelles (1956-2000)

    Le Chêne, Monique

    2015-01-01

    Au milieu des années 1950, une industrie originale se met en place dans la baie de Sallenelles, située à quelques kilomètres de Caen : le ramassage et le commerce de la plouze, un ver marin très apprécié des pêcheurs. La plouze, appellation normande du Nereis diversicolor, est un ver rougeâtre qui vit enfoui à une dizaine de centimètres de la surface du sol et se déplace à la manière d’un mille-pattes. Il est utilisé comme appât pour la pêche de loisir en bord de mer. Jusqu’aux années 1980, c...

  5. Environmental effects of the growth rate of intertidal invertebrates and some implications for foraging waders

    Wanink, Jan H.; Zwarts, Leo

    The paper describes effects of intertidal height and sediment type on growth rate of the bivalves Cerastoderma edule, Macoma balthica, Mya arenaria, Mytilus edulis and Scrobicularia plana, and of the worms Arenicola marina, Nephtys hombergii and Nereis diversicolor in the eastern part of the Dutch Wadden Sea. In most species, exposure time was negatively correlated with length growth, although interfering effects of sediment type could not be ruled out. When controlled for the effects of exposure time, clay content of the sediment appeared to affect the growth of all species, but in different ways. The variation was related to the foraging methods of the invertebrates. Foraging waders may use the spatial variation in growth rate of the invertebrates to optimize the exploitation of individual cohorts.

  6. Recognition of protein folds via dipolar couplings

    Alignment of proteins in dilute liquid crystalline medium gives rise to residual dipolar couplings which provide orientational information of vectors connecting the interacting nuclei. Considering that proteins are mainly composed of regular secondary structures in a finite number of different mutual orientations, main chain dipolar couplings appear sufficient to reveal structural resemblance. Similarity between dipolar couplings measured from a protein and corresponding values computed from a known structure imply homologous structures. For dissimilar structures the agreement between experimental and calculated dipolar couplings remains poor. In this way protein folds can be readily recognized prior to a comprehensive structure determination. This approach has been demonstrated by showing the similarity in fold between the hitherto unknown structure of calerythrin and sarcoplasmic calcium-binding proteins from Nereis diversicolor and Branchiostoma lanceolatum with known crystal structures

  7. Recognition of protein folds via dipolar couplings

    Annila, Arto [VTT Chemical Technology (Finland); Aitio, Helena [University of Helsinki, Institute of Biotechnology (Finland); Thulin, Eva [University of Lund, Department of Physical Chemistry 2 (Sweden); Drakenberg, Torbjoern [VTT Chemical Technology (Finland)

    1999-07-15

    Alignment of proteins in dilute liquid crystalline medium gives rise to residual dipolar couplings which provide orientational information of vectors connecting the interacting nuclei. Considering that proteins are mainly composed of regular secondary structures in a finite number of different mutual orientations, main chain dipolar couplings appear sufficient to reveal structural resemblance. Similarity between dipolar couplings measured from a protein and corresponding values computed from a known structure imply homologous structures. For dissimilar structures the agreement between experimental and calculated dipolar couplings remains poor. In this way protein folds can be readily recognized prior to a comprehensive structure determination. This approach has been demonstrated by showing the similarity in fold between the hitherto unknown structure of calerythrin and sarcoplasmic calcium-binding proteins from Nereis diversicolor and Branchiostoma lanceolatum with known crystal structures.

  8. Influence of food quality on the assimilation, retention and distribution of selected trace elements and radionuclides in the Mediterranean crab Pachygrapsus marmolatus

    Carrier-free or high specific activity radiotracer solutions of 109Cd , 65Zn, 110mAg, 60Co, 75Se and 241Am were used in a mixture to label mussels (Mytilus edulis) for six days in sea water containing a suspension of phytoplankton cells (Isochrysis galbana). In addition, worms (Nereis diversicolor) were directly labeled from water with these same radioisotopes for six days. Two sets of crabs (Pachygrapsus marmolatus) were fed ad libitum for a few minutes with prelabelled mussel soft parts or worms. Crabs fed radiolabeled mussel soft parts or worms were then dissected after 55 or 42 days of loss, respectively. Subsequent whole body radioanalysis showed that the assimilation efficiencies, biological half-lives for retention, and fecal excretion were different for the six radioisotopes in the two crab sets

  9. Polychaete tube walls as zonated microhabitats for marine bacteria.

    Reichardt, W.

    1984-01-01

    Le sédiment sableux riche en sulfures et à dominante anoxique d'une lagune peu profonde du fjord de Kiel, héberge une population dense d'un ver polychète : Nereis diversicolor (280 cm3 m"2 en biomasse volume), Les parois des tubes qui contrastent par leur coloration brune d'au moins 1,5 mm d'épaisseur avec la masse de sédiment noir réduit, constituent jusqu'à 6 % du volume total des carottes de 10 cm. La présence d'Û2 n'est décelée que dans les tous premiers millimètres de la couche de surfac...

  10. Efeito da bioturbação na distribuição de metais e de isótopos estáveis de Pb em sedimentos de sapal, no estuário do Tejo

    Cesário, Rute Isabel Talhadas

    2007-01-01

    A bioturbação causada pelas plantas Sarcocornia fruticosa e Spartina maritima e pelo poliqueta Nereis diversicolor foi estudada em sedimentos do sapal do Rosário (Tejo). Foram colhidos cores de sedimento vegetado e não vegetado para a determinação das concentrações de Zn, Cu, Cd e Pb e das razões isotópicas 206Pb/207Pb e 206Pb/208Pb em profundidade. Estes parâmetros foram também determinados nas plantas. As concentrações destes metais na biomassa subterrânea foram 1-3 ordens de grandeza super...

  11. Freshwater springs on intertidal sand flats cause a switch in dominance among polychaete worms

    Zipperle, Andreas; Reise, Karsten

    2005-08-01

    Effects of freshwater seepage on benthic macrofauna were investigated on the sandy tidal flats near the island of Sylt (German Wadden Sea) in 2002. Several permanent seepage areas (50 to 200 m offshore; up to 200 m 2 in area) were examined, in which salinity ranged from 22-29 outside to 0-16 psu inside seepage areas in the upper 20 cm of sediment during summer low tides. The freshwater seepage areas were characterised by an absence of lugworms ( Arenicola marina) and a twelve-fold increase in nereid polychaetes ( Nereis diversicolor and N. virens) relative to non-seepage areas. Lugworms and ragworms were scarce in a transition zone, which was colonised by juvenile lugworms. We suggest that nereid polychaetes avoid competition with bioturbating lugworms by adapting to areas of low salinity (freshwater seepage).

  12. Isolation of a member of ets gene family in the polychaete annelid Perinereis cultrifera.

    Bocquet-Muchembled, B; Leroux, R; Chotteau-Lelièvre, A; Fontaine, F

    2001-01-01

    Numerous genes belonging to the ets gene family have been described for a few years. The founder of this family is the v-ets proto-oncogene, which is the viral counterpart of the chicken c-ets-1 proto-oncogene. Main research was carried out both on Vertebrates, Drosophila and the nematod Caenorhabditis elegans. Previously, two genes of this family named Nd ets and Nd erg, were isolated in the polychaete annelid Hediste (Nereis) diversicolor. Here we have described the isolation of one gene from the ets family in another polychaete annelid named Perinereis cultrifera. By polymerase chain reaction using degenerated primers, we have amplified an approximatively 515 pb genomic region encoding the ETS domain and another domain designed as "R" domain by Qi et al. (1992) and which can mediate transactivation. By using this method for isolating members of the ets gene family, we are going to realize a phylogenetic study of the phylum of polychaete annelids. PMID:11761710

  13. Burrowing and avoidance behaviour in marine organisms exposed to pesticide-contaminated sediment

    Mohlenberg, F.; Kiorboe, T.

    1983-02-01

    Behavioural effects of marine sediment contaminated with pesticides (6000 ppm parathion, 200 ppm methyl parathion, 200 ppm malathion) were studied in a number of marine organisms in laboratory tests and in situ. The burrowing behaviour in Macoma baltica, Cerastoderma edule, Abra alba, Nereis diversicolor and Scoloplos armiger was impaired in the contaminated sediment compared to control. The impairment was most pronounced in the laboratory tests, where almost no burrowing occured. In a very simple laboratory set-up, highly significant avoidance of the contaminated sediment was demonstrated for Crangon crangon and Solea solea, but not for Carcinus maenas and Pomatoschistus minutus. The validity of both behavioural tests was supported by in situ observations and investigations on the distribution of the species. It is concluded that both tests are useful tools in the assessment of the impact of contaminated sediments.

  14. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations.

    Moreira, Susana M; Moreira-Santos, Matilde; Guilhermino, Lúcia; Ribeiro, Rui

    2006-01-01

    This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Müller as food source, was first developed. The sensitivity of the postexposure feeding response was verified by comparing it to that of lethality, upon cadmium exposure. The influence of environmental conditions prevailing during exposure (salinity, temperature, substrate, light regime, and food availability) on postexposure feeding was also addressed. The potential of this in situ assay was then investigated by deploying organisms at ten sites, located in reference and contaminated Portuguese estuaries. Organism recovery ranged between 90% and 100% and a significant postexposure feeding depression (16.3-72.7%) was observed at all contaminated sites relatively to references. PMID:16002194

  15. The Effect of Macrofauna on Porewater Profiles and Nutrient Fluxes in the Intertidal Zone of the Humber Estuary

    Mortimer, R. J. G.; Davey, J. T.; Krom, M. D.; Watson, P. G.; Frickers, P. E.; Clifton, R. J.

    1999-06-01

    Macrofauna, nutrient fluxes, porewater chemistry and sediment characteristics were measured at six intertidal mudflat sites in the Humber Estuary, U.K., during the different seasons. Nereis diversicolor , Macoma balthica and Corophium volutator were found to be the dominant macrofauna. Salinity was the baseline control on macrofauna distribution but this was overprinted by periodic impoverishment due to sediment mobilization. High resolution gel probe porewater samplers provided direct evidence for the impact of burrows on porewater chemistry. The macrofauna modified nutrient fluxes during periods of mud flat stability. Nereis caused a decrease in silicate and phosphate effluxes but enhanced ammonia release and nitrate uptake. Macoma enhanced ammonia and nitrite release. The impact of Corophium was not possible to discern. The Humber is a large, highly dynamic macrotidal estuary in which sediment resuspension has a large impact on porewater profiles, nutrient fluxes and macrofaunal communities. Simple patterns and inter-relationships which are seen in small sheltered estuaries are not observed in the Humber.

  16. Influence de la Bioturbation sur l'Activité Dénitrifiante dans des Sédiments Marins Côtiers. Effet d'un Apport Exogène de Matière Organique: les Hydrocarbures

    Gilbert, Franck

    1994-01-01

    L'objectif principal de ce travail était de mettre en évidence l'influence de la bioturbation induite par le macrobenthos sur la dénitrification dans un sédiment marin soumis à un apport ponctuel massif de matière organique (hydrocarbures). Deux types d'expérimentations complémentaires ont été réalisées: - In vitro, pour étudier les effets d'une population de Polychètes galéricoles Nereis diversicolor, - In situ (golfe de Fos) afin de mettre en évidence l'influence de la macrofaune autochtone...

  17. Hairy suckers: the surface microstructure and its possible functional significance in the Octopus vulgaris sucker

    Francesca Tramacere

    2014-05-01

    Full Text Available Octopus suckers are able to attach to any smooth surface and many rough surfaces. Here, we have discovered that the sucker surface, which has been hypothesised to be responsible for sealing the orifice during adhesion, is not smooth as previously assumed, but is completely covered by a dense network of hair-like micro-outgrowths. This finding is particularly important because it provides another demonstration of the role of hair-structures in a sealing mechanism in water, similar to that previously described for clingfish and abalones. Moreover, the discovered hairs may provide an additional adhesive mechanism that works in concert with suction. The discovered surface structures might be potentially interesting for biomimetics of novel technical suction cups with improved adhesion capabilities on non-smooth surfaces.

  18. Hairy suckers: the surface microstructure and its possible functional significance in the Octopus vulgaris sucker.

    Tramacere, Francesca; Appel, Esther; Mazzolai, Barbara; Gorb, Stanislav N

    2014-01-01

    Octopus suckers are able to attach to any smooth surface and many rough surfaces. Here, we have discovered that the sucker surface, which has been hypothesised to be responsible for sealing the orifice during adhesion, is not smooth as previously assumed, but is completely covered by a dense network of hair-like micro-outgrowths. This finding is particularly important because it provides another demonstration of the role of hair-structures in a sealing mechanism in water, similar to that previously described for clingfish and abalones. Moreover, the discovered hairs may provide an additional adhesive mechanism that works in concert with suction. The discovered surface structures might be potentially interesting for biomimetics of novel technical suction cups with improved adhesion capabilities on non-smooth surfaces. PMID:24991492

  19. Bioinspired Design: Magnetic Freeze Casting

    Porter, Michael Martin

    Nature is the ultimate experimental scientist, having billions of years of evolution to design, test, and adapt a variety of multifunctional systems for a plethora of diverse applications. Next-generation materials that draw inspiration from the structure-property-function relationships of natural biological materials have led to many high-performance structural materials with hybrid, hierarchical architectures that fit form to function. In this dissertation, a novel materials processing method, magnetic freeze casting, is introduced to develop porous scaffolds and hybrid composites with micro-architectures that emulate bone, abalone nacre, and other hard biological materials. This method uses ice as a template to form ceramic-based materials with continuously, interconnected microstructures and magnetic fields to control the alignment of these structures in multiple directions. The resulting materials have anisotropic properties with enhanced mechanical performance that have potential applications as bone implants or lightweight structural composites, among others.

  20. Molecular energy dissipation in nanoscale networks of dentin matrix protein 1 is strongly dependent on ion valence

    The fracture resistance of biomineralized tissues such as bone, dentin, and abalone is greatly enhanced through the nanoscale interactions of stiff inorganic mineral components with soft organic adhesive components. A proper understanding of the interactions that occur within the organic component, and between the organic and inorganic components, is therefore critical for a complete understanding of the mechanics of these tissues. In this paper, we use atomic force microscope (AFM) force spectroscopy and dynamic force spectroscopy to explore the effect of ionic interactions within a nanoscale system consisting of networks of dentin matrix protein 1 (DMP1) (a component of both bone and dentin organic matrix), a mica surface and an AFM tip. We find that DMP1 is capable of dissipating large amounts of energy through an ion-mediated mechanism, and that the effectiveness increases with increasing ion valence

  1. Multiple Features Subset Selection using Meta-Heuristic Function

    L. S. Maurya

    2011-11-01

    Full Text Available This paper is being presented on Multiple Features Subset Selection Using Meta-heuristic Function. Classification problems require selection of a subset of attributes or features from a much larger dataset to represent the patterns to be classified. Many excellent multiple feature selection method such as Hill Climbing (HC, Simulated Annealing (SA, Genetic Algorithms (GAs, Tabu Search (TS has been prevalent amongst research community. However, these approaches still encounter when the multiple feature of dataset is available and it need to choose those attribute which is best amongst the available features. So, in this paper basically considering the issue of multiple features are analyzed as well as implemented and tested on different dataset. The experiment is being conducted abalone dataset. It may conclude that the algorithm shows highest accuracy amongst all other method which is being used in this paper, Therefore we are focusing on the classification of multiple features

  2. Effects of soy supplementation on blood lipids and arterial function in hypercholesterolaemic subjects

    Hermansen, K; Hansen, B; Jacobsen, R;

    2005-01-01

    BACKGROUND: Studies on soy supplementation suggest a cardioprotective potential. OBJECTIVE: To examine the effects on LDL cholesterol and arterial function as a result of dietary enrichment with soy supplementation. DESIGN: A Randomized, double blind, parallel intervention trial. SETTING......: Subjects were randomly assigned to 24 weeks of daily intake of either a soy supplement, Abalon (30 g soy protein, 9 g cotyledon fibre and 100 mg isoflavones) or placebo (30 g of casein). The soy supplement and placebo were provided in two sachets daily that were stirred in water. Fasting plasma lipids, TNF...... in 32 subjects, arterial dilatory capacity, compliance, and distensibility were recorded before and after the intervention. RESULTS: In the main study, no difference in fasting plasma lipid levels or insulin sensitivity was found between soy-based supplement and placebo. A significant postprandial...

  3. Influence of benthic macroinvertebrates on the erodability of estuarine cohesive sediments: Density- and biomass-specific responses

    Kristensen, Erik; Neto, João Magalhães; Lundkvist, Morten; Frederiksen, Lars; Pardal, Miguel Ângelo; Valdemarsen, Thomas; Flindt, Mogens Rene

    2013-12-01

    The impact of three dominating benthic invertebrates on sediment stability and erosion conditions of cohesive sediments in the Mondego Estuary, Portugal, was examined in laboratory annular flume experiments. The purpose was to test how the life habits and body size of the three involved species (Hydrobia ulvae, Nereis diversicolor and Scrobicularia plana) in terms of density or biomass influence sediment erosion. All three species decreased the free-stream erosion threshold (uc) and increased erosion rate (E), since their feeding activities diminished the surface stabilizing effect of extracellular polymeric substances (EPS) produced by microphytobenthos. S. plana had the highest and H. ulvae the lowest impact when related to density (factor of 29 for uc and factor of 19 for E), while H. ulvae was more important than S. plana when related to biomass (factor of 4 for uc and factor of 6 for E). N. diversicolor had intermediate density-specific (4-6 times higher than H. ulvae) and lowest biomass-specific (2-3 times lower than S. plana) effects on erosion. It appears that faunal erosion impacts preferably should be reported in biomass units for comparative purposes because individual behavioural effects of a small-bodied species like H. ulvae functionally can be relatively more important than those of a 100 times heavier S. plana individual. This is clearly evidenced from the strongly diminished response in suspended Chlorophyll-a content in the presence of the former than the latter species, which is caused by an efficient microphytobenthos grazing by H. ulvae. It is also important to emphasize that the total faunal impact on erosion threshold in a certain area is dictated by combination of contributions from individual species. The total outcome is unpredictable and controlled by synergistic and antagonistic species-specific effects, species interactions as well as environmental and sediment conditions.

  4. Burial of Zostera marina seeds in sediment inhabited by three polychaetes: Laboratory and field studies

    Delefosse, M.; Kristensen, E.

    2012-07-01

    The large number of seeds produced by eelgrass, Zostera marina, provides this plant with a potential to disperse widely and colonise new areas. After dispersal, seeds must be buried into sediment for assuring long-term survival, successful germination and safe seedling development. Seeds may be buried passively by sedimentation or actively through sediment reworking by benthic fauna. We evaluated the effect of three polychaetes on the burial rate and depth of eelgrass seeds. Burial was first measured in controlled laboratory experiments using different densities of Nereis (Hediste) diversicolor (400-3200 ind m- 2), Arenicola marina (20-80 ind m- 2), and the invasive Marenzelleria viridis (400-1600 ind m- 2). The obtained results were subsequently compared with burial rates of seed mimics in experimental field plots (1 m2) dominated by the respective polychaetes. High recovery of seeds in the laboratory (97-100%) suggested that none of these polychaetes species feed on eelgrass seeds. N. diversicolor transported seeds rapidly (animal abundance. Only 2% of seed mimics casted in the field plots were recovered, suggesting that physical dispersion by waves and currents was considerably important for horizontal distribution. However, polychaete affected significantly the vertical distribution of seeds. Overall the effects of these three polychaetes indicate that benthic macroinvertebrates may significantly impact eelgrass seed bank at the ecosystem scale. Some species have a positive effect by burying seeds to shallow depths and thereby reducing seed predation and facilitating seed germination, while other species bury seeds too deep for successful seed germination and seedling development.

