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1.
分别自沙蜇和白色霞水母提取刺丝囊毒素蛋白,以小鼠皮下结缔组织细胞(A9)和人横纹肌瘤细胞(A-673)为受试对象,比较两种水母的刺丝囊毒素蛋白对其的细胞毒性,以期为评估和管理两种水母的毒害风险提供科学依据。结果显示:沙蜇和白色霞水母刺丝囊毒素对培养中的A9和A-673细胞存活率都具有抑制作用,且该抑制作用呈显著的时间和剂量依赖性。白色霞水母刺丝囊毒素对A9和A-673细胞毒性的半数效应浓度(如:对A9和A-673的EC50-24h分别为49.8μg/mL和43.6μg/mL)低于沙蜇刺丝囊毒素的半数效应浓度(如:对A9和A-673的EC50-24h分别为78.0μg/mL和70.1μg/mL);两种水母毒素对A-673或A9的细胞毒性强于已报道的根口类和旗口类水母毒素对哺乳动物肺、肝、血管平滑肌、神经、乳腺等的细胞毒性。由此可见,白色霞水母刺丝囊毒素的细胞毒性更强,横纹肌、结缔组织对水母刺丝囊毒素作用敏感。研究结果对于评估水母毒害风险和制定防护对策有重要意义。 相似文献
2.
从霞水母Cyanea sp.中分离刺丝囊,提取刺丝囊毒素(NV),并研究了温度、pH和几种化学组分对其溶血活性稳定性的影响.实验结果表明,在4～37℃范围内NV的溶血活性与温度变化密切相关,毒素在4℃以下几乎没有发生溶血反应,在37℃以下反应45 min以后,溶血活性达到最大值;毒素的溶血活性对pH敏感,在pH 7.8时.溶血活性最强,溶血率为93.53%.EDTA、NaCl和还原型谷胱甘肽(GSH)对NV溶血活性都具有稳定作用.通过正交实验发现,GSH对溶血活性的影响最大,当提取液中含有1.0 mmol/L GSH和5.0 mmol/L NaCl时毒素的溶血活性最强.DTT(二硫苏糖醇)明显降低毒素的溶血活性,说明毒素中溶血蛋白的活性很可能与分布在蛋白质表面的二硫键有关.Ca2+虽然能够增强毒素的溶血活性但是对毒素并没有稳定作用,所以Ca2+可能只是毒素溶血活性的活化剂.甘油对毒素的稳定作用不明显. 相似文献
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4.
为了探讨植物激素在藻类生理与抗逆方面的作用,本文比较了不同浓度的茉莉酸甲酯(MJ)和水杨酸(SA)对坛紫菜(Pyropia haitanensis)生长、藻胆蛋白、可溶性蛋白、脯氨酸含量和叶绿素荧光参数的影响。结果显示100?mol/L SA的添加可使坛紫菜生长率达到对照组的1.57倍,而MJ对藻的生长影响不显著。50?mol/L MJ和100?mol/L SA显著促进了坛紫菜藻胆蛋白和可溶性蛋白的积累。50?mol/L MJ和100?mol/L SA添加后在48 h脯氨酸含量分别为对照组的2.67倍和1.75倍。25~50?mol/L MJ对坛紫菜的Fv/Fm和Y(II)影响不显著,而100?mol/L SA则可以提高这两个叶绿素荧光参数。该研究表明适当浓度的MJ和SA可以促进坛紫菜生长,提高其光合能力,在一定程度上增强坛紫菜的抗逆性。 相似文献
5.
