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1.
为提高对虾养殖过程中的饵料利用率并减少养殖废水的排放,作者以凡纳滨对虾(Litopenaeus vannamei)为实验对象,研究了不同饵料种类、投喂方式、体质量、充气量、光照强度、水温及盐度对其相对摄食量的影响。结果表明:配合饲料组对虾的相对摄食量显著高于冰鲜虾肉组;连续单颗投喂时对虾的相对摄食量较高;相对摄食量随对对虾体重升高而显著(P0.01)下降,而且不同规格的对虾在竞争条件下平均相对摄食量会降低;充气量6 L/min组对虾的相对摄食量明显高于另外两组;弱光环境下对虾的相对摄食量较高;水温和盐度对相对摄食量的影响极显著(P0.01),在32℃时对虾获得最大相对摄食量,在盐度为5时相对摄食量最小,高盐度下组间差异不显著(P0.05)。因此,在实际生产中应采取少量多次的投饵策略,并根据环境条件的变化合理的调整投饵量。 相似文献
2.
实验生态条件下研究十溴联苯醚(BDE-209)的急性毒性胁迫对褶皱臂尾轮虫(Branchionus plicatilis)运动行为与摄食行为的影响,探讨可用以表征胁迫-响应的生物标志物。结果表明:(1)BDE-209胁迫24h显著性增加了褶皱臂尾轮虫的运动抑制率,由此得到24h半数有效抑制浓度(24h-EC_(50))为9.084mg/L,但未达到半数致死作用;(2)当分别以四种海洋微藻:小球藻(Chlorella vulgaris)、青岛大扁藻(Platymonas helgolandica)、等鞭金藻8701(Isochrysis galbana)和小新月菱形藻(Cylindrotheca closterium)为单一饵料来源时,褶皱臂尾轮虫对四种饵料单胞藻的滤水率(F)和摄食率(G)均随着胁迫时间和胁迫浓度的增加而不断下降,呈现出明显的浓度依赖性,说明BDE-209胁迫能显著抑制褶皱臂尾轮虫的摄食作用。(3)将其中三种微藻等生物量混合投喂时,褶皱臂尾轮虫对三种微藻的滤水率和摄食率与单一饵料投喂条件相比均发生变化,且对各种微藻的选食率(Sr)和摄食总生物量均随着胁迫时间和浓度的增加呈下降趋势,选择性指数(Si)发生变化,对小球藻的摄食选择性最高。滤水率的变化较其它指标更敏感,可用以指示浮游动物在个体水平上响应外源环境变化的标志物。结果表明,BDE-209胁迫能有效改变褶皱臂尾轮虫的摄食与选食行为,且其最适宜的饵料是小球藻。 相似文献
3.
三角褐指藻和亚心形扁藻对太平洋纺锤水蚤繁殖与生化指标的影响 总被引：1，自引：0，他引：1
采用实验生态的方法,探讨三角褐指藻(Phaeodactylum tricornutum)、亚心形扁藻(Platymonassubcordiformis)对太平洋纺锤水蚤(Acartia pacifica)繁殖及其生化指标的影响.实验结果表明,三角褐指藻对太平洋纺锤水蚤产卵量和卵的孵化率均具有抑制作用,随着投喂时间的增加,太平洋纺锤水蚤的产卵量由15.02±3.15 ind/d下降到3.25±3.15 ind/d(p<0.05),其卵的孵化率由22.88%±2.49%下降到14.84%±1.20%(p<0.05).而投喂亚心形扁藻的太平洋纺锤水蚤其产卵量和卵的孵化率与对照组无显著差异(p>0.05).投喂三角褐指藻后,太平洋纺锤水蚤的超氧化物歧化酶(SOD)活力相对于投喂亚心形扁藻的增加了20.94±0.04μg/mg,其谷胱甘肽过氧化物酶(GPX)活力增加了15.812±1.240 U/mg.这表明相对于亚心形扁藻,三角褐指藻对太平洋纺锤水蚤的抗氧化性酶具有诱导作用. 相似文献
4.
奥利亚罗非鱼饥饿后补偿生长对血液理化指标的影响 总被引：2，自引：0，他引：2
设计了3种不同的奥利亚罗非鱼摄食类型:A组(鲜活饵料组)、B组(饥饿3周后饱食投喂组)和C组(人工饲料组),研究了奥利亚罗非鱼在不同的摄食类型下血液生理生化指标变化的情况,并试图解释补偿生长时快速生长的机理。实验结果表明,B组补偿生长期间(后2周)的增重率和特定生长率显著高于C组的(P<0.05),高于A组的;B组第4周时血清总蛋白、碱性磷酸酶、钙离子、胆固醇、甘油三脂、血红细胞、血红蛋白与第3周的相比显著上升(P<0.05),且上述指标除碱性磷酸酶外,均高于同时期A组和C组的,因此认为,上述指标的升高促进了细胞的合成代谢,从而实现了补偿生长时的快速生长。 相似文献
5.
