大珠母贝群体大小、体重组成变化的初步观察

大珠母贝Pinctada maxima(Jameson)是一种栖息于热带海区的大型双壳类,是南海特有的珍贵的珍珠贝类。它的个体大,大者壳长达32厘米以上,体重达4—5公斤。它产的大型优质珍珠价值昂贵;贝壳珍珠粉是贵重药材;贝壳是精美工艺品的原料。海南岛沿岸有比较丰富的大珠母贝资源,但由于近几年来乱采滥捕大珠母贝的现象越来越严重,大珠母贝资源受到严重破坏。     

大珠母贝Pinctada maxima(Jameson)亲贝人工促熟培育与诱导排放精卵的研究

用亚心形扁藻Platymonassubcoriformis,湛江等鞭藻Isochrysiszhanjiangensis及某些配合饲料培育大珠母贝pinctadamaxima(Jameson)亲贝,可以促进性腺发育成熟并保持易于诱导排放状态。在需要进行人工育苗时,给亲贝以一定的刺激,即可诱导产卵排精。采用这种方法进行大珠母贝人工育苗,受精率和活率都比剖贝取卵授精的方法高。而且不用杀死大珠母贝亲贝。     

大珠母贝游离有核养殖珍珠研究取得重要成果并通过鉴定

利用大珠母贝(Pinctada maxima J.)培育大型珍珠,是当今国内外研究的重要课题之一。 中国科学院南海海洋研究所和海南行政区水产研究所经过八年的协力合作,在大珠母贝的生物学、游离有核养殖珍珠、人工苗培育、病虫害防治以及新型珠核等几方面都取得重要阶段成果。如在游离有核养殖珍珠的试验研究中,由于解决了插核前期处理和     

合浦珠母贝、长耳珠母贝和大珠母贝种间人工杂交的研究——Ⅰ.人工杂交和杂交后代的观察

合浦珠母贝Pinctada fucata、长耳珠母贝 P.chemnitzi、大珠母贝 P.maxima都是海产珍珠养殖的种类,它们在形态、生理生态及分布等方面都存在较大的差异。为了改良合浦珠母贝育珠性状,提高贝体的生活力,我们从1976年开始进行了上述三种珠母贝的种间杂交试验研究,并获得几种杂交组合的后代。     

合浦珠母贝、长耳珠母贝和大珠母贝种间人工杂交的研究——Ⅲ.同工酶谱的比较研究

为了进一步从分子水平验证前文所述的形态学和细胞学的观察结果,并了解杂交后代基因表达的调控机理,我们进行了同工酶谱的比较研究。 一、材料和方法 1.实验材料 合浦珠母贝、长耳珠母贝和大珠母贝是野生贝。大珠母贝采自海南岛西部海域,其他二种采自广西合浦海区。杂交贝(图1:2,4,6)是1976—1980年间在徐闻珍珠场用人工杂交授精方法育成。活贝运回实验室后,置-30℃低温冰箱内贮存备用。     

大珠母贝外套膜基因PMMG1的克隆、表达及其特征分析

EF-hand结构域在真核生物细胞内钙离子吸收和运输中发挥重要作用,在贝类中可能参与贝壳和珍珠质的形成。根据已报道的贝类中具有EF-hand结构域的碱基序列设计简并引物,从大珠母贝外套膜cDNA文库中筛选得到PMMG1基因(大珠母贝外套膜基因1)。PMMG1基因全长618 bp,开放读码框编码140个氨基酸,N-端的22个氨基酸肽段为信号肽。PMMG1氨基酸序列与合浦珠母贝PFMG1的一致性为56%,预测有两个EF-hand结构域。选取编码PMMG1成熟蛋白的cDNA序列插入pET-32a质粒构建表达载体,通过IPTG诱导,Ni2+-NTA亲和层析柱纯化,成功获得预期大小的融合蛋白。凝胶电泳迁移率的变化证明PMMG1蛋白具有结合Ca2+/Mg2+的活性,组织特异性表达表明PMMG1基因在外套膜的表达量远高于其他组织。大珠母贝外套膜基因PMMG1的克隆与表达研究为进一步研究该蛋白在珍珠质矿化中的作用、探讨珍珠质形成的分子生物学机制奠定了一定基础。     