一种钵水母—黄金水母(Chrysaora pacifica)被怀疑是海月水母(Aurelia aurita)碟状幼体的潜在捕食者,为了验证这一假设,在实验室可控条件下进行了以黄金水母幼水母为捕食者、海月水母碟状幼体为猎物的捕食实验。实验结果表明黄金水母幼水母(伞径:9-15mm)能够以海月水母碟状幼体(ca. 2mm)为食。在2 h的实验中,黄金水母幼水母最多摄食了15只海月水母碟状幼体(实验容器容积为450mL)。黄金水母幼水母对海月水母碟状幼体的摄食率在44ind./L和111ind./L的密度下分别为0.8±0.6/ind.·h和1.3±1.0/ind.·h。滤水率在两个密度下分别为0.029±0.024和0.051±0.041L/ind.·h。滤水率随着饵料密度的降低显著提高。实验结果证实黄金水母是海月水母碟状幼体的重要潜在捕食者,并且其对海月水母碟状幼体的捕食可能是影响天然海域中海月水母碟状幼体成活率的重要因素。 相似文献
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南黄海夏秋季纤毛虫等微小型浮游动物丰度和生物量变动及其与沙海蜇旺发的关系 总被引：1，自引：1，他引：0
大型水母沙海蜇旺发已成为黄海夏季的一个常见的生态现象。然而,沙海蜇旺发与微小型浮游动物尤其是纤毛虫的相互作用关系依然不明。本研究基于2013年6月(水母旺发初期)、8月和9月(水母旺发期)三个航次的调查,对黄海水母高发的I(33°N)、G(34°N)、E(35°N)断面的表层微小型浮游动物的丰度及生物量分布变化与水母发生关系进行探讨。微型鞭毛虫丰度6月平均丰度和生物量分别为357ind./m L和3.92μg C/L,至8月降为145ind./m L和2.55μg C/L,9月回升至160ind./m L和2.84μg C/L。共鉴定纤毛虫31属64种,三个月份纤毛虫的种类组成差别不大。纤毛虫6月的平均丰度和生物量分别为2282ind./L和8.93μg C/L,至8月降为933ind./L和3.92μg C/L,9月回升至2319ind./L和6.55μg C/L。与丰度和生物量的较大变化不同,纤毛虫6月的平均生产力为12.74μg C/(L·d),8月降至7.39μg C/(L·d),9月略增至7.79μg C/(L·d)。桡足类无节幼体仅见于6月(10.59ind./L)和8月(8ind./L),在沙海蜇旺发的8月其平均生物量(0.08μg C/L)和生产力(0.032μg C/(L·d))远低于纤毛虫。本研究表明,在南黄海水母发生过程中,纤毛虫在微小型浮游动物的生物量和生产力中占据了主导地位,并受到水母旺发的直接和间接(级联效应)影响。 相似文献
7.
以改良 K 培养液为基础,通过设定不同的 N、P 浓度水平,探讨 N、P 营养盐对克氏前沟藻 Amphidinium klebsii(三亚株)生长及产毒特性的影响.研究结果表明, N、P 均为影响克氏前沟藻生长和产毒的重要因素.低浓度的N、P(N浓度≤4.665×10?4mol·L?1, P浓度≤2.000×10?5mol·L?1)不利于克氏前沟藻生物量的积累,但能促进其生长及毒素的产生;中浓度的N、P(4.665×10?4mol·L?1相似文献
8.
采用不同浓度Zn2 处理坛紫菜叶状体,用紫外分光光度法,测定了光合色素的含量。研究了金属Zn2 对坛紫菜叶状体中光合色素:叶绿素a、藻红蛋白、藻蓝蛋白和别藻蓝蛋白的影响。结果表明:Zn2 在0.5~5.0μmol/L时,有利于光合色素的合成;但在5μmol/L时,叶绿素a含量开始下降,在Zn2 浓度>10μmol/L时各光合色素含量也随浓度的升高而下降,对光合色素产生毒害作用。除去Zn2 后,都表现出向对照组恢复靠近的趋势,但别藻蓝蛋白的恢复较慢。 相似文献
9.
《中国海洋大学学报(自然科学版)》2016,(9)
为进一步丰富水螅水母的多样性记录,同时为海洋生物学和生物海洋学研究提供水母分类学资料,本文对2011年9月采自南海中西部水域的2个疑似水母新种进行了详细研究,通过显微观察、绘图和分类学特征分析,并与其它相似种类进行比较,确定其为2个新种,隶属于花水母亚纲(Anthomedusae Haeckel)、丝螅水母目(Filifera Kühn)、高手水母科(Bougainvillidae Lütken)、单肢水母属(Nubiella Bouillon,1980),将其分别命名为锥形单肢水母(N.conica Li,Huang et Liu.sp.nov.)和半球单肢水母(N.hemisphaerica Li,Lin et Chen,sp.nov.)。模式标本保存于中国海洋大学环境科学与工程学院。 相似文献
10.
