多齿围沙蚕的亲体培育

对多齿围沙蚕(Perinereis nuntia Savigny)亲体的培养条件进行了研究.结果表明:多齿围沙蚕的适宜培养温度为16～32℃,盐度为25～32.培养时以粉末饵料为佳,16～32℃摄食活泼,摄食时间为15～20min,16℃以下摄食量减少,12℃以下基本不摄食.在19～20℃、保持潮湿条件下,可存活28 d.异沙蚕体形成与温度有关,特别是在经历了一定的低温期(2～4℃)后,再提高温度至18～25℃,可以有效地促进异沙蚕体形成.在人工养殖情况下,异沙蚕体的形成及群浮并未出现半月相型规律,成熟后只要有微弱的光照,任何时间加水覆盖水槽均可见到异沙蚕体群浮.     

人工养殖条件下多齿围沙蚕亲体培育和繁殖生物学的初步研究

通过生态学及组织学方法对人工养殖条件下多齿围沙蚕(Perinereis nuntia Savigny)亲体培育条件及繁殖生物学进行了研究.结果表明,多齿围沙蚕雌雄异体,非成熟季节外观上无法辨别雌雄,性成熟时,雌(异沙蚕体)灰绿色,雄(异沙蚕体)红白色.生殖细胞起源于体腔膜上皮,不久就释放到体腔中,在体腔内卵原细胞和精原细胞http://ebook/成都,今夜请将我遗忘/index.htm分裂增殖形成卵原细胞群和精原细胞群,体腔中充满了外形不规则或近圆形的滋养细胞,细胞内可见嗜伊红颗粒,滋养细胞之间可见发达的微血管.卵原细胞群不断增殖发育,至初级卵母细胞后游离至体腔中继续发育为次级卵母细胞和成熟卵子;精原细胞群形成精子合胞体(syncytium),各级精母细胞在合胞体内发育,直至形成成熟精子时才分散游离.水温18℃以上,多齿围沙蚕的生长体经培育才可能形成异沙蚕体.特别是在经历了一定的低温期后,再提高温度可以有效的促进异沙蚕体形成.胚胎发育的适宜温度为18～25℃;适宜盐度为25～32.胚胎发育过程经历卵裂期、囊胚期、原肠期、担轮幼虫期、后担轮幼虫期、膜内游毛幼虫期等阶段,在水温25℃、盐度30条件下,从受精至孵出3刚节幼虫约需65 h.3刚节游毛幼虫至10刚节幼体约需28 d.     

双齿围沙蚕对潮汐更替的行为响应

潮汐更替对潮间带生物的生理和行为影响显著,底内动物可以通过行为过程建立适宜的微环境适应潮间带环境变化。本实验运用行为学观测装置研究了双齿围沙蚕对潮汐更替的行为响应特征。实验设置3个温度梯度（15℃、20℃和25℃）和4个时间段（T1: 退潮前、T2: 退潮后、T3: 涨潮30 min内和T4: 涨潮30 min后）,每个处理组设6个重复。结果显示,在同一时间段内,随着温度的升高,双齿围沙蚕的径向起伏频率、径向起伏泵水速率、轴向爬行速度和头尾对调次数呈增大的趋势,头尾对调一次的时间逐渐缩短。同一温度下,双齿围沙蚕在T3时间段内的径向起伏频率、轴向爬行速度、径向起伏泵水速率、径向起伏泵水效率、轴向爬行时间和头尾对调次数均高于其他时间段,头尾对调一次的时间均有短于其他时间段的趋势;T1和T4时间段内的所有运动指标均无显著差异（p>0.05）。20℃时,双齿围沙蚕在T3时间段比T1时间段的径向起伏频率和泵水速率的增幅均高于15℃和25℃时。同一时间段内,双齿围沙蚕径向起伏时间的最大值和轴向爬行时间的最小值均出现在20℃。15℃和20℃时,双齿围沙蚕在T1和T3时间段内的轴向爬行速度均无显著差异（p>0.05）。但是在25℃时,T3时间段内双齿围沙蚕的轴向爬行速度显著高于T1时间段（p<0.05）。结果表明,双齿围沙蚕的运动强度随温度升高而增强,在水温为20℃时,其在沉积物中的运动状态较佳。退潮后双齿围沙蚕轴向爬行运动较为缓慢;刚涨潮时,双齿围沙蚕的运动强度显著增加;涨潮30 min后,双齿围沙蚕的运动逐渐恢复到与退潮前相近的状态。双齿围沙蚕可以通过一系列运动行为应对潮汐更替产生的不利条件。     

日本刺沙蚕的性信息素研究

日本刺沙蚕（Ｎｅｒｅｉｓ ｊａｐｏｎｉｃａ）广泛分布于中国沿海，是鱼、虾的优良饵料，冬末春初敏殖时离开河口向盐较高的海区移动。与多齿围沙蚕，褐片阔沙蚕等其它沙蚕不同，日本刺沙蚕在繁殖过程中不出现完全变态，但是与其它沙蚕一样，其繁殖过程也受一组性信息素控制。从雌性熟的日本刺沙蚕体腔液中提取并鉴定出一种有生物活性的挥发性物质－辛二烯－［３，５］－酮－［２］，这种化合物可以增加群浮个体在配子释放之前婚舞     

