中国对虾受精生物学的研究

于１９８８－１９９１年在青岛对中国对虾进行受精能力和受精生物学的研究。对虾采用加温和不加温培育，然后用人工授精法－－水域法和滴管法授精研究精卵受精能力；应用扫描和透射电以及石蜡切片技术，精卵的形态结构和受精过程的变化。结果表明，水域法授精，精子入水后３ｈ仍具有受精能力；卵子入水后１ｍｉｎ之内受精率最高只达６２．７％。而滴客法授精，受精率最高可达到９８％。平均值也在６０－８０％之间。保持在低温的亲虾     

宽壳全海笋受精和早期胚胎发育过程的细胞学观察

用普通光镜和石蜡切片技术,系统观察了宽壳全海笋卵子在受精和早期胚胎发育过程中的外形和核相变化。结果发现,宽壳全海笋成熟未受精卵呈梨形或卵圆形,核相处于第一次成熟分裂前期,有明显的生发泡和核仁;精子为鞭毛型,全长(44.042±1.166)μm,头部呈椭圆形,前端的顶体略呈钝锥状;在水温24℃条件下,精、卵混合后,精子迅速附着于卵子表面,启动卵子发育;受精后6~9 min,生发泡逐渐萎缩、破裂,随后精子进入卵内并轻微膨胀;受精后20,30 min,受精卵先后排出第一、第二极体,完成第一次和第二次成熟分裂;成熟分裂结束后,精、卵核体积迅速膨胀,核膜重新出现,形成弥散状的雌、雄原核,雄原核形成略早于雌原核;受精后40 min左右,雌、雄原核在卵子中央以原核联合的方式结合,随后联合核的染色体共同排列在纺锤体的赤道板上,形成第一次有丝分裂的中期分裂相;随着有丝分裂的进行,染色体被纺锤丝拉向两极,结果在受精后约50 min形成2个大小不等的卵裂球,第一次卵裂结束;第二次卵裂过程与第一次卵裂基本相同,只是卵裂方向与第一次卵裂基本垂直,在受精后65~70 min,第二次卵裂完成,形成1大3小4个卵裂球。另外,实验中发现了少量的多精入卵和多极分离现象。     

宽壳全海笋受精及早期卵裂的细胞学研究

采用HOECHST 33258染色荧光显微方法,对宽壳全海笋 Barnea dilatata(Souleyet)受精卵早期发育中的生发泡破裂、极体排放、两性原核联合、早期卵裂、多精入卵等细胞学事件进行了研究.结果显示,宽壳全海笋成熟未受精卵呈梨形或卵圆形,处于第一次成熟分裂前期,生发泡尚存;在水温26℃±1℃条件下进行受精.受精后6～9 min,生发泡逐渐萎缩、破裂;受精后18、25 min,受精卵先后排出第一、第二极体,完成第一次和第二次成熟分裂;受精后35 min,雌、雄原核在卵子中央发生染色体联合;随后,联合核的染色体共同排列在纺锤体的赤道板上,形成第一次有丝分裂的中期分裂相;受精后45 min,形成2个大小不等的卵裂球,完成第一次卵裂;第二次卵裂过程与第一次卵裂基本相同,只是卵裂方向与第一次卵裂基本垂直,在受精后60～65 min,第二次卵裂完成,形成1大3小4个卵裂球.另外,实验中发现了明显的第一极体分裂现象争极少量的多精入卵现象.     

Diel Vertical Migration of the Marine Cladoceran Podon Leuckarti: Variations with Reproductive Stage

Diel vertical migration (DVM) of the marine cladoceran Podon leuckarti was investigated with reference to their reproductive stages and size. Males and females, except for gamogenic females with an advanced resting egg (GA), aggregated at the near-bottom layer or at the surface during the day and dispersed into the water column at night. Both the near-bottom aggregation and the surface aggregation during daytime are suggested to be behavior that reduces the predation risk from visual predators. However, GA aggregated in the near-bottom layer during daytime and avoided the surface layer. The near-bottom aggregation might be more effective behavior for GAs to reduce risk of visual predation than the surface aggregation because of the conspicuous resting egg they carried. These results show that carrying an advanced resting egg influenced the DVM of P. leuckarti.     

