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1.
盐度30、pH7.5～8.5、温度27～30℃条件下,将刚刚蜕壳的远海梭子蟹放入不同钙浓度梯度(0～400 mg/L)的人工海水中,进行钙浓度对远海梭子蟹蟹壳硬化影响的实验。结果表明:0～12.5 mg/L浓度组的软壳持续时间在10.4～11.4 h之间,25～200 mg/L浓度组的软壳持续时间在6.1～7.7 h,400 mg/L浓度组的软壳持续时间为4.4 h;不同浓度组下,壳宽的增加差异不显著(P﹥0.05),壳长的增加差异也不显著(P﹥0.05);50 mg/L浓度组与400 mg/L浓度组体重增加差异显著(P<0.05),其它各浓度组之间体重增加差异不显著(P﹥0.05)。 相似文献
2.
【目的】研究波纹龙虾(Panulirus homarus)胚胎对生态因子的耐受能力,为龙虾繁殖提供数据。【方法】采用封闭静水实验方法和常规生物急性毒性实验法。在温度(30±0.5)℃,盐度30,pH(8.10±0.1)和溶解氧(DO)为(5.0±0.5)mg/L条件下,分别进行温度、盐度、pH的骤变和渐变对波纹龙虾胚胎存活影响研究;根据急性毒性预实验结果设置等对数间距浓度值,进行氨氮和亚硝酸盐氮对波纹龙虾胚胎的急性毒性实验。【结果与结论】波纹龙虾胚胎发育的温度、盐度和pH耐受范围分别为7~36℃、15~45和5.8~9.4;波纹龙虾胚胎适宜温度为15~30℃,适宜盐度为30~35,适宜pH为7.0~8.5;氨氮和亚硝酸盐氮毒性效应与浓度和暴露时间呈正相关。氨氮和亚硝酸盐氮暴露24~96 h,波纹龙虾胚胎存活率组间存在显著性差异(P<0.05)。氨氮对波纹龙虾胚胎24、48、72和96 h的半致死浓度(LC50)分别是180.46、61.11、41.87、26.58 mg/L,安全浓度(SC)为2.66 mg/L;亚硝酸盐氮对波纹龙虾胚胎24、48、72和96 h的LC50分别是839.50、423.75、214.48、135.41 mg/L,SC为13.54 mg/L。 相似文献
3.
An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane desalter was used to reduce the high concentrations of sodium salts in samples. In this method, trace nitrate was eluted from the concentrator column to the analytical columns, while the matrix flowed to waste. Neither chemical pre-treatment nor sample dilution was required. In the optimized separation conditions, the method showed good linearity （R〉0,99） in the 0.05 and 50 mg/L concentration range, and satisfactory repeatability （RSD〈5%, n=6）. The limit of detection for nitrate was 0.02 mg/L. Results showed that the valve switching system was suitable and practical for the determination of trace nitrate in seawater. 相似文献
4.
A field observation was carried out in the Changjiang （Yangtze） River Estuary from May 19 to 26, 2003. A total of 29 stations, including 2 anchored stations, were occupied through almost the whole salinity gradient. Based on the observation data, biogeochemistry of chemical oxygen demand （COD） was examined. Spatial distribution pattern of COD shows that it decreased downstream. The COD concentration varied generally within a narrow range of 1.24-1.60 mg/L in the zone around the river mouth, beyond which it decreased rapidly to 0.20 mg/L. In the mixed water zone, the fluctuation in COD was smaller at 2 m above the bottom layer than at the surface layer in 48 h. In the seawater zone, the 48-h fluctuation at the surface was the largest, followed by that of 5 m below the surface and 2 m above the bottom layers in a range of from 2.50 to 0.55 mg/L. Freshwater discharge was the dominant source of COD in the estuary. The average COD beyond the river mouth was 2.7 mg/L, which accorded with the Chinese seawater quality Grade I. Relationships between dissolved oxygen and biogeochemical parameters such as suspended particulate matter, dissolved organic matter and chlorophyll-a were also discussed. 相似文献
5.