海南岛大珠母贝遗传多样性分析

利用RAPD技术首次对中国海南岛环岛的大珠母贝（Pinctada maxima Jameson）遗传多性进行分析。从20条10bp引物中选取7条引物用于群体遗传多样性分析，共检测出22个位点，其中11个位点（占50％）显多态性，Shannon多样性值为0．117。用非加权配对算数平均法（UPGMA）聚类分析的结果：12个体间遗传相似系数最大为1．000，最小为0．706，平均遗传相似系数为0．8438。表明海南岛大珠母贝群体间遗传多样性不一，遗传分化较大，因此很有必要对遗传多样性水平较高的种群，划定保护范围加以重点保护，以扩大和恢复大珠母贝的种质资源。     

广东大亚湾合浦珠母贝生长速度的观察

能产生名贵珍珠的合浦珠母贝Pinctada martensi(Dunker)是一种栖息在近岸内湾的暖水性双壳类,是国内外珍珠养殖的主要母贝。 珍珠养殖包括母贝养成和植核育珠两大部分。从母贝育种至养成可供植核的大贝,不论从珍珠养殖的生物学考虑还是从企业的经济效     

热带海洋珍珠贝类立克次体(RLO)病研究 Ⅷ.养殖大珠母贝贝苗养成期群体RLO病流行病学研究

大珠母贝人工养殖过程中,幼贝死亡是一个严重的问题。1993年11月至1995年5月,采用现场调查、实验室研究和数理分析相结合的方法,在海南省临高县新盈珍珠贝养殖场自然海区吊养的A,B,C3批养殖贝和陵水新村珍珠贝养殖场养殖池吊养的D批养殖贝的发病和死亡情况进行了流行病学凋查.结果显示,大珠母贝幼贝群体的死亡是以暴发性方式发生,幼贝群体的大批量死亡高峰一般发生在4～6月龄期,8个月以后随着龄期的延长,死亡率显著降低.幼贝群体死亡率与贝体平均体长的关系是4cm以下的贝体死亡率较高,1～3cm阶段处于死亡高峰期内,5cm以上的贝体死亡率显著降低.大珠母贝幼贝群体的死亡率与类立克次体感染(即RLO平均感染严重度指数SI)之间存在显著的相关性,在RLO感染的高峰之后或当中部相应伴随贝群体死亡率的高峰,随着RLO感染的降低,贝群体的死亡率也明显降低。在4批养殖贝群体中,仅在A批养殖贝群体样本中发现有少量纤毛虫寄生(感染率为87.5%,感染强度为3.56个/10倍物镜).这几批幼贝群体的死亡与海水温度、盐度之间均无相关性。     

大珠母贝Pinctada maxima（Jameson）亲贝人工促熟培养与诱导排放精？…

用亚心形扁藻Ｐｌａｔｙｍｏｎａｓ ｓｕｂｃｏｒｄｉｆｏｒｍｉｓ,湛江等鞭藻Ｉｓｏｃｈｒｙｓｉｓ ｚｈａｎｊｉａｎｇｅｎｓｉｓ及某些配合饲料培育大珠母贝ｐｉｎｃｔａｄａ ｍａｘｉｍａ（Ｊａｍｅｓｏｎ）亲贝,可以促进性尕发育成熟并保持易于诱导排放状态。在需要进行人工育苗时,给亲贝以一定的刺激,即可诱导产卵精。彩这种方法进行大珠母贝人工育苗,受精率和成活率都比剖贝取卵授精的方法高。而且不用杀死大珠母贝亲     