  5. Effects of repeated field applications of two formulations of Bacillus thuringiensis var. israelensis on non-target saltmarsh invertebrates in Atlantic coastal wetlands.

    Caquet, Thierry; Roucaute, Marc; Le Goff, Pierre; Lagadic, Laurent

    2011-07-01

    Bacillus thuringiensis var. israelensis (Bti) is commonly used for selective control of larval populations of mosquitoes in coastal wetlands. A two year-study was implemented to investigate whether repeated treatments with Bti applied either as a liquid (VectoBac® 12AS) or a water-dispersible granule (VectoBac® WG) formulation may affect the abundance and diversity of non-target aquatic invertebrates in saltmarsh pools. Taxonomic composition of the invertebrate communities was typical of brackishwater intermittent ecosystems, with a dominance of annelids, crustaceans and nematocerans. Conditions were contrasted between the two years of the survey, both in terms of annual cumulative rainfall and rainfall distribution throughout the year. As a consequence, the hydroperiod and some other environmental characteristics associated with pool drying played a major role in the dynamics of the invertebrate community. In summer 2006, pool drying reduced the abundance of the polychaete worm Nereis diversicolor, of the amphipod crustacean Corophium volutator and of chironomid larvae. These taxa were able to recolonize rapidly the pools after flooding in September 2006. In 2007, rainfall was more regularly distributed across the year, and the pools did not get dry. Hydrozoans, Chironomini and Orthocladiinae larvae, and oligochaetes were more abundant in treated than in control pools, especially in VectoBac® WG-treated pools. No adverse effects of the treatments were shown on the abundance of N. diversicolor, C. volutator and midge larvae, suggesting that the availability of these food sources for birds was not negatively affected by Bti applications. It is concluded that, as currently performed in Western France coastal wetlands, land-based treatments of saltmarsh pools for larval mosquito control with Bti, used either as VectoBac® 12AS or VectoBac® WG, did not adversely impact non-target aquatic invertebrate communities. PMID:21592573

  6. The situation of marine sediments in the pathway of radionuclides to man

    It is widely accepted that the marine sediments are the major reservoir of the radionuclides which are discharged into the coastal sea water. The radionuclides sorpted on the sediments would be recycled in the sea water and be accumulated by marine organisms. And some of the sorpted radionuclides would be transfered to the worm (a kind of benthos) habited in the sediments through their surface or digestive tract and then to the fishes which prey upon the benthos. Therefore, it is important to learn whether the sediments as a ''sink'' may not later become a ''source'' of these contaminants. In this paper, the problem is discussed refering to few reports which are published up to this time. Renfro estimated that about one per cent of 65Zn in the sediment would be transfered to Nereis diversicolor which directly contacts with the sediments: On the recycling of 65Zn from the sediments to the sea water, Seymour and Nelson determined the 65Zn level of 8/100 in the sea water after twelve months following shutdown of reactor. Thus they calculated the ecological half-lives which were affected by the radionuclides retention of the sediments. In our laboratory experiment on the interaction of sediments and Nereis diversicolor using 95Zr, 106Ru, 137Cs and 60Co, the similar results were observed except 137Cs which showed rather high rate of remobilization from the sediments to the sea water. Thus, it could be generally considered that the transfer of radionuclides via sediment would be minor to man. However, it should be born in mind that the increased amount of radionuclides by continuous discharge into sea may raise the level of radionuclides in the sediments and then benthos even with one per cent transfer rate from sediment to benthos. (auth.)

  7. Genotoxic damage in polychaetes: a study of species and cell-type sensitivities.

    Lewis, Ceri; Galloway, Tamara

    2008-06-30

    The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and differences in sensitivities of their different coelomic cell types determined by use of the comet assay. A. marina was found to be the most sensitive to genotoxic damage induced by the direct-acting mutagen methyl methanesulfonate (MMS), and showed dose-dependent responses to MMS and the polycyclic aromatic hydrocarbon benzo(a)pyrene. Significant differences in sensitivity were also measured for the different types of coelomocyte. Eleocytes were more sensitive to induction of DNA damage than amoebocytes in both N. virens and N. diversicolor. Spermatozoa from A. marina showed significant DNA damage following in vitro exposure to MMS, but were less sensitive to DNA damage than coelomocytes. This investigation has clearly demonstrated that different cell types within the same species and different species within the polychaetes show significantly different responses to genotoxic insult. These findings are discussed in terms of the relationship between cell function and sensitivity and their implications for the use of polychaetes in environmental genotoxicity studies. PMID:18579434

  8. Bioaccumulation of native polycyclic aromatic hydrocarbons from sediment by a polychaete and a gastropod: freely dissolved concentrations and activated carbon amendment.

    Cornelissen, Gerard; Breedveld, Gijs D; Naes, Kristoffer; Oen, Amy M P; Ruus, Anders

    2006-09-01

    The present paper describes a study on the bioaccumulation of native polycyclic aromatic hydrocarbons (PAHs) from three harbors in Norway using the polychaete Nereis diversicolor and the gastropod Hinia reticulata. First, biota-sediment accumulation factors (BSAFs) were measured in laboratory bioassays using the original sediments. Median BSAFs were 0.004 to 0.01 kg organic carbon/kg lipid (10 PAHs and 6 organism-sediment combinations), which was a factor of 89 to 240 below the theoretical BSAF based on total sediment contents (which is approximately one). However, if BSAFs were calculated on the basis of measured freely dissolved PAH concentrations in the pore water (measured with polyoxymethylene passive samplers), it appeared that these BSAFfree values agreed well with the measured BSAFs, within a factor of 1.7 to 4.3 (median values for 10 PAHs and six organism-sediment combinations). This means that for bioaccumulation, freely dissolved pore-water concentrations appear to be a much better measure than total sediment contents. Second, we tested the effect of 2% (of sediment dry wt) activated carbon (AC) amendments on BSAE The BSAFs were significantly reduced by a factor of six to seven for N. diversicolor in two sediments (i.e., two of six organism-sediment combinations), whereas no significant reduction was observed for H. reticulata. This implies that either site-specific evaluations of AC amendment are necessary, using several site-relevant benthic organisms, or that the physiology of H. reticulata caused artifactually high BSAF values in the presence of AC. PMID:16986789

  9. Effects of sediment organic matter quality on bioaccumulation, degradation, and distribution of pyrene in two macrofaunal species and their surrounding sediment.

    Granberg, Maria E; Selck, Henriette

    2007-09-01

    Sediment dwelling macrofauna (infauna) are important vectors for the transfer of sediment-associated contaminants to higher trophic levels. Sedimenting organic matter constitutes an important food source for all benthic organisms and changes seasonally in terms of quantity and quality. Sediment organic matter (SOM) quality affects organism activity and feeding behaviour, and is therefore also likely to affect contaminant fate in benthic systems. We investigated the impact of SOM quality (enrichment with either labile Tetraselmis sp. or refractory lignin) on the accumulation and metabolism of sediment-associated pyrene in Nereis diversicolor (Annelida) and Amphiura filiformis (Echinodermata), as well as the combined effect of SOM quality and infaunal bioturbation on pyrene distribution and metabolism in the sediment. After 45 d of exposure, SOM quality almost doubled pyrene bioaccumulation in both species, while pyrene metabolism remained unaffected. Metabolites comprised approximately 80% of the total tissue pyrene in N. diversicolor and approximately 40% in A. filiformis. A. filiformis arms contained one fifth of the disk pyrene concentration. Approximately 20% of the pyrene found in A. filiformis arms was found to be covalently bound to, e.g. DNA, RNA or proteins, thus reducing pyrene bioavailability to arm-cropping predators. The sedimentary pyrene distribution and metabolism was species-dependent, but correlated poorly with prevailing knowledge on species-specific bioturbation patterns. This was attributed to the comparably high biodegradability of the contaminant thus altering its sorptive characteristics and function as inert tracer. Subduction of pyrene and metabolites occurred, and the fraction of pyrene covalently bound to SOM increased with depth, thereby removing pyrene from the bioavailable pool. Our results imply that bioaccumulation and trophic transfer of sediment-associated PAH should increase following fresh organic matter input, e.g. after

  10. Fusion of nacre, mussel, and lotus leaf: bio-inspired graphene composite paper with multifunctional integration

    Zhong, Da; Yang, Qinglin; Guo, Lin; Dou, Shixue; Liu, Kesong; Jiang, Lei

    2013-06-01

    Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self-cleaning, anti-corrosion, and remarkable mechanical properties underwater.Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self

  11. Multifunctional layered magnetic composites

    Maria Siglreitmeier

    2015-01-01

    Full Text Available A fabrication method of a multifunctional hybrid material is achieved by using the insoluble organic nacre matrix of the Haliotis laevigata shell infiltrated with gelatin as a confined reaction environment. Inside this organic scaffold magnetite nanoparticles (MNPs are synthesized. The amount of MNPs can be controlled through the synthesis protocol therefore mineral loadings starting from 15 wt % up to 65 wt % can be realized. The demineralized organic nacre matrix is characterized by small-angle and very-small-angle neutron scattering (SANS and VSANS showing an unchanged organic matrix structure after demineralization compared to the original mineralized nacre reference. Light microscopy and confocal laser scanning microscopy studies of stained samples show the presence of insoluble proteins at the chitin surface but not between the chitin layers. Successful and homogeneous gelatin infiltration in between the chitin layers can be shown. The hybrid material is characterized by TEM and shows a layered structure filled with MNPs with a size of around 10 nm. Magnetic analysis of the material demonstrates superparamagnetic behavior as characteristic for the particle size. Simulation studies show the potential of collagen and chitin to act as nucleators, where there is a slight preference of chitin over collagen as a nucleator for magnetite. Colloidal-probe AFM measurements demonstrate that introduction of a ferrogel into the chitin matrix leads to a certain increase in the stiffness of the composite material.

  12. Enrichment and isolation of crude oil degrading bacteria from some mussels collected from the Persian Gulf.

    Bayat, Zeynab; Hassanshahian, Mehdi; Hesni, Majid Askari

    2015-12-15

    To date, little is known about existing relationships between mussels and bacteria in hydrocarbon-contaminated marine environments. The aim of this study is to find crude oil degrading bacteria in some mussels at the Persian Gulf. Twenty eight crude oil degrading bacteria were isolated from three mussels species collected from oil contaminated area at Persian Gulf. According to high growth and degradation of crude oil four strains were selected between 28 isolated strains for more study. Determination the nucleotide sequence of the gene encoding for 16S rRNA show that these isolated strains belong to: Shewanella algae isolate BHA1, Micrococcus luteus isolate BHA7, Pseudoalteromonas sp. isolate BHA8 and Shewanella haliotis isolate BHA35. The residual crude oil in culture medium was analysis by Gas Chromatography (GC). The results confirmed that these strains can degrade: 47.24%, 66.08%, 27.13% and 69.17% of crude oil respectively. These strains had high emulsification activity and biosurfactant production. Also, the effects of some factors on crude oil degradation by isolated strains were studied. The results show that the optimum concentration of crude oil was 2.5% and the best degradation take place at 12% of salinity. This research is the first reports on characterization of crude oil degrading bacteria from mussels at Persian Gulf and by using of these bacteria in the field the effect of oil pollution can be reduce on this marine environment. PMID:26581816

  13. Modelling the reworking effects of bioturbation on the incorporation of radionuclides into the sediment column: implications for the fate of particle-reactive radionuclides in Irish Sea sediments

    A microcosm laboratory experiment was conducted to determine the impact of biological reworking by the ragworm Nereis diversicolor on the redistribution of particle-bound radionuclides deposited at the sediment-water interface. Over the course of the 40-day experiment, as much as 35% of a 137Cs-labelled particulate tracer deposited on the sediment surface was redistributed to depths of up to 11 cm by the polychaete. Three different reworking models were employed to model the profiles and quantify the biodiffusion and biotransport coefficients: a gallery-diffuser model, a continuous sub-surface egestion model and a biodiffusion model. Although the biodiffusion coefficients obtained for each model were quite similar, the continuous sub-surface egestion model provided the best fit to the data. The average biodiffusion coefficient, at 1.8 ± 0.9 cm2 y-1, is in good agreement with the values quoted by other workers on the bioturbation effects of this polychaete species. The corresponding value for the biotransport coefficient was found to be 0.9 ± 0.4 cm y-1. The effects of non-local mixing were incorporated in a model to describe the temporal evolution of measured 99Tc and 60Co radionuclide sediment profiles in the eastern Irish Sea, influenced by radioactive waste discharged from the Sellafield reprocessing plant. Reworking conditions in the sediment column were simulated by considering an upper mixed layer, an exponentially decreasing diffusion coefficient, and appropriate biotransport coefficients to account for non-local mixing. The diffusion coefficients calculated from the 99Tc and 60Co cores were in the range 2-14 cm2 y-1, which are consistent with the values found by other workers in the same marine area, while the biotransport coefficients were similar to those obtained for a variety of macrobenthic organisms in controlled laboratories and field studies. -- Research highlights: →N. diversicolor redistributes up to 35% particle-bound radionuclide over 40

  14. Modelling the reworking effects of bioturbation on the incorporation of radionuclides into the sediment column: implications for the fate of particle-reactive radionuclides in Irish Sea sediments

    Cournane, S., E-mail: sean.cournane@gmail.co [UCD School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Leon Vintro, L.; Mitchell, P.I. [UCD School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)

    2010-11-15

    A microcosm laboratory experiment was conducted to determine the impact of biological reworking by the ragworm Nereis diversicolor on the redistribution of particle-bound radionuclides deposited at the sediment-water interface. Over the course of the 40-day experiment, as much as 35% of a {sup 137}Cs-labelled particulate tracer deposited on the sediment surface was redistributed to depths of up to 11 cm by the polychaete. Three different reworking models were employed to model the profiles and quantify the biodiffusion and biotransport coefficients: a gallery-diffuser model, a continuous sub-surface egestion model and a biodiffusion model. Although the biodiffusion coefficients obtained for each model were quite similar, the continuous sub-surface egestion model provided the best fit to the data. The average biodiffusion coefficient, at 1.8 {+-} 0.9 cm{sup 2} y{sup -1}, is in good agreement with the values quoted by other workers on the bioturbation effects of this polychaete species. The corresponding value for the biotransport coefficient was found to be 0.9 {+-} 0.4 cm y{sup -1}. The effects of non-local mixing were incorporated in a model to describe the temporal evolution of measured {sup 99}Tc and {sup 60}Co radionuclide sediment profiles in the eastern Irish Sea, influenced by radioactive waste discharged from the Sellafield reprocessing plant. Reworking conditions in the sediment column were simulated by considering an upper mixed layer, an exponentially decreasing diffusion coefficient, and appropriate biotransport coefficients to account for non-local mixing. The diffusion coefficients calculated from the {sup 99}Tc and {sup 60}Co cores were in the range 2-14 cm{sup 2} y{sup -1}, which are consistent with the values found by other workers in the same marine area, while the biotransport coefficients were similar to those obtained for a variety of macrobenthic organisms in controlled laboratories and field studies. -- Research highlights: {yields

  15. 福建省渔业工程与装备学科发展报告%Report on the advances in Fisheries Engineering and Equipment research in Fujan province

    郑国富; 朱健康; 许肖梅; 李林帮; 沈美耀; 郭明忠; 张澄茂; 颜阔秋; 叶翚

    2011-01-01

    渔业工程与装备是渔业生产现代化水平的重要标志之一,也是推进渔业生产方式转变的重要途径,是现代渔业科技不可或缺的重要组成。本文报道了福建省近年来所涉及的渔业工程与装备学科的发展现状,包括陆基养殖、港湾鱼类及鲍网箱养殖、深水区抗风浪网箱养殖、微孔增氧技术、湿颗粒饲料加工机械、大型网箱养殖安全监控技术、新型锚技术开发、闭式循环活鱼运输船、浮筏式消波堤、人工鱼礁、休闲渔业和风(能)光(太阳能)互补型海水淡化装置等。分析学科目前存在的问题并提出中期发展目标及“十二五”主攻方向。%The technical level of Fisheries Engineering and Equipment is one of the most important factors to indicate the mod- eruization of Fisheries. The researches and studies on Fisheries Engineering and Equipment is an indispensable branch of modem fisheries science and is an important measure to change fisheries production mode. Notability progresses have been achieved in researches and studies on Fisheries Engineering and Equipment in Fujian Province since 2000 year. The research advances about the facilities and Equipments and Engineering and their problems existed are reported in this paper. The facilities and engineering reported here include facilities and engineering applied in the land - based sea - farming such as pond and factory; the new cages made of HDPE for culturing fishes and for culturing abalone with new structure for abalone to adsorb; the equipments reported in- clude the machinery for manufacturing the granule of soft feed; the monitor for detecting the escape of fishes in offshore cages; new kind anchors and their anchoring technology; the boats equipped with water circle recycling to transport live fishes; the HDPE raft for the abatement of waves ; recreational fisheries and the small dissalting device driven by wind power and solar ener- gy; the

  16. Variation in volatile leaf oils of seven eucalyptus species harvested from Zerniza arboreta (Tunisia).

    Elaissi, Ameur; Medini, Hanène; Simmonds, Monique; Lynen, Frederic; Farhat, Farhat; Chemli, Rachid; Harzallah-Skhiri, Fethia; Khouja, Mohamed Larbi

    2011-02-01

    Leaves of seven species of the genus Eucalyptus L'Hér., viz., E. cladocalyx F. Muell., E. citriodora Hook., E. diversicolor F. Muell., E. fasciculosa F. Muell., E. grandis W. Hill, E. ovata Labill., and E. botryoides Sm., were harvested from Zerniza arboreta (region of Sejnene, northwest of Tunisia) in June 2007. Of the latter species, leaves were collected from trees having two origins, Morocco and Italy. Hydrodistillation of the dried leaves provided essential oils in yields varying from 0.4±0.0 to 3.3±0.1%, according to the species. E. citriodora had the highest mean percentage of essential oil amongst the species examined, whereas the lowest one was obtained for E. botryoides originating from Morocco. Analysis by GC (RI) and GC/MS allowed the identification of 140 compounds, representing 92.5 to 99.4% of the total oil composition. The contents of the different samples varied according to the species. The main components were 1,8-cineole (2), followed by α-pinene (1), p-cymene, borneol, α-terpineol, cryptone, spathulenol, trans-pinocarveol (4), bicyclogermacrene (5), caryophyllene oxide, and β-phellandrene. Principal components analysis and hierarchical cluster analysis separated the eight Eucalyptus leaf essential oils into five groups, each constituting a chemotype. PMID:21337508

  17. Bioaccumulation and biological effects of cigarette litter in marine worms.

    Wright, Stephanie L; Rowe, Darren; Reid, Malcolm J; Thomas, Kevin V; Galloway, Tamara S

    2015-01-01

    Marine debris is a global environmental issue. Smoked cigarette filters are the predominant coastal litter item; 4.5 trillion are littered annually, presenting a source of bioplastic microfibres (cellulose acetate) and harmful toxicants to marine environments. Despite the human health risks associated with smoking, little is known of the hazards cigarette filters present to marine life. Here we studied the impacts of smoked cigarette filter toxicants and microfibres on the polychaete worm Hediste diversicolor (ragworm), a widespread inhabitant of coastal sediments. Ragworms exposed to smoked cigarette filter toxicants in seawater at concentrations 60 fold lower than those reported for urban run-off exhibited significantly longer burrowing times, >30% weight loss, and >2-fold increase in DNA damage compared to ragworms maintained in control conditions. In contrast, ragworms exposed to smoked cigarette filter microfibres in marine sediment showed no significant effects. Bioconcentration factors for nicotine were 500 fold higher from seawater than from sediment. Our results illustrate the vulnerability of organisms in the water column to smoking debris and associated toxicants, and highlight the risks posed by smoked cigarette filter debris to aquatic life. PMID:26369692

  18. Disturbance caused by freshwater releases of different magnitude on the aquatic macroinvertebrate communities of two coastal lagoons

    Cañedo-Argüelles, Miguel; Rieradevall, Maria

    2010-06-01

    The response of the aquatic macroinvertebrate communities to freshwater releases of different magnitude and persistence was investigated in two Mediterranean coastal lagoons (Ca l'Arana and Ricarda). The study was carried out during 14 months (June 2004-July 2005) in which different environmental variables and the macroinvertebrate communities associated with two different habitats, the Phragmites australis belt and the deep area of the lagoons, were sampled monthly. Additionally, potential colonizing sources were identified through the analysis of Chironomidae pupal exuviae. The initial response of the communities to the freshwater releases was similar, being characterized by a peak of opportunistic taxa (mainly Naididae), but the late response was different for each lagoon. In the Ca l'Arana, the magnitude of the freshwater release was higher (salinity dropped below five, which is the limit commonly established for most freshwater species) and its persistence was also higher, allowing the colonization of the lagoon by new insect taxa, which replaced the brackish water species. In the Ricarda, the salinity never dropped beyond five and pre-disturbance conditions were rapidly re-established. This, together with the acclimatizing mechanisms showed by the species Chironomus riparius and Hediste diversicolor, permitted the recovery of the pre-disturbance macroinvertebrate community.

