Modulation of p53 gene expression in the intertidal copepod Tigriopus japonicus exposed to alkylphenols

The copepod, Tigriopus japonicus has been recognized as an excellent marine model species for ecotoxicological studies. The present study cloned and characterized the p53 gene of this copepod and studied its expression pattern. We discovered that p53 expression patterns varied among different developmental stages of the copepod, having the highest expression in the adult. Such variation was possibly associated with the molting cycle. By using real-time RT-PCR, we further investigated the modulatory pattern of the p53 gene in the copepod after exposure to three alkylphenols (i.e. nonylphenol, octylphenol, and bisphenol A) which are known as endocrine disruption chemicals (EDCs). The results showed that the three alkylphenols significantly induced p53 gene expression in the copepod, indicating the involvement of p53 in such stress-responses. Thus, the copepod p53 gene provides one of the stress-response biomarkers for exposure to EDC-like compounds.     

Photobehaviors ofthe calanoid copepod Calanus sinicus from the Yellow Sea to visible and UV-B radiation as a function of wavelength and intensity

The effects of wavelength-specific visible light, white light, and ultraviolet-B (UV-B, 280- 315 nm) on selected behaviors, grazing rate, spawning rate, and hatching rate of the marine copepod Calanus sinicus collected from the Yellow Sea were studied. Calanus sinicus placed in a partitioned experimental system responded positively phototaxis to blue-cyan and yellow light but negatively to orange light and UVB. No obvious dodge activity was found among C. sinicus irradiated with <0.005 mW/cm^2 UV-B. Under 0.20, 0.30 and 0.50 mW/cm^2 UV-B radiation, the lethal half times of individuals were 30.47, 2.86, and 1.96 h, respectively. Grazing of C. sinicus was restrained at >0.10 mW/cm^2 UV-B, whereas yellow-red light stimulated grazing. Egg production rate was highest at a white-light intensity of 1.58 mW/cm^2, with an average rate of 10.04 eggs/(female·d). These results are consistent with the observed phenomenon that C. sinicus in the Yellow Sea mostly spawn near dawn. Our results indicate that light intensity and spectrum are important factors affecting the diel vertical migration of C. sinicus under natural conditions in the Yellow Sea.     

复方有机疗效助长剂在日本对虾幼体培育中的应用

以复方有机疗效助长剂（简称Q．S．）的不同剂量和不同投喂方式对日本对虾（Penaeusjaponicus）各期幼体培育进行三批的试验，分析了Q．S．在日本对虾幼体培育中的应用效果。在水温24～29℃，盐度22～29下，无节幼体至仔虾经15d（10月4～19日）培育，试验组和对照组的存活率、平均体长分别是52．9％（40．2％～72．4％），10．05mm（9．30～11．7mm）和31．7％与8．8mm。试验表明，在幼体培育中Q．S．以“水浴”为主，以一定比例掺进饵料为辅的方式最为有效；结果还表明，Q．S．在日本对虾各期幼体的培育中具有显著的提高存活率和促进生长的作用。本文还就提高幼体存活率、促生长与虾苗质量之间的关系进行了讨论。     

紫外辐射对鱼类及水生无脊椎动物影响的研究进展

全球性的气候变化严重地威胁着自然生态环境间的平衡。在影响生态系统功能的诸多因素中,太阳紫外辐射的增强逐渐成为最受关注的全球性环境问题之一。太阳紫外辐射对地球生物的生命过程有着举足轻重的影响。生物体一旦吸收了高能量的紫外辐射,则可对其各种生理过程产生影响,打破内稳态,尤其是紫外辐射对DNA的损伤作用,是诱导一系列生物效应的主要原因。本文综述了近年来与鱼类及水生无脊椎动物有关的紫外辐射研究。从紫外辐射对生物不同发育时期的影响、生物对紫外线响应方式、紫外辐射与其他因素复合影响三个层面进行总结。通过总结紫外辐射对鱼类及水生无脊椎动物的影响,可为预测紫外辐射在水生生态系统中的作用提供助力,为海洋生物对环境变化的生理响应研究提供参考。     

The influence of solar ultraviolet radiation on the photochemical production of H2O2 in the equatorial Atlantic Ocean

