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11.
Charles F. Phleger Matthew M. Nelson Ami K. Groce S. Craig Cary Kathryn Coyne John A.E. Gibson Peter D. Nichols 《Deep Sea Research Part I: Oceanographic Research Papers》2005,52(12):2333-2352
The lipid composition was determined for 5 species of polychaete annelids collected by the Deep Submergence Vehicle ALVIN from high temperature chimneys at the 2500 m depth hydrothermal vent field of the East Pacific Rise. These are the first lipid biomarker analyses reported for these hydrothermal vent polychaetes. Lipid content was low in all samples (1.6–35.9 mg g–1 wet mass) and was dominated by polar lipid (78–90% of total lipid) with 8–19% sterol (ST), and very low storage lipid (triacylglycerol and wax ester). Total polyunsaturated fatty acids (PUFA) were moderately high (22–31% of total fatty acids (FA)) with extremely low or no docosahexaenoic acid (DHA, 22:6(n-3)). Eicosapentaenoic acid (EPA, 20:5(n-3)) levels were 5–6% in Alvinella pompejana and A. caudata and 10.3–13.7% in an errantiate polychaete (likely Hesionidae) and Hesiolyra bergii. There were greater PUFA and a greater EPA/AA (AA is arachidonic acid, 20:4(n-6)) ratio in the anterior versus the posterior half of A. pompejana, which may correlate to the strong temperature gradient reported in its tube. Total nonmethylene interrupted diunsaturated fatty acids (NMID) were 4–9% of total FA for most polychaete species and included several 20:2 and 22:2 components. The principal monounsaturated fatty acids (MUFA) included 18:1(n-7)c (14–19%), 16:1(n-7)c (2.6–10%) and 20:1(n-11)c (3–7% of total FA). These polychaete species may desaturate and elongate the bacterial-derived 18:1(n-7)c to obtain the essential FA EPA and AA. The major ST in the polychaetes is cholesterol (89–98% of total ST) with less cholesterol in the gut contents of A. pompejana. Other ST included 24-ethylcholesterol (1.5–5% of total ST) with lesser amounts of 24-methylenecholesterol, desmosterol, lathosterol, 24-methylcholesterol, 24-ethylcholesterol, and the stanols dehydrocholestanol and cholestanol. The high ST levels could play a role in thermal adaptation of membranes at the hydrothermal vent environment. Differences in the FA profiles separated the closely related species A. pompejana and A. caudata from Paralvinella grasslei, H. bergii, and the errantiate polychaete (likely Hesionidae). 相似文献
12.
Bettina Knig Oliver Kohls Gerhard Holst Ronnie N. Glud Michael Kühl 《Marine Chemistry》2005,97(3-4):262-276
We describe the fabrication of organically modified sol–gel (ORMOSIL) planar optodes for mapping the two-dimensional oxygen distribution in sediments. All sensor foils were based on the use of ruthenium(II)-tris-(4,7-diphenyl-1,10-phenantrolin)-perchlorate, which is a fluorescent dye quenched dynamically by oxygen. Sensors made with different sol–gel immobilisation matrices, different concentrations of precursors and indicator dye, as well as different types of scattering particles co-immobilised in the sensor foil were investigated systematically. Optimal sensor performance was obtained with dye concentrations of 2–10 mmol/kg in an immobilisation matrix made of diphenyldiethoxy-silan and phenyltriethoxy-silan precursors with addition of organically coated TiO2 particles. The sensors exhibited a good mechanical stability and a high sensitivity from 0% to 100% oxygen, which remained constant over at least 36 days. The planar optodes were used with a fluorescent lifetime imaging system for direct mapping of the spatio-temporal variation in oxygen distribution within marine sediment inhabited by the polychaete Hediste diversicolor. The measurements demonstrated the spatio-temporal heterogeneity of the oxygen distribution in bioturbated sediments due to burrow structures and non-constant irrigation activity of the polychaete, which is difficult to resolve with microsensors or with traditional biogeochemical techniques. 相似文献
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14.
Fullerene (nC60) and nanosilver (nAg) are nanomaterials with bactericide properties. The increments in their use raise questions about their potential environmental impacts, including estuarine ones. The polychaete Laeonereis acuta (Nereididae) secretes mucus that is colonized by bacteria communities. We analyzed the antioxidant and oxidative damage responses of anterior, middle and posterior region of L. acuta and bacteria communities after nC60 or nAg exposure during 24 h. Molecular analysis showed a prevalence of Vibrio genera in the communities. Bacteria biomass was lowered in worms exposed to 1.0 mg/L of nAg. nC60 reduced total antioxidant capacity of bacteria from worms exposed to 0.1 mg/L. Worms anterior region presented lower antioxidant capacity after exposure to 1.0 mg nC60/L, and the same was observed in the posterior region of worms exposed to 1.0 mg nAg/L. Lipid peroxidation was reduced in the anterior region of worms exposed to nC60 and the opposite was observed in the posterior region. 相似文献
15.
Paul K.S. Shin Singaram Gopalakrishnan Alice K.Y. Chan P.Y. Qian Rudolf S.S. Wu 《Marine pollution bulletin》2014
Marine benthic polychaete Capitella sp. I is widely known to adapt to polluted habitats; however, its response to xenobiotics under hypoxic conditions has been rarely studied. This research aimed to test the hypothesis that interactive effects of hypoxia and congener BDE-47 of polybrominated diphenyl ethers (PBDE), which is ubiquitous in marine sediments, may alter the settlement of Capitella sp. I. Our results revealed that under hypoxic condition, settlement success and growth in body length of Capitella larvae were significantly reduced compared to those under normoxia of similar BDE-47 concentration. While no significant changes in morphology of settled larvae were noted in both exposure conditions, the presence of BDE-47 could enhance polychaete growth. The present findings demonstrated that the interactive effects of hypoxia and environmentally realistic concentrations of BDE-47 in sediments could affect polychaete settlement, which, in turn, reduce its recruitment and subsequent population size in the marine benthic ecosystem. 相似文献
16.