  19. Capping in situ with activated carbon in Trondheim harbor (Norway) reduces bioaccumulation of PCBs and PAHs in marine sediment fauna.

    Samuelsson, Göran S; Hedman, Jenny E; Elmquist Kruså, Marie; Gunnarsson, Jonas S; Cornelissen, Gerard

    2015-08-01

    Three types of thin-layer caps with activated carbon (AC) were tested in situ in experimental plots (10 × 10 m) in Trondheim harbor, Norway, using AC + clay, AC-only or AC + sand. One year after capping, intact sediment cores were collected from the amended plots for ex situ surveys of the capping efficiency in reducing the PAH and PCB aqueous concentrations and bioaccumulation by the polychaete Hediste diversicolor and the clam Abra nitida. Reduced pore water concentrations were observed in all AC treatments. The capping efficiency was in general AC + clay > AC-only > AC + sand. AC + clay reduced bioaccumulation of PAH and PCB congeners between 40% and 87% in the worms and between 67% and 97% in the clams. Sediment capped with AC-only also led to reduced bioaccumulation of PCBs, while AC + sand showed no reduction in bioaccumulation. Thus the best thin-layer capping method in this study was AC mixed with clay. PMID:26121661

  20. New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

    Kantimati G Kulkarni

    Full Text Available Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment. These observations testify the fossilization potential of pellets and provide an explanation to their origin in the geological record. Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms. The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate.

  1. New Insights into Polychaete Traces and Fecal Pellets: Another Complex Ichnotaxon?

    Kulkarni, Kantimati G; Panchang, Rajani

    2015-01-01

    Neoichnological observations help refine paleoichnological records. The present study reports extensive observations on the distribution, morphology, occurrence and association of burrows and fecal pellets of the polychaete Nereis diversicolor in the Kundalika Estuary on the west coast of India. Our holistic study of these modern-day traces suggests it to be a complex trace arising from domichnial, fodinichnial and possibly pascichnial behavior of polychaetes. The study for the first time reports extensive fecal pellet production, distribution and their preservation as thick stacks in modern estuarine environment. These observations testify the fossilization potential of pellets and provide an explanation to their origin in the geological record. Their occurrence as strings associated with mounds not only suggests pascichnial behaviour of polychaetes but also allows the assignment of post-Paleozoic Tomaculum to the activity of polychaete worms. The production of fecal pellets in such large quantities plays a major role in increasing the average grain size of the substrate of these estuarine tidal flats, thereby improving aeration within the substrate. PMID:26439262

  2. Contemporary condition of macrozoobenthos in ultrashallow zone of Taman Bay, Sea of Azov

    Spiridonov, V. A.; Kolyuchkina, G. A.; Belyaev, N. A.; Basin, A. B.; Kozlovsky, V. V.

    2016-03-01

    The distribution of macrozoobenthic communities was studied in a vast ultrashallow (0-1.2 m deep) zone of northwestern Taman Bay (separated from the Kerch Strait by Chushka spit) in 2008-2009. Fifty-two species of benthic invertebrates were recorded. The species number, as well as Shannon and Pielou diversity indices, increased along Chushka spit from base to tip. The usual inhabitants of lagoons and estuaries of the Mediterranean Basin and the open Sea of Azov dominated in benthic communities: mollusks Abra segmentum and Hydrobia acuta and polychaetes Heteromastus filiformis and Hediste diversicolor (the latter only in summer). Changes in the community structure were largely determined by the seasonal dynamics of dominant species populations, which was similar to their dynamics in certainother transitional water bodies of the Mediterranean Basin. These changes indicate normal running of seasonal processes in the macrobenthic communities of Taman Bay in 2008 rather than the consequences of a catastrophic black oil spill in the Kerch Strait in November 2007.

  3. Patterns in estuarine macrofauna body size distributions: The role of habitat and disturbance impact

    Dolbeth, Marina; Raffaelli, Dave; Pardal, Miguel Ângelo

    2014-01-01

    Schwinghamer's (1981) habitat architecture hypothesis for body mass spectra in marine sediments predicts a single macrofauna mode in response to the bulk nature of the sediment. This proposition was examined for intertidal macrofauna from a well-studied estuarine system, using kernel density estimation to define modality and the locations of peaks and troughs. Three sedimentary environments and habitats were examined along a disturbance gradient related to eutrophication. Our results indicate that bimodality is likely to occur within the macrofauna size range, which weakens the habitat architecture model and casts doubts on the mechanisms behind other modes in benthic size spectra. The location of the modes and intervening trough were not conservative and not apparently related to sediment grain size or habitat structure, but somewhat dependent on the presence of particular species: the presence or absence of large numbers of individuals of Hydrobia ulvae and larger-bodied taxa such as Scrobicularia plana and Hediste diversicolor. Alternative competing hypotheses are explored for the observed results, including Warwick's (1984) phylogenetic explanation, but taking into consideration both species composition and disturbance impact, it seems most likely Holling's (1992) textural discontinuity hypothesis, as a measure of resilience, could be a plausible explanation.

  4. Ellipsomyxa gobii (Myxozoa: Ceratomyxidae) in the common goby Pomatoschistus microps (Teleostei: Gobiidae) uses Nereis spp. (Annelida: Polychaeta) as invertebrate hosts.

    Køie, Marianne; Whipps, Christopher M; Kent, Michael L

    2004-03-01

    Nereis diversicolor O.F. Müller and N. succinea Frey et Leuckart (Polychaeta, Nereidae) living in brackish shallow areas in Denmark are naturally infected with tetractinomyxon actinospores. Infected Nereis spp. were experimentally fed to various potential fish hosts, and the actinosporean stages developed into myxosporean stages of Ellipsomyxa gobii Køie, 2003 (Ceratomyxidae) in the gallbladder of the common goby Pomatoschistus microps (Krøyer) (Gobiidae). The European eel Anguilla anguilla (L.), three-spined stickleback Gasterosteus aculeatus L., small sand eel Ammodytes tobianus L., flounder Platichthys flesus (L.), European plaice Pleuronectes platessa L. and common sole Solea solea (L.) did not become experimentally infected. In Danish shallow brackish areas P. microps is naturally infected with E. gobii, in some areas with a prevalence >90%. We compared small subunit ribosomal DNA sequences of the actinosporean with E. gobii from P. microps. Sequences were identical, which further verifies that both forms belong to the same organism. This is the first myxozoan two-host life cycle in the marine environment. PMID:15139372

  5. Comparative study of plutonium and americium bioaccumulation from two marine sediments contaminated in the natural environment

    Hamilton, T.F.; Smith, J.D. (Melbourne Univ., Parkville (Australia). Dept. of Inorganic Chemistry); Fowler, S.W.; LaRosa, J.; Holm, E. (International Atomic Energy Agency, Monaco-Ville (Monaco). Lab. of Marine Radioactivity); Aarkrog, A.; Dahlgaard, H. (Risoe National Lab., Roskilde (Denmark))

    1991-01-01

    Plutonium and americium sediment-animal transfer was studied under controlled laboratory conditions by exposure of the benthic polychaete Nereis diversicolor (O. F. Mueller) to marine sediments contaminated by a nuclear bomb accident (near Thule, Greenland) and nuclear weapons testing (Enewetak Atoll). In both sediment regimes, the bioavailability of plutonium and {sup 241}Am was low, with specific activity in the tissues <1% (dry wt) than in the sediments. Over the first three months, a slight preference in transfer of plutonium over {sup 241}Am occurred and {sup 241}Am uptake from the Thule sediment was enhanced compared to that from lagoon sediments of Enewetak Atoll. Autoradiography studies indicated the presence of hot particles of plutonium in the sediments. The results highlight the importance of purging animals of their gut contents in order to obtain accurate estimates of transuranic transfer from ingested sediments into tissue. It is further suggested that enhanced transuranic uptake by some benthic species could arise from ingestion of highly activity particles and organic-rich detritus present in the sediments. (author).

  6. The impact of fish predation on shallow soft bottoms in brackish waters (SW Finland); an experimental study

    Mattila, J.; Bonsdorff, E.

    The impact of fish predation on shallow soft bottoms was studied by field and laboratory experiments. The field manipulations (caging experiments) were carried out in 2 shallow (1.5 m) bays in the northern Baltic Sea. An a priori hypothesis that fish do not structure macrozoobenthic communities in shallow soft-bottom areas was tested. Short-term aquarium experiments clearly showed that perch ( Perca fluviatilis L.), roach ( Rutilus rutilus L.) and ruffe ( Acerina cernua (L.)) are all effective predators on benthic macroinvertebrates ( Corophium volutator) Pallas and Nereis diversicolor O.F. Müller) under laboratory conditions. Thus fish can be considered a potential structuring force on benthic communities in shallow soft-bottom areas. Caging experiments of one to two month's duration (partial and total exclosure of fish and enclosure with perch) induced only minor changes in the benthic community. These results support the a priori hypothesis. One of our main conclusions is, however, that fish predation and other biotic interactions (competition, disturbance, etc.) together with abiotic factors play some role in the structuring processes. Multilevel testing is needed in studies on biotic interactions in the marine environment. Results from a specific environment should not automatically be applied to other kinds of habitats.

  7. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations

    This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Mueller as food source, was first developed. The sensitivity of the postexposure feeding response was verified by comparing it to that of lethality, upon cadmium exposure. The influence of environmental conditions prevailing during exposure (salinity, temperature, substrate, light regime, and food availability) on postexposure feeding was also addressed. The potential of this in situ assay was then investigated by deploying organisms at ten sites, located in reference and contaminated Portuguese estuaries. Organism recovery ranged between 90% and 100% and a significant postexposure feeding depression (16.3-72.7%) was observed at all contaminated sites relatively to references. - A new sub-lethal toxicity assay is presented for marine invertebrates

  8. Disturbance of benthic infauna by sediment-reworking activities of the lugworm Arenicola marina

    Flach, E. C.

    The influence of the lugworm Arenicola marina on the abundance of other benthic species was studied in the westernmost part of the Wadden Sea. Small squares (1 m 2) within depopulated 144-m 2 plots were recolonized with various (naturally-occurring) lugworm densities (0-10-20-40-80 and 0-25-50-75-100 per m 2). These plots were sampled during the summer. Lugworms were found to have a strongly negative effect on the densities of C. volutator. At 0-density lugworms, the numbers of C. volutator were high. These were halved at 17 lugworms per m 2 ( i.e. the mean density on the tidal flats of the Dutch Wadden Sea), and were further reduced at higher lugworm densities ( e.g. 20% remained at 40 lugworms per m 2). Laboratory observations of Corophium behaviour in the presence of Arenicola suggest that sediment-reworking lugworms stimulate Corophium to emigrate. Effects of lugworms on other benthic species were also studied in the same way. Lugworms were found to have strongly negative effects on the juvenile densities of various worm and bivalve species ( Nereis diversicolor, Nephtys hombergii, Heteromastus filiformis, Scoloplos armiger, Pygospio elegans, Capitella capitata and Mya arenaria, Cerastoderma edule, Macoma balthica, Angulus tenuis, respectively).

  9. Biological impact of eutrophication in the bay of somme and the induction and impact of anoxia

    Desprez, M.; Rybarczyk, H.; Wilson, J. G.; Ducrotoy, J. P.; Sueur, F.; Olivesi, R.; Elkaim, B.

    The first effects of eutrophication in the Bay of Somme became apparent in the years 1982-1985, when the cockle population collapsed. Areas of high mortality were mapped. Following exceptionally high summer temperatures, other effects were seen in 1982, 1983 and 1989, notably a mass mortality of the benthos. It appeared that the mortality of the benthos was a direct result of anoxia in the water promoted by phytoplankton blooms which were due to high nitrogen levels (nitrates from river and land runoff; ammonium from estuarine bivalve populations). Effects from the change in the benthic community (the disappearance of Cerastoderma edule and the proliferation of Pygospio elegans) were also apparent higher up in the food chain, viz. changes in the diet of the two main predators of the bivalve, the oystercatcher ( Haematopus ostralegus) and the common gull ( Larus canus). Following respirometry measurements of the water, sediment and the major macrobenthic species ( Cerastoderma edule, Macoma balthica, Nereis diversicolor, Hydrobia ulvae), a model for anoxia was constructed.

  10. Relationship between the lability of sediment-bound metals (Cd, Cu, Zn) and their bioaccumulation in benthic invertebrates

    Amiard, J.-C.; Geffard, A.; Amiard-Triquet, C.; Crouzet, C.

    2007-04-01

    The present study has investigated metal contamination at nine sites (10 sampling stations) from the English Channel to the Mediterranean Sea, including low level and highly contaminated sediments. Both total and labile concentrations of metals were determined in superficial sediments. The influence of different pHs was tested and metal lability at pHs encountered in the gut of invertebrates (the ragworm Nereis diversicolor, the blue mussel Mytilus edulis, the Japanese oyster Crassostrea gigas) was compared with the distribution of metals in various operationally defined geochemical fractions. Cd showed the highest lability and Cu the lowest, whereas Zn lability was intermediate. Metal concentrations were determined in bivalves at six sites and in worms at three sites. Cd in living organisms and labile Cd in sediments increased in proportion over the gradient of contamination. This relationship did not always hold for Cu and Zn and these exceptions are discussed. Even if sediments are not the only source of metal contamination in marine invertebrates, the procedure proposed here to assess metal bioavailability by remobilising sediment-bound metals at physiological pHs, seems a significant improvement of the existing methodologies of risk assessment.

  11. An in situ postexposure feeding assay with Carcinus maenas for estuarine sediment-overlying water toxicity evaluations

    Moreira, Susana M. [Instituto de Ciencias Biomedicas de Abel Salazar (ICBAS), Departamento de Estudos de Populacoes, Largo Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Moreira-Santos, Matilde [Instituto do Ambiente e Vida, Departamento de Zoologia da Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal); Guilhermino, Lucia [Instituto de Ciencias Biomedicas de Abel Salazar (ICBAS), Departamento de Estudos de Populacoes, Largo Abel Salazar 2, 4099-003 Porto (Portugal); Centro Interdisciplinar de Investigacao Marinha e Ambiental, Laboratorio de Ecotoxicologia, Rua dos Bragas 289, 4050-123 Porto (Portugal); Ribeiro, Rui [Instituto do Ambiente e Vida, Departamento de Zoologia da Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)]. E-mail: rui.ribeiro@zoo.uc.pt

    2006-01-15

    This study developed and evaluated a short-term sublethal in situ toxicity assay for estuarine sediment-overlying waters, with the crab Carcinus maenas (L.) based on postexposure feeding. It consisted of a 48-h in situ exposure period followed by a short postexposure feeding period (30 min). A precise method for quantifying feeding, using the Polychaeta Hediste (Nereis) diversicolor Mueller as food source, was first developed. The sensitivity of the postexposure feeding response was verified by comparing it to that of lethality, upon cadmium exposure. The influence of environmental conditions prevailing during exposure (salinity, temperature, substrate, light regime, and food availability) on postexposure feeding was also addressed. The potential of this in situ assay was then investigated by deploying organisms at ten sites, located in reference and contaminated Portuguese estuaries. Organism recovery ranged between 90% and 100% and a significant postexposure feeding depression (16.3-72.7%) was observed at all contaminated sites relatively to references. - A new sub-lethal toxicity assay is presented for marine invertebrates.

  12. Effects of eutrophication on contaminant cycling in marine benthic systems

    Gunnarsson, Jonas; Granberg, Maria; Rosenberg, Rutger [Goeteborg Univ. (Sweden). Dept. of Marine Ecology; Bjoerk, Mikael; Gilek, Michael [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    2000-08-01

    Effects of inputs of organic matter were studied on bioavailability and cycling of hydrophobic organic contaminants (HOCs) in benthic ecosystems of the Baltic and Kattegat Seas. In laboratory experiments, effects of microalgae additions were studied on the bioaccumulation of HOCs (PCBs and PAHs) by the blue mussel Mytilus edulis, the brittle star Amphiura filiformis, and the polychaete Nereis diversicolor. Contrary to the equilibrium partitioning theory, bioaccumulation was proportional to the concentrations of algae and organic carbon. This was attributed to the high nutritional quality of the algal organic carbon and suggests that feeding rather than equilibrium partitioning governed bioaccumulation in these species. In the field, annual mass fluxes of PCBs in blue mussels and in brittle stars were estimated, as well as contaminant transfer to higher trophic levels. Our results suggest that: i) Eutrophication processes may contribute to increase HOC accumulation in benthic species. ii) Temporal variation in the quantity and quality of organic carbon needs to be considered when assessing contamination of benthic systems. iii) Macrofaunal feeding activities are important for the benthic-pelagic coupling of HOCs. iv) Bioturbation enhances the release of HOCs from sediment to overlying water.