A hybrid efficient method to downscale wave climate to coastal areas

Long-term time series of sea state parameters are required in different coastal engineering applications. In order to obtain wave data at shallow water and due to the scarcity of instrumental data, ocean wave reanalysis databases ought to be downscaled to increase the spatial resolution and simulate the wave transformation process. In this paper, a hybrid downscaling methodology to transfer wave climate to coastal areas has been developed combining a numerical wave model (dynamical downscaling) with mathematical tools (statistical downscaling). A maximum dissimilarity selection algorithm (MDA) is applied in order to obtain a representative subset of sea states in deep water areas. The reduced number of selected cases spans the marine climate variability, guaranteeing that all possible sea states are represented and capturing even the extreme events. These sea states are propagated using a state-of-the-art wave propagation model. The time series of the propagated sea state parameters at a particular location are reconstructed using a non-linear interpolation technique based on radial basis functions (RBFs), providing excellent results in a high dimensional space with scattered data as occurs in the cases selected with MDA. The numerical validation of the results confirms the ability of the developed methodology to reconstruct sea state time series in shallow water at a particular location and to estimate different spatial wave climate parameters with a considerable reduction in the computational effort.     

致读者

今天与尊谋面的《海洋科学》已非昨日那个二十年如一日的双月刊,而是崭新的月刊了。这在国内海洋科技期刊,尤其是排名在500家“中国自然科学核心期刊”里的海洋期刊中,恐怕暂时也算鲜见。促动我们下决心实施这一举措的,固然是历史潮流的涌动,是为了祖国海洋科研创新事业的进步所致,但大部分原因还在于自身生长的需要,遵循适正道者而生存的自然法则吧。这是实话实说,为了勿需再向读者诸君做更多的表白,以求能博得看者多多少少的理解和支持。不管是少部分的原因还是大部分的缘由,我们最终的目的是要把刊物办好,而不是将这个月刊办…     

Array technology as a tool to monitor exposure of fish to xenoestrogens

A variety of anthropogenic chemicals are capable of binding to the estrogen receptor of vertebrate species. Binding of these compounds can interfere with homeostasis by disrupting normal gene expression patterns. The purpose of this study was to investigate the feasibility of applying array technology as a monitoring tool for detecting the presence and distribution of estrogenic compounds in coastal habitats using sheepshead minnows as our model. cDNA clones that were isolated from differential display, including vitellogenin alpha and beta, vitelline envelope protein (ZP2), and transferrin, among others, were spotted on the macroarray. The results of these experiments demonstrate a characteristic expression pattern of estrogen responsive genes in sheepshead minnows exposed to 17 beta-estradiol (E2).     

Granting quasi-property rights to aquaculturists to achieve sustainable aquaculture in China

The quality of the aquaculturists’ rights over their farms plays a vital role in achieving sustainable aquaculture industry. In effect, ownership over natural resources in the light of private law is not established because it is not tradable in China. But the users’ rights over the natural resources have already been recognized under the current Chinese laws. This paper introduces concept of property rights, describes and analyzes the aquaculturists’ rights over the farms under the current Chinese laws. Because of flow of water, agricultural nature, and so-called State ownership over the natural resources, fish farms present a complicated property rights problem in China. Some flaws in the aquaculturists’ rights are identified under the existing laws. To protect the interests of farmers and to pursue sustainable aquaculture, quasi-property rights should be granted to fish farmers.     

Ionospheric response to Kuril undersea earthquakes according to GPS satellite data

The effects that the two Kuril undersea earthquakes of November 15, 2006, and January 13, 2007, had on the ionosphere are considered on the basis of the results of measurements of variations in the ionosphere’s total electron content obtained from the network of Russian GPS stations. Owing to a favorable location of the stations, the ionosphere’s response to these earthquakes is studied in the vicinity of and far (up to distances on the order of 1000 km) from their epicenters. It is found that the apparent velocity of propagation of ionospheric disturbances (1–3 km/s) significantly exceeds the velocity of propagation of tsunami waves caused by earthquakes; this fact can be used in forecasting tsunamis. It is shown that, in parallel with the known type of ionospheric response to earthquakes in the form of an N-wave, there is also its response in the form of an inverted N-wave in the vicinity of and far from their epicenters. The causes of occurrence of the response in the form of an inverted N-wave are interpreted.     