【目的】探究禁食暂养对卵形鲳鲹有水保活生理响应的影响,为卵形鲳鲹的保活运输奠定基础。【方法】通过测定暂养过程中水体的总氨氮和pH值、卵形鲳鲹血液生理生化指标、肌肉氧化应激指标等的变化,分析确定卵形鲳鲹有水保活的禁食暂养条件。【结果与结论】禁食暂养过程中,随着暂养时间的延长,水体总氨氮含量与pH值显著上升,但在禁食暂养时间为6 h时,其总氨氮质量浓度为3.22 mg/L和pH值为7.80;禁食暂养6 h可以降低或减少卵形鲳鲹的应激,使血液中乳酸脱氢酶(LDH)和谷草转氨酶(AST)活性以及皮质醇(Cortisol)、血糖(GLU)、尿素氮(BUN)和总胆固醇(T-CHO)含量处于较低水平,分别为2785.53 U/L、19.04 U/L、158.72 ng/mL、2.98 mmol/L、4.35 mmol/L和4.96 mmol/L;同时减轻了应激带来的肌肉组织氧化损失,使过氧化氢酶(CAT)活性和丙二醛(MDA)含量维持在较低水平,分别为6.34 U/L和5.86 mmol/L;卵形鲳鲹适宜的暂养条件为在鱼水比m鱼∶m水=1∶20和(25±1)℃的洁净海水中暂养6 h。 相似文献
6.
ＩＮＴＲＯＤＵＣＴＩＯＮＰｅｎａｅｕｓｊａｐｏｎｉｃｕｓｉｓａｎｅｕｒｏｘｙｂｉｏｔｉｃｐｅｎａｅｉｄｐｒａｗｎ ,ｗｈｏｓｅｐｒｏｐｅｒｓａｌｉｎｉｔｙｒａｎｇｅｆｏｒｇｒｏｗｔｈｉｓ2 0 -30ａｎｄｏｐｔｉｍａｌｓａｌｉｎｉｔｙｒａｎｇｅｉｓ 2 5-30 (ＷａｎｇａｎｄＬｉｕ ,1 991 ;ＷａｎｇａｎｄＹｕ ,1 999) .Ｉｔｈａｓｇｒｅａｔｏｓｍｏｒｅｇｕｌａｔｉｏｒｙｃａｐａｃｉｔｙ (ＭａｎｔｅｌａｎｄＦａｍｅｒ,1 983) .Ｂｕｔｉｔｓｂｅｓｔｅｎｖｉｒｏｎｍｅｎｔｆｏｒｒｅｐｒｏｄｕｃｔｉｏｎａｎｄｄｅｖｅｌ… 相似文献
7.
The concentration of Fe(Ⅱ) is high in some groundwater supplies used in turbot culture,and the toxicity of waterborne Fe(Ⅱ) is unknown.We investigated the stress responses of juvenile turbot,Scophthalmus maximus,exposed to Fe(Ⅱ) of different concentrations (0.01,0.05,0.1,0.5,1,and 2 mg/L) for 1,7,14,and 28 d,under the same ambient conditions of other parameters.Changes in respiratory rate,hematological parameters,and gill structure were determined.The results show that waterborne Fe(Ⅱ) did not cause severe hematological perturbation to turbot.A low-medium Fe(Ⅱ) concentration (lower than 0.1 mg/L) could boost the respiratory rate,and caused no or very limited damage to fish.A high Fe(Ⅱ) concentration (0.1 mg/L or higher),however,caused gill damage,such as vacuoles in branchial lamellae,epithelial necrosis,and hypertrophy of epithelial cells,and even death after extended exposure time.Therefore,excess waterborne Fe(Ⅱ) and long-term exposure to Fe(Ⅱ) could be responsible for poor growth and high mortality of turbot in culture.The concentration of waterborne Fe(Ⅱ) in turbot culture should be kept below 0.1 mg/L. 相似文献
8.
We measured sulfide-based ATP production by isolated mitochondria from four tissues of Urechis unicinctus and the effects of inhibitors of respiratory complexes on ATP production were evaluated. The results show that these mitochondria could oxidize sulfide to produce ATP. The yield of sulfide-stimulated ATP varied from 5 nmol ATP/min/mg to 90 nmol ATP/min/mg according to the sulfide concentration and the source of the mitochondria. The maximum ATP synthesis occurred in hindgut mitochondria using 5 μmol/L sulfide as a substrate. The effects of inhibitors (Rotenone, Antimycin A, Cyanide, and Salicylhydroxamic acid) on mitochondrial ATP production varied with the source of the mitochondria. Our results indicate that sulfide-based ATP production and the associated electron transport pathway are tissue-specific in U. unicinctus. 相似文献
9.
用 0 .1、0 .5、1.0、2 .0和 5.0 mg/ L NH3- N分别刺激建鲤 10 d和 2 0 d后 ,测定了建鲤非特异性免疫指标 ,估测不同浓度的 NH3- N对建鲤非特异性免疫指标的影响。 0 .1、0 .5mg/ L的 NH3- N对建鲤NBT阳性细胞、溶菌酶活性无影响 ,1.0 mg/ L的 NH3- N可使 NBT阳性细胞数和溶菌酶活性降低 ,而2 .0和 5.0 mg/ L则使 NBT阳性细胞数和溶菌酶活性显著下降 ( P<0 .0 5)。这些结果表明水体中 0 .1、0 .5mg/ L的 NH3- N对建鲤非特异性免疫功能无影响 ,1.0 mg/ L的 NH3- N略有影响 ,而 2 .0和 5.0mg/ L的 NH3- N则明显降低了建鲤的非特异性免疫功能 相似文献
10.