台湾海峡花水母亚纲新种和新组合记述 总被引：4，自引：2，他引：4
经研究台湾海峡花水母亚纲有7个新种:长柄高手水母(Bougainvillia longistyla n.sp)、十字八束水母(Koellikerina staurogaster n.sp.)、无手单肢水母(Nubiella atentaculata n.sp.)、江阴隔膜水母(Leuckartiara jianyinensis n.sp.)、漂浮隔膜水母(L.neustona n.sp.)、钝海帽水母(Halitiara obtusus n.sp.)、顶拟海帽水母(Halitiarella apicea n.sp.)和2个新组合:细潜水母(Merga minutum(Xu,Huang and Chen,1991))transl.nor.大囊镰螅水母(Zanclea macrocystae(Xu,Huang and Chen 1991))transl.nov.对螅芽拟镰螅水母(Teissiera polypofera(Xu,Huangand Chen,1991))重新描绘并讨论其分类位置.增补了锥胃内胞水母(Euphysilla pyramidata(Kramp,1955))在胃壁上具有水母芽的图. 相似文献
11.
2015年5月搭载“北斗”渔业调查船、使用渔拖网的采样方式,在整个黄海及东海北部进行系统的走航式大面调查,记录了30°N—39°N海区内的大型水母种类组成、伞径大小及生物量分布,估算和比较了大型水母与其他渔业生物的生物量。结果表明,5月整个调查区,大型水母的总生物量估算值5.9万t,绝大部分由黄海中部的多管水母和洋须水母生物量贡献所致。出现的大型水母种类伞径分布呈单峰型。不同种类的水母分布具有明显地理区域和水文偏好性。其中,洋须水母主要分布于黄海中、北部50m水深以深水域,多管水母主要分布于黄海中部50m水深以浅的西侧以及整个东海北部;沙海蜇多为幼体,分布于黄、东海交汇区31°N—33°N间;霞水母较为集中出现于31°N以南、123°N以西近海。各水母种类的高密区的底层水温按洋须水母、沙海蜇、四叶小舌水母、霞水母呈升高趋势。东海多管水母分布区的底层水温与沙海蜇相近;黄海多管水母分布区的底层水温较洋须水母略高。沙海蜇和四叶小舌水母较其他水母的适温范围宽。霞水母和洋须水母处于相对高盐区域。 相似文献
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James N. Butler 《Marine Chemistry》1992,38(3-4)
Displaying “calculated minus observed” data for precise titrations of seawater with strong acid permits direct evaluation of important parameters and detection of systematic errors.At least two data sets from the GEOSECS (Geochemical Ocean Sections) program fit an equilibrium model (which includes carbonate, borate, sulfate, silicate, fluoride, and phosphate) within the most stringent experimental error, less than 2 μmol kg−1. The effect of various parameters on the fit of calculated to observed values depends strongly on pH. Although standard potential E0, total alkalinity At, total carbonate Ct, and first acidity constant of carbon dioxide pK1 are nearly independent, and can be determined for each data set, other parameters are strongly correlated. Within such groups, all but one parameter must be determined from data other than the titration curve.Adding an acid-base pair to the theoretical model (e.g. Cx=20 μmol kg−1, pKx=6.2) produces a deviation approaching 20 μmol kg−1 at constant Ct; however, adjustment of Ct by about −18 μmol kg−1 to produce a good fit leaves only ± 1.5 μmol kg−1 residual deviation from the reference values. Thus, at current standards of precision, an unidentified weak acid cannot be distinguished from carbonate purely on the basis of the titration curve shape.There are few full sets of numerical data published, and most show larger systematic errors (3–12 μmol l−1) than the above; one well-defined source is experiments performed in unsealed vessels. Total carbonate can be explicitly obtained as a function of pH by a rearrangement of the titration curve equation; this can reveal a systematic decrease in Ct in the pH range 5–6, as a result of CO2 gas loss from the titration vessel. Attempts to compensate for this by adjustment of At, Ct, or pK1 produce deviations which mimic those produced by an additional acid-base pair.Changing from the free H+ scale (for which [HSO4−] and [HF] are explicit terms in the alkalinity) to the seawater scale (SWS) (where those terms are part of a constant factor multiplying [H+]) requires modification of the titration curve equation as well as adjustment of acidity constants. Even with this change, however, omission of pH-dependent terms in [HSO4−] and [HF] produces small systematic errors at low pH.Shifts in liquid junction potential also introduce small systematic errors, but are significant only at pH <3. High-pH errors due to response of the glass electrode to Na+ as well as H+ can be adequately compensated to pH 9.5 by a linear selectivity expression. 相似文献
13.
