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1.
报道了KCl对方斑东风螺(Babylonia aerolato Link)浮游幼虫变态的诱导作用.结果表明,在水体200 mL,幼虫20只,KCl连续作用12 h的条件下,当KCl浓度不超过8×10-3 mol/L且幼虫日龄小于12 d时,诱导变态率为0～15%,诱导效果不稳定;当KCl浓度达到11×10-3 mol/L且幼虫日龄达到15 d时,浮游幼虫变态率超过95%.在水体850 L,幼虫2.0×105～2.5×105只,KCl连续作用9 h的条件下,KCl浓度为17×10-3mol/L,日龄15 d的幼虫变态率达90%.浮游幼虫日龄越大,KCl添加浓度越高,作用时间越长,KCl诱导变态作用越明显.KCl对方斑东风螺幼虫有毒性作用,日龄越小,浓度越大,作用时间越长,毒性越大.日龄12 d的浮游幼虫,KCl添加浓度11×10-3mol/L作用20 h诱导变态的稚螺,未发现其生长和存活受到KCl的不良影响.综合本实验的结果,KCl诱导变态较为安全有效的条件是:浮游幼虫日龄不小于15 d,添加浓度11×10-3～14×10-3 mol/L,作用时间不超过12 h. 相似文献
2.
报道了KCl对方斑东风螺(Babylonia aerolatoLink)浮游幼虫变态的诱导作用。结果表明,在水体200 mL,幼虫20只,KCl连续作用12 h的条件下,当KCl浓度不超过8×10-3mol/L且幼虫日龄小于12 d时,诱导变态率为0~15%,诱导效果不稳定;当KCl浓度达到11×10-3mol/L且幼虫日龄达到15 d时,浮游幼虫变态率超过95%。在水体850 L,幼虫2.0×105~2.5×105只,KCl连续作用9 h的条件下,KCl浓度为17×10-3mol/L,日龄15 d的幼虫变态率达90%。浮游幼虫日龄越大,KCl添加浓度越高,作用时间越长,KCl诱导变态作用越明显。KCl对方斑东风螺幼虫有毒性作用,日龄越小,浓度越大,作用时间越长,毒性越大。日龄12 d的浮游幼虫,KCl添加浓度11×10-3mol/L作用20 h诱导变态的稚螺,未发现其生长和存活受到KCl的不良影响。综合本实验的结果,KCl诱导变态较为安全有效的条件是:浮游幼虫日龄不小于15 d,添加浓度11×10-3~14×10-3mol/L,作用时间不超过12 h。 相似文献
3.
两种东风螺幼虫附着和变态的化学诱导研究 总被引：15，自引：1，他引：15
在持续24h作用下,12×10-3mol/dm3 K+可有效地诱导台湾东风螺(Babylonia formosae)和方斑东风螺(B.aerolata)的浮游幼虫90%以上完全变态.持续作用24h,15×10-3mol/dm3 K+对方斑东风螺幼虫有毒害作用,但作用12h可取得较好的诱导效果.增加K+诱导变态的稚贝能正常活动和摄食.增加K+诱导的幼虫变态率随幼虫平均壳高的增大而提高.L-多巴、肾上腺素和去甲肾上腺素在5.5×10-6～5.5×l0-5mol/dm3时对方斑东风螺幼虫的变态无诱导活性,而多巴胺在10-4mol/dm3时可诱导较12×10-3mol/dm3 K+约少一半的变态率.钾通道阻滞剂TEA对K+诱导两种东风螺幼虫变态无阻抑作用.根据添加KCl诱导幼虫变态试验结果,初步认为幼虫获得变态能力时的壳高,在台湾东风螺是860.2～1009.8μm,在方斑东风螺是849.6～956.0μm.两种东风螺的浮游幼虫均有变态延迟现象. 相似文献
4.
