盐度对长江口3种滤食性贝类滤水率、摄食率、同化率的影响

采用实验生态学方法研究了盐度对长江口缢蛏(Sinonovacula constricta)、河蚬(Corbicula fluminea)和光滑河蓝蛤(Potamocorbula laevis)滤水率、摄食率、同化率的影响。缢蛏组设6个盐度梯度(5,10,15,20,25,30),光滑河蓝蛤组设6个盐度梯度(5,10,15,20,25,30),河蚬组设6个盐度梯度(0,5,10,15,20,25),并测定了此3种滤食性贝类的生物学参数。结果显示,3种滤食性贝类的滤水率、摄食率和同化率随着盐度的上升而增加,当上升到一定盐度时达到峰值,然后随着盐度的升高而降低。盐度20时,缢蛏滤水率、摄食率和同化率达到峰值,分别为0.57L/h、5.38mg POM/h和0.72%。盐度10时,光滑河蓝蛤滤水率和同化率达到峰值,分别为0.46L/h和0.53%,摄食率在盐度15时达到峰值3.80mg POM/h。盐度5时河蚬滤水率和摄食率都达到峰值,分别为0.39 L/h和2.48 mg POM/h,同化率在盐度0时已达到峰值0.51%,并随盐度上升而下降。上述结果表明,盐度对3种滤食性贝类的3个摄食生理指标均有显著影响。     

Numerical simulation of the thermal maturation, oil generation and migration in the Songliao Basin, Northeastern China

The discovery of the giant Daqing oil field in the Songliao Basin led to the realisation of the significant petroleum potential of non-marine basins. In order to reconstruct the basin evolution and oil formation, an integrated organic geochemical-basin modelling study along a regional transect across the Songliao Basin was conducted. It provided a regional heat flow evolution model, and revealed post-orogenic or late syn-orogenic maturation in the Central Depression and pre-orogenic maturation in the Southeast Uplift Zone. Kinetic parameters of petroleum generation for the lacustrine source formations are the basis for the simulation of oil generation and migration in the Songliao Basin. Using the principle activation energy peaking at 54 kcal/mol and a pre-exponential factor of about 4.2·10²⁷ Ma⁻¹, the simulation obtained a relatively good match with the measured transformation ratios. The Qingshankou Formation in the West and East Central Depressions constituted the major source in the basin. Major oil generation, migration and accumulation occurred during the Early Tertiary. In the West Central Depression, the generated oils migrated upwards into the Yaojia Formation followed by the updip migration into the Daqing Anticline and towards the local structural high along the West Slope. In contrast, the oil migration in the East Central Depression was dominated by the downward movement from the lower member of the Qingshankou Formation followed by the updip migration towards the Caoyang Anticline. The simulated oil accumulations are in good agreement with discovered oil fields, implying a potential application of the model for prediction and evaluation of new exploration targets in the basin.     

激素在诱导鲻鱼卵母细胞成熟中的作用机制

本文报道了在注射促性腺激素和促黄体素释放素类似物诱导鲻鱼卵母细胞成熟过程中,其胞质中高尔基体、油球数量和核的形态均发生显著变化,并据此分析了这两种激素在诱导鲻鱼卵母细胞成熟中的作用机理。     

Reproductive cycle,size at first maturation and fecundity in the golden ling,Genypterus blacodes,in Chile

Reproductive aspects of the golden ling, Genypterus blacodes, from the southern Chilean fishery are presented. Gonad samples were obtained from commercially caught fish between September 1999 and October 2000. Stage of sexual maturity, gonadosomatic index (GSI), and size of females at 50% maturation determined by logistic methods and by plotting the mean GSI by total length, are presented for both years. Batch fecundity was calculated from subsampling mature ovaries containing oocytes in advanced stages of maturity. Changes in GSI and monthly diameters of oocytes showed that ling had a spawning season which extended between August and November. The sizes at first maturity in 1999 and 2000 were 86.6 and 84.8 cm total length (TL), respectively, using the logistic model, and 84 cm for both years using the mean GSI‐size plotting method. The mean batch fecundity was 333 330 oocytes per individual for fish sized 85–120 cm TL. Fecundity increased with increasing weight and total length.     