Hydrogen peroxide (H₂O₂) was measured in marine surface waters of the eastern Atlantic Ocean between 25°N and 25°S. H₂O₂ concentrations decreased from 80 nM in the north to 20 nM in the south, in agreement with earlier observations. A diel cycle of H₂O₂ production as a function of sunlight in surface waters was followed twice whilst the ship steamed southward. Around 23°N a distinct diel cycle could be measured which correlated well with irradiance conditions.The wavelength dependency of H₂O₂ formation was studied near the equator. For 16 hours, water samples were incubated with wavelength bands of the solar spectrum, i.e. visible (VIS: 400–700 nm), VIS and ultraviolet A radiation (UVAR: 320–400 nm) and VIS, UVAR and ultraviolet B radiation (UVBR: 280–320 nm). A significant relationship was found between wavelength band and the production of H₂O₂. In addition, a clear positive relationship between intensity and production was found. UVAR was 6.5 times more efficient than VIS in producing 1 nM of H₂O₂, whereas UVBR was 228 times more efficient than VIS. When these data were weighted with respect to the energy of the solar spectrum at zenith hour, 28% of the H₂O₂ was formed by VIS, 23% was formed by UVAR and 48% was formed by UVBR. Considering the strong attenuation of UVBR in marine waters as compared with UVAR and VIS radiation, the role of UVAR deeper in the water column is recognised. Furthermore results of this research emphasise the importance of VIS radiation in the formation of H₂O₂.     

Effects of the copepod community structure on fecal pellet flux in Kagoshima bay,a deep,semi-enclosed embayment

Seasonal changes in the shape and size composition of fecal pellets were investigated with sediment trap samples from 50 and 150 m in Kagoshima Bay to evaluate how the mesozooplankton community affects fecal pellet flux. Deep vertical mixing was evident in March, and thermal stratification was developed above 50 m in June, August and November. Chlorophyll a, suspended particulate organic carbon (POC) and copepod abundance were uniform throughout the water column during the seasonal mixing and concentrated above 50 m in the stratified seasons. Calanoids were the most predominant copepods in March and poecilostomatoids composed more than 45% of the copepod community in June, August and November. Fecal pellet fluxes at 50 and 150 m were the highest in March, nearly half of POC flux. The relative contribution declined considerably in the other months, especially for less than 4% of POC flux in August. The decline was corresponded to the predominance of cyclopoids and poecilostomatoids. Cylindrical pellets dominated the fecal matters at both depths throughout the study period, while larger cylindrical pellets nearly disappeared at 150 m in June, August and November. Copepod incubation revealed that cylindrical and oval pellets were egested by calanoids and the other copepods, respectively. We suggest that cylindrical fecal pellets produced by calanoid copepods contribute to feces flux but the predominance of poecilostomatoids and/or cyclopoids decreases feces flux via the increase of oval pellets and fragmentation of larger cylindrical pellets.     

复方有机疗效助长剂在日本对虾养殖中的应用效果评析

初步评估了复方有机疗效助长剂在日本对虾养殖中的应用效果。在水湿１９－２９℃、盐度１７－２８下，经４０ｄ饲养，实验池对虾的平均体长为３．９４ｃｍ，增长率为０．８ｍｍ／ｄ平均体重显０．７８ｇ，而对照池对虾的平均体长是２．５４ｃｍ，增长率为０．４３ｍｍ／ｄ，平均体重为０．２５ｇ。实验池对虾的平均体长与体重分别是对照池的１．５５倍、３．１２倍。     

Possible effects of climate change on estuarine nutrient fluxes: a case study in the highly nutrified Schelde estuary (Belgium, The Netherlands)

Global change models predict effects of climate change on hydrological regimes at the continental scale in Europe. The aim of this study was to gain a better understanding of the possible effect of changing external forcing conditions on the functioning of estuarine ecosystems. In densely populated areas, anthropogenic nutrient enrichment and consequent alteration of nutrient biogeochemical cycles have already had a big impact on these ecosystems. The average yearly discharge of the upper Schelde estuary increased nearly threefold over the period 1996–2000, from 28 m³ s⁻¹ in 1996 to 73 m³ s⁻¹ in 2000. The continuously rising discharge conditions over the five-year period were used as a reference situation for possible future effects of climate on ecological functioning through increase of discharge. At high discharges, nutrient (NH₄⁺, NO₃⁻, dissolved silica and PO₄³⁻) concentrations in the tidal fresh- and brackish water showed a decrease of up to 50% while total discharged nutrient loadings increased up to 100%. Opposite effects of increasing discharge on NH₄⁺, NO₃⁻ and dissolved silica concentrations in summer and winter, resulted in the flattening out of seasonal cycles for these nutrients. Under high discharge conditions, silica uptake by diatom communities was lowered. Dissolved silica loadings to the coastal area increased concurrently with total silica loadings upstream. Salt intrusion to the marine parts of the estuary decreased. This resulted in a downstream shift of the salinity gradient, with lower salinity observed near the mouth. As a result, TDIN, NO₃⁻ and dissolved silica concentrations doubled at the mouth of the estuary.     