于2008年3月至2009年1月用电感耦合等离子体质谱法(ICP-MS)对湛江港海水中的铜(Cu)、锌(Zn)、铅(Pb)、镉(Cd)进行调查。分析结果表明:2008年湛江港湾海水中Cu、Zn、Pb、Cd含量较低,年平均含量分别为4.46×10-3mg/L、14.2×10-3mg/L、0.795×10-3mg/L、0.588×10-3mg/L,总体上表层海水中Cu、Zn、Pb、Cd的含量均略低于底层海水。各季度海水中重金属含量的比较结果为:Cu的含量秋季>春季>夏季>冬季,Zn的含量夏季>春季>秋季>冬季,Pb的含量秋季>夏季>春季>冬季,Cd的含量冬季>夏季>秋季>春季。湛江港湾的Cu、Zn、Pb、Cd的含量均在中部水域湛江港码头核心作业区最高,港湾外较低;Zn、Cd在港湾内的含量较高。按照单因子污染指数法评价,湛江港湾海水中的Cu、Zn、Pb、Cd含量均低于国家二类海水水质标准规定的限值,水质较好。 相似文献
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12.
A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin(CYP) and deltamethrin(DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments. 相似文献
13.
周银环 《广东海洋大学学报》2008,28(1):35-39
用单因子对比实验和正交实验的方法研究了氮、磷、铁和硅对简单双眉藻生长的影响。结果表明:简单双眉藻对于硝酸钠和尿素均能很好地利用,其相对生长常数无显著差异,对柠檬酸铁和三氯化铁的利用亦无显著差异,FeC6H5O7-Fe的适宜浓度为0.1～0.5mg/L;Na2SiO3-Si的适宜浓度为0.8～1.6mg/L。正交实验表明,简单双眉藻氮、磷、铁、硅的最佳浓度(mg/L)配比为6.6∶0.66∶0.1∶0.4。 相似文献
14.
Membrane preconcentration of iron in seawater samples and on-site determination in spectrophotometry
A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe(Ⅱ)-ferrozine complex was reacted with cetyltrimethylammonium bromide (CTAB) to form a Fe(Ⅱ)-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 g/L. The detection limit of this method reached 0.19 g/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation (n = 7) was 1.9% for samples containing 10 g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student’s t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive. 相似文献
15.
A method is described for determining dimethylI sulfide (DMS) in seawater. DMS was first extractedfrom the seawater using organic reagent, then reverse-extracted by 5% HgCl2. In the laboratory DMS wasreleased by concentrated HCI and finally measured by GC-FPD. The limit of detection me O.05 ng ofS. Measurements of DMS along surface transects and on wtital profibe across the EaSt China Sca (Ers)continental sheif showed tha itS conodIations of S in the surface seawater ranged from 64-180 ng/L andthat itS vertical djstribuion was divided into 3 trpes. Model talculations of a stagnant film show a DMSflux of 10.6 umol/m_2d the air-sea inteIha. 相似文献
16.
Fe^2＋ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe^2＋ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentrations of Fe^2＋. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1-102.1μg/L, 10-100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentrations, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually. 相似文献
17.
吕庆芳 《广东海洋大学学报》2003,23(4):57-61
以粉蕉的吸芽为试材 ,进行了离体快速繁殖研究 ,结果表明 :以改良MS +BA4 .0mg/L(单位下同 ) +AD5.0 +NAA0 .1作诱导培养基 ,外植体褐变率低 ,芽的诱导率高 ,且芽的生长良好 ;以改良MS +BA3- 6 +NAA0 .1为继代培养基 ,可以获得较高的不定芽增殖率 ,在增殖过程中 ,给予一定的低温处理和变化调整BA的用量 ,可以保持较高的增殖率 (2 .6倍以上 ) ,而且芽的长势好 ;生根培养以 1/ 2MS +IBA1.0 +NAA0 .2 +AC1为宜。 相似文献
18.