贻贝(Mytilus edulis)发育早期酸性和碱性磷酸酶活性

采用组织化学和分光光度技术对贻贝卵、胚胎和早期幼虫酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活性进行了定位和定量研究,以探讨贝类早期发育过程中的免疫防御机制。组织化学显示,从卵细胞到D型面盘幼虫各个时期都呈ACP和AKP阳性,卵细胞中阳性颗粒较大且分布比较均匀,受精卵中央着色较深,卵裂期核区呈强阳性且大分裂球内阳性颗粒较多,原肠胚和担轮幼虫外层细胞阳性较强,面盘幼虫外套膜边缘膜、内脏团和面盘基部呈强阳性。生化测定ACP和AKP活力,均是卵细胞最低,随着发育酶活力逐步提高,其中ACP活力在受精后和囊胚期明显提高,囊胚期达到最高峰,其后又略有下降;AKP活力在卵裂期、担轮幼虫和面盘幼虫提高较大,面盘幼虫期酶活力最高。ACP和AKP可能在贻贝的发育早期抵抗病原生物侵染方面发挥重要作用。     

南黄海中华哲水蚤昼夜垂直分布

在南黄海定点研究了中华哲水蚤（Calanus sinicus）各个发育期的昼夜垂直分布，分析了该种2000年6月的昼夜垂直分布规律。结果表明，中华哲水蚤雌体在后半夜上升到表层产卵，形成卵的高密集区；随后，卵在大约20h内边沉降边孵化成NI期无节幼体，导致相应时间内卵的密度减少；NIII到CV期幼体的垂直分布规律基本相同，其密集群的平均深度主要分布在30m的温、盐跃层。讨论了温、盐跃层，叶绿素a，捕食者等因素对它们垂直分布的影响。     

栉孔扇贝成熟卵形态与超微结构的研究

实验研究栉孔扇贝成熟卵的形态与超微结构。观察表明卵子表面呈蜂窝状,无卵极标志。受精前质膜形态模糊,属非典型单位膜。卵质内含有线粒体、内质网、高尔基体等细胞器,但缺乏中心粒复合体。皮层内含有皮层颗粒。卵黄形态不同,来源于多种细胞器。卵子的成熟核相为第一次成熟分裂中期。     

Identification and classification of vertical chlorophyll patterns in the Benguela upwelling system and Angola-Benguela front using an artificial neural network

Information on the vertical chlorophyll structure in the ocean is important for estimating integrated chlorophyll a and primary production from satellite. For this study, vertical chlorophyll profiles from the Benguela upwelling system and the Angola-Benguela front were collected in winter to identify characteristic profiles. A shifted Gaussian model was fitted to each profile to estimate four parameters that defined the shape of the curve: the background chlorophyll concentration (B ₀), the height parameter of the peak (h), the width of the peak (σ) and the depth of the chlorophyll peak (z_m ). A type of artificial neural network called a self-organizing map (SOM) was then used on these four parameters to identify characteristic profiles. The analysis identified a continuum of chlorophyll patterns, from those with large surface peaks (>10 mg m^?3) to those with smaller near-surface peaks (<2 mg m^?3). The frequency of occurrence of each chlorophyll pattern identified by the SOM showed that the most frequent pattern (～12%) had a near-surface peak and the least frequent pattern (～2%) had a large surface peak. These characteristic profile shapes were then related to pertinent environmental variables such as sea surface temperature, surface chlorophyll, mixed layer depth and euphotic depth. Partitioning the SOM output map into environmental categories showed large peaks of surface chlorophyll dominating in water with cool temperature, high surface chlorophyll concentration and shallow mixed layer and euphotic depth. By contrast, smaller peaks of subsurface chlorophyll were in water with warmer temperature, lower surface chlorophyll concentration, intermediate mixed layer and deep euphotic depth. These relationships can be used semi-quantitatively to predict profile shape under different environmental conditions. The SOM analysis highlighted the large variability in shape of vertical chlorophyll profiles in the Benguela. This suggests that an ideal typical chlorophyll profile, as used in the framework of biogeochemical provinces, may not be applicable to this dynamic upwelling system.     

An individual-based model study of anchovy early life history in the northern Humboldt Current system

We used an individual-based model of anchovy (Engraulis ringens) early life history coupled with hydrodynamic outputs from the regional oceanic modeling system (ROMS) to investigate the factors driving variability in egg and larval survival rates in the northern Humboldt upwelling region off Peru. Individuals were released within a coastal area and followed for a period of 30 days. Those that were still in the coastal area at that time were considered as retained. We investigated the spatial and temporal variability in the release locations of the individuals retained, and compared these to observed egg concentration patterns reconstructed from a 40-year period of monitoring. A first set of simulations using passive particles to represent anchovy eggs and larvae revealed a large sensitivity of the results to the initial vertical distribution of particles. We then conducted two additional sets of simulations that included the effect of egg buoyancy, larval vertical swimming behavior and lethal temperature. We obtained (1) maximal coastal retention close to the surface in winter and in deeper layers in summer, (2) a large influence of egg buoyancy and of larval vertical behavior on coastal retention in all seasons, (3) a partial match between dates and locations of enhanced retention and observed egg concentration patterns and (4) a low effect of lethal temperature on survival except when associated with high egg density. The model suggests that an optimal temporal spawning pattern for maximizing coastal retention would have two maximums, the most significant in austral winter and the second in summer. This pattern agrees roughly with observed spawning seasonality, but with temporal discrepancy of about two months in the peaks of both series. Spatially, we obtained higher retention from 10 S to 20 S, whereas the observed maximum egg concentration was located between 6°S and 14°S. Among the three sets of simulations, the one taking into account larval vertical swimming behavior lead to the best match with the data.     

Improved representation of topographic effects by a vertical adaptive grid in vector-ocean-model (VOM). Part I: Generation of adaptive grids

This is the first part of a publication that describes the generation of adaptive grids (this part), and simulations with vector-ocean-model (VOM) in unstructured grids resulting from the adaptation (part II). A static vertical adaptive grid in z-coordinates allows improving the approximation of topography and vertical resolution at slopes. Adaptive grids use elements from a set of grid sizes by multiplying a basic smallest cell size with powers of two, as in cell division. Grids with locally isotropic vertical resolution at surface, seabed, and slopes can be generated whereby resolution decreases towards the ocean interior. The adaptation to topography yields unstructured grids that are organised in a one-dimensional vector by column-wise storage of cells, discarding land cells. The vector storage suggested the model’s name. Grids are generated by an iterative procedure that relies on rules, i.e. criteria and directives to control the grid structure in favour of a good representation of physics and smooth numerical operations. The directives govern vertical resolution at sea surface and seabed, and at slopes. For the latter vertical resolution is extended in the horizontal. In the ocean interior horizontal distances between changes in grid size can be controlled for the sake of smooth numerics. The use of a z-grid that avoids transformation errors, the depth-independence of vertical resolution, and the lateral extension of vertical resolution at slopes towards the ocean interior are the most significant differences of adaptive grids in comparison to vertical coordinate transformations. Unstructured grids do not rely on a smoothing of topography and can be used within any of the horizontal Arakawa-grids. For the same topography directives allow creating various grids as demonstrated for a shelf-ocean topography. The number of cells per column in two unstructured grids generated for the North Atlantic may locally well exceed typical layer numbers in conventional model matrices. But the domain average is similar to layer numbers of today’s ocean models. Thus, with the same investment of cells per domain a higher resolution in slope regions can be achieved by unstructured grids as compared to conventional z-grids.     

Some regular patterns in the distribution of sediment contamination in the coastal waters along Japan

Observations of sediment contamination along the coast of Japan were analyzed. When the pollutant concentration is divided by the fine particle fraction in the sediment, a regular pattern is observed in the quantitative relationship among the degree and the area of contamination and the discharge rate of pollutant released continuously into the water along the coast. This regularity was observed with respect to COD,n-hexane soluble substances and heavy metals, and could be expressed by a formula.Polluted particles were supposed to disperse through suspension in the bottom water layer, and thus their distribution in the surface sediment is expected to become similar to effluent dispersion in the surface water.     

Localization of nitric oxide synthase in the developing gonads of amphioxus Branchiostoma belcheri tsingtauense

The localization of nitric oxide synthases （NOS） is dealed with in the developing gonads of amphioxus Branchiostoma belcheri tsingtauense. It was found by NADPH-diaphorase staining that （1） NOS activity was present in the nuclear membranes of germinal vesicles during the entire period ofoocyte development; （2） NOS was localized in both the nuclear membranes and the perinuclear region of cytoplasm in the vitellogenetic oocytes; （3） NOS was relocated in the cortical layer in the mature egg; （4） NOS activity was present in spermatocytes, but not in the spermatogonia in the middle of October; （5） NOS was detected in both spermatozoa and spermatids as well as spermatocytes during the breeding season. This is the first report on the distribution pattern of NOS in the developing gonads in protochordates. These results suggest a role for NOS in the functioning of the nuclear membranes and yolk synthesis during oogenesis and in cell division and differentiation during spermatogenesis.     

可口革囊星虫(Phascolosoma esculenta)肾管的显微及超微结构特征

采用显微及亚显微观察方法, 研究了可口革囊星虫肾管的形态结构特征。结果表明, 可口革囊星虫肾管由排泄囊及排泄管组成, 外表面具瓶形突起。肾管壁从内到外由上皮层、肌层、细胞外基质及外膜构成。上皮层的单层柱状细胞在肾管腔面成束排列、单层立方细胞围绕瓶形突起内腔排列, 两种上皮细胞的游离面均着生微绒毛及纤毛, 细胞质中细胞器发达, 并含有不同大小、形态及电子致密度的颗粒; 柱状细胞基底面质膜内陷形成基底迷路。肌层由环肌及纵肌组成。细胞外基质主要由胶原原纤维构成, 内含颗粒细胞。外膜由足细胞及多纤毛细胞构成。肾管通过肾孔通体外、肾口通体腔。肾管的结构特征与其对体腔液的过滤排泄功能相适应, 繁殖季节肾管兼具生殖管的作用。     

鼠尾藻(Sargassum thunbergii)有性生殖过程与育苗

采用室内培养和野外实地观测的方法,研究了鼠尾藻的生长发育和有性生殖过程,并在此基础上进行了有性生殖人工育苗实验。结果表明,鼠尾藻在海水温度高于22℃时,生殖托开始发育,海水温度超过23℃以后,生殖托的生长速度加快,海水温度超过24℃时,生殖托生长速度最快并迅速成熟,在海水温度达到26℃时,观察到了卵的集中排放挂托现象。鼠尾藻卵的排放较为齐整且有一定的先后顺序,生殖托基部的卵最先排出,中部次之,最后是顶部,雄托排精时间要稍晚于雌托排卵时间。受精卵大约在受精1h后进行第一次细胞分裂,分裂面与长轴垂直,大约2h后进行第二次分裂,下端细胞的分裂面平行于第一次分裂方向,而上端细胞的分裂面则垂直,随后大约每2—4h细胞分裂一次。从卵挂托到幼胚脱落一般需要24—48h。观察发现,生殖窝不仅存在于生殖托上,在部分生殖枝上也有分布。在鼠尾藻的人工育苗的实验中,胚苗在苗帘上的生长状态良好。     

Changes of water temperature near Ocean Weather Station T before and after passage of a typhoon

Temperature field in the vicinal area of station T (29N, 135E) before and after Typhoon 6411 in summer 1964 is analysed from measurements with BT. At a location 68 km distant from the path of the typhoon, temperature at each depth became lower in the upper layer from surface to 50 m deep and became higher in the lower layer from 50 m to 130 m deep in connection with passage of the typhoon than temperature at each depth in these layers before the typhoon, respectively. Heat loss in the upper layer and heat gain in the lower layer are estimated to be almost comparable in amount. Equivalence in the heat gain and loss suggests that temperature changes were caused by vertical mixing due to strong wind of the typhoon. At a location 164 km distant from the path of the typhoon, however, heat gain of the lower layer from 35 m to 250 m deep exceeded heat loss of the upper layer from surface to 35 m deep. In addition to vertical mixing, horizontal advection or some other processes should be taken into account in order to explain the temperature changes in the area a little distant from the typhoon path. For recovery of the temperature changes at these locations 8 days were needed. This recovery time is almost equal to those in the case of some other typhoons, about which the discussion was made in the previous paper (Maeda, 1965).     

Distribution and seasonal variation of phosphorus in Tokyo Bay

Phosphorus dynamics in Tokyo Bay waters were investigated along with other oceanographic variables. Seasonal variations of dissolved inorganic phosphorus (DIP) and particulate phosphorus (PP) are inversely correlated with each other, and reflect variation in biological activity. A high concentration of PP in summer surface waters is caused by high primary production. The PP settled in the deeper layer is decomposed, and orthophosphate is regenerated within the water column and in sediments. Even during summer stratification period, the regenerated orthophosphate is occasionally advected upward by wind-induced water mixing and contributes to phytoplankton growth in the upper layer. Some dissolved organic phosphorus is producedin situ from PP, but it may be rapidly decomposed in the water column. The ratios of Cchlorophylla and CN in particulate matter suggest that phytoplankton in the summer surface waters of Tokyo Bay are limited neither by nitrogen nor by phosphorus. The PN ratio in particulate matter varies substantially but it is positively correlated with the ambient concentration of DIP. Phytoplankton take up and store phosphorus within their cells when ambient DIP exceeds their demand. An abundance of total phosphorus in the summer water column can be attributed to increased discharge of river waters, although enhanced release of orthophosphate from anoxic sediments cannot be discounted.     

毛嵌线螺的研究Ⅰ.繁殖及幼虫发生特征

毛嵌线螺(Cymatium pileare)的繁殖过程包括交配、产卵、孵育及幼虫从卵囊中游出等4个阶段。交配一般在产卵前10～15d进行,产卵后母体并不离开卵群,而是持续静伏在卵群的开口上进行孵育,直至其中的幼虫离开卵囊。温度和盐度对毛嵌线螺受精卵的发育有重要影响,在22～30℃的适宜温度区域内,将受精卵孵育成能自由生活的晚期面盘幼虫需438日度左右的总积温。毛嵌线螺受精卵的发育与其他前鳃类腹足动物相似,包括卵裂、囊胚期、原肠期及面盘幼虫期4个阶段。     

Japanese anchovy egg accumulation at the sea surface or pycnocline—Observations and model

Near surface vertical distributions of Japanese anchovy eggs (isolated and pelagic) were studied at western Wakasa Bay, Japan. Samples were collected in horizontal tows with four plankton nets simultaneously operated at different four depths of 0, 0.5, 1.0, and 2.0 m. The egg concentration was found to decrease exponentially with depth. The egg concentration profile can be explained by considering the balance of the eggs' ascent and vertical diffusion. Taking further into account vertical difference in rising/sinking rates of the eggs, a clear accumulation of the eggs on a pycnocline, observed elsewhere, also can be explained. Vertical eddy diffusivity in the surface layer in a calm sea was 1–10 cm² s^–1, as estimated from the egg concentration profile and the velocities of the eggs in the vertical direction.