  13. Effects of bioturbation on the fate of oil in coastal sandy sediments--an in situ experiment.

    Timmermann, Karen; Banta, Gary T; Klinge, Lars; Andersen, Ole

    2011-03-01

    Effects of bioturbation by the common lugworm Arenicola marina on the fate of oil hydrocarbons (alkanes and PAHs) were studied in situ during a simulated oil spill in a shallow coastal area of Roskilde fjord, Denmark. The fate of selected oil compounds was monitored during 120 d using GC-MS and bioturbation activity (feces production and irrigation) was measured regularly during the experiment and used as input parameters in a mechanistic model describing the effects of A. marina on the transport and degradation of oil compounds in the sediment. The chemical analytical data and model results indicated that A. marina had profound and predictable effects on the distribution, degradation and preservation of oil and that the net effect depended on the initial distribution of oil. In sediment with an oil contaminated subsurface-layer A. marina buried the layer deeper in the sediment which clearly enhanced oil persistence. Conversely, A. marina stimulated both the physical removal and microbial degradation of oil compounds in uniformly oil contaminated sediments especially in deeper sediment layers (10-20 cm below the surface), whereas the fate of oil compounds deposited in surface layers (0-5 cm) mainly was affected by removal processes induced by wave actions and other bioturbating infauna such as Nereis diversicolor, Corophium volutator and Hydrobia spp. present in the experimental plots. PMID:21186046

  14. Imaging oxygen distribution in marine sediments. The importance of bioturbation and sediment heterogeneity.

    Pischedda, L; Poggiale, J C; Cuny, P; Gilbert, F

    2008-06-01

    The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns: the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sediment-water interface. PMID:18247133

  15. Synchronous fluorescence spectrometry of 1-hydroxypyrene: a rapid screening method for identification of PAH exposure in tissue from marine polychaetes.

    Giessing, Anders M B; Mayer, Lawrence M; Forbes, Thomas L

    2003-12-01

    The uptake of polycyclic aromatic hydrocarbons (PAHs) by marine deposit-feeding invertebrates can be determined by screening for PAH-derived metabolites. We identified 1-hydroxypyrene as the only intermediate metabolite in tissue of four species of deposit-feeding polychaetes, Nereis diversicolor, Nereis virens, Arenicola marina, and Capitella sp. I exposed to pyrene spiked sediment. Synchronous fluorescence spectroscopy (SFS) provides a fast and simple method for both qualitative and quantitative analysis of 1-hydroxypyrene in all four species. The SFS assay was validated using HPLC with ultraviolet detection. A good correlation between 1-hydroxypyrene concentrations determined by the two methods was observed. We used HPLC with fluorescence detection combined with enzymatic hydrolysis of conjugated metabolites to investigate species specific metabolite patterns. A tentative aqueous metabolite identification scheme indicates that Nereid polychaetes predominately make use of glucuronide conjugation whereas Capitella sp. I. and Arenicola marina appear to utilize predominantly sulfate and/or glucoside conjugation. The usefulness of 1-hydroxypyrene as a biomarker for PAH exposure in deposit-feeding invertebrates is discussed. PMID:12927741

  16. Factors Affecting the Distribution of the Amphipod Corophium volutatorin Two Estuaries in South-east England

    Hughes, R. G.; Gerdol, V.

    1997-05-01

    The distribution of Corophium volutator(Pallas) in the estuaries of the Rivers Blackwater and Crouch in South-east England was examined by taking samples of mud from 137 sites at approximately 0·5 m below mean high water of neap tidal level. Corophium volutatorwere approximately twice as abundant in creeks and semi-enclosed bays than on the open mud flats, a difference that was significant statistically. There was no correlation between the abundance of C. volutatorand the median particle size of the sediment nor the mud content. There was a significant but weak negative correlation between the abundance of C. volutatorand the polychaete Nereis diversicolor. The aggregation of C. volutatorin the creeks and bays was attributed to their dispersal behaviour of swimming on the flood tide, which would sweep the amphipods into such areas where the tide rises but does not flow laterally. On the open mud flats, displacement of swimming amphipods by the flood tide further upstream and into semi-enclosed areas would occur. Their dispersal behaviour places C. volutatorin the creeks and bays within the saltmarsh vegetation, where their bioturbatory feeding habits may be responsible, in part, for the significant loss of pioneer zone vegetation that occurs there.

  17. Influence of biological and ecological factors on the bioaccumulation of polybrominated diphenyl ethers in aquatic food webs from French estuaries.

    Bragigand, Virginie; Amiard-Triquet, Claude; Parlier, Emmanuel; Boury, Pauline; Marchand, Philippe; El Hourch, Mohamed

    2006-09-15

    Previous studies have shown the worldwide presence of six congeners of polybrominated diphenyl ethers (PBDEs) in marine biota (BDE-28, -47, -99, -100, -153 and -154). The objective of the present study was to document their presence, their level and their transfer in the food web of two major estuaries in France, the Loire and the Seine. PBDEs were quantified in eight principal species from the Loire, representing primary consumers (the bivalve Scrobicularia plana), omnivores (the worm Nereis diversicolor, the shrimps Crangon crangon, Palaemon elegans and Palaemon serratus, the flatfish Platichthys flesus and Solea solea) and supercarnivores (the eel Anguilla anguilla). In the Seine, only worms, bivalves, sole and eels have been studied. Parameters, which can interfere with the interpretation of contamination data (organ distribution, influence of weight or size of specimens, lipid richness, intrinsic variability), have been examined. BDE-47 was the predominant congener in all biota. Higher contamination was observed in most of the species collected from the Seine, in agreement with the higher human presence and economic activity in the Seine than in the Loire basin. PBDEs have been shown to biomagnify in both of the studied estuarine food webs. However, assessment of PBDE transfer from seafood products exposed to contaminants in the Seine estuary showed that human daily intake is far below the no observed adverse effect levels. PMID:16764911

  18. Macroalgal mats and species abundance: a field experiment

    Hull, S. C.

    1987-11-01

    A field experiment was carried out whereby the density of macroalgae ( Enteromorpha spp.) was manipulated and the resultant changes in sediment infaunal density were monitored. Four densities of Enteromorpha spp. were used: 0,0·3, 1, and 3 kg FW m -2, corresponding to control, low-, medium-, and high-density plots. The experiment ran from May to October 1985 and was sampled on three occasions. By July, the density of Corophium volutator was reduced at all weed levels when compared to control plots, whereas densities of Hydrobia ulvae, Macoma balthica, Nereis diversicolor, and Capitella capitata, all increased. Samples taken in October when the weed mats were buried in the sediment showed fewer differences than in July. Macoma, Nereis, and Capitella were still significantly more abundant at medium and high weed densities. Corophium showed no significant treatment effect. There was, however, a highly significant difference in population size structure for Corophium. Measurements of sediment redox potential and silt content under medium- and high-density plots revealed rapid anoxia with a significant increase in siltation.

  19. Experimental results on bioaccumulation of metals and organic contaminants from marine sediments.

    Ruus, Anders; Schaanning, Morten; Oxnevad, Sigurd; Hylland, Ketil

    2005-04-30

    A test-system for the assessment of bioavailability and bioaccumulation of metals and organic contaminants in marine benthic organisms is described and results from studies where this system has been applied are assessed. Sediments tested were polluted harbour sediment (from Norway), and clean sediments spikes with metal containing weight materials for drilling muds. Contaminants that may bioaccumulate under relevant conditions are indicated. The test-system uses two species of ecological relevance (Nereis diversicolor and Hinia reticulata). Interspecies differences in bioaccumulation were found for several compounds, which show the importance of using species with different modes of living in such tests. Compared to other PAHs, pyrene was found to bioaccumulate to a high degree (BioAccumulation Ratio, BAR=213.5>sediment concentration ratio, SCR=97.4; bioaccumulation factor, organism dw. conc. to sediment dw. conc., BAF=1.02), which shows that extrapolating bioaccumulation results between different substances is difficult. When assessing bioavailability of specific compounds, it is most adequate to perform direct measurements on exposed organisms, such as the experiments described here. The high bioaccumulation of compounds such as pyrene and nickel may in some cases be attributed to manipulation of the sediments and (for pyrene) lack of subsequent aging, thereby overestimating bioavailability. PMID:15820107

  20. Indicators of heavy-metal contamination in the Looe Estuary (Cornwall) with particular regard to silver and lead

    Bryan, G.W.; Hummerstone, L.G.

    1977-01-01

    The Looe Estuary in Cornwall has two equal branches, one receiving lead and silver from old mines and the other receiving silver from a presumed industrial source. Analyses of these and eight other metals have been made in seaweed (Fucus) as an indicator of levels in the water, in herbivorous gastropods (winkle Littorina littorea; limpet Patella vulgata), in filter feeders (mussel Mytilus edulis; cockle Cerastoderma edule) as indicators of contamination in suspended particles and in deposit feeders (bivalve molluscs Scrobicularia plana and Macoma balthica; ragworm Nereis diversicolor) as indicators of available metals in sediments. There was little evidence of contamination with dissolved silver in the estuary but considerable evidence of contamination by particles of freshwater origin. Although the concentrations of particulate silver from the two sources were of the same order of magnitude, the influence of the non-mining source was much greater, a concentration of silver 425 times normal being observed in Scrobicularia at an upstream station. It was concluded that particles, perhaps of silver sulfide, from the mining source were of much lower biological availability than those from the other source where silver may be adsorbed on to particles. Unlike silver, contamination with lead followed a similar pattern in different species. Of the other metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn) the most abnormal levels in the different species were observed for copper.

  1. Interactions between macro-algal mats and invertebrates in the Ythan estuary, Aberdeenshire, Scotland

    Raffaelli, D.

    2000-07-01

    Blooms of opportunistic green macro-algae are a common feature of coastal areas and their effects on mudflat invertebrates can be dramatic. On the Ythan estuary, Aberdeenshire, Scotland, we have carried out a number of manipulative field experiments designed to evaluate the effects on invertebrates of different species of macro-algae with contrasting ecologies, and the effects of invertebrates on the development of the blooms. Macro-algal mats were found to have dramatic nega- tive effects on the density of the amphipod Corophium volutator, with higher algal biomasses having greater impact. The mechanism for this interaction seems to be interference by the algal filaments with the feeding behaviour of the amphipod. In contrast, the polychaete Capitella spp. increases in abundance under macro-algal mats due to enrichment of the sediment with organic material. These two interactions are seen at all scales, in areas of less than 1 m2 to the scale of the entire estuary, irrespective of the species composition of the macro- algal mats. Bioturbation by Corophium and grazing by the snail Hydrobia ulvae had little effect on macro-algal biomass, but there were less algae when the polychaete Nereis diversicolor was present. The most significant interaction in this system is the pronounced negative impact of algal mats on the abundance of Corophium, probably the most important invertebrate species in the diets of the estuary's shorebirds, fish and epibenthic crustaceans.

  2. The use of lipid markers to define sources of organic matter in sediment and food web of the intertidal salt-marsh-flat ecosystem of Mont-Saint-Michel Bay, France

    Meziane, Tarik; Bodineau, Laurent; Retiere, Christian; Thoumelin, Guy

    1997-12-01

    Salt marsh plants and seven surface sediment samples along a transect in the intertidal flat area of Mont-Saint-Michel Bay were analysed for fatty acids and sterols. The presence of lipid markers of halophytes (long-chain fatty acids, 18:3ω3, and phytosterols) in the surface layers of the sediment confirms the export of organic matter from the salt marsh to the intertidal flat. The spatial distribution of this organic matter over the tidal-flat area was controlled by the tidal currents and the presence of mussel beds. Lipid markers of diatoms (20:5ω3 and brassicasterol) and bacteria (18:1ω7 and odd, linear and branched, fatty acids) were also found in the surface sediments. Diatoms and benthic bacteria as well as organic matter from the salt marsh were the significant food sources available to the macrozoobenthos on the intertidal flat. The ingestion of these food types by the dominant species of the macrozoobenthos was confirmed by the presence of their respective lipid markers in the animals. The presence of these markers in animals subjected to a starvation experiment confirmed that these food types are really assimilated. The lipid composition of the starved animals indicated that the species studied were able to accumulate the fatty acid 20:5ω3 (considered to be a diatom marker), and that the annelid Nereis diversicolor supported an internal bacterial population.

  3. Interplay between filter-feeding zoobenthos and hydrodynamics in the shallow Odense Fjord (Denmark) - Earlier and recent studies, perspectives and modelling

    Riisgård, H. U.; Lassen, J.; Kortegaard, M.; Møller, L. F.; Friedrichs, M.; Jensen, M. H.; Larsen, P. S.

    2007-11-01

    The shallow Odense Fjord (Denmark) is characterized by a large biomass of filter-feeding polychaetes ( Nereis diversicolor), clams ( Mya arenaria), cockles ( Cerastoderma glaucum), and amphipods ( Corophium volutator). The present paper summarizes studies on zoobenthic filter-feeding in Odense Fjord from the last 10 years. The general principles discovered are extracted and compared to available tools for modelling of the primary characteristics of interplay between benthic filter-feeders and hydrodynamics. Earlier works have been supplemented with data from a recent field study conducted in the shallow inner part of the fjord. Based on data from this study site, the reduction in phytoplankton for fully mixed and incompletely mixed flows has been modelled. It was found that fully mixed flow results in a potential half-life for phytoplankton of only 1.3 h, whereas for the incompletely mixed water the half-life is 2.7 times longer. The field measurements clearly demonstrate the presence of a strong interplay between filter-feeders and hydrodynamics, but although a certain grazing impact is evident from vertical chlorophyll a profiles with often strongly reduced near-bottom concentrations it is not straightforward to identify and model even the main bio-physical processes that prevent the dense populations of filter-feeders to completely control the phytoplankton biomass in Odense Fjord.

  4. Diopatra neapolitana (Polychaeta: Onuphidae) as a second intermediate host of Gymnophallus choledochus (Digenea: Gymnophallidae) in the Aveiro estuary (Portugal): distribution within the host and histopathology.

    Rangel, L F; Santos, M J

    2009-10-01

    This is the first host record of Gymnophallus choledochus metacercariae infecting the polychaete Diopatra neapolitana in the Aveiro estuary (Portugal). The metacercariae were found unencysted, and their morphology is similar to that presented by metacercariae harbored by Nereis diversicolor and Cerastoderma edule, although they are larger in size. In D. neapolitana, the prevalence and mean intensity of the infection was very high, at 100% and 202 +/- 139 metacercariae per host, respectively, suggesting that this polychaete is the most suitable host for G. choledochus in the Aveiro estuary. In terms of distribution within the host, the metacercariae were found almost exclusively in the branchial segments (97.4%). This, in conjunction with the close relationship between the mean intensity and branchial surface area, suggests that the branchiae may be the site of entry into the polychaete. Within the branchial segments, the sites selected by the metacercariae are the parapodia (68.9%), where they are mostly located inside the setal sac, and the longitudinal muscles (22.3%), causing hypertrophy and rupture of the muscle bundles, respectively. These histological changes suggest a reduction in polychaete mobility, which should aid the easy predation of infected hosts by birds and thus facilitate the continuity of the G. choledochus life cycle. PMID:19441876

  5. Some methodological aspects of metallothionein evaluation.

    Bragigand, Virginie; Berthet, Brigitte

    2003-01-01

    The specificity of the methods used for metallothioneins (MTs) determination in both field and laboratory studies is crucial to a relevant interpretation of the results. The technique applied in the present study is commonly used, but several potential problems may limit its validity: (i). the stability of the metal-SH links during heating and the possibility of metal exchanges between MTs and others compounds; (ii). the presence of heat-stable thiol compounds with high molecular weight or very low molecular weight, which may subsist in the supernatant and interfere during global analysis of MTs; (iii). the subsistence of metals not bound to MT in the supernatant after heating; and (iv). the impact of reducing agents such as mercaptoethanol on the metal-binding ligands. Our investigations were conducted mainly on oysters (Crassostrea gigas) and polychaetes (Hediste/Nereis diversicolor) sampled, respectively, in two French metal-rich sites, the Gironde estuary and Boulogne harbour. This study, which allowed us to clarify most of the potential problems noted above, indicates the importance of dealing with methodological difficulties. PMID:12507607

  6. Transport of exogenous organic substances by invertebrate integuments: the field revisited.

    Gomme, J

    2001-04-01

    The notion that some marine invertebrates can use integumental uptake of organic compounds as a nutritional supplement dates back to the late 19th and early 20th centuries. This article provides a brief overview of more than a century's research, as it relates to significant stages in the development of experimental methods and concepts of general physiology. Emphasis is placed on changing paradigms and on the interplay between this specialized field of investigation and the mainstream of physiological thought. The present status of the field is summarized. The general consensus is challenged on the basis of previously published and new data from the author's laboratory. Particular emphasis is placed on data pointing toward an ultra-rapid turnover of amino acids in part of the epidermal space of the polychaete worm Nereis diversicolor. It is suggested that intra-epidermal L-alanine is compartmentalized metabolically or physically, and the consequences of this proposition are discussed in view of the general concepts of secondary active transport and intracellular isosmotic regulation. Future studies in this area of comparative physiology should concentrate not only on the molecular characteristics of the transporter proteins, but also on the way their function is integrated in the cellular physiology of the transporting cells. J. Exp. Zool. 289:254-265, 2001. PMID:11241396

  7. Temporal variability of denitrification in estuarine sediments

    Law, C. S.; Rees, A. P.; Owens, N. J. P.

    1991-07-01

    Sediment denitrification rates and fluxes of nitrous oxide, nitrate, nitrite and ammonium were determined at two intertidal sites in the Tamar estuary (S.W. England). High sediment nitrate uptake rates were recorded throughout the year, whereas the nitrite and ammonium fluxes were positive (from sediment to water column), with the former resulting from nitrification. Nitrous oxide flux was also positive, being largely attributable to denitrification with some contribution from nitrification or nitrification-denitrification coupling. No relationship was apparent between denitrification rate and nitrate concentration in the overlying water, invalidating the notion that denitrification automatically regulates nitrate during periods of elevated ambient concentration. However, denitrification exhibited a strong covariance with the degree of sediment bioturbation ( Nereis diversicolor), which was considered to be attributable to increased transport and supply of nitrate via Nereis burrows. Denitrification accounted for 8·5% of the annual total nitrate loading to the Tamar estuary, although a maximum of 100% was observed in summer when the phytoplankton nutrient requirement would also be highest.

  8. Tolerance and biomarkers as useful tools for assessing environmental quality in the Oued Souss estuary (Bay of Agadir, Morocco).

    Ait Alla, A; Mouneyrac, C; Durou, C; Moukrim, A; Pellerin, J

    2006-05-01

    The aim of this study was to assess aquatic environmental quality of Oued Souss (Agadir, Morocco). This estuary has been subjected for a long time to large amounts of sewage discharges and industrial effluents. Since November 2002, no waste outlets have been discharged in this site due to their connection to a wastewater purification plant. Firstly, we have compared metal tolerance of the annelid polychaete (Nereis diversicolor) originating from Oued Souss and a relatively clean site (Oualidia, Morocco). Secondly, we have evaluated with a multi-marker approach (acetylcholinesterase [AChE], glutathione-S-transferases [GSTs], catalase, thiobarbituric acid reactive substances [TBARs]) responses of worms to the pollution gradient. Results have shown that worms from Oued Souss have acquired tolerance to copper and zinc due to a long-term sub-lethal metal exposure and this metal tolerance was maintained in spite of the end of wastewater discharges in this site. Higher catalase, GSTs and TBARs values have been observed in worms from Oued Souss sampled before implantation of wastewater treatment. The multi-marker approach confirms that these worms have been submitted to various contaminants. In contrast, high inhibition in AChE activities measured in worms from Oued Souss could be explained by the continuous agricultural influence of nearest areas. The level of contamination was probably maintained since biomarker values were generally higher in worms from Oued Souss when compared to Oualidia. PMID:16413830

  9. Chromium in intertidal sediments of the Clyde, UK: potential for remobilisation and bioaccumulation.

    Hursthouse, Andrew S; Matthews, Joy M; Figures, Julie E; Iqbal-Zahid, Parveen; Davies, Ian M; Vaughan, D Huw

    2003-06-01

    Detailed surveys of intertidal sediments have been performed along the north and south shores of the Inner Clyde estuary, UK. Surface sediment data reveal significant spatial variation in Cr content and an association with major sediment characteristics and location within the estuary. Depth variation for Cr and other heavy metals cannot be explained by variation in major geochemical controls such as grain size and organic matter and highlights the impact of historical contamination on sediment quality. These elevated levels at depth may still have environmental impact through redox-reactivity, in association with iron and manganese. Sequential extraction of sediments and pore water analysis of Cr(VI) and Cr(III) provide detailed information on release potential from the sediments. The implication of Cr mobility for biota in the estuary has been assessed by the analysis of a common marine bivalve, Mytilus edulis (Blue Mussel) and a burrowing polychaete, Nereis diversicolor (rag worm) from a number of survey sites. Bioconcentration factors for Mytilus indicate that the weakly held portion of sediment Cr is available for uptake and in the case of Nereis, bioaccumulation appears to be inhibited by sediment organic matter. PMID:12901165

  10. High abundance of small zoobenthos around biogenic structures in tidal sediments of the Wadden Sea

    Reise, K.