Based on the layer by layer(Lb L)assembly technology,the nano-scale composite membrane with excellent structure can be prepared by changing the polyelectrolyte and controlling the deposition conditions.Polyamines and phosphate ions(Pi)can be self-organized to form supramolecular systems which could be exploited to stabilize the interfacial architecture.The LbL membrane was made of the positively charged poly(allylamine hydrochloride)(PAH)self-organized with Pi and the negatively charged poly(sodium 4-styrene sulfonate)(PSS)alternatively on top of a poly(acrylonitrile)(PAN)substrate.Compared to the membrane without Pi,the membrane assembled by PAH/Pi improved forward of flux and reduced flux of salt.The concentration of PAH and PSS,deposition time,pH and number of layers showed significant influences on the performance of the membrane.In this experiment,we systematically investigated the preparation conditions and under the optimized conditions the prepared membrane exhibited high water fluxes of 13.5 L m~(-2) h~(-1) with corresponding salt to water flux,Js/Jv,ratio of 0.07 g L~(-1) tested by forward osmosis when DI water as feed solution and 2 mol L~(-1) MgCl_2 as draw solution. 相似文献
19.
为探究宜昌长江南岸岩溶区地下水中水生动物群落分布特征及环境响应规律,在2018年7月至8月对宜昌长江南岸15处表层岩溶泉及9处岩溶大泉中水生动物进行采集,同时对地下水理化指标进行测试。共采集到809个动物个体,共有13个亚纲,同时包括多个物种的暗层和非暗层种。结果发现:①不同动物在地下水空间分布上各异,在表层岩溶泉,Copepoda的暗层种和Ostracoda的暗层种大量存在(31.3%, 23.7%),Trichoptera和Diptera少量存在(0.4%, 2.9%);在岩溶大泉,Copepoda(非暗层种)和Amphipoda大量存在(25.0%, 8.3%),Ostracoda的暗层种少量存在(2.2%)。②不同地下水的环境也表现出差异,区内岩溶大泉pH, Na+, Ca2+, Mg2+等指标的极差(分别为0.64, 1.25, 34.0, 22.1 mg/L)小于表层岩溶泉(分别为2.45, 5.68, 59.6, 33.4 mg/L),表现出更稳定的环境特征。③通过对各环境因子以及不同物种的逐步回归分析得出,表层岩溶泉的主控环境因子为pH, Na+, Mg2+,岩溶大泉的主控环境因子为pH, SO42-, Mg2+;表层岩溶泉的主要代表性生物群落为Ostracoda, Diptera, Turbellaria的暗层物种,岩溶大泉的主要代表性生物群落为Mollusca, Diptera, Decapoda。④通过路径分析发现,生物通过种间相互作用,对环境因子具有直接与间接响应。在表层岩溶泉,Diptera主要通过与Ostracoda的种间关系对Na+和Mg2+起间接响应,另外Ostracoda, Diptera, Turbellaria的暗层种对pH有直接响应;在岩溶大泉,Mollusca主要通过Diptera对pH起间接响应,Diptera通过Decapoda对SO42-起间接响应,另Mollusca, Diptera, Decapoda对Mg2+直接响应。研究发现生物分布规律是对于环境因子的直接作用和生物之间的间接作用共同响应结果。 相似文献
20.
《中国海洋湖沼学报》2021,(5)
The oxygen minimum zones(OMZs) are globally expanding,yet the variation pattern of microbial communities related to dissolved oxygen levels remain unclear.Spatial variability of bacterial diversity and community composition(repre sented by 16 S rRNA) of six stations was investigated within the water column in the seamount area of Tropical Western Pacific Ocean(TWPO) in May 2019.The seawater has dissolved oxygen(DO) concentration of 3.01-6.68 mg/L and the core of the oxygen minimum zones was located between the depths of 650 m and 1 750 m.The bacterial alpha-diversity showed unimodal pattern with the decreasing DO with depths and peaked in the upper oxycline(UO) of OMZs.The bacterial community structure of the mixed layer(ML) and the bottom layer clustered and separated from each other,while those of UO and the OMZ core(OM) clustered and overlapped.Overall,bacterial community composition transitioned from being Alphaproteobacteria and Gammaproteobacteria-dominant in ML to being Gammaproteobacteria and Nitrososphaeria/Deltaproteobacteria-dominant in UO and OM,and then changed to being Clostridia and unidentified Actinobacteria-dominant in the bottom layer.Moreover,both bacterial alpha-diversity and the abundant classes fitted varying sectioned functions with DO.The DO solely explained 40.37% of the variation of bacterial community composition among layers(P0.001).The predicted function profiling showed that the water column was predominant by chemoheterotrophy,cyanobacteria,and photoautotrophy in ML,by chemoheterotrophy and nitrate/sulfide cycling in UO and OM,and by chemoheterotrophy and ferme ntation in the bottom layer.Our findings revealed the DO-associated variation in bacterial diversity and community composition,and help to clarify the potential responses of microbes and their involved biogeochemical processes to the expansion and intensification of OMZs. 相似文献