本文报道了4种微藻不同浓度对方斑东风螺幼虫生长和变态的影响.结果表明,幼虫对4种微藻都能摄食,当投喂不同浓度的牟氏角毛藻、湛江叉鞭金藻时,摄食角毛藻(20×104cells/cm3)生长最快达77.9μm/d、变态率52.5%;摄食金藻(20×104cells/cm3)变态率最高达59.0%、生长速度70.4μm/d,随金藻浓度的上升,幼虫生长速度和变态率都上升.投喂不同浓度的青岛大扁藻时,最高变态率是24.4%(1×104cells/cm3),最快生长速度是59.3μm/d(7×104cells/cm3),随扁藻浓度的上升,幼虫的生长速度上升而变态率下降.摄食云微型藻幼虫生长缓慢,浮游期全部死亡.幼虫单独摄食角毛藻、金藻和扁藻,其首次出现变态个体的日龄分别是10、11、14d,而完成变态的日龄分别是22~23d、21~23d和26~28d.比较上述4种微藻,角毛藻和金藻是方斑东风螺幼虫的最适饵料,根据大水体人工育苗的具体条件,合适浓度应为角毛藻(5~10)×104cells/cm3,金藻(10~15)×104cells/cm3.而扁藻不宜单独投喂,作为辅助饵料较合适. 相似文献
5.
《海洋湖沼通报》2016,(5)
以不同浓度的氯化钾(KCl)和γ-氨基丁酸(GABA)处理皱纹盘鲍后期面盘幼虫,处理不同时间后,观察并分析KCl和GABA对皱纹盘鲍幼虫附着变态的诱导作用。结果表明,低浓度组,KCl(10mmol/L、12h)和GABA(10~(-6) mmol/L、6和12h)均可显著提高其附着和变态率,GABA组诱导效果优于KCl组,GABA(10~(-6) mmol/L、6h)处理组优于12h处理组。高浓度组,KCl(100、200和300mmol/L)和GABA(10~(-4)、10~(-3)和10~(-2) mmol/L)随着浓度的提升和诱导时间的延长,幼虫附着变态率降低,死亡率升高。综合考虑附着率、变态率、死亡率及实验成本等因素,低浓度的KCl(10mmol/L、12h)和GABA(10-6 mmol/L、6h)都可以广泛应用于生产中,来提高幼虫的附着变态率,增加发育的同步性,降低死亡率。 相似文献
6.
以不同浓度的氯化钾(KCl)和γ-氨基丁酸(GABA)处理皱纹盘鲍后期面盘幼虫,处理不同时间后,观察并分析KCl和GABA对皱纹盘鲍幼虫附着变态的诱导作用。结果表明,低浓度组,KCl(10mmol/L、12h)和GABA(10-6 mmol/L、6和12h)均可显著提高其附着和变态率,GABA组诱导效果优于KCl组,GABA(10~(-6) mmol/L、6h)处理组优于12h处理组。高浓度组,KCl(100、200和300mmol/L)和GABA(10~(-4)、10~(-3)和10~(-2) mmol/L)随着浓度的提升和诱导时间的延长,幼虫附着变态率降低,死亡率升高。综合考虑附着率、变态率、死亡率及实验成本等因素,低浓度的KCl(10 mmol/L、12h)和GABA(10~(-6) mmol/L、6h)都可以广泛应用于生产中,来提高幼虫的附着变态率,增加发育的同步性,降低死亡率。 相似文献
7.
几种神经活性物质对海湾扇贝幼虫变态诱导作用的研究 总被引：14，自引：3，他引：11
本文研究了儿茶酚胺类和金属离子对海湾扇贝幼虫变态的诱导作用,结果显示;外加10-4-10-6mol/dm3的肾上腺素,10-5mol/dm3的去甲肾上腺素和L-多巴具有十分显着的诱导能力;外加10-15mmol/dm3K+和Ca2+处理幼虫一段时间后,对其变态有明显促进作用。实验研究了最适浓度下肾上腺素、L-多巴和KCl不同处理时间对幼虫变态的影响,表明幼虫对肾上腺素和L-多巴表现出很高的敏感性,而对KCl则表现出对时间和剂量较强的依赖性。 相似文献
8.