Jellyfish populations in the southeastern Atlantic off the coast of Namibia have increased subsequent to the decline of small pelagic fisheries at the end of the 1960s, although the environment there has also become warmer and the waters off Walvis Bay have become richer in zooplankton in recent years. Laboratory experiments were conducted with the scyphozoan jellyfish Chrysaora fulgida to investigate the effects of food density (0, 30, 70, 100 or 150 Artemia nauplii 200 ml?1), feeding frequency (once daily or once every third day) and water temperature (12, 16 or 20 °C) on the asexual reproduction, growth and development of polyps. The results of a generalised linear mixed-effects model reveal that all variables impacted asexual reproduction, with greater polyp production attained at higher food concentrations, increased feeding frequencies and increased temperatures. The most common mode of asexual reproduction was by lateral budding. These laboratory results suggest that polyps of C. fulgida may have proliferated off Namibia in recent times, which would contribute to increased numbers of jellyfish there. 相似文献
14.
Predation by jellyfish on large and emergent zooplankton: Implications for benthic–pelagic coupling 总被引：1，自引：0，他引：1
Kylie A. Pitt Anne-Laure Clement Rod M. Connolly Delphine Thibault-Botha 《Estuarine, Coastal and Shelf Science》2008,76(4):827-833
Stable carbon isotopes were used to determine the contribution of emergent demersal zooplankton to the diet of the scyphozoan jellyfish Catostylus mosaicus at Smiths Lake, New South Wales, Australia. A preliminary study in 2004 indicated that there was no difference in the δ13C of ectodermal tissue and mesoglea of the medusae. In 2005, medusae and zooplankton present during the day and night were sampled and isotopic signatures were modelled using IsoSource. Modelling indicated that: (1) mollusc veligers and copepods sampled during the day contributed <13% of the carbon to the jellyfish; (2) copepods sampled at night contributed up to 25%; and (3) the large, emergent decapod Lucifer sp. contributed 88–94%. We hypothesised, therefore, that medusae derive most of their carbon from emergent species of zooplankton. In 2006, sampling done in 2005 was repeated three times over a period of 4 weeks to measure short-term temporal variation in isotopic signatures of medusae and zooplankton, and emergent demersal zooplankton was specifically sampled using emergence traps. Short-term temporal variation in isotopic signatures was observed for some taxa, however, actual variations were small (<1.5‰) and the values of medusae and zooplankton remained consistent relative to each other. IsoSource modelling revealed that mysid shrimp and emergent copepods together contributed 79–100% of the carbon to the jellyfish, and that the maximum possible contribution of daytime copepods and molluscs was only 22%. Jellyfish apparently derive most of their carbon from emergent zooplankton and by capturing small numbers of relatively large taxa, such as Lucifer sp. or mysid shrimp. Small but abundantly captured zooplankton (such as mollusc veligers) contribute only minor amounts of carbon. Jellyfish have a major role in the transfer of carbon between benthic and pelagic food webs in coastal systems. 相似文献
15.