日本刺沙蚕的性信息素研究

日本刺沙蚕（Ｎｅｒｅｉｓｊａｐｏｎｉｃａ）广泛分布于中国沿海，是鱼、虾的优良饵料，冬末春初繁殖时离开河口向盐度较高的海区移动。与多齿围沙蚕，褐片阔沙蚕等其它沙蚕不同，日本刺沙蚕在繁殖过程中不出现完全变态，但是与其它沙蚕一样，其繁殖过程也受一组性信息素控制。从雌性成熟的日本刺沙蚕体腔液中提取并鉴定出一种有生物活性的挥发性物质──辛二烯－［３，５］－酮－［２］，这种化合物可以增加群浮个体在配子释放之前婚舞时的游动速度．但不诱导配子释放。在许多沙蚕中有着性信息素作用的５－甲基－３－庚酮，在日本刺沙蚕体腔液中没有发现，也没有性信息素作用。     

双齿围沙蚕对温度、盐度和干露的耐受性研究

本论文主要研究双齿围沙蚕(Perinereis aibuhitensis)对盐度突变、温度突变和盐度渐变、温度渐变及干露的耐受性。实验结果表明:双齿围沙蚕耐受盐度的范围比较广泛,为5~45,适宜的盐度范围为20~30,求得双齿围沙蚕96 h半致死盐度上限为33.1。适宜温度范围为20~30℃,对低温有很强的耐受力。双齿围沙蚕在低温保湿干露10 d未发生死亡,大量死亡集中在13~14 d。本研究结果表明:双齿围沙蚕对环境的适应性较强,耐温、耐盐范围较广,且具有很强的耐干露能力。     

沙蚕科性信息素的种间作用

本文对海洋多毛类沙蚕科4属7种沙蚕:褐片阔沙蚕(Platynereis dumerilii)、双管阔沙蚕(P.bicanaliculata)、日本刺沙蚕(Neanthes japonica)、琥珀刺沙蚕(N.succinea)、多齿围沙蚕(Perinereis nuntia)、绿沙蚕(Nereis virens)和涂沙蚕(N.fucata)性信息素的种间作用进行了电生理和行为反应的研究.结果表明,同属的双管阔沙蚕和褐片阔沙蚕及日本刺沙蚕和琥珀刺沙蚕的异沙蚕体的体腔液可以互相诱导异性的异沙蚕体发生婚舞(naptial dance)和释放配子;雌性或雄性的多齿围沙蚕、雄性的绿沙蚕和涂沙蚕的异沙蚕体体腔液分别可以诱导异性褐片阔沙蚕异沙蚕体发生婚舞并释放配子;但雌性或雄性褐片阔沙蚕、雄性的日本利沙蚕、琥珀刺沙蚕和涂沙蚕的异沙蚕体的体腔液却不能诱导异性多齿围沙的异沙蚕体发生婚舞或释放配子.不过,雌性褐片阔沙蚕异沙蚕体的体腔液能引起雄性多齿围沙蚕异沙蚕体脑电活性的增强.     

腺带刺沙蚕的早期发育

１９８３年７—１２月于室内进行了腺带刺沙蚕Ｎｅａｎｔｈｅｓｇｌａｎｄｉｃｉｎｃｔａ人工授精、孵化及幼体培养观察．该种沙蚕在性成熟时没有异沙蚕型出现。水温在１３．０—２９．３℃范围内，沙蚕均能完成胚胎发育和幼体发育。担轮幼虫期在膜内渡过，五刚节疣足幼虫开始摄食，七剧节疣足幼虫开始钻砂，沙蚕幼虫体节在２０节之前体节与体长呈明显的直线正相关。     

沙蚕的营养分析与功能研究

对2种双齿围沙蚕和国产鱼粉进行了营养组成分析。结果表明,2种双齿围沙蚕在营养构成上差别不大,只是在脂肪和灰分以及钙、铁上有差别;与国产鱼粉相比,在所测定的各种营养指标上,2种双齿围沙蚕的营养性超过国产鱼粉：其中呈味氨基酸超过高达5％左右,各种微量元素也相差较大。沙蚕的营养性、诱食性以及适口性均超过国产鱼粉。     

双齿围沙蚕的营养成分与食用安全

本文对福建近海天然与养殖的双齿围沙蚕(Perinereis aibuhitensis)进行基本成分、氨基酸、脂肪酸、矿物元素以及沙蚕毒素进行测定.结果表明,不论是天然或是养殖的,双齿围沙蚕均富含粗蛋白质(60%,干基)和氨基酸(TAA∶54.27%~56.80%);必需氨基酸(EAA/TAA约37%,EAA/NEAA≥0.58)基本符合联合国粮农组织(FAO)、世界卫生组织(WHO)推荐的理想蛋白模式;呈味氨基酸所占的比例(FAA/TAA约45%)也较高.其油脂含量为9.9%~12.5%,且脂肪酸中富含n-3 PUFAs.双齿围沙蚕体所含的必需矿物元素种类齐全,Fe、Zn、I、Se等含量丰富;而有毒元素(Pb、Hg、Cd、总As与无机砷)的含量却较其它海洋水产动物低.沙蚕毒素的分析结果表明,新鲜的双齿围沙蚕均含有沙蚕毒素(1.68~2.42 mg/kg),而经80℃以上烘干或煮熟后的NTX为未检出.因此,不论是天然的还是养殖的双齿围沙蚕均属于高蛋白质,且富含n-3 PUFAs和微量必需.     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

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.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

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。     

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.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

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.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

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.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.