    1981-12-01

    On the tidal flats of the island of Sylt (eastern part of the North Sea) the quantity of micro- and meiofauna associated with shoots of seagrass (Zostera noltii), with infaunal bivalves (Macoma balthica), and with tubes and burrows of polychaetes (Pygospio elegans, Pectinaria koreni, Nereis diversicolor, Nereis virens, Arenicola marina) was found to add up to 5 to 33 % of the overall abundance. These structures, taken together, account for 10 to 50 % of the faunal abundance on an average tidal flat at Sylt. The quantitative effect of biogenic structures at the sediment surface (casts and funnels) is small compared to that of tubes and burrows penetrating the anaerobic subsurface layer. In providing stable oxic microenvironments these elite structures frequently bring together more individuals than occur in the entire reducing sediment below surface. Faunal composition of irrigated dwellings of large infauna is different from that of the oxic surface sediment. The common denominator of all elite structures of the subsurface is an oxic halo. Burrows without such a halo are unattractive. There is no evidence that owners of burrows prey on their smaller inmates.

  11. Solution structure and internal dynamics of NSCP, a compact calcium-binding protein.

    Rabah, Ghada; Popescu, Razvan; Cox, Jos A; Engelborghs, Yves; Craescu, Constantin T

    2005-04-01

    The solution structure of Nereis diversicolor sarcoplasmic calcium-binding protein (NSCP) in the calcium-bound form was determined by NMR spectroscopy, distance geometry and simulated annealing. Based on 1859 NOE restraints and 262 angular restraints, 17 structures were generated with a rmsd of 0.87 A from the mean structure. The solution structure, which is highly similar to the structure obtained by X-ray crystallography, includes two open EF-hand domains, which are in close contact through their hydrophobic surfaces. The internal dynamics of the protein backbone were determined by studying amide hydrogen/deuterium exchange rates and 15N nuclear relaxation. The two methods revealed a highly compact and rigid structure, with greatly restricted mobility at the two termini. For most of the amide protons, the free energy of exchange-compatible structural opening is similar to the free energy of structural stability, suggesting that isotope exchange of these protons takes place through global unfolding of the protein. Enhanced conformational flexibility was noted in the unoccupied Ca2+-binding site II, as well as the neighbouring helices. Analysis of the experimental nuclear relaxation and the molecular dynamics simulations give very similar profiles for the backbone generalized order parameter (S2), a parameter related to the amplitude of fast (picosecond to nanosecond) movements of N(H)-H vectors. We also noted a significant correlation between this parameter, the exchange rate, and the crystallographic B factor along the sequence. PMID:15819893

  12. Identification and quantification of n-octyl esters of alkanoic and hexanedioic acids and phthalates as urban wastewater markers in biota and sediments from estuarine areas.

    Chaler, Roser; Cantón, Lourdes; Vaquero, Menchu; Grimalt, Joan O

    2004-08-13

    A gas chromatographic method for the identification and quantification of n-octyl esters (from n-octyl tetradecanoate to n-octyl hexa-cosanoate including dioctyl hexanedioate) and phthalates [dibutyl phthalate, benzyl butyl phthalate and di(2-ethylhexyl) phthalate] in sediments and biota from estuarine environments is described. Standards used for identification and quantification of some n-octyl esters were synthesized. The method has allowed the analysis of these compounds in polychaeta (Nereis diversicolor), oysters (Crassostea angulata), crabs (Carcinus maenas) and fish (Chelon labrosus, Platichtys flesus and Chondostroma polylepis) that were collected at different locations of the Urdaibai estuary (Bizkaia, Basque Country, Spain). Total phthalates and n-octyl esters ranged between 0.01 and 12 microg g(-1) and 0.05 and 9.4 microg g(-1), respectively, and were predominantly found in polychaeta and fish. Sediments did not contain these compounds in significant amount, only benzyl butyl phthalate, dioctyl hexanedioate and di(2-ethylhexyl) phthalate were found above limit of detection (0.01-0.05 microg g(-1)). PMID:15387189

  13. Bioavailability of PAHs in aluminum smelter affected sediments: evaluation through assessment of pore water concentrations and in vivo bioaccumulation.

    Ruus, Anders; Bøyum, Olav; Grung, Merete; Næs, Kristoffer

    2010-12-15

    Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized. PMID:21077669

  14. Characterization of a novel EF-hand homologue, CnidEF, in the sea anemone Anthopleura elegantissima.

    Hauck, Laura L; Phillips, Wendy S; Weis, Virginia M

    2007-04-01

    The superfamily of EF-hand proteins is comprised of a large and diverse group of proteins that contain one or more characteristic EF-hand calcium-binding domains. This study describes and characterizes a novel EF-hand cDNA, CnidEF, from the sea anemone Anthopleura elegantissima (Phylum Cnidaria, Class Anthozoa). CnidEF was found to contain two EF-hand motifs near the C-terminus of the deduced amino acid sequence and two regions near the N-terminus that could represent degenerate EF-hand motifs. CnidEF homologues were also identified from two other sea anemone species. A combination of bioinformatic and molecular phylogenetic analyses was used to compare CnidEF to EF-hand proteins in other organisms. The closest homologues identified from these analyses were a luciferin binding protein (LBP) involved in the bioluminescence of the anthozoan Renilla reniformis, and a sarcoplasmic calcium-binding protein (SARC) involved in fluorescence of the annelid worm Nereis diversicolor. Predicted structure and folding analysis revealed a close association with bioluminescent aequorin (AEQ) proteins from the hydrozoan cnidarian Aequorea aequorea. Neighbor-joining analyses grouped CnidEF within the SARC lineage along with AEQ and other cnidarian bioluminescent proteins rather than in the lineage containing calmodulin (CAM) and troponin-C (TNC). PMID:17280859

  15. Molecular cloning and characterization of a gene encoding a 13.1 kDa antigenic protein of Naegleria fowleri.

    Shin, H J; Cho, M S; Jung, S U; Kim, H I; Park, S; Kim, H J; Im, K I

    2001-01-01

    An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunoscreening with sera obtained from mice that were either immunized with an amoebic lysate or infected with trophozoites. The coding nucleotide sequence of the cloned gene consisted of 357 bases that were translated into 119 amino acids. This gene was designated as nfa1. The predicted amino acid sequence of Nfa1 protein has two potential glycosylation and three potential phosphorylation sites, and its predicted secondary structure consists of four helices and three corners. The deduced amino acid sequence of Nfa1 protein shares 43% identity with the myohemerythrin (myoHr) protein from a marine annelid, Nereis diversicolor, including 100% identity in conserved regions and iron-binding residues. A phylogenetic tree constructed from amino acid sequences placed the N. fowleri Nfa1 protein outside of a cluster of myoHr proteins from eight invertebrates. A purified recombinant protein that migrated as a 13.1 kDa species in SDS-PAGE was produced. This recombinant protein exhibited a strong immunoreactivity with infected, immune, and anti-Nfal sera. In addition, an anti-Nfa1 serum reacted with an amoeba lysate in immunoblotting analysis. The present nfal gene encoding the myoHr-like protein is the first myoHr gene cloned from protozoa, and the Nfal antigen may be useful in diagnostic studies PMID:11831780

  16. The life cycle of Dichelyne (Cucullanellus) minutus (Nematoda: Cucullanidae).

    Køie, M

    2001-01-01

    Mature specimens of the nematode Dichelyne (Cucullanellus) minutus (Rudolphi, 1819) (Ascaridida, Cucullanidae, Seuratoidea) were obtained from the intestine of flounder Platichthys flesus (L.) caught in the Oresund, Denmark. Plaice Pleuronectes platessa L. and common goby Pomatoschistus microps (Kröyer) also harbour this species. The eggs embryonate on the seabottom. Larvae about 440 microm long, and believed to be in their third stage, hatch from the eggs. These larvae are not directly infective to flounders or gobies. The polychaete Nereis diversicolor O.F. Muller acts as obligatory intermediate host. Experimental infections showed that larvae >600 microm long and provided with achitinous tooth survived in flounder and common goby. The third-stage larvae moult to fourth-stage larvae in the fish gut wall. Mature worms occur in the lumen of the anterior part of the intestine. All developmental stages may be transferred from one flounder to another; thus the flounder may acquire the parasite also by devouring infected gobies. PMID:11817453

  17. Dynamic organization of microtubules and microtubule-organizing centers during the sexual phase of a parasitic protozoan, Lecudina tuzetae (Gregarine, Apicomplexa).

    Kuriyama, Ryoko; Besse, Colette; Gèze, Marc; Omoto, Charlotte K; Schrével, Joseph

    2005-12-01

    Lecudina tuzetae is a parasitic protozoan (Gregarine, Apicomplexa) living in the intestine of a marine polychaete annelid, Nereis diversicolor. Using electron and fluorescence microscopy, we have characterized the dynamic changes in microtubule organization during the sexual phase of the life cycle. The gametocyst excreted from the host worm into seawater consists of two (one male and one female) gamonts in which cortical microtubule arrays are discernible. Each gamont undergoes multiple nuclear divisions without cytokinesis, resulting in the formation of large multinucleate haploid cells. After cellularization, approximately 1000 individual gametes are produced from each gamont within 24 h. Female gametes are spherical and contain interphase cytoplasmic microtubule arrays emanating from a gamma-tubulin-containing site. In male gametes, both interphase microtubules and a flagellum with "6 + 0" axonemal microtubules extend from the same microtubule-organizing site. At the beginning of spore formation, each zygote secretes a wall to form a sporocyst. Following meiotic and mitotic divisions, each sporocyst gives rise to eight haploid cells that ultimately differentiate into sporozoites. The ovoid shaped sporocyst is asymmetric and forms at least two distinctive microtubule arrays: spindle microtubules and microtubule bundles originating from the protruding apical end corresponding to the dehiscence pole of the sporocyst. Because antibodies raised against mammalian centrosome components, such as gamma-tubulin, pericentrin, Cep135, and mitosis-specific phosphoproteins, react strongly with the microtubule-nucleating sites of Lecudina, this protozoan is likely to share common centrosomal antigens with higher eukaryotes. PMID:16240430

  18. Infectious diseases affect marine fisheries and aquaculture economics

    Lafferty, Kevin D.; Harvell, C. Drew; Conrad, Jon M.; Friedman, Carolyn S.; Kent, Michael L.; Kuris, Armand M.; Powell, Eric N.; Rondeau, Daniel; Saksida, Sonja M.

    2015-01-01

    Seafood is a growing part of the economy, but its economic value is diminished by marine diseases. Infectious diseases are common in the ocean, and here we tabulate 67 examples that can reduce commercial species' growth and survivorship or decrease seafood quality. These impacts seem most problematic in the stressful and crowded conditions of aquaculture, which increasingly dominates seafood production as wild fishery production plateaus. For instance, marine diseases of farmed oysters, shrimp, abalone, and various fishes, particularly Atlantic salmon, cost billions of dollars each year. In comparison, it is often difficult to accurately estimate disease impacts on wild populations, especially those of pelagic and subtidal species. Farmed species often receive infectious diseases from wild species and can, in turn, export infectious agents to wild species. However, the impact of disease export on wild fisheries is controversial because there are few quantitative data demonstrating that wild species near farms suffer more from infectious diseases than those in other areas. The movement of exotic infectious agents to new areas continues to be the greatest concern.

  19. Using Macrocystis pyrifera (L. C. Agardh from southern Chile as a source of applied biological compounds

    Andrés Mansilla

    2011-04-01

    Full Text Available The exploitation of seaweeds in Chile has been carried out for more than 60 years. More recently, seaweeds have been used for the production of alginate, agar and carrageenan, agricultural fertilizers and industrial aquaculture (feed for abalone and sea urchins, increasing the added value of this natural resource. In the Magellan Region (56ºS, the giant kelp Macrocystis pyrifera (L. C. Agardh presents the most extensive kelp forest, reaching a biomass of approximately 12 kg.m-2. Recent studies have shown potential benefits from adding M. pyrifera- derived flour to salmonid feed. Research is currently underway to evaluate the useof brown algae-derived products for marine aquaculture feed of Oncorhynchus mykiss in tanks. There was no apparent adverse effect on the evaluated parameters that can be attributed to the incorporation of M. pyrifera meal in the diets fed to salmonids. Even when the control diet had numerically the best performance in zootechnical terms, the analysis of variance of all parameters evaluated showed no significant differences with regard to diets containing M. pyrifera meal. These results demonstrated that seaweed meal has important benefits for animal health and nutrition that could be applied or tested in other marine organisms of commercial importance.

  20. Selection in the rapid evolution of gamete recognition proteins in marine invertebrates.

    Vacquier, Victor D; Swanson, Willie J

    2011-11-01

    Animal fertilization is governed by the interaction (binding) of proteins on the surfaces of sperm and egg. In many examples presented herein, fertilization proteins evolve rapidly and show the signature of positive selection (adaptive evolution). This review describes the molecular evolution of fertilization proteins in sea urchins, abalone, and oysters, animals with external fertilization that broadcast their gametes into seawater. Theories regarding the selective forces responsible for the rapid evolution driven by positive selection seen in many fertilization proteins are discussed. This strong selection acting on divergence of interacting fertilization proteins might lead to prezygotic reproductive isolation and be a significant factor in the speciation process. Since only a fraction of all eggs are fertilized and only an infinitesimal fraction of male gametes succeed in fertilizing an egg, gametes are obviously a category of entities subjected to intense selection. It is curious that this is never mentioned in the literature dealing with selection, perhaps because we know so little about fitness differences among gametes. (Ernst Mayr, 1997). PMID:21730046

  1. Pre-assessment of dose rates of 134Cs, 137Cs, and 60Co for marine biota from discharge of Haiyang Nuclear Power Plant, China

    Haiyang Nuclear Power Plant to be built in China was selected as a case for the dose pre-assessment for marine biota in this study. The concentrations of Cs and Co in organisms (turbot, yellow croaker, swimming crab, abalone, sea cucumber, and sea lettuce), seawater, and bottom sediment sampled on-site were measured by neutron activation analysis, and the site-specific transfer parameters (concentration ratios and distribution coefficients) of Cs and Co were calculated. 134Cs, 137Cs, and 60Co activity concentrations in the organisms and the sediment at the site were calculated with the site-specific transfer parameters and the anticipated activity concentrations in the liquid effluent of the nuclear power plant. The ERICA tool was used to estimate the dose rates of 134Cs, 137Cs, and 60Co to the selected organisms based on the biological models developed. The total dose rates of 134Cs, 137Cs, and 60Co to the six organisms were all <0.001 μGy h−1. - Highlights: • Pre-assessment for biota dose rates from Haiyang Nuclear Power Plant was made. • The site-specific transfer parameters were obtained by neutron activation analysis. • The dose rates of 134Cs, 137Cs, and 60Co to the organisms were <0.001 μGy h−1

  2. Development and Validation of a Novel LC-MS/MS Opioid Confirmation Assay: Evaluation of β-glucuronidase Enzymes and Sample Cleanup Methods.

    Yang, He S; Wu, Alan H B; Lynch, Kara L

    2016-06-01

    With the rise in the use and misuse of prescription opioids, there is an increasing need for the confirmed identification of opioid analgesics in toxicology laboratories. The goals of this study were to (i) systematically evaluate the hydrolysis efficiency of four β-glucuronidase enzymes under optimized condition; (ii) evaluate compound recovery, matrix effects and precision of three protein precipitation plates and (iii) develop and validate a qualitative liquid-chromatography mass spectrometry (LC-MS/MS) assay to identify 13 opioids in urine. A recombinant β-glucuronidase exhibited the best overall hydrolysis efficiency for seven opioid glucuronide conjugates compared with β-glucuronidase from red abalone, Escherichia coli and Patella vulgata One of the protein precipitation plates tested exhibited overall better recovery of the opioids and lower ion suppression compared with the other two plates. An ESI positive mode LC-MS/MS assay for qualitative opioid analysis was developed and validated. Linearity, LOD, precision, matrix effect, recovery, carryover and interference of the method were evaluated. Sixty-two patient samples were analyzed by both a legacy GC-MS opioid method and the LC-MS/MS method, and 22 samples were analyzed by the LC-MS/MS and an LC-MS/MS reference method. The results of the comparisons showed good concordance. Overall, we described an efficient sample preparation procedure for a sensitive qualitative opioid confirmation assay in urine. PMID:27121711

  3. Evolution of phosphagen kinase V. cDNA-derived amino acid sequences of two molluscan arginine kinases from the chiton Liolophura japonica and the turbanshell Battilus cornutus.

    Suzuki, T; Ban, T; Furukohri, T

    1997-06-20

    The cDNAs of arginine kinases from the chiton Liolophura japonica (Polyplacophora) and the turbanshell Battilus cornutus (Gastropoda) were amplified by polymerase chain reaction (PCR), and the complete nucleotide sequences of 1669 and 1624 bp, respectively, were determined. The open reading frame for Liolophura arginine kinase is 1050 nucleotides in length and encodes a protein with 349 amino acid residues, and that for Battilus is 1077 nucleotides and 358 residues. The validity of the cDNA-derived amino acid sequence was supported by chemical sequencing of internal tryptic peptides. The molecular masses were calculated to be 39,057 and 39,795 Da, respectively. The amino acid sequence of Liolophura arginine kinase showed 65-68% identity with those of Battilus and Nordotis (abalone) arginine kinases, and the homology between Battilus and Nordotis was 79%. Molluscan arginine kinases also show lower, but significant homology (38-43%) with rabbit creatine kinase. The sequences of arginine kinases could be used as a molecular clock to elucidate the phylogeny of Mollusca, one of the most diverse animal phyla. PMID:9217008

  4. Biological identification and determination of optimum growth conditions for four species ofNavicula

    ZHAO Xiaobo; PANG Shaojun; LIU Feng; SHAN Tifeng; LI Jing

    2014-01-01

    Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy (SEM) and sequence comparisons of two segments of genes (small ribosomal subunit and large subunit of Rubisco), the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm (OD680) under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates (RGR) peaked at the highest tested level (0.25 mmol/L). The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.