《African Journal of Marine Science》2013,35(3):391-399
Rates of respiration and ammonia excretion of Euphausia hanseni and Nematoscelis megalops were determined experimentally at four temperatures representative of conditions encountered by these euphausiid species in the northern Benguela upwelling environment. The respiration rate increased from 7.7 µmol O2 h?1 gww ?1 at 5 °C to 18.1 µmol O2 h?1 gww ?1 at 20 °C in E. hanseni and from 7.0 µmol O2 h?1 gww ?1 (5 °C) to 23.4 µmol O2 h?1 gww ?1 (20 °C) in N. megalops. The impact of temperature on oxygen uptake of the two species differed significantly. Nematoscelis megalops showed thermal adaptations to temperatures between 5 °C and 10 °C (Q10 = 1.9) and metabolic constraint was evident at higher temperatures (Q10 = 2.6). In contrast, E. hanseni showed adaptations to temperatures of 10–20 °C (Q10 = 1.5) and experienced metabolic depression below 10 °C (Q10 = 2.6). Proteins were predominantly metabolised by E. hanseni in contrast to lipids by N. megalops. Carbon demand of N. megalops between 5 and 15 °C was lower than in E. hanseni versus equal food requirements at 20 °C. It is concluded that the two species display different physiological adaptations, based on their respective temperature adaptations, which are mirrored in their differential vertical positioning in the water column. 相似文献
16.
Lúcia Maria O. Gusmão Xiomara Franchesca G. Diaz Mauro de Melo Jr Ralf Schwamborn Sigrid Neumann‐Leitão 《Marine Ecology》2015,36(1):93-103
Jellyfish are often the most prominent components of plankton, with severe consequences for fisheries and tourism. However, in tropical regions, there is much uncertainty about these consequences due to the lack of basic data. Our objective was to improve the knowledge about jellyfish in the Western Atlantic, with an emphasis on understanding diversity, abundance, and distribution patterns. Samples were collected at 34 stations in 1995 using a 300‐μm‐mesh Bongo net. The 21 species identified belonged to Hydromedusae (11), Siphonophora (nine), and Scyphomedusae (one). The overall mean density was low (5.2 ± 5.3 ind. m?3). Total Hydromedusae biomass was 130.86 mg C m?3, and total Siphonophora biomass was 19.04 mg C m?3. Chelophyes appendiculata (Eschscholtz, 1829) was the most frequent species captured in the oceanic samples, and Aglaura hemistoma (Péron & Lesueur, 1810) was the most common in the neritic region. The latter species is sometimes characterized as a bloom associated with the most polluted and eutrophic river plumes. The main role of jellyfish species in the area is as a higher‐order carnivore. A cross‐shelf significant difference (P < 0.05) was registered, with higher species numbers in oceanic regions and higher densities and biomass in neritic regions. 相似文献
17.
Collapse of zooplankton stocks during Liriope tetraphylla (Hydromedusa) blooms and dense mucilaginous aggregations in a thermohaline stratified basin 
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下载免费PDF全文 Izzet Noyan Yilmaz 《Marine Ecology》2015,36(3):595-610
A growing number of studies report an increase in jellyfish populations worldwide that may have consequences for marine planktonic food web dynamics. The principal objective of this study was to understand the changes in a zooplankton community during blooms of Liriope tetraphylla and subsequent mucilage events in the Sea of Marmara, a small highly stratified transitional basin between the Black and Aegean Seas. Liriope blooms observed in 2006 and 2007 reached a maximum abundance of 2978 ind.·m?3, following the species' first observation in 2005. Jellyfish species are known to play a key guild role by restructuring plankton communities and in the Sea of Marmara Liriope caused a temporal regime shift from a crustacean‐ to a jellyfish‐controlled system. A rapid decline in abundance of most important zooplankton species followed the Liriope increase, together with a drastic shift in community structure. The dominant summer–autumn species Penilia avirostris (Cladocera) vanished in the autumn of 2006 and was diminished ~30‐fold in 2007 when compared with years without Liriope. The decline in zooplankton and the devastating effects of mucilage on pelagic ecosystem and socio‐economics through restricting commercial fisheries implied sensitivity of the already perturbed Marmara ecosystem to changes in predator densities and environmental stability. 相似文献
18.