以不同浓度的氯化钾(KCl)溶液处理仿刺参(Apostichopus japonicus)樽形幼虫,处理不同时间后,分析KCl对仿刺参幼虫附着变态的诱导作用。结果表明,使用较低浓度的KCl溶液(10、30和50 mmol/L)分别诱导仿刺参樽形幼虫6、12和24 h均可以显著提高其附着变态率,诱导24 h附着变态率分别提高27.67%、32.67%和19.67%。较高浓度的KCl溶液(100、300和500 mmol/L)也可以诱导仿刺参幼虫附着变态,但随着KCl浓度的升高和诱导时间的延长,幼虫死亡率逐渐升高。低浓度KCl溶液,特别是在30 mmol/L诱导仿刺参幼虫12 h时,可以显著提高幼虫的附着变态率,增加发育的同步性,降低死亡率,对仿刺参幼虫变态的诱导效果较好。 相似文献
9.
L-DOPA对西施舌眼点幼虫附着变态诱导的研究 总被引：2，自引：0，他引：2
采用试验水体中添加化学诱导物的方法研究L-DOPA(L-多巴)对西施舌(Coelomctraantiquata)眼点幼虫附着变态的诱导作用。结果表明,L-DOPA能诱导西施舌眼点幼虫变态,但对其附着的诱导效果不明显。用直径小于1 mm的细沙为附着基质,1×10-6mol/L的L-DOPA处理西施舌眼点幼虫12 h,变态率为73.3%,对照组为62.6%。浓度为1×10-7mol/L的L-DOPA处理西施舌幼虫12 h,生长速率为25.6%,对照组为14.7%,表明适当浓度的L-DOPA能促进西施舌幼虫的生长。在无沙附着的条件下,西施舌幼虫可正常附着变态,但生长速率较低且变态后死亡率高。 相似文献
10.
用KCl、肾上腺素（EPI）、去甲肾上腺素（NE）、L—DOPA和GABA（γ-氨基丁酸）进行了不同浓度不同处理时间对硬壳蛤（Mercenaria mercenaria L ）幼虫变态诱导实验。结果表明，KCl、肾上腺素、去甲肾上腺素和DDOPA对硬壳蛤幼虫的变态均有诱导作用，而GABA的诱导作用不显著。KCl的最佳诱导浓度随处理时间不同而有所不同。处理时间为1～24，48，72h时KCl的最佳诱导浓度分别为33．56，20．13～26．85，13．42mmol／L。肾上腺素和去甲肾上腺素的诱导作用与浓度和处理时间均有关。肾上腺素的最佳处理浓度为100μmol／L，最佳处理时间均为8h，此时幼虫变态率提高最大，为36．97个百分点。当去甲肾上腺素的诱导浓度为100μmol／L，处理时间为8～16h时，幼虫变态率提高也较大，均大于18个百分点，死亡率增加，但均低于30个百分点，当去甲肾上腺素诱导浓度为500μmol／L时，虽然在8～16h的处理时间范围内，幼虫变态提高率也较大，均大于18个百分点，但当处理时间超过8h，在16～48h范围内，幼虫死亡率提高明显增大，均大于50个百分点。L-DOPA的适宜诱导浓度为10～50μmol／L，适宜处理时间为8～24h，此时幼虫变态率均提高30个百分点以上，最高可提高79．43个百分点。GABA的诱导作用较弱，最佳诱导浓度随处理时间的不同而有所不同，处理时间为24h和48h时，最佳诱导浓度为0．1μmol／L；处理时间为0．5～16h时，最佳诱导浓度为100μmol／L。 相似文献
11.
研究了赤潮异弯藻(Heterosigma akashiwo)在不同浓度的Fe(NH4)2(SO4)2.6H2O(Fe1)和FeSO4.7H2O(Fe2)(浓度分别为:高铁150 nmol/L、低铁50 nmol/L,缺铁0 nmol/L Fe0)中的种群消长过程、单位细胞总多糖特征、光合色素chla、chlc变化以及NO3--N的吸收情况。结果表明,Fe2 浓度影响到赤潮异弯藻的消亡:缺铁组比高铁组种群消亡慢。在平台期和衰亡期时,Fe1各组单位细胞总多糖含量均明显高于Fe2各组。从平台期到衰亡期,各组单位细胞多糖含量明显增加,Fe2各组增量最大,Fe1各组多糖倍增与Fe0相似。亚铁离子浓度的进一步增加有利于单位细胞色素chla和chlc的积累。亚铁离子的不同化合物状态影响到多糖和光合色素的累积,但不影响种群生长率和对NO3--N的吸收。 相似文献
12.