太平洋牡蛎幼体附着变态差异蛋白质组研究

太平洋牡蛎(Crassostrea angulata)是中国主要的海洋养殖经济物种之一,具有重要的经济价值和商业价值,附着变态是牡蛎幼体从受精卵发育到成体所需的重要阶段,其分子机制的研究对牡蛎养殖育苗具有重要的指导意义.本研究利用双向电泳技术分离筛选牡蛎幼体附着变态过程中的差异表达的蛋白,进一步利用质谱技术鉴定幼体附着变态过程中发育相关的关键蛋白,共筛选出128个差异蛋白,鉴定并注释了39种蛋白.通过对差异表达蛋白功能分析,筛选获得了与纤毛组建相关的筑丝蛋白和与稳定钙离子胞内浓度相关的钙网蛋白,为揭示牡蛎幼体面盘组织及纤毛的退化消失和钙离子有效诱导幼体附着变态的机制提供分子数据.同时还获得了调节脂肪酸β-氧化、三羧酸循环和糖酵解重要生理功能的关键酶蛋白:乙酰辅酶A脱氢酶、异柠檬酸脱氢酶和3-磷酸甘油醛脱氢酶,以及调节无脊椎动物机体能量存储和释放的酶蛋白:精氨酸激酶和ATP合成酶,进一步阐明了牡蛎幼体在附着变态过程中能量调节的分子机制.     

温度变化对刺参同工酶的影响

采用同工酶电泳方法,对在不同温度处理下刺参(Apostichopus japonicus)的乳酸脱氢酶(LDH)、酯酶(EST)和超氧化歧化酶(SOD)的表达情况进行分析。本文结果显示刺参组织内无LDH同工酶的表达。在10℃到20℃的温度突变处理中,12 h内EST和SOD均有新增酶带,在20℃到10℃的温度突变1 h内EST表达有新增酶带。3 h内SOD表达有新增酶带。在不同变温幅度的处理中,EST和SOD只有1条酶带。这表明,刺参对温度突变可产生积极的响应,对于其适应环境温度的变化具有重要意义。     

Studies on the dissolution of diatomaceous silica as a function of heating

Diatomaceous silica, pretreated at various temperatures between 125 and 900C, was subjected to dissolution experiments and was analyzed using X-ray diffraction and infrared spectra. The diatomaceous silica preheated up to 900C, dissolved throughly into the solution of 2 per cent Na₂CO₃. On the digestion in the solution of 2 per cent Na₂SO₄, the dissolution of the silica decreased as the pretreating temperature increase; the degree of dissolution was different for various species. According to infrared absorption studies, the diatomaceous silica pretreated at a temperature below 500C preserved the reversibility of dehydration-rehydration almost qualitatively, while heating above 500C the samples lost the reversibility. Deformation of some kinks of diatomaceous silica pretreated above 500C, was percepted on infrared absorption spectra around 1,150 cm^–1. The samples pretreated up to 900 C, however, did not show such an internal structural change as could be identified by the X-ray diffraction analysis. The content of Al and Fe in diatomaceous silica was low and have not much difference in quality among diatom species. From these experimental results, it was adequately understandable that diatomaceous silica, which has a metastable character, is variable in the silica forms among species and its process and rate of transformation of internal structure and/or surface sites by the treatment at given temperatures also show differences.     

Microwave radiation from water surface as related to its temperature variations in the presence of ripples (a laboratory study)

In this paper the results are presented of measurements of microwave radiation at centimeter wavelengths from water surface under controllable laboratory conditions which included changes in the surface temperature and generation of ripples caused by wind and by ventilator with velocity of air stream up to 3 m/s.     

Acute toxicity of five sediment-associated metals, individually and in a mixture, to the estuarine meiobenthic harpacticoid copepod Amphiascus tenuiremis

The acute effects of many individual, seawater-solubilized metals on meiobenthic copepods and nematodes are well known. In sediments, however, metals most often occur as mixtures, and it is not known whether such mixtures exhibit simple additive toxicity to meiobenthos. The estuarine meiobenthic copepod Amphiascus tenuiremis was tested in four acute (96-h) sediment bioassays to determine sediment and pore-water LC50s for single-metal exposures to copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn). Laboratory-cultured copepods were exposed to clean 98% silt:clay sediments spiked with metal chloride solutions to yield five exposure concentrations plus a control. Trimmed Spearman-Karber analysis gave sediment 96-h LC50 values of 4.4 mumole Cu/g, 5.7 mumole Ni/g, 11.9 mumole Pb/g, 10.3 mumole Zn/g, and pore-water 96-h LC50 values of 2 mumole/l, 11.7 mumole/l, and 5.7 mumole/l for Cu, Ni, and Zn, respectively. Male survival after exposure to Cu, Pb, and Ni was significantly less than female survival (alpha = 0.05). Toxicity of a combined USEPA priority metal mixture to A. tenuiremis was assessed using sediment spiked equitoxically with Cd, Cu, Ni, Pb, and Zn. The sum toxic unit that produced a median lethal dose was 0.72. The mixture had a significantly greater than additive effect on A. tenuiremis survival, with the mixture being 1.4x more toxic than that expected by simple additivity.     