研究了不同饵料种类(小沙丁鱼肉-NSF,鳗鱼配合饲料-CEFF,海水鱼配合饲料-CMFF)和摄食水平(从饥饿至饱食)对军曹鱼 Rachycentron canadum 幼鱼(平均初始体重约28g)生长和氮收支的影响,并建立了不同饵料种类时的生长-摄食关系和氮排泄-摄食关系.结果表明,投喂3种不同饵料的军曹鱼幼鱼湿重、干重和氮特定生长率均随摄食水平的增加呈显著增长趋势,其中,投喂NSF和CEFF组的特定生长率与摄食水平之间表现为减速增长曲线,投喂CMFF组的表现为直线;饱食时,投喂NSF和CEFF组的特定生长率接近而明显高于投喂CMFF组.投喂NSF和CEFF组的食物转化效率随摄食水平的增加而增长或呈先增长后下降的趋势,在饱食或次饱食(约为饱食量的70%)摄食水平组有最大值,而投喂CMFF组的食物转化效率随摄食水平的增加而持续增长,在饱食摄食水平时有最大值;除食物湿重转化效率外,投喂NSF组的食物转化效率最高,其次为投喂CEFF组,而两者均明显高于投喂CMFF组.3个饵料组的军曹鱼幼鱼摄食氮、排粪氮、生长氮和排泄氮均随摄食水平的增加呈显著增长趋势;投喂NSF和CEFF组的摄食氮、生长氮和排泄氮明显高于投喂CMFF组,而投喂CMFF组的排粪氮最高,其次为投喂CEFF组,且两者明显高于投喂NSF组.军曹鱼幼鱼投喂NSF、CEFF和CMFF时饱食和次饱食摄食水平的氮收支方程分别为:100CN=1.1(0.9)FN+27.0(29.3)GN+71.9(69.8)UN、100CN=5.2(4.3)FN+27.0(28.7)GN+67.8(67.0)UN和100CN=9.9(8.4)FN+21.6(10.1)GN+68.5(81.5)UN(氮收支方程括号中的为次饱食数据);3个饵料组军曹鱼幼鱼饱时和次饱食时摄食氮中用于排粪的比例较小且变化不大,投喂NSF和CEFF组次饱食时摄食氮中用于生长的比例较饱食时略大而用于排泄的比例较饱食时略小,但投喂CMFF组饱食时摄食氮中用于生长的比例明显高于而用于排泄的比例明显低于次饱食摄食水平时.因此,军曹鱼幼鱼的氮排泄和氮收支方程受摄食水平和饵料种类双重因素的影响,但不管投喂何种饵料,摄食氮增大是导致鱼类氮排泄增加的主要原因.综合考虑生长、食物转化效率、氮排泄和氮收支方程各因素,军曹鱼由幼鱼优先选择投喂的饵料为NSF,其次为CEFF,在本实验的生长阶段,两者的适宜投喂水平以占饱食量的70%-100%为佳. 相似文献
6.
采用生理生态学方法,研究了中华原钩虾(Eogammaruspossjeticus)对黄海绿潮原因种浒苔(Ulva prolifera)及海水池塘4种优势大型海藻,即肠浒苔(Ulva intestinalis)、扁浒苔(Ulva compressa)、线形硬毛藻(Chaetomorphalinum)和丝毛藻(Cloniophorasp.)的摄食率,比较了对浒苔与其他不同类型饵料(包括人工饵料)的摄食,开展了不同密度的中华原钩虾对浒苔的现场摄食研究。结果显示,中华原钩虾的摄食率、饵料吸收率与海藻的含水量成呈正相关,表明该端足类存在明显的补偿性摄食行为。对不同类型饵料的摄食结果显示,中华原钩虾除了摄食海藻,对豆粕、虾饲料等人工饵料也具有较高的饵料吸收率,表明其可人工投喂培育。中华原钩虾具有一定摄食节律,夜晚摄食量高于白昼,表明夜晚投喂有利于中华原钩虾摄食,可减少饵料污染,有利于清洁生产。现场摄食实验结果显示,中华原钩虾摄食量随养殖密度的增加而增加,但其摄食率和存活率与养殖密度呈负相关,表明高密度时中华原钩虾竞争摄食增加了饵料消耗,同时中华原钩虾为抵抗养殖密度过高造成的竞争而增加能量等消耗。 相似文献
7.