为了评估海洋酸化和富营养化耦合作用对近海浮游生态环境的影响,本研究以天津市近岸海域浮游植物群落的生物地球化学指标为研究对象,分别采用一次性及连续培养的方式模拟自然水华及稳态条件,探究其对二氧化碳(CO2)和硝酸盐浓度变化及二者耦合作用的响应。实验条件设置如下:1)对照:二氧化碳分压p(CO2)40.53 Pa、无硝酸盐添加;2)酸化:p(CO2)101.3 Pa、无硝酸盐添加;3)加N:p(CO2)40.53 Pa、添加硝酸盐50 μmol·L–1;4)酸化加N:p(CO2)101.3 Pa、添加硝酸盐50 μmol·L–1。实验结果表明,硝酸盐加富比酸化更加显著地促进浮游植物群落总叶绿素(Chl a)生物量及颗粒有机碳(POC)和颗粒有机氮(PON)积累,酸化和加N使浮游植物群落粒径大小升高。连续培养实验表明,酸化和N加富对Chl a、生物硅(BSi)、PON浓度、PON与颗粒有机磷(POP)比值(N/P)、POC与BSi比值(C/BSi)及沉降速率有协同交互作用,对POP和POC浓度及POC与PON比值(C/N)有拮抗性交互作用。在一次性培养后,酸化显著降低了浮游植物群落的沉降速率;而在连续培养后,酸化和N加富使浮游植物群落沉降速率显著升高。这些结果表明酸化和N加富对与近岸浮游植物相关的生物地球化学循环及在不同生长阶段的种群碳沉降存在不同的潜在影响及交互效应。 相似文献
13.
钝顶螺旋藻的硝酸还原酶与氢酶之间的电子竞争 总被引：2，自引：0，他引：2
于1994年6－11月，运用生物化学方法以钝项螺旋藻为材料制备整体细胞和无细胞提取物。测定表明，整体细胞硝酸还原酶与氢酶活性的相互关系和无细胞提取物氢酶与硝酸还原酶的（对还原甲基紫精）Km值，分别为2．299×10－7mol／L和1．098×10－7mol／L；证实在硝酸还原酶与氢酶之间存在着电子竞争。 相似文献
14.
Concentrations of Se in the pore-water and in the solid phase, and the concentrations of other diagenetic constituents (Fe, Mn, phosphate, ammonium and I) in pore-water, were determined in a sediment core from a 350-m deep station in the lower St. Lawrence Estuary. The concentration of dissolved Se in pore-water was 2.1 nmol kg−1 at the surface of the core, increasing to a maximum of 7.6 nmol kg−1 at a depth of 12 cm, and thereafter decreasing gradually with depth. This profile is similar to the profiles of Fe and phosphate, whose concentration maxima occur around 10 cm. The concentration of total sedimentary Se remained almost constant with depth (≈ 0.75 mg kg−1); however, a significant enrichment of oxalate-leachable Se was observed in the top 2 cm. The sedimentary cycling of Se appears to be closely related to that of Fe: adsorption of Se onto Fe oxyhydroxide at or near the sediment-water interface, release of the adsorbed Se by the reduction of Fe oxyhydroxide, and removal by formation of ferroselite (FeSe2) at depth. The pore-water flux of Se was estimated by two different methods, firstly from the pore-water gradient, and secondly by applying a box model to the oxalate-leachable solid-phase Se data. The methods agree well both giving values for the flux of 0.11 nmol cm−2 year−1. This agreement suggests that the loss of labile Se in the sediment is balanced by the upward flux of dissolved Se. 相似文献
15.
Measurements have been made, by amperometric titration using anodic stripping voltammetry, of the zinc-binding properties of organic material released by Thalassiosira fluviatilis in culture over a period from the beginning of growth to senescence. After the onset of the stationary phase, titration curves showed two inflection points, interpreted as indicating the presence of two analytically distinguishable ligand assemblages (L1 and L2). The complexing capacities (CL) of these assemblages changed with time, CL1 increasing linearly from <0.5 × 10?8 M to 2.0 × 10?6 M into the stationary phase and then more rapidly during senescence, and CL2 increasing after its initial appearance to a final value of 4.4 × 10?6 M. These changes were accompanied by systematic decreases in the corresponding conditional