Artificial neural network to translate offshore satellite wave data to coastal locations

Owing to the spatial averaging involved in satellite sensing, use of observations so collected is often restricted to offshore regions. This paper discusses a technique to obtain significant wave heights at a specified coastal site from their values gathered by a satellite at deeper offshore locations. The technique is based on the approach of Artificial Neural Network (ANN) of Radial Basis Function (RBF) and Feed-forward Back-propagation (FFBP) type. The satellite-sensed data of significant wave height; average wave period and the wind speed were given as input to the network in order to obtain significant wave heights at a coastal site situated along the west coast of India. Qualitative as well as quantitative comparison of the network output with target observations showed usefulness of the selected networks in such an application vis-à-vis simpler techniques like statistical regression. The basic FFBP network predicted the higher waves more correctly although such a network was less attractive from the point of overall accuracy. Unlike satellite observations collection of buoy data is costly and hence, it is generally resorted to fewer locations and for a smaller period of time. As shown in this study the network can be trained with samples of buoy data and can be further used for routine wave forecasting at coastal locations based on more permanent flow of satellite observations.     

Tolerance and hormesis--increased resistance to copper in hydroids linked to hormesis

Cultured clones of the colonial hydroid Laomedeaflexuosa have been used over some years as an experimental model to study the dynamics of growth control [J. Mar. Biol. Ass. UK (1981a) 61, 35; Aquatic Toxicology (1981b) 1, 227; Journal of Applied Toxicology (2000a) 20, 93]. Exposure to toxic agents has been an essential element of the approach, providing the stimulus to elicit adaptive control system responses. While the work has provided interpretations of physiological interest, it has also given insights to some toxicological phenomena. It is proposed that hormesis, as a stimulation of growth due to exposure to low concentrations of copper (1-10 microg l(-1)), is due to increases in the preferred rate of the growth control mechanism. This increases the capacity to counteract inhibition and confers intolerance to the inhibitor, while overcorrections to low concentrations cause hormesis.     

从ODP到IODP

大洋钻探计划（ODP）结束以后实施的整合大洋钻探计划（IODP）与以往钻探计划不同的是将以多个钻探平台为主，其航次将进入过去ODP无法进入的地区，将在古环境、海底资源（包括气体水合物）、地震机制、大洋岩石圈、海平面变化、深部生物圈等研究方面有所突破。从ODP到IODP有一过渡机构－ISAS，于2001年6月开始运作，到IODP开始实施时结束使命。ISAS将负责航次建议书的接受与评估、确保ODP与IODP的平稳过渡及负责与IODP有关的公共活动等工作。     

Letters to the editor

A preliminary scuba survey of oligotrophic Lake Rotoma in 1972 revealed a vegetation mainly composed of native hydrophytes in which exotics were at an early stage of colonisation. In 1973 the presence of species was recorded in 5708 quadrats (625 cm²) at 1 m intervals along a total of 50 line transects placed systematically around the lake. Water depth was measured, and quadrat cover and substrate type were subjectively estimated. Species frequency calculations showed that the dominant vegetation pattern was a characean meadow of Chara fibrosa f. acanthopitys (A.Br.) R.D.W., Nitella leptostachys var. leonhardii (R.D.W.) R.D.W., and N. pseudoflabellata var. mucosa (Nordst.) Bailey. The charophytes extended over a depth range of 1–17.5 m on a wide variety of substrates and gradients. Native vascular plants were absent from many transects, and had a depth range only from 0 to 4.5 m, with most occurring above 3.5 m. The Low Mixed Community, found in shallow water less than 1.25 m in depth at the northeast end of the lake, provided this area with a high species diversity. Exotic hydrophytes had established in many areas around the lake. The distribution of Lagarosiphon major (Ridley) Moss and Elodea canadensis Michx. appeared to coincide with boating access and fallen submerged trees over a depth range of 0–6.0 m, although much of the available habitat had not yet been exploited. Emergent species were most abundant within the southwest inlet and also in the lagoons surrounding the lake where sheltered conditions and shallow gradients prevail.