温度对美国硬壳蛤滤食率、耗氧率和排氨率的影响

在实验条件下，采用静水方法，测定了水温11．5、22．5、28．0、32．0℃下，硬壳蛤的滤食率、耗氧率和排泄率。结果表明，在11，5～22．5℃-之间，硬壳蛤的上述生理指标随温度的升高而增加，差异显著。而在22．5、28．0、32．0℃之间，生理指标的差异并不十分显著，间接说明了硬壳蛤对温度的较强适应能力，适合在浙江省等东南沿海进行推广养殖。     

Substrate control on formation and maturation of glauconites in the Middle Eocene Harudi Formation, western Kutch, India

Formation and maturation of glauconites within the early Middle Eocene Harudi Formation, built up in a lagoon to shelf transition in western Kutch, India is addressed taking recourse to a combined sedimentological, micropalaeontological and mineralogical investigation. The glauconite is authigenic and its occurrence coincides with maximum flooding. The glauconite is more matured within the fecal pellets and is less matured within the intra-particle pores of bioclasts namely, foraminifera, ostracoda, gastropoda and bryozoa. SEM-EDS, XRD and geochemical studies clearly document that the infilling within the intra-particle pores of bioclasts belong to nascent to slightly evolved glauconite (<5 wt% K₂O), while the pellet belongs to slightly evolved to evolved glauconite (5-7 wt% K₂O). Based on chemical characteristics and SEM investigations the glauconitization process can be best explained by the ‘verdissement theory’. The glauconite possibly formed as initial authigenic glauconitic smectite precipitates; while the pellet matured subsequently by addition of K, the process was hindered in case of infillings. The maturation process also involved addition of Si and release of Al, with or without release of Mg. The glauconite maturation was facilitated in case of fecal pellets because of higher porosity, inter-granular nature of pores and availability of necessary elements in semi-confined micro-environments. In contrast, the maturation was aborted at an early stage in case of infillings because of the minute, closed nature of the pores and prevalent alkaline conditions not allowing dissolution of calcitic tests. A low negative cerium anomaly suggests glauconite formation in sub-oxic micro-environments, created by decay of organic matters within the fecal pellets and bioclasts. A clear case of substratum control on glauconitization becomes apparent.     

污损生物对大亚湾养殖珍珠贝的滤食、呼吸和排泄的影响

污损生物是影响贝类养殖业生产效率的重要因素。污损生物不仅附着在养殖网笼上,而且也大量附着在养殖生物的贝壳上。大部分污损生物是滤食性捕食者,这些污损生物与养殖生物竞争食物,氧气与空间导致贝类生长速度减慢,死亡率提高。本实验以大亚湾养殖网笼里的珍珠贝及附着的污损生物为对象,研究有污损生物附着的珍珠贝及没有污损附着的珍珠贝在滤食,耗氧及排泄上的差异,同时对网笼上附着的污损生物优势种的滤食,呼吸及排泄也进行了测定,用以说明污损生物对养殖生物滤食,耗氧和排泄的影响。研究结果表明,有污损附着的珍珠贝及没有污损附着的珍珠贝在滤食率,耗氧率和氮磷排泄率上存在明显差异,有污损附着的珍珠贝的滤食率,NH4-N和PO4-P的排泄率要高于没有污损附着的珍珠贝。同时在网笼上附着的优势污损生物的滤食,耗氧和排泄也不容忽视,他们对食物的滤食,溶氧的消耗及氮磷排泄的贡献也很大。本研究结果表明,不管是附着在养殖生物贝壳上还是附着在网笼上的污损生物与养殖生物之间存在食物及氧气的竞争,污损生物对水中氮、磷浓度的提高贡献也很大,因此在养殖中,污损生物的影响不容忽视。     

凡纳滨对虾摄食与生长的实验研究

在实验室测定了不同条件下凡纳滨对虾 (Litopenaeusvannamei)的摄食率、生长率及食物转化率 ,并探讨了体质量和温度等因子的影响。结果表明 ,温度和体质量对凡纳滨对虾的摄食率及生长率有显著的影响 ,温度对食物转化率影响不明显。在温度 1 6～ 3 1℃的范围内 ,摄食率及生长率随温度的升高而增加 ;相同温度下 ,随个体质量的增加摄食率、生长率及食物转化率下降。凡纳滨对虾摄食率 (RF)、生长率 (RG)和食物转化率 (EF)与温度和体质量的复回归关系分别为 :RF=0 .461W- 0 .793e0 .12 2T(r2 =0 .876,P <0 .0 1 ) ,RG =0 .1 63W- 1.398e0 .174T(r2 =0 .784,P <0 .0 1 ) ,EF=0 .3 84W- 0 .54 6 e0 .0 4 6T(r2 =0 .5 2 9,P <0 .0 5 )。     

Thermal maturation, potential source rocks and hydrocarbon generation in Mesozoic rocks, Lougheed Island area, Central Canadian Arctic archipelago