  5. Economic effects of oil and gas development on marine aquaculture leases. Study 17. Final report

    There are three primary mariculture products grown in California waters: oysters, mussels, and abalone. In total, the California mariculture industry earns revenues of about $6.5 million. Water quality degradation was the primary concern of most growers. Coliform bacteria and pesticide residues are currently threatening several shallow-water sites. Lease holders (and potential lease holders) for deep-water sites state that coliform bacteria from municipal sewer outfalls and offshore oil and gas drilling effluents are the greatest dangers to their profitability. The Southern California Educational Initiative is an attempt to determine whether such concerns are warranted. A simple model of economic externalities was described to highlight the scientific data one must gather so as to choose the optimal production levels for both energy and mariculture resources. That information is necessary to assess the economic consequences to the California mariculture industry of chronic exposure to oil and gas development. The co-development model shows that the marginal (incremental) effects of oil production on mariculture costs needs to be assessed. The model also shows that if the effects are moderated by distance from the point of discharge, such changes must be estimated in order to determine optimal lease boundaries. The report concludes that interdisciplinary cooperation is essential for designing a co-development plan that maximizes the social welfare to be gained from developing multiple coastal resources

  6. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system.

    Johnson, Christine K; Tinker, Martin T; Estes, James A; Conrad, Patricia A; Staedler, Michelle; Miller, Melissa A; Jessup, David A; Mazet, Jonna A K

    2009-02-17

    The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. This threatened population has struggled to recover despite protection, so we followed radio-tagged sea otters and evaluated infection with 2 disease-causing protozoal pathogens, Toxoplasma gondii and Sarcocystis neurona, to reveal risks that increased the likelihood of pathogen exposure. We identified patterns of pathogen infection that are linked to individual animal behavior, prey choice, and habitat use. We detected a high-risk spatial cluster of S. neurona infections in otters with home ranges in southern Monterey Bay and a coastal segment near San Simeon and Cambria where otters had high levels of infection with T. gondii. We found that otters feeding on abalone, which is the preferred prey in a resource-abundant marine ecosystem, had a very low risk of infection with either pathogen, whereas otters consuming small marine snails were more likely to be infected with T. gondii. Individual dietary specialization in sea otters is an adaptive mechanism for coping with limited food resources along central coastal California. High levels of infection with protozoal pathogens may be an adverse consequence of dietary specialization in this threatened species, with both depleted resources and disease working synergistically to limit recovery. PMID:19164513

  7. Extreme accumulations of natural polonium-210 in certain marine organisms

    Concentration levels of polonium-210 reported for sea water are reviewed, and activities accumulated by various marine plant and animal species are discussed. Special mention is made of detailed studies of one giant algae upon whose outer surfaces intense accumulations of polonium have been discovered recently. Some concentrations found in two organisms intimate with algae, the abalones and the sea hares, are reported. Concentrations are listed pertaining to organisms selected from the open ocean in order to show that intense polonium concentrations are not restricted to organisms living near the continents where precursors of polonium originate. A brief discussion of conditions on one of the marine mammals, the dolphin, next is made. Then comments are made upon a benthic species (the sable fish) that prefers to live close to the deep sea floor, presumably so as to eat detritus. They also eat many of the smaller organisms that compete for the natural deep sea fallout of food, and many of these live in close contact with the muds and clays of the sea floor that are rich in radium. Some of the behavior and anatomical features and polonium-210 distribution in one of the most interesting and valuable of fishes, the North Pacific albacore (Thunnus alalunga) is described. This species has been used previously to tell us something about nuclear fallout distributions in the North Pacific Ocean during the past decade and repeatedly has directed attention to features of this ocean that might hardly be detected otherwise. (U.S.)

  8. An undergraduate laboratory activity on molecular dynamics simulations.

    Spitznagel, Benjamin; Pritchett, Paige R; Messina, Troy C; Goadrich, Mark; Rodriguez, Juan

    2016-03-01

    Vision and Change [AAAS, 2011] outlines a blueprint for modernizing biology education by addressing conceptual understanding of key concepts, such as the relationship between structure and function. The document also highlights skills necessary for student success in 21st century Biology, such as the use of modeling and simulation. Here we describe a laboratory activity that allows students to investigate the dynamic nature of protein structure and function through the use of a modeling technique known as molecular dynamics (MD). The activity takes place over two lab periods that are 3 hr each. The first lab period unpacks the basic approach behind MD simulations, beginning with the kinematic equations that all bioscience students learn in an introductory physics course. During this period students are taught rudimentary programming skills in Python while guided through simple modeling exercises that lead up to the simulation of the motion of a single atom. In the second lab period students extend concepts learned in the first period to develop skills in the use of expert MD software. Here students simulate and analyze changes in protein conformation resulting from temperature change, solvation, and phosphorylation. The article will describe how these activities can be carried out using free software packages, including Abalone and VMD/NAMD. © 2016 by The International Union of Biochemistry and Molecular Biology, 44:130-139, 2016. PMID:26751047

  9. Review of the RNA Interference Pathway in Molluscs Including Some Possibilities for Use in Bivalves in Aquaculture

    Leigh Owens

    2015-03-01

    Full Text Available Generalised reviews of RNA interference (RNAi in invertebrates, and for use in aquaculture, have taken for granted that RNAi pathways operate in molluscs, but inspection of such reviews show little specific evidence of such activity in molluscs. This review was to understand what specific research had been conducted on RNAi in molluscs, particularly with regard to aquaculture. There were questions of whether RNAi in molluscs functions similarly to the paradigm established for most eukaryotes or, alternatively, was it more similar to the ecdozoa and how RNAi may relate to disease control in aquaculture? RNAi in molluscs appears to have been only investigated in about 14 species, mostly as a gene silencing phenomenon. We can infer that microRNAs including let-7 are functional in molluscs. The genes/proteins involved in the actual RNAi pathways have only been rudimentarily investigated, so how homologous the genes and proteins are to other metazoa is unknown. Furthermore, how many different genes for each activity in the RNAi pathway are also unknown? The cephalopods have been greatly overlooked with only a single RNAi gene-silencing study found. The long dsRNA-linked interferon pathways seem to be present in molluscs, unlike some other invertebrates and could be used to reduce disease states in aquaculture. In particular, interferon regulatory factor genes have been found in molluscs of aquacultural importance such as Crassostrea, Mytilus, Pinctada and Haliotis. Two possible aquaculture scenarios are discussed, zoonotic norovirus and ostreid herpesvirus 1 to illustrate the possibilities. The entire field of RNAi in molluscs looks ripe for scientific exploitation and practical application.

  10. Synergistic Biomineralization Phenomena Created by a Combinatorial Nacre Protein Model System.

    Chang, Eric P; Roncal-Herrero, Teresa; Morgan, Tamara; Dunn, Katherine E; Rao, Ashit; Kunitake, Jennie A M R; Lui, Susan; Bilton, Matthew; Estroff, Lara A; Kröger, Roland; Johnson, Steven; Cölfen, Helmut; Evans, John Spencer

    2016-04-26

    In the nacre or aragonite layer of the mollusk shell, proteomes that regulate both the early stages of nucleation and nano-to-mesoscale assembly of nacre tablets from mineral nanoparticle precursors exist. Several approaches have been developed to understand protein-associated mechanisms of nacre formation, yet we still lack insight into how protein ensembles or proteomes manage nucleation and crystal growth. To provide additional insights, we have created a proportionally defined combinatorial model consisting of two nacre-associated proteins, C-RING AP7 (shell nacre, Haliotis rufescens) and pseudo-EF hand PFMG1 (oyster pearl nacre, Pinctada fucata), whose individual in vitro mineralization functionalities are well-documented and distinct from one another. Using scanning electron microscopy, flow cell scanning transmission electron microscopy, atomic force microscopy, Ca(II) potentiometric titrations, and quartz crystal microbalance with dissipation monitoring quantitative analyses, we find that both nacre proteins are functionally active within the same mineralization environments and, at 1:1 molar ratios, synergistically create calcium carbonate mesoscale structures with ordered intracrystalline nanoporosities, extensively prolong nucleation times, and introduce an additional nucleation event. Further, these two proteins jointly create nanoscale protein aggregates or phases that under mineralization conditions further assemble into protein-mineral polymer-induced liquid precursor-like phases with enhanced ACC stabilization capabilities, and there is evidence of intermolecular interactions between AP7 and PFMG1 under these conditions. Thus, a combinatorial model system consisting of more than one defined biomineralization protein dramatically changes the outcome of the in vitro biomineralization process. PMID:27072850

  11. Introducción de especies en ambientes marinos chilenos: no solo exóticas, no siempre evidentes Introduction of species in Chilean marine environments: not only exotic, not always evident

    PATRICIO A. CAMUS

    2005-03-01

    Full Text Available El éxito económico del cultivo de especies marinas exóticas en Chile y el amplio desarrollo de la acuicultura en toda la costa, están convirtiendo la introducción de especies en una práctica frecuente. Algunas acciones han tenido impactos ecológicos importantes, y otras más recientes como el cultivo de abalones ya estarían provocándolos de forma indirecta, por la fuerte extracción de macroalgas usadas como alimento. Sin embargo, el fenómeno de introducción no se limita a especies exóticas, y puede abarcar la introducción accidental o intencional de cualquier especie nativa o con distribución en Chile, a cualquier ambiente donde no está presente por causas naturales. En este sentido, sería un fenómeno más común y con mayor extensión geográfica de lo supuesto, practicada por largo tiempo en la acuicultura y actividades relacionadas, involucrando también a organismos seleccionados o modificados genéticamente. Por otra parte, la normativa nacional e internacional parece ser insuficiente o poco eficaz para regular estas actividades, y hasta puede estar en conflicto con grandes intereses económicos. Potencialmente, el impacto histórico conjunto de estas prácticas sería alto, pero en general no se ha evaluado o es poco conocido. Conviene notar que la introducción no es infrecuente en la investigación marina científica o tecnológica, pero su efecto es tan desconocido como en otros ámbitos. Sería deseable que la comunidad científica del área de biología marina chilena tomara una posición más clara ante el problema, ya que la acuicultura comienza a verse como una disciplina en conflicto con la conservaciónThe economical success associated to the cultivation of exotic marine species in Chile, and the high development of aquaculture along the whole coast, are converting the introduction of species into a frequent practice. Some of these actions have had important ecological impacts, and others, more recent, such as

  12. Influence of trophic position on organochlorine concentrations and compositional patterns in a marine food web.

    Ruus, Anders; Ugland, Karl Inne; Skaare, Janneche Utne

    2002-11-01

    The accumulation of polychlorinated biphenyls (PCBs), DDTs (p,p'-DDT [1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane], o,p'-DDT [1,1,1-trichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethane], p,p'-DDD [1,1,-dichloro-2,2-bis(4-chlorophenyl)ethane], o.p'-DDD [1,1-dichloro-2-(2-chlorophenyl)-2-(4-chlorophenyl)ethane], and p,p'-DDE [1,1-dichloro-2,2-bis(4-chlorophenyl)ethene]), chlordanes (trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane), hexachlorocyclohexanes (alpha-, beta-, and gamma-isomers), hexachlorobenzene, and mirex was investigated in a marine food web from southeastern Norway. The food web consisted of the polychaete Nereis diversicolor, lesser sandeel (Ammodytes tobianus), three species of gobys (Gobiusculus flavescens, Pomatoschistus sp., and Gobius niger), bullrout (Myoxocephalus scorpius), cod (Gadus morhua), herring gull (Larus argentatus), and harbor seal (Phoca vitulina). The results show that interspecies differences in organochlorine (OC) compositional patterns in the food web depend on several factors (allometric, biochemical, physical, and physicochemical) specific to both the chemicals and the organisms. The importance of dietary accumulation and metabolic capacity increases toward higher trophic levels, while the OC patterns are to a larger extent determined by the lipophilicity and water solubility of the compounds at lower trophic levels. Furthermore, stable nitrogen isotopes provided a continuous measure of trophic position, rendering us capable of quantifying the increases in the concentrations of sigma PCB, sigma dichorodiphenyltrichloroethane (DDT), and sigma chlordane (CHL) and the percentages of highly chlorinated PCBs through the food web. The information provided may be important for future modeling of the fate of organochlorine contaminants in marine food webs. PMID:12389914

  13. Nursery fidelity, food web interactions and primary sources of nutrition of the juveniles of Solea solea and S. senegalensis in the Tagus estuary (Portugal): A stable isotope approach

    Vinagre, C.; Salgado, J.; Costa, M. J.; Cabral, H. N.

    2008-01-01

    Stable carbon and nitrogen isotopes were used to assess site fidelity of Solea solea and Solea senegalensis juveniles, to investigate food web interactions and to determine the dominant nutrient pathways in two nursery areas in the Tagus estuary, Portugal. Samples of water from the main sources and from the nursery areas and respective saltmarsh creeks were collected for isotope analysis, as well as sediment, benthic microalgae, saltmarsh halophytes, S. solea, S. senegalensis and its main prey, Nereis diversicolor, Scrobicularia plana and Corophium spp. While site fidelity was high in 0-group juveniles, it was lower for 1-group juveniles, possibly due to an increase in mobility and energy demands with increasing size. Analysis of the food web revealed a complex net of relations. Particulate organic matter from the freshwater sources, from each nursery's waters and saltmarsh creeks presented similar isotopic composition. Sediment isotopic composition and saltmarsh halophytes also did not differentiate the two areas. All components of the food web from the benthic microalgae upwards were isotopically different between the nursery areas. These components were always more enriched in δ13C and δ15N at the lower nursery area than at the nursery located upstream, appearing as if there were two parallel trophic chains with little trophic interaction between each other. A mixture of carbon and nitrogen sources is probably being incorporated into the food web. The lower nursery area is more dependent upon an isotopically enriched energy pathway, composed of marine particulate organic matter, marine benthic microalgae and detritus of the C 4 saltmarsh halophyte Spartina maritima. The two nursery areas present a different level of dependence upon the freshwater and marine energy pathways, due to hydrological features, which should be taken into account for S. solea and S. senegalensis fisheries and habitat management.

  14. Macrofaunal communities in the habitats of intertidal marshes along the salinity gradient of the Schelde estuary

    Hampel, Henrietta; Elliott, M.; Cattrijsse, A.

    2009-08-01

    The macrobenthos is important in benthic remineralization processes; it represents a trophic link and is also often used as a bio-indicator in monitoring programs. Variations of the environmental parameters strongly influence the structure of the macrobenthic communities in the marshes and since macrobenthos is the most important food item for marsh-visiting fish species in the Schelde, the variation in food resources can have a strong effect on the higher trophic level. The present study deals with the variation in macrobenthic communities in different habitats of intertidal marshes along the salinity gradient and the differences between the marsh creeks and the intertidal part of the estuary. The study measured density and species richness together with the biomass, and sampled a large intertidal channel and a smaller creek within five marshes along the salinity gradient of the Schelde estuary every six weeks between May and October in 2000. The small creeks had a smaller grain size and higher organic matter content than those in the large channel although the differences in the environmental parameters did not explain the different communities in the two habitats. Marshes had distinct macrobenthic communities but the abundance of macrofauna fluctuated along the estuary without an identifiable spatial trend. In contrast, the total biomass increased towards the euhaline area due to the domination of Nereis diversicolor. Diversity showed a significant positive correlation with the salinity. Comparison of the macrofaunal communities in the marsh with those on the intertidal flats of the estuary indicated similar trends in density, biomass and diversity along the salinity gradient. The density was similar in both habitats whereas biomass was much higher in the intertidal habitats of the estuary, partly due to the higher biomass of molluscs and annelids. Diversity indices were higher in the marsh, and the freshwater area had more species than in the estuary.

  15. Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

    Raffaelli Dave

    2011-02-01

    Full Text Available Abstract Background Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO2 concentrations (370, 600, and 1000 ppmv, temperature (6°C, 12°C, and 18°C and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. Results The effects of elevated CO2 concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Conclusions Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore

  16. Quantifying bioirrigation using ecological parameters: a stochastic approach†

    Meile Christof

    2002-02-01

    Full Text Available Irrigation by benthic macrofauna has a major influence on the biogeochemistry and microbial community structure of sediments. Existing quantitative models of bioirrigation rely primarily on chemical, rather than ecological, information and the depth-dependence of bioirrigation intensity is either imposed or constrained through a data fitting procedure. In this study, stochastic simulations of 3D burrow networks are used to calculate mean densities, volumes and wall surface areas of burrows, as well as their variabilities, as a function of sediment depth. Burrow networks of the following model organisms are considered: the polychaete worms Nereis diversicolor and Schizocardium sp., the shrimp Callianassa subterranea, the echiuran worm Maxmuelleria lankesteri, the fiddler crabs Uca minax, U. pugnax and U. pugilator, and the mud crabs Sesarma reticulatum and Eurytium limosum. Consortia of these model organisms are then used to predict burrow networks in a shallow water carbonate sediment at Dry Tortugas, FL, and in two intertidal saltmarsh sites at Sapelo Island, GA. Solute-specific nonlocal bioirrigation coefficients are calculated from the depth-dependent burrow surface areas and the radial diffusive length scale around the burrows. Bioirrigation coefficients for sulfate obtained from network simulations, with the diffusive length scales constrained by sulfate reduction rate profiles, agree with independent estimates of bioirrigation coefficients based on pore water chemistry. Bioirrigation coefficients for O2 derived from the stochastic model, with the diffusion length scales constrained by O2 microprofiles measured at the sediment/water interface, are larger than irrigation coefficients based on vertical pore water chemical profiles. This reflects, in part, the rapid attenuation with depth of the O2 concentration within the burrows, which reduces the driving force for chemical transfer across the burrow walls. Correction for the depletion of O2

  17. Starting a DNA barcode reference library for shallow water polychaetes from the southern European Atlantic coast.

    Lobo, Jorge; Teixeira, Marcos A L; Borges, Luisa M S; Ferreira, Maria S G; Hollatz, Claudia; Gomes, Pedro T; Sousa, Ronaldo; Ravara, Ascensão; Costa, Maria H; Costa, Filipe O

    2016-01-01

    Annelid polychaetes have been seldom the focus of dedicated DNA barcoding studies, despite their ecological relevance and often dominance, particularly in soft-bottom estuarine and coastal marine ecosystems. Here, we report the first assessment of the performance of DNA barcodes in the discrimination of shallow water polychaete species from the southern European Atlantic coast, focusing on specimens collected in estuaries and coastal ecosystems of Portugal. We analysed cytochrome oxidase I DNA barcodes (COI-5P) from 164 specimens, which were assigned to 51 morphospecies. To our data set from Portugal, we added available published sequences selected from the same species, genus or family, to inspect for taxonomic congruence among studies and collection location. The final data set comprised 290 specimens and 79 morphospecies, which generated 99 Barcode Index Numbers (BINs) within Barcode of Life Data Systems (BOLD). Among these, 22 BINs were singletons, 47 other BINs were concordant, confirming the initial identification based on morphological characters, and 30 were discordant, most of which consisted on multiple BINs found for the same morphospecies. Some of the most prominent cases in the latter category include Hediste diversicolor (O.F. Müller, 1776) (7), Eulalia viridis (Linnaeus, 1767) (2) and Owenia fusiformis (delle Chiaje, 1844) (5), all of them reported from Portugal and frequently used in ecological studies as environmental quality indicators. Our results for these species showed discordance between molecular lineages and morphospecies, or added additional relatively divergent lineages. The potential inaccuracies in environmental assessments, where underpinning polychaete species diversity is poorly resolved or clarified, demand additional and extensive investigation of the DNA barcode diversity in this group, in parallel with alpha taxonomy efforts. PMID:26129849

  18. Trophic resource partitioning within a shorebird community feeding on intertidal mudflat habitats

    Bocher, Pierrick; Robin, Frédéric; Kojadinovic, Jessica; Delaporte, Philippe; Rousseau, Pierre; Dupuy, Christine; Bustamante, Paco

    2014-09-01

    In ecological systems, it is necessary to describe the trophic niches of species and their segregation or overlap to understand the distribution of species in the community. In oceanic systems, the community structure of top predators such as seabird communities has been well documented with many studies in several biogeographical areas. But for coastal habitats, very few investigations on the trophic structure have been carried out in avian communities. In this study, the trophic resource partitioning was investigated on eight of the most abundant species of a shorebird community on the central Atlantic coast of France. Our work comprised a comprehensive sample of birds with different ecomorphogical patterns and data on their main prey to encompass potential sources of overlap and segregation in this community. We examined the stable carbon (δ13C) and nitrogen (δ15N) isotopic composition of blood to investigate the trophic structure (1) on a temporal scale by comparing migration and wintering periods; (2) on a spatial scale through inter-site comparisons; and (3) on the community level within groups of phylogenetically related species. Diets appeared different in several cases between periods, between sites and between juveniles and adults for the same sites. A clear trophic partitioning was established with four functional groups of predators in winter inside the community. The Grey Plover, the Bar-tailed Godwit, the Curlew and a majority of the dunlins were worm-eaters mainly feeding on Nereis diversicolor or Nephtys hombergii. Two species were predominantly deposit-suspensivorous mollusc-eaters, including the Red Knot and the Black-tailed Godwit feeding mainly on Macoma balthica. The Oystercatcher fed mainly on suspensivorous molluscs like Cerastodrema edule and two species including the Redshank and some dunlins adopted opportunistic behaviours feeding on mudflat and/or in marshes.