We collected polychaete diversity and abundance data at a range of impacted and reference sites near an alumina refinery in Melville Bay, northern Australia. The aims were to measure the impact of sediment modified by the alumina refinery discharge on polychaete communities and secondly to gather baseline data from which to measure future changes. Polychaete communities in both soft-bottom habitats and subtidal areas adjacent to mangrove forests were studied. We also developed and deployed an artificial substratum device to sample polychaetes associated with hard-substrate habitats. For each habitat, polychaete community composition was different between impacted and reference sites and at multiple time points. The impact of future changes either from bioremediation or management practices can be measured against these baseline data. Indicator species analysis was used to identify polychaete species that were significantly different at the locations tested, and we discuss their potential as indicator species. 相似文献
17.
Wu Qiquan 《海洋学报(英文版)》1996,15(4):515-527
ＰｏｌｙｃｈａｅｔｅｅｃｏｌｏｇｙｉｎｗｅｓｔｏｆＴａｉｗａｎＳｔｒａｉｔａｎｄａｒｏｕｎｄＴａｉｗａｎＳｈｏａｌＷｕＱｉｑｕａｎＡｂｓｔｒａｃｔ：Ｔｈｉｓｐａｐｅｒｄｅａｌｓｗｉｔｈ．ｃｏｍｐｒｅｈｅｎｓｉｖｅｌｙ，ｆｏｒｔｈｅｆｉｒｓｔｔｈｅ，ｔ... 相似文献
18.
Chirananda De 《Marine Georesources & Geotechnology》2002,20(3):209-220
The marine polychaete Diopatra cuprea (Bosc) produces tubes that protrude above the sediment surface. To the part above the sediment surface the worm attaches foreign particles. A sharp boundary separates the parts above and below the sediment surface. With subsequent erosion, part of the tube without attached particles becomes exposed and this exposed part indicates the amount of erosion. With subsequent sedimentation, the tubes are enlarged upward and the sharp boundary is found below the sediment surface indicating the amount of subsequent sedimentation. This mode of construction of tubes during an average life span of two years renders tubes as simple but excellent natural tools for precise and easy measurement of the latest annual rates of erosion and deposition in coastal areas, data that are essential for the solving of coastal engineering and geoenvironmental problems. Comparison of this tool with expensive long-term coastal profiling data in four areas in the Bay of Bengal coast indicates its correctness and high applicational value.
This revised model can be applied to modern coastal environments only for calculating latest annual rates of both erosion and deposition as correctly as latest physical techniques. Being based on the similar organosedimentary principle, it distinctively contrasts with the earlier model of Myers which provides information on the amount of sediment accumulation only without any time connotation and, it may generate erroneous results if applied to the geologic past unless some limitations evolved in the processes of dewatering, compaction, lithification and diagenesis are removed. 相似文献
This revised model can be applied to modern coastal environments only for calculating latest annual rates of both erosion and deposition as correctly as latest physical techniques. Being based on the similar organosedimentary principle, it distinctively contrasts with the earlier model of Myers which provides information on the amount of sediment accumulation only without any time connotation and, it may generate erroneous results if applied to the geologic past unless some limitations evolved in the processes of dewatering, compaction, lithification and diagenesis are removed. 相似文献
19.
Lu Wang Ying Fan Cunjun Yan Chunzi Gao Zhaodong Xu Xiaoshou Liu 《Marine pollution bulletin》2017,114(1):258-268
Bottom aquaculture of bivalves is a high-yield culture method, which is increasingly adopted by shellfish farmers worldwide. However, the effects of bottom aquaculture on benthic ecosystems are not well-known. Manila clam (Ruditapes philippinarum), is a widely distributed bottom aquaculture mollusk species. To assess the ecological impacts of Manila clam bottom aquaculture, clams and other macrofaunal assemblages were investigated during four cruises (July and November 2011, February and May 2012) at six sampling sites in Jiaozhou Bay, China. Correlation analysis showed that macrofaunal assemblages had significant negative correlations with the abundance of Manila clams. However, according to the results of several biotic indices, a low disturbance was detected by Manila clam bottom aquaculture. In conclusion, AMBI (AZTI'S Marine Biotic Index) and M-AMBI (Multivariate AZTI Marine Biotic Index) indices are more suitable for assessing ecological quality than polychaete/amphipod ratios when the disturbance is slight, such as at a bivalve bottom aquaculture. 相似文献
20.
Tang Senming Chen Xiaolin Zhuang Dongf Wu Shengsan Lin Yu Cai Ziping Zheng Fengwu 《海洋学报(英文版)》1994,13(3):425-431
ＥｆｆｅｃｔｓｏｆｄｉｅｓｅｌｏｉｌｏｎｔｈｅｐｏｌｙｃｈａｅｔｅＡｎｎｅｌｉｄａｉｎｍｏｄｅｌｂｅｎｔｈｉｃｅｃｏｓｙｓｔｅｍ￥ＴａｎｇＳｅｎｍｉｎｇ；ＣｈｅｎＸｉａｏｌｉｎ；ＺｈｕａｎｇＤｏｎｇｆａ；ＷｕＳｈｅｎｇｓａｎ；ＬｉｎＹｕ；ＣａｉＺｉｐ... 相似文献