Significant oil and gas accumulations occur in and around Lougheed Island, Arctic Canada, where hydrocarbon prospectivity is controlled by potential source rock distribution and composition. The Middle to Upper Triassic rocks of the Schei Point Group (e.g. Murray Harbour and Hoyle Bay formations) contain a mixture of Types I and II organic matter (Tasmanales marine algae, amorphous fluorescing bituminite). These source rocks are within the oil generation zone and have HI values up to 600 mg HC/g Corg. The younger source rocks of the Lower Jurassic Jameson Bay and the Upper Jurassic Ringnes formations contain mainly gas-prone Type II/III organic matter and are marginally mature. Vitrinite reflectance profiles suggest an effective geothermal gradient essentially similar to the present-day gradient (20 to 30°C/km). Maturation gradients are low, ranging from 0.125 to 0.185 log%Ro/km. Increases in subsidence rate in the Early Cretaceous suggest that the actual heat flow history was variable and has probably diminished from that time. The high deposition rates of the Christopher Formation shales coincide with the main phase of rifting in Aptian-Albian times. Uplift and increased sediment supply in the Maastrichtian resulted in a new sedimentary and tectonic regime, which culminated in the final phase of the Eurekan Orogeny. Burial history models indicate that hydrocarbon generation in the Schei Point Group took place during rifting in Early Cretaceous, long before any Eurekan deformation.     

Barbados: maturation,source rock potential and burial history within a Cenozoic accretionary complex

A number of diagenetic properties were studied in sedimentary rocks exposed along a 25 km across-strike transect on Barbados, the crest of the Barbados accretionary complex. The island of Barbados consists of three structural levels: a lower (mostly Eocene or undated) basal complex composed of quartzose turbidites, hemipelagites and melange; an intermediate level (Eocene to Miocene) of nappes composed mostly of calcareous pelagite; and a Pleistocene coral cap. Diagenetic studies concentrated on the basal complex although preliminary data from the nappes are also presented. The following subjects were studied: (1) clay mineralogy (% illite interlayers in mixed-layer clays); (2) vitrinite reflectance; (3) organic type and maturation, by Rock-Eval pyrolysis; (4) thermal alteration index of spores and pollen; (5) dry bulk density; (6) silica mineralogy. Taken together, the data can be interpreted to indicate maximum temperatures attained during diagenesis of less than 80°C. Based on a uniform palaeogeothermal gradient of 15°C km^?1, and a temperature at the sediment/water interface of 10°C, maximum burial depths of basement complex rocks were about 2–5 km. Minimum possible burial depths are < 1 km. No across-strike changes in maturation are observed indicating that these trench-associated rocks were uplifted uniformly. Mudstones are typically rich in total organic carbon (> 1 %), and are immature. Organic matter was derived mostly from terrigenous or oxidized sources (type III kerogens), although some marine planktonic sources are indicated locally (type II kerogens). Organic matter is therefore primarily gas-prone.     

胶州湾养殖菲律宾蛤仔的清滤率、摄食率、吸收效率的研究

2003年6月,利用模拟现场流水系统采用生物沉积法对胶州湾养殖的菲律宾蛤仔的清滤率、摄食率、吸收效率及其与蛤仔规格之间的关系进行了现场实验研究。结果表明,个体的清滤率在0.18—0.40L/h范围内,平均为0.31L/h(SD=0.068),个体清滤率和摄食率随壳长增加而增加,但吸收效率与个体大小无关。蛤仔对颗粒有机物(POM)、颗粒有机碳(POC)、颗粒有机氮(PON)及叶绿素的吸收效率不同,对叶绿素的吸收效率最高,平均为(81.8±7.9)%,对POM、POC和PON的吸收效率分别平均为(64.2±10.7)%(、55.7±9.8)%和(53.9±9.6)%。结合胶州湾蛤仔的生物量和野外调查数据,分析了春季养殖蛤仔对胶州湾初级生产力和颗粒有机碳的摄食压力及可能对整个湾的物质循环的影响。根据本文的结果估算,菲律宾蛤仔对本实验海区初级生产力和颗粒有机碳现存量的摄食压力分别为560%和90%。养殖的蛤仔通过滤食已经能够影响甚至控制养殖区的浮游植物的生长或初级生产力,甚至与整个胶州湾叶绿素a浓度的季节性变化趋势相吻合,因为胶州湾叶绿素浓度冬、夏季高,春、秋季节低,而蛤仔的生长旺季刚好在春、秋两季。     

皱瘤海鞘神经递质和性类固醇激素含量与性腺发育成熟的关系

运用免疫组织化学和化学发光免疫分析方法研究了皱瘤海鞘(Styela plicata)神经递质多巴胺(DA)、5-羟色胺(5-HT)及其受体以及性类固醇激素含量与性腺发育成熟的关系.结果显示,DA和5-HT免疫活性定位在脑神经节中大小2种类型的神经细胞,DA免疫活性还定位在不同发育时期神经腺上皮细胞.5-HT受体免疫活性存在于脑神经节小型神经细胞和大生长期神经腺上皮细胞.在小生长期和大生长期性腺中均检测到DA、5-HT及其受体,提示DA和5-HT可能参与调节皱瘤海鞘的性腺发育.皱瘤海鞘为雌雄同体,化学发光免疫分析证实,海鞘性腺能够合成和分泌性类固醇激素,大生长期性腺中雄激素、孕激素和雌激素的含量分别为25.8±0.0、38.9±0.2和14.3±0.6pg/mg,提示性腺既是生殖组织也是内分泌组织.上述发现为证明尾索类海鞘可能像头索类文昌鱼一样,具有原始的生殖内分泌调控轴(脑神经节-神经腺-性腺)提供科学依据.     