2019年5月,利用渔业底拖网,对我国黄海以及东海北部海域进行了全面系统的大型水母调查,分析了大型水母的种类组成、伞径大小和生物量以及与温度、盐度的关系。结果表明,本次调查主要捕获到沙海蛰、霞水母、洋须水母、多管水母四种大型水母,沙海蛰生物量最高,多管水母分布范围最广、数量最大。沙海蛰集中分布在调查海域南部,各海域伞径差异显著,在黄东海交界海域采集到幼水母体(10cm),生物量高值区出现在东海北部离岸海域,可达6422.16kg/km2;白色霞水母集中分布在东海北部,在近岸海域采集到幼水母体(6—7cm),生物量高值区位于离岸海域,可达7417.49kg/km2;洋须水母集中分布在黄海水深较深海域,北部海域个体较大,在黄海中部、南部交界处采集到幼水母体(10cm),生物量较低,高值区出现在黄海中部与南部,可达449.94kg/km2;多管水母分布范围较广,东海北部海域个体伞径较大,在山东半岛东部发现幼水母体(5cm),生物量高值区出现在黄海中部近岸海域,可达4901.42kg/km2。对比文献资料,发现整个调查海域,大型水母总体生物量比2015年同期有所增加。本文为研究该海域大型水母的年际变化规律提供数据基础。 相似文献
19.
The concentrations of total carbonate (Ct), sulphate, sulphide, thiols and oxygen, the ratio between the stable sulphur isotopes 34S and 32S in sulphate and sulphide, and the density (used to calculate salinity) were determined on samples from the water column of Framvaren, a superanoxic fjord in southern Norway. From a depth of 18m (the oxic-anoxic boundary) the initial sulphate concentration, ([SO4]init), as calculated from salinity, is significantly higher than the sum of the measured sulphur species. This is attributed to a loss of sulphur from the water column. The amount of total carbonate produced, corrected for the initial concentration (Ct - 2.4 Sal/35) is found to be proportional to the amount of sulphate consumed, ([SO4]init - [SO4]), according to the following relation Ct- 2.4 Sal/35 = 1.84 ([SO4]init - [SO4]). Isotopic fractionation caused by bacterial sulphate reduction in the anoxic part of the water column produces sulphide with a δ34S 40‰ lower than the δ34S for sulphate at corresponding depths. The isotopic fractionation also results in δ34S value for the remaining sulphate at depths below 80 m being considerably higher than the mean value for ocean water, which is close to + 20‰. The δ34S values for sulphate at depths between 10 and 50 m were lower than + 20‰ which indicates oxidation of sulphide, which follows upon diffusion of sulphide from deeper parts of the water column and inflow of oxygenated seawater over the sill into the anoxic water of the fjord. A conclusive scenario of the Framvaren sulphur chemistry is presented. 相似文献
20.
《African Journal of Marine Science》2013,35(1):523-529
Feeding periodicity, consumption rate, absorption efficiency, respiration rate and ammonia excretion were measured as functions of wet body mass in abalone collected from the western and southern Cape coasts. A well developed diel feeding rhythm was evident, consumption being restricted to the period 16h00–08h00. Food intake averaged 8,1 per cent of wet flesh mass·d?1 at 14°C and 11,4 percent at 19°C. The daily consumption rate was related to body mass by the relationships C(g) = 0,54 W(g)0,67 at 14°C and C(g) = 0,35 W(g)0,77 at 19°C. Absorption efficiency averaged 37 per cent and was independent of body size. Equations relating respiration rate to wet body mass were R(m? O2·h?1) = 0,03 W(g)0,83 at 14°C and R = 0,03 W(g)0,94 at 19°C. No significant differences were detected between day and night rates or between fed and starved individuals. The rate of ammonia excretion (μmole·h?1) was related to wet body mass (g) by the equations U = 0,22 W0,43 at 14°C and U = 0,03 W0,85 at 19°C. 相似文献