Prediction of the refractive index of seawater as a function of temperature,pressure, salinity and wavelength

An equation is given for predicting the absolute refractive index of seawater as a function of wavelength (in the visible region), temperature, pressure and salinity. This equation is based on the pure-water equation of H. Eisenberg, on the Tammann hypothesis and the Tait-Gibson equation of state for seawater. Comparison with experimental results (to 1380 bars) indicate an accuracy of ca. 0.0001 or better is achieved in the $\text{T-P}$ range of oceanographic interest.     

Temporal variation in abundance and fecundity of the invading copepod Eurytemora americana in Bahía Blanca Estuary during an unusual year

Eurytemora americana has been only reported as invader in Bahía Blanca Estuary, Argentina within the South Hemisphere. There are a few experimental researches under laboratory conditions done with this species and its reproductive behaviour around the world is very scarce. Consequently, it is still not possible to completely understand its population dynamics. In the present study, E. americana reproductive temporal behaviour and relationships among abundance, female size, egg production and hatching success were examined in the Bahía Blanca Estuary, during 2007 pulse. In order to determine the potential relationships between these variables and the environmental variables, experimental incubations were conducted in the laboratory simulating natural conditions. Spearman’s rank correlation was used to analyze the relationships among all variables. Temporal change of biotic and environmental variables was corroborated by a Mann–Whitney/Kruskal–Wallis non-parametric tests, with significant differences (p ? 0.01) in all variables throughout the study. Abundance population results showed very high values in relation to those recorded in recent years in Bahía Blanca Estuary. This response could be due to the unusual combination of environmental factors (polar wave with temperatures ≤6 °C and a drought period with high salinities, 32.7–36.6) recorded during the studied winter period. Significant positive correlations between abundance and salinity (p < 0.01, n = 226), and hatching success (p < 0.01, n = 25) as well as a significant negative correlation between abundance and chlorophyll a (p < 0.01, n = 226) were found. Although E. americana shows a k-strategy within its annual pulse, it presented two markedly distinct behaviours depending on temporal environmental variability. From July to early september, when the estuary evidenced high salinity, low temperature and high food availability, E. Americana showed large females, large clutch size and high hatching success. When environmental conditions became unfavorable from September to October, small females, small clutch size and very low hatching success were observed. The latter is associated with diapause egg laying which ensures population recruitment. According to our findings the particular combination of low temperatures, high salinities and high available food (i.e. variables which each year modulate its pulse) during 2007 winter–spring, favored the great development of E. americana. This invading species in its opportunistic role has managed to exploit a vacant niche in the estuary, developing two different behaviours within the k-strategy depending on change in environmental conditions.     

应用沉积物酸解烃指示南海东部油气潜力的研究

根据沉积物中酸解烃、热释烃以及蚀变碳酸盐,热释光等研究结果,讨论南海东部海区沉积物中烃类气体各组分的含量分布和组合特征,同时与我国其他海域作比较.用Bernaard和Faber关于海洋沉积物烃类气体成因的判断方法,探讨本调查区的烃类气体成因类型,数理统计分析结果与样品烃类气体的异常值相对应.     

The study on the bottom friction and the breaking coefficient for typhoon waves in radial sand ridges--the Lanshayang Channel as an example

Owing to the interactions among the complex terrain, bottom materials, and the complicate hydrodynam-ics, typhoon waves show special characteristics as big waves appeared at the high water level (HWL) ...     

Feeding activity of the copepod Acartia hongi on phytoplankton and micro-zooplankton in Gyeonggi Bay,Yellow Sea

To improve our understanding of the trophic link between micro-zooplankton and copepods in Gyeonggi Bay, Yellow Sea, the diet composition, ingestion rates, and prey selectivity of Acartia hongi, known as the most abundant and widespread copepod species, was estimated by conducting in situ bottle incubation throughout the different seasons. The results showed that A. hongi preferentially grazed on ciliate and heterotrophic dinoflagellate of a size ranging from 20 to 100 μm rather than phytoplankton. Although micro-zooplankton comprised only an average 13.7% of the total carbon available in the natural prey pool, micro-zooplankton accounted for >70% of the total carbon ration ingested by A. hongi throughout the year, except for winter diatom blooming periods when A. hongi obtained about 60% of its carbon ration from phytoplankton. Our results demonstrated that A. hongi modified their diet composition and feeding rates in response to change in composition and size of prey available to them, and that A. hongi preferentially ingested micro-zooplankton over phytoplankton. Feeding activity of A. hongi could therefore affect the species composition and size structure of natural plankton communities in this study area, particularly the micro-zooplankton. Strongly selective feeding and high grazing pressure by A. hongi on micro-zooplankton shows the role of trophic coupling between copepods and the microbial food web in the pelagic ecosystem of Gyeonggi Bay.