2013年4月29日至2013年11月21日全部采用人工配合饲料对松江鲈鱼仔、幼鱼进行了投喂研究,在水温18.2~22.6℃的室内循环水中,松江鲈鱼通过升索S1~S8苗种料投喂,体重由平均0.084g/尾增至23.55g/尾,体长由平均1.95cm增至12.45cm;最大个体体长14cm,体质量33.5g;最小体长8cm,体质量14.5g。研究表明:仔鱼开口摄食外源性营养时,应以投喂卤虫幼虫为主,逐步减少卤虫幼虫,增加S1人工饲料,直至养到2cm左右,全部采用人工配合饲料喂养松江鲈鱼达到成熟规格完全可行,其平均日增长量0.115g/尾,饲料系数平均为1.1,总特定生长率(SGR)为2.76%d~(-1)。期间定时测定养殖水体的温度、pH、盐度、DO、COD、氨氮、亚硝酸盐、硝酸盐等水质指标均在正常范围内。实验还表明,在盐度范围20.3~27.1的条件下松江鲈鱼可以养至成熟规格。 相似文献
8.
饲料中高水平铜对斜带石斑鱼(Epinephelus coioides)生长和铜、铁、锰、锌含量的影响 总被引：1，自引：0，他引：1
采用铜适量(4.47mg/kg)和铜过量(1127.51mg/kg)的两种饲料投喂初始体重为(12.9±0.2)g的斜带石斑鱼(Epinephelus coioides)8周,研究饲料中过量铜对斜带石斑鱼生长性能、形态学指标、体组成和鱼体微量元素含量的影响。结果表明,当饲料铜含量由4.47mg/kg升高到1127.51mg/kg时,斜带石斑鱼增重率由228%下降到63%,饲料效率由1.12下降到0.51,肠脂比由2.90%下降到1.69%。全鱼和肝脏中的铜含量均随饲料铜水平的增加而显著增加,斜带石斑鱼全鱼铜含量由2.98mg/kg上升到34.98mg/kg,肝脏铜含量由36.6mg/kg上升到1364.0mg/kg。但饲料中过量铜对斜带石斑鱼的存活率、鱼体肥满度、脏体比、肝体比和全鱼体组成没有显著性影响。摄食高铜饲料的斜带石斑鱼肝脏锌含量显著升高,锌可能在铜的解毒过程中起着重要的作用。 相似文献
9.
为研究饲料中添加β-胡萝卜素对中华绒螯蟹成体雌蟹育肥效果的影响,分别在饲料中添加不同浓度的人工合成β-胡萝卜素,配制五组实验饲料(β-胡萝卜素测定含量分别为3.3、56.7、108.9、207.9和320.0 mg/kg)投喂生殖蜕壳后雌蟹,评价了饲料中添加β-胡萝卜素对增重率(WGR)、性腺指数(GSI)、肝胰腺指数(HSI)、常规生化组成、抗氧化和免疫指标、色泽参数和类胡萝卜素含量的影响。结果显示:(1)饲料中添加人工合成β-胡萝卜素对雌蟹育肥期间的WGR、GSI和HSI均无显著影响,但饲料中添加β-胡萝卜素显著增加了中华绒螯蟹肝胰腺中总脂含量;(2)就抗氧化和免疫指标而言,肝胰腺和血淋巴中SOD、T-AOC、GSH-Px、AKP和ACP免疫相关酶活均随着饲料中β-胡萝卜素添加量的增加呈“先增加后降低”的变化趋势,饲料中β-胡萝卜素含量为100～200 mg/kg时,组织中抗氧化和免疫相关酶活最高;(3)卵巢、肝胰腺和蟹壳中虾青素和β-胡萝卜素含量均随着饲料中β-胡萝卜素添加量的增加而显著增加,但饲料中添加β-胡萝卜素仅显著增加了卵巢和肝胰腺红度值(a*)。综上,饲料中添加人工合成... 相似文献
10.
投饵水平对凡纳对虾生长、饲料利用和虾体主要成分的影响 总被引：3，自引：0，他引：3
为测定投饵水平对凡纳对虾生长、饲料利用和虾体组成的影响进行了为期一个月的生长实验。实验虾平均体重为0．09g左右,投喂含蛋白质42．15％、能量为18．9kJ/g的饲料,日投饲量分别为虾体重量的4％,6％,7%,8％,10％。结果表明,随着投饵水平的增加,增重率、特定生长率显著提高,而饲料系数、表观消化率和蛋白质效率却显著下降。对对虾虾体组成的分析表明,投饵水平对对虾虾体灰分、脂肪含量的影响显著。根据对虾生长及饲料利用的指标,凡纳对虾幼虾的适宜投饵水平为9．87％。 相似文献
11.
Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
12.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
13.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
14.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
15.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
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Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献
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The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
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Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献