  19. Have the bioavailabilities of trace metals to a suite of biomonitors changed over three decades in SW England estuaries historically affected by mining?

    Rainbow, P S; Kriefman, S; Smith, B D; Luoma, S N

    2011-03-15

    Many estuaries of southwest England were heavily contaminated with toxic metals associated with the mining of copper and other metals, particularly between 1850 and 1900. The question remains whether the passage of time has brought remediation to these estuaries. In 2003 and 2006 we revisited sites in 5 metal-contaminated estuaries sampled in the 1970s and 1980s - Restronguet Creek, Gannel, West Looe, East Looe and Tavy. We evaluate changes in metal contamination in sediments and in metal bioavailabilities in sediments and water to local organisms employed as biomonitors. We find that the decline in contamination in these estuaries is complex. Differences in bioavailable contamination in the water column were detectable, as were significant detectable changes in at least some estuaries in bioavailable metal contamination originating from sediments. However, in the 100 years since mining activities declined, bioavailable contamination has not declined to the regional baseline in any estuary affected by the mine wastes. The greatest decline in contamination occurred in the one instance (East Looe) where a previous industrial source of (Ag) contamination was considered. We used the macroalgae Fucus vesiculosus and Ascophyllum nodosum as biomonitors of dissolved metal bioavailabilities and the deposit feeders Nereis diversicolor and Scrobicularia plana as biomonitors of bioavailable metal in sediments. We found no systematic decrease in the atypically high Ag, Cu, Pb and Zn concentrations in the estuarine sediments over a 26 year period. Accumulated metal (Ag, As, Cu, Pb, and Zn) concentrations in the deposit feeders are similarly still atypically high in at least one estuary for each metal, and there is no consistent evidence for general decreases in sediment metal bioavailabilities over time. We conclude that the legacy of mining in sheltered estuaries of southwest England is the ongoing presence of sediments rich in metals bioavailable to deposit feeders, while

  20. Is porewater an important route of metals to macrobenthic organisms? Example of an estuarine field study

    Srinetr, V.; Baeyens, W. [Free Univ., Brussels (Belgium). Lab. for Analytical Chemistry; Ysebaert, T.; Meire, P. [Inst. of Nature Conservation, Hasselt (Belgium)

    1995-12-31

    Porewater is recently hypothesized as a direct and important route of metal exposure to benthic organisms. However, only a few research studies clearly indicate its usefulness in monitoring and assessment of metal pollution. This study aims to answer whether porewater is really a significant route of metals to macrobenthic organisms in a natural sediment environment. Therefore, seven intertidal locations along the salinity gradient of the Schelde estuary (Belgium-The Netherlands) were investigated during a one year period (1993--1994). Metal analysis was performed on monthly samples of dominant macrobenthic species including the bivalves Macoma balthica, Scrobicularia plana, Cerastodema edule and Mya arenaria, the amphipod Corophium volutator and the polychaete Nereis diversicolor. Metal analysis includes manganese, chromium, nickel, copper, zinc, arsenic, selenium, cadmium and lead. The results show temporal and spatial variation of metals in both macrobenthic organisms and porewater. Levels of some metals in porewater, for example cadmium, lead, and copper are higher in winter months than in summer months in coherence with higher levels found in some benthic species. For some benthic species, metal contents were directly related to metal concentrations in porewater. However, no firm conclusion can be drawn that porewater is the only main source of bioavailable metals to benthic organisms and all metal species in porewater are bioavailable. In order to understand metal bioavailability in the sediment environment, a combination of information from a multidisciplinary approach (geochemistry, benthic ecology and toxicology) is needed. In fact, this study fits within the framework of a Triad-approach, conducted on sediments of the Schelde estuary.

  1. Conformational and dynamics simulation study of antimicrobial peptide hedistin-heterogeneity of its helix-turn-helix motif.

    Xu, Guohua; Wu, Min; Wang, Lin; Zhang, Xu; Cao, Shufen; Liu, Maili; Cui, Yanfang

    2009-12-01

    Hedistin is an antimicrobial peptide isolated from the coelomocytes of Nereis diversicolor, possessing activity against a large spectrum of bacteria including the methicillin resistant Staphylococcus aureus and Vibrio alginolyticus. The three-dimensional structure of hedistin in both aqueous solution and deuterated dodecylphosphocholine (DPC) micelles was examined using circular dichroism (CD) and nuclear magnetic resonance (NMR) techniques. And, the early events of the antibacterial process of hedistin were simulated using palmitoyl-oleoyl-phophatidylcholine (POPC) lipid bilayers and molecular dynamics (MD) simulation methods. Hedistin lacks secondary structure in aqueous solution, however, in DPC micelles, it features with a heterogeneous helix-turn-helix moiety and exhibits obvious amphipathic nature. The turn region (residues Val9-Thr12) in the moiety is a four-residue hinge, lying in between the first N-terminal alpha-helix (residues Leu5-Lys8) and the second alpha-helix (residues Val13-Ala17) regions and causing an approximately 120 degrees angle between the axes of the two helices. The segmental and nonlinear nature of hedistin structure is referred to as the heterogeneity of its helix-turn-helix motif which was found to be corresponding to a kind of discrete dynamics behavior, herein coined as its dynamical heterogeneity, at the early stage (0-50 ns) of the MD simulations. That is, the first helix segment, prior to (at 310 K) or following (at 363 K) the second helix, binds to the lipid head-group region and subsequently permeates into the hydrophobic lipid tail region, and the hinge is the last portion entering the lipid environment. This result implies that hedistin may adopt a "carpet" model action when disrupting bacterial membrane. PMID:19819221

  2. Distribution pattern of benthic invertebrates in Danish estuaries: The use of Taylor's power law as a species-specific indicator of dispersion and behavior

    Kristensen, Erik; Delefosse, Matthieu; Quintana, Cintia O.; Banta, Gary T.; Petersen, Hans Christian; Jørgensen, Bent

    2013-03-01

    The lack of a common statistical approach describing the distribution and dispersion pattern of marine benthic animals has often hampered the comparability among studies. The purpose of this study is therefore to apply an alternative approach, Taylor's power law, to data on spatial and temporal distribution of 9 dominating benthic invertebrate species from two study areas, the estuaries Odense Fjord and Roskilde Fjord, Denmark. The slope (b) obtained from the power relationship of sample variance (s2) versus mean (μ) appears to be species-specific and independent of location and time. It ranges from a low of ~ 1 for large-bodied (> 1 mg AFDW) species (e.g. Marenzelleria viridis, Nereis diversicolor) to a high of 1.6-1.9 for small-bodied (< 1 mg AFDW) species (e.g. Pygospio elegans and Tubificoides benedii). Accordingly, b is apparently a valuable species-specific dispersion index based on biological factors such as behavior and intraspecific interactions. Thus, at the examined spatial scale, the more intense intraspecific interactions (e.g. territoriality) cause less aggregated distribution patterns among large- than small-bodied invertebrates. The species-specific interactions seem sufficiently strong to override environmental influences (e.g. water depth and sediment type). The strong linear relationship between the slope b and intercept log(a) from the power relationship is remarkably similar for all surveys providing a common slope of - 1.63 with the present sampling approach. We suggest that this relationship is an inherent characteristic of Taylor's power law, and that b as a dispersion index may be biased by e.g. sampling errors when this relationship is weak. The correlation strength between b and log(a) could therefore be envisioned as a data quality check.

  3. Modelling the reworking effects of bioturbation on the incorporation of radionuclides into the sediment column: implications for the fate of particle-reactive radionuclides in Irish Sea sediments.

    Cournane, S; León Vintró, L; Mitchell, P I

    2010-11-01

    A microcosm laboratory experiment was conducted to determine the impact of biological reworking by the ragworm Nereis diversicolor on the redistribution of particle-bound radionuclides deposited at the sediment-water interface. Over the course of the 40-day experiment, as much as 35% of a (137)Cs-labelled particulate tracer deposited on the sediment surface was redistributed to depths of up to 11 cm by the polychaete. Three different reworking models were employed to model the profiles and quantify the biodiffusion and biotransport coefficients: a gallery-diffuser model, a continuous sub-surface egestion model and a biodiffusion model. Although the biodiffusion coefficients obtained for each model were quite similar, the continuous sub-surface egestion model provided the best fit to the data. The average biodiffusion coefficient, at 1.8 +/- 0.9 cm(2) y(-1), is in good agreement with the values quoted by other workers on the bioturbation effects of this polychaete species. The corresponding value for the biotransport coefficient was found to be 0.9 +/- 0.4 cm y(-1). The effects of non-local mixing were incorporated in a model to describe the temporal evolution of measured (99)Tc and (60)Co radionuclide sediment profiles in the eastern Irish Sea, influenced by radioactive waste discharged from the Sellafield reprocessing plant. Reworking conditions in the sediment column were simulated by considering an upper mixed layer, an exponentially decreasing diffusion coefficient, and appropriate biotransport coefficients to account for non-local mixing. The diffusion coefficients calculated from the (99)Tc and (60)Co cores were in the range 2-14 cm(2) y(-1), which are consistent with the values found by other workers in the same marine area, while the biotransport coefficients were similar to those obtained for a variety of macrobenthic organisms in controlled laboratories and field studies. PMID:20732733

  4. Contaminants in fine sediments and their consequences for biota of the Severn Estuary.

    Langston, W J; Pope, N D; Jonas, P J C; Nikitic, C; Field, M D R; Dowell, B; Shillabeer, N; Swarbrick, R H; Brown, A R

    2010-01-01

    When the first MPB special issue was published 25 years ago it was suggested that high body burdens of metals and selected organic pollutants in the Severn Estuary were the result of anthropogenic loadings from a variety of sources. The objective of this synopsis is to illustrate recent trends for contaminants (metals, PAHs, PCBs) in sediments and benthic biota and to consider the evidence for improved environmental quality over the last quarter of a century. Contaminants in sediments and sediment-dwelling fauna such as Hediste(=Nereis)diversicolor are, generally, evenly distributed over the estuary - which is the consequence of extensive re-suspension and redistribution of fine sediment by strong tidal currents. Such dispersal tends to mask the influences of individual discharges and physical characteristics are considered to be the major drivers affecting biodiversity in the Severn Estuary, often overshadowing contaminant concerns. Following the closure of major industries and the introduction of stricter pollution control, many inputs have ceased or been reduced and there are indications that environmental concentrations are now lower. Bioaccumulation of most contaminants has declined accordingly (with the possible exception of Cr). Intuitively, better environmental quality should be linked to ecological improvements. However, due to the dynamic nature of the system (and a lack of biological-effects data) it is difficult to establish direct relationships between inputs, body burdens and biological/ecological consequence. Uniquely, the long-term integrated monitoring program of AstraZeneca (Avonmouth) indicates that recovery of faunal diversity and abundance has occurred in mid-sections of the estuary in recent years implying that contaminants have indeed been a forcing feature for Severn biota. In this context, we highlight contaminant issues and biogeochemical changes which may need to be addressed in connection with the development of proposals for tidal

  5. On the ecology of meiofauna in an organically polluted estuarine mudflat

    Bouwman, Lucas A.; Romeijn, Karin; Admiraal, Wim

    1984-12-01

    The structure, distribution and seasonal changes of the benthic meiofauna in an organically polluted, tidal, brackish-water mudflat in the Ems-Dollart estuary were analysed. Towards the outfall of polluted fresh water, macrofauna disappeared, numbers of meiofauna increased but the diversity of the meiofauna decreased. In the area surrounding the outfall the numbers and biomass of nematodes and oligochaetes increased rapidly in spring and remained high until autumn ( c. 13 × 10 6 individuals m -2; c. 2gCm -2). The benthic fauna comprised small numbers of species, dominated by a few fast-growing diatom-feeding nematodes ( Eudiplogaster pararmatus and Dichromadora geophila) and oligochaetes ( Amphichaeta sannio and Paranais litoralis). Eudiplogaster pararmatus exhibits brood care and it tolerates low salinities. Dichromadora geophila which is oviparous, behaved similarly regarding tolerances, life cycle and feeding but this species was less successful than Eudiplogaster in colonizing the mudflats near the outfall. The success of the two naidid oligochaete species results from their method of reproduction by means of binary fission. Most organisms fed on benthic diatoms. In spite of intensive mineralization in the mudflat, only one bacteria-feeding organism was found in abundance (the nematode Leptolaimus papilliger). The absence of macrofaunal organisms, e.g. Nereis diversicolor, is probably also responsible for the development of high densities of meiofauna in the upper sediment layers of the mudflats in the vicinity of the outfall. The heavy load of organic waste entering the Dollart reduced the diversity within the benthic ecosystem, but nevertheless a simple system remained, based on the recurrent reoxidation of the sediment surface.

  6. Benthic biodiversity patterns in Ria de Aveiro, Western Portugal: Environmental-biological relationships

    Rodrigues, Ana Maria; Quintino, Victor; Sampaio, Leandro; Freitas, Rosa; Neves, Ramiro

    2011-12-01

    This study characterizes the macrobenthic gradients in Ria de Aveiro, Western Portugal. Ria de Aveiro is the meeting place of a number of river basins, resulting in a transition system of complex geometry, with channels running parallel to the coast line, north and south of the entrance, but also inland, creating an intricate system of navigation channels, islands and intertidal sand and mudflats. This renders unique characteristics to this system within the framework of transitional waters. The study was based on the analysis of samples from 248 sites, covering the full salinity gradient and the entire channel system. A total of 120 taxa in more than 76,350 specimens were identified. The most abundant and frequent taxa were all annelids, namely Alkmaria romijni, Streblospio shrubsolii, Tharyx sp., Tubificoides benedii, Nereis diversicolor, Capitella sp., Pygospio elegans, Polydora ligni and an unidentified oligochaete. The spatial distribution of the fauna was found to be mainly related to hydrodynamics and the salinity gradient, whereas sediment grain-size characteristics were much less important. Shear stress, flux, current velocity, salinity and sediment redox potential were the environmental variables which best related to the biological data. Benthic assemblages succeed from the euhaline pole, at the entrance, to the limnetic poles, located in the inner parts of the channels. In this succession, mean abundance increased from the outward to the inward assemblages but species richness and diversity were higher in intermediate assemblages. These descriptors decrease abruptly in the limnetic areas. Using the M-AMBI index, the ecological quality of Ria de Aveiro revealed moderate, poor and bad status. However, the ecological status spatial trend closely followed the benthic assemblages succession, their species richness and diversity, indicating the need for proper reference conditions and inter-calibration exercises in the transition waters before final

  7. Predation of intertidal infauna on juveniles of the bivalve Macoma balthica

    Hiddink, J. G.; ter Hofstede, R.; Wolff, W. J.

    2002-03-01

    Juveniles of the bivalve Macoma balthica live on tidal flats in the Wadden Sea. This study examined the interaction of Macoma with the infaunal polychaetes Arenicola marina and Nereis diversicolor and the gastropod Retusa obtusa. The distribution of M. balthica spat on the flats, shortly after settlement in April, showed a positive correlation with the Arenicola distribution and a negative correlation with Nereis distribution. There were no locations where Macoma spat and Retusa occurred together. In August, Macoma spat had grown too large for predation by intertidal infauna. Small individuals of Macoma spat were found in stomachs of Arenicola (0.14 worm -1) and Nereis (0.05 worm -1). Laboratory experiments showed that Nereis and Retusa could reduce Macoma spat abundance, both in the absence and presence of sediment and alternative prey. Arenicola reduced the abundance of small Macoma (Nereis in 0.03 m 2 cages and examined the effect on Macoma density several weeks later. We found a significant negative relation between densities of polychaetes and Macoma spat for both polychaete species in these experimental plots. Peculiarly, we found a significant positive relation between manipulated Nereis density and adult Macoma density in the cages; we cannot explain this. Consumption rates, calculated both from stomach contents and from field experiments, were 45 to 102 Macoma m -2 d -1 for Arenicola and 5 to 116 Macoma m -2 d -1 for Nereis. These values are higher than recorded consumption rates by epibenthic predators in the same area. Nevertheless, between-year differences in year-class strength could not be explained by differential abundance of these polychaetes. In conclusion, Arenicola and Nereis had a negative effect on the abundance of Macoma <1.5 mm, which was at least partly caused by direct consumption. Retusa obtusa can eat juvenile Macoma, but probably did not so in the study area, because there were no locations where Retusa and Macoma spat occurred together

  8. Disposition of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in two Norwegian epibenthic marine food webs.

    Ruus, Anders; Berge, John Arthur; Bergstad, Odd Aksel; Knutsen, Jan Atle; Hylland, Ketil

    2006-03-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a group of halogenated hydrocarbons, comprising 210 different, theoretically possible congeners. They are relatively hydrophobic and persistent to biodegradation, thereby rendering them subject to bioaccumulation. This study was conducted in Frierfjord and Eidangerfjord in the Grenland fjord system, Norway, heavily polluted by PCDD/PCDF discharges from the 16,600,859 magnesium production at Herøya from 1951 to 2001. Pooled samples of surface-sediments and the following organisms were collected for the Frierfjord and Eidangerfjord study areas: common shrimp (Crangon crangon), polychaetes (mainly Nereis diversicolor), shore crab (Carcinus maenas), cod (Gadus morhua), flounder (Platichthys flesus), trout (Salmo trutta), herring (Clupea harengus), benthic amphipods and zooplankton. Concentrations of 2,3,7,8-PCDD/Fs were quantified in pooled samples for all species. The relative abundances of stable isotopes of nitrogen (delta(15)N) were evaluated in the organisms as a measure of chemically-derived trophic level. Contrary to earlier studies on other persistent organochlorines, it was found that the concentrations of PCDD/Fs declined with increasing trophic level. Principal Component Analysis (PCA) also showed differences between species in the pattern of PCDD/Fs. Higher chlorinated congeners constituted lower percentages of the PCDD/F-concentrations higher in the food chain as compared to lower trophic levels. In general, congener patterns did not differ between fjords. Infauna (polychaetes) and zooplankton had congener patterns most similar to the pollution source. The results indicate lower accumulation of higher chlorinated congeners in species at higher trophic levels (fish), presumably due to low membrane permeability (high molecular size) and possibly slow transport through intestinal aqueous phases because of low aqueous solubility. PMID:16169571

  9. Impact of enzymatic and alkaline hydrolysis on CBD concentration in urine.

    Bergamaschi, Mateus M; Barnes, Allan; Queiroz, Regina H C; Hurd, Yasmin L; Huestis, Marilyn A

    2013-05-01

    A sensitive and specific analytical method for cannabidiol (CBD) in urine was needed to define urinary CBD pharmacokinetics after controlled CBD administration, and to confirm compliance with CBD medications including Sativex-a cannabis plant extract containing 1:1 ∆(9)-tetrahydrocannabinol (THC) and CBD. Non-psychoactive CBD has a wide range of therapeutic applications and may also influence psychotropic smoked cannabis effects. Few methods exist for the quantification of CBD excretion in urine, and no data are available for phase II metabolism of CBD to CBD-glucuronide or CBD-sulfate. We optimized the hydrolysis of CBD-glucuronide and/or -sulfate, and developed and validated a GC-MS method for urinary CBD quantification. Solid-phase extraction isolated and concentrated analytes prior to GC-MS. Method validation included overnight hydrolysis (16 h) at 37 °C with 2,500 units β-glucuronidase from Red Abalone. Calibration curves were fit by linear least squares regression with 1/x (2) weighting with linear ranges (r(2) > 0.990) of 2.5-100 ng/mL for non-hydrolyzed CBD and 2.5-500 ng/mL for enzyme-hydrolyzed CBD. Bias was 88.7-105.3 %, imprecision 1.4-6.4 % CV and extraction efficiency 82.5-92.7 % (no hydrolysis) and 34.3-47.0 % (enzyme hydrolysis). Enzyme-hydrolyzed urine specimens exhibited more than a 250-fold CBD concentration increase compared to alkaline and non-hydrolyzed specimens. This method can be applied for urinary CBD quantification and further pharmacokinetics characterization following controlled CBD administration. PMID:23494274

  10. Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.

    Manríquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camaño, Andrés

    2013-12-01

    The Chilean abalone or "loco" (Concholepas concholepas, Bruguière 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. PMID:24099753

  11. Effects of Bushen Yishou Capsule Residues on Culture of Pleurotus abalonus Han, K.M.Chen et.S.Cheng and Nutrition Composition Analysis%补肾益寿胶囊药渣栽培鲍鱼菇及营养成分分析

    陈今朝; 谭永忠; 王新惠; 王慧超

    2012-01-01

    用补肾益寿胶囊药渣、木屑为主要原料栽培鲍鱼菇,筛选最适栽培配方并测定鲍鱼菇的营养成分.结果表明,栽培鲍鱼菇的最佳配方是补肾益寿胶囊药渣40%、木屑40%、麦麸18%、石膏1%和蔗糖1%.此时,鲍鱼菇菌丝体的日均长速为0.34 cm/d,生物学效率为55.8%.鲍鱼菇碳水化合物、粗蛋白、粗纤维、灰分和粗脂肪的含量分别为48.80%、19.76%、8.12%、9.21%和13.25%.%In this paper, Pleurotus abalonus Han, K. M. Chen et. S. Cheng was cultivated with Bushen Yishou capsule residues and wood chips as main raw materials, meanwhile, the most suitable cultivation formula was screened, and the nutrients composition of P. abalones was determined. The results showed that the optimal media for cultivating P. abalonus consists of 40 % Bushen Yishou capsule residues, 40 % wood chips, 18 % wheat bran,1 % gypsum and 1 % sucrose. The average daily speed of mycelia was 0. 34cm/d, while its biological efficiency was 55. 8 %. Carbohydrates, crude protein, crude fibre, ash and crude fat content of P. abalonus were 48. 80 % ,19.76 % ,8.12 % ,9.21 % and 13.25 % , respectively.

  12. Mapping Sargassum beds off, ChonBuri Province, Thailand, using ALOS AVNI2 image

    Noiraksar, Thidarat; Komatsu, Teruhisa; Sawayama, Shuhei; Phauk, Sophany; Hayashizaki, Ken-ichi

    2012-10-01

    Sargassum species grow on rocks and dead corals and form dense seaweed beds. Sargassum beds play ecological roles such as CO2 uptake and O2 production through photosynthesis, spawning and nursery grounds of fish, feeding ground for sea urchins and abalones, and substrates for attached animals and plants on leaves and holdfasts. However, increasing human impacts and climate change decrease or degrade Sargassum beds in ASEAN countries. It is necessary to grasp present spatial distributions of this habitat. Thailand, especially its coastal zone along the Gulf of Thailand, is facing degradation of Sargassum beds due to increase in industries and population. JAXA launched non-commercial satellite, ALOS, providing multiband images with ultra-high spatial resolution optical sensors (10 m), AVNIR2. Unfortunately, ALOS has terminated its mission in April 2011. However, JAXA has archived ALOS AVNIR2 images over the world. They are still useful for mapping coastal ecosystems. We examined capability of remote sensing with ALOS AVNIR2 to map Sargassum beds in waters off Sattahip protected area as a natural park in Chon Buri Province, Thailand, threatened by degradation of water quality due to above-mentioned impacts. Ground truth data were obtained in February 2012 by using continual pictures taken by manta tow. Supervised classification could detect Sargassum beds off Sattahip at about 70% user accuracy. It is estimated that error is caused by mixel effect of bottom substrates in a pixel with 10 x 10 m. Our results indicate that ALOS AVNIR2 images are useful for mapping Sargassum beds in Southeast Asia.

  13. Gastropod arginine kinases from Cellana grata and Aplysia kurodai. Isolation and cDNA-derived amino acid sequences.

    Suzuki, T; Inoue, N; Higashi, T; Mizobuchi, R; Sugimura, N; Yokouchi, K; Furukohri, T

    2000-12-01

    Arginine kinase (AK) was isolated from the radular muscle of the gastropod molluscs Cellana grata (subclass Prosobranchia) and Aplysia kurodai (subclass Opisthobranchia), respectively, by ammonium sulfate fractionation, Sephadex G-75 gel filtration and DEAE-ion exchange chromatography. The denatured relative molecular mass values were estimated to be 40 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated enzyme from Aplysia gave a Km value of 0.6 mM for arginine and a Vmax value of 13 micromole Pi min(-1) mg protein(-1) for the forward reaction. These values are comparable to other molluscan AKs. The cDNAs encoding Cellana and Aplysia AKs were amplified by polymerase chain reaction, and the nucleotide sequences of 1,608 and 1,239 bp, respectively, were determined. The open reading frame for Cellana AK is 1044 nucleotides in length and encodes a protein with 347 amino acid residues, and that for A. kurodai is 1077 nucleotides and 354 residues. The cDNA-derived amino acid sequences were validated by chemical sequencing of internal lysyl endopeptidase peptides. The amino acid sequences of Cellana and Aplysia AKs showed the highest percent identity (66-73%) with those of the abalone Nordotis and turbanshell Battilus belonging to the same class Gastropoda. These AK sequences still have a strong homology (63-71%) with that of the chiton Liolophura (class Polyplacophora), which is believed to be one of the most primitive molluscs. On the other hand, these AK sequences are less homologous (55-57%) with that of the clam Pseudocardium (class Bivalvia), suggesting that the biological position of the class Polyplacophora should be reconsidered. PMID:11281267

  14. GFP facilitates native purification of recombinant perlucin derivatives and delays the precipitation of calcium carbonate.

    Eva Weber

    Full Text Available Insolubility is one of the possible functions of proteins involved in biomineralization, which often limits their native purification. This becomes a major problem especially when recombinant expression systems are required to obtain larger amounts. For example, the mollusc shell provides a rich source of unconventional proteins, which can interfere in manifold ways with different mineral phases and interfaces. Therefore, the relevance of such proteins for biotechnological processes is still in its infancy. Here we report a simple and reproducible purification procedure for a GFP-tagged lectin involved in biomineralization, originally isolated from mother-of-pearl in abalone shells. An optimization of E. coli host cell culture conditions was the key to obtain reasonable yields and high degrees of purity by using simple one-step affinity chromatography. We identified a dual functional role for the GFP domain when it became part of a mineralizing system in vitro. First, the GFP domain improved the solubility of an otherwise insoluble protein, in this case recombinant perlucin derivatives. Second, GFP inhibited calcium carbonate precipitation in a concentration dependent manner. This was demonstrated here using a simple bulk assay over a time period of 400 seconds. At concentrations of 2 µg/ml and higher, the inhibitory effect was observed predominantly for HCO(3 (- as the first ionic interaction partner, but not necessarily for Ca(2+. The interference of GFP-tagged perlucin derivatives with the precipitation of calcium carbonate generated different types of GFP-fluorescent composite calcite crystals. GFP-tagging offers therefore a genetically tunable tool to gently modify mechanical and optical properties of synthetic biocomposite minerals.

  15. A rapidly evolving secretome builds and patterns a sea shell

    Green Kathryn

    2006-11-01

    Full Text Available Abstract Background Instructions to fabricate mineralized structures with distinct nanoscale architectures, such as seashells and coral and vertebrate skeletons, are encoded in the genomes of a wide variety of animals. In mollusks, the mantle is responsible for the extracellular production of the shell, directing the ordered biomineralization of CaCO3 and the deposition of architectural and color patterns. The evolutionary origins of the ability to synthesize calcified structures across various metazoan taxa remain obscure, with only a small number of protein families identified from molluskan shells. The recent sequencing of a wide range of metazoan genomes coupled with the analysis of gene expression in non-model animals has allowed us to investigate the evolution and process of biomineralization in gastropod mollusks. Results Here we show that over 25% of the genes expressed in the mantle of the vetigastropod Haliotis asinina encode secreted proteins, indicating that hundreds of proteins are likely to be contributing to shell fabrication and patterning. Almost 85% of the secretome encodes novel proteins; remarkably, only 19% of these have identifiable homologues in the full genome of the patellogastropod Lottia scutum. The spatial expression profiles of mantle genes that belong to the secretome is restricted to discrete mantle zones, with each zone responsible for the fabrication of one of the structural layers of the shell. Patterned expression of a subset of genes along the length of the mantle is indicative of roles in shell ornamentation. For example, Has-sometsuke maps precisely to pigmentation patterns in the shell, providing the first case of a gene product to be involved in molluskan shell pigmentation. We also describe the expression of two novel genes involved in nacre (mother of pearl deposition. Conclusion The unexpected complexity and evolvability of this secretome and the modular design of the molluskan mantle enables

  16. Mercury contents in shellfish sold in Qingdao City and their health risk:Distribution and health risk assessment%青岛市售贝类中总汞含量分布及人群健康风险

    张磊; 张磊

    2014-01-01

    In order to understand the status of mercury pollution in the shellfish of Qingdao City, and mercury health risk for the population via consumption of shellfish production, a total of 181 samples for 8 types of shellfish including Ruditapes philippinarum, Argopectens irradias, Meretrix meretrix L, Sinonovacula, Haliotis asinine, Busycon canaliculatu, Ostrea riuularis Gould, Neptunea arthritica cumingii Crosse, were collected from the markets of 8 administrative regions in Qingdao from October in 2012 to April in 2013. The mercury contents in the shellfish samples were determined by the cold vapor atomic absorption spectrophotometry. The range of mercury contents in all the kinds of shellfish was from 0.001 mg·kg-1 to 0.098 mg·kg-1 . The average mercury content in Ruditapes philippinarum, Argopectens irradias, Meretrix meretrix L, Sinonovacula, Haliotis asinina Busycon canaliculatu, Ostrea riuularis Gould, Neptunea arthritica cumingii Crosse was 0.02, 0.039, 0.012, 0�013, 0.031, 0.030, 0.021, 0.020 mg·kg-1 , respectively. Among the production areas of shellfish in Qingdao, the samples from Hong Island had the highest average mercury content of 0.046 mg·kg-1 , followed by that from Longkou of 0. 027 mg·kg-1 . Shellfish samples from Rushan and Rizhao had the lowest mercury contents, which were 0. 002 mg·kg-1 and 0. 003 mg·kg-1 , respectively. The mercury concentrations were under the limit of national permitted levels in foods ( GB 2762-2012, 0.5 mg·kg-1 ) . The results of the assessments of mercury intake indicated that the amount of mercury intake through consumption of shellfish was far below the acceptable daily intake recommended by FAO/WHO. However, the calculation results of the target hazard quotient ( THQ) based on the new reference dose set by US Environmental Protection Agency showed that there was high mercury health risk for children living in the target areas through the exposure path of the consumption of shellfish products.%为了解青岛

  17. Alteration of organic matter during infaunal polychaete gut passage and links to sediment organic geochemistry. Part I: Amino acids

    Woulds, Clare; Middelburg, Jack J.; Cowie, Greg L.

    2012-01-01

    Of the factors which control the quantity and composition of organic matter (OM) buried in marine sediments, the links between infaunal ingestion and gut passage and sediment geochemistry have received relatively little attention. This study aimed to use feeding experiments and novel isotope tracing techniques to quantify amino acid net accumulation and loss during polychaete gut passage, and to link this to patterns of selective preservation and decay in sediments. Microcosms containing either Arenicolamarina or Hediste (formerly Nereis) diversicolor were constructed from defaunated sediment and filtered estuarine water, and maintained under natural temperature and light conditions. They were fed with 13C-labelled diatoms daily for 8 days, and animals were transferred into fresh, un-labelled sediment after ∼20 days. Samples of fauna, microcosm sediment and faecal matter were collected after 8, ∼20 and ∼40 days, and analysed for their bulk isotopic signatures and 13C-labelled amino acid compositions. Bulk isotopic data showed that, consistent with their feeding modes, Hediste assimilated added 13C more quickly, and attained a higher labelling level than Arenicola. Both species retained the added 13C in their biomass even after removal from the food. A principal component analysis of 13C-labelled amino acid mole percentages showed clear differences in composition between the algae, faunal tissues, and sediment plus faecal matter. Further, the two species of polychaete showed different compositions in their tissues. The amino acids phenylalanine, valine, leucine, iso-leucine, threonine and proline showed net accumulation in polychaete tissues. Serine, methionine, lysine, aspartic and glutamic acids and tyrosine were rapidly lost through metabolism, consistent with their presence in easily digestible cell components (as opposed to cell walls which offer physical protection). All sample types (polychaete tissues, sediments and faecal matter) were enriched in

  18. БЕНТОСНЫЕ СООБЩЕСТВА ОЗЕРА КАРАКОЛЬ

    Карапун, Михаил; Зайцев, Вячеслав; Обухова, Ольга; Юрченко, Вера; Бисекенов, Тайыр

    2009-01-01

    Озеро Караколь обширное проточное мелководное водохранилище в районе восточного побережья Среднего Каспия, вблизи г. Актау, включено в список ключевых орнитологических территорий. Исследовались его основные морфометрические характеристики и особенности макрозообентосных сообществ (численность и качественный состав). Установлено, что доминантами в весенний период являются двухстворчатый моллюск Abra ovata и многощетинковый червь Nereis diversicolor. Проведена оценка уровня кормности озера. Сте...

  19. Benthic grazers and suspension feeders: Which one assumes the energetic dominance in Königshafen?

    Asmus, H.

    1994-06-01

    Size-frequency histograms of biomass, secondary production, respiration and energy flow of 4 dominant macrobenthic communities of the intertidal bay of Königshafen were analysed and compared. In the shallow sandy flats ( Nereis-Corophium-belt [ N.C.-belt], seagrass-bed and Arenicola-flat) a bimodal size-frequency histogram of biomass, secondary production, respiration and energy flow was found with a first peak formed by individuals within a size range of 0.10 to 0.32 mg ash free dry weight (AFDW). In this size range, the small prosobranch Hydrobia ulvae was the dominant species, showing maximal biomass as well as secondary production, respiration and energy flow in the seagrass-bed. The second peak on the size-frequency histogram was formed by the polychaete Nereis diversicolor with individual weights of 10 to 18 mg AFDW in the N.C.-belt, and by Arenicola marina with individual weights of 100 to 562 mg AFDW in both of the other sand flats. Biomass, productivity, respiration and energy flow of these polychaetes increased from the Nereis-Corophium-belt, to the seagrass-bed, and to the Arenicola-flat. Mussel beds surpassed all other communities in biomass and the functional parameters mentioned above. Size-frequency histograms of these parameters were distinctly unimodal with a maximum at an individual size of 562 to 1000 mg AFDW. This size group was dominated by adult specimens of Mytilus edulis. Averaged over the total area, the size-frequency histogram of energy flow of all intertidal flats of Königshafen showed one peak built by Hydrobia ulvae and a second one, mainly formed by M. edulis. Assuming that up to 10% of the intertidal area is covered by mussel beds, the maximum of the size-specific energy flow will be formed by Mytilus. When only 1% is covered by mussel beds, then the energy flow is dominated by H. ulvae. Both animals represent different trophic types and their dominance in energy flow has consequences for the food web and the carbon flow of the

  20. Marine biodiversity in South Africa: an evaluation of current states of knowledge.

    Charles L Griffiths

    Full Text Available Continental South Africa has a coastline of some 3,650 km and an Exclusive Economic Zone (EEZ of just over 1 million km(2. Waters in the EEZ extend to a depth of 5,700 m, with more than 65% deeper than 2,000 m. Despite its status as a developing nation, South Africa has a relatively strong history of marine taxonomic research and maintains comprehensive and well-curated museum collections totaling over 291,000 records. Over 3 million locality records from more than 23,000 species have been lodged in the regional AfrOBIS (African Ocean Biogeographic Information System data center (which stores data from a wider African region. A large number of regional guides to the marine fauna and flora are also available and are listed. The currently recorded marine biota of South Africa numbers at least 12,914 species, although many taxa, particularly those of small body size, remain poorly documented. The coastal zone is relatively well sampled with some 2,500 samples of benthic invertebrate communities have been taken by grab, dredge, or trawl. Almost none of these samples, however, were collected after 1980, and over 99% of existing samples are from depths shallower than 1,000 m--indeed 83% are from less than 100 m. The abyssal zone thus remains almost completely unexplored. South Africa has a fairly large industrial fishing industry, of which the largest fisheries are the pelagic (pilchard and anchovy and demersal (hake sectors, both focused on the west and south coasts. The east coast has fewer, smaller commercial fisheries, but a high coastal population density, resulting in intense exploitation of inshore resources by recreational and subsistence fishers, and this has resulted in the overexploitation of many coastal fish and invertebrate stocks. South Africa has a small aquaculture industry rearing mussels, oysters, prawns, and abalone-the latter two in land-based facilities. Compared with many other developing countries, South Africa has a well