厦门港真刺唇角水蚤的生长率

本文以实验室培养为主,结合自然种群调查,观测厦门港真刺唇角水蚤各发育阶段体长、体重的增长状况,并研究了其生长率与温度、发育期的关系。     

Polyculture of the lined seahorse, Hippocampus erectus Perry, 1810 with two species of macroalgae in aquaria

A two-month study was conducted to test the e?ects of macroalgae on the growth and survivorship of juvenile lined seahorse (Hippocampus erectus) in aquaria. Twenty-day old seahorses were cultured in the tanks with green alga Chaetomorpha linum, red alga Gracilaria tikvahiae, green plastic artiˉcial plant (stargrass), and black plastic net, respectively. Increases in wet mass and standard length for the seahorses were signiˉcantly higher in the tanks with macroalgae than those without macroalgae. The seahorse survivorships in the two macroalgal treatments were also signiˉcantly higher than those of the two treatments without macroalgae. In the treatments with macroalgae, the DO and pH were higher than those without marcoalgae. During the experiment, the color of seahorses was changed to certain extent. In the green background (the treatments with C. linum and stargrass), 24.1%{28.4% of black seahorses decreased over time; whereas in the black (plastic net) or brown (G. tikvahiae) background treatments, 14.1%{16.3% of yellow seahorses decreased over time, for matching that of the background. Furthermore, the survival rate of seahorse was correlation with DO and pH, and strong correlation with standard length, wet mass and CF. Polyculture with macroalgae, survival rates of seahorse were higher than without macroaglae.     

Experimental investigation of thermal maturation on shale reservoir properties from hydrous pyrolysis of Chang 7 shale,Ordos Basin

Thermal maturity has a significant impact on hydrocarbon generation and the storage capacity within shales, but explicit and quantitative characterization of that impact on continental shales is scarce. To better understand how thermal maturation affects the organic and inorganic changes of the continental shale reservoirs, hydrous pyrolysis was performed to simulate the maturation process. TOC, Rock-Eval and adsorption isotherms tests were used to obtain various geochemical parameters of the shale solid residues. The results indicate that with pyrolysis temperature increasing from ambient temperature to 550 °C, the vitrinite reflectance increases from 0.5% to 2.5% Ro and the TOC (total organic carbon) loss weight reaches 25%. Regarding porosity, the fraction of micro-to meso-pores in the shale increases with an increase in the pyrolysis temperature, whereas the macro-pores do not change significantly. The total amount of gas adsorption does not necessarily increase as the TOC is consumed, but the gas adsorption capacity per unit of TOC increases with increasing thermal maturity. Our finding provides theoretical modelling for identifying shale gas development prospective zones according to thermal maturity mapping and for predicting quantitatively the geochemical and inorganic changes that occur with thermal evolution.     

环境因子对菲律宾蛤仔摄食生理生态的影响

于 1 998年 1— 6月 ,在中国科学院海洋研究所实验室内采用静水方法对采自胶州湾潮间带的菲律宾蛤仔 (以下简称蛤仔 )进行摄食率、清滤率和吸收率的测定。结果表明 :(1 )蛤仔摄食率和清滤率随着个体体重的增加而增大 ,而单位重量的摄食率和清滤率随个体体重的增加而减小 ,它们之间呈幂函数关系。 (2 )底质对蛤仔摄食生理影响的实验表明 :铺砂可以显著地提高蛤仔的摄食生理指标。 (3)在一定的饵料浓度范围内 ,摄食率和清滤率随着浓度的增加而增大 ,呈幂函数关系。当饵料浓度达到一定值后 ,清滤率迅速下降 ,而摄食率只略微有所下降 ,基本上保持平稳不变。这说明蛤仔可以通过调节清滤率来稳定摄食率。 (4)蛤仔吸收率和饵料浓度及个体大小无明显相关性。 (5)水温 1 5℃ ,投喂小球藻的条件下 ,实验结果显示蛤仔 [壳长 (3.53± 0 .0 2 )cm、软体部干重 (0 .41± 0 .0 2 )g]产生假粪的阈值为2 .1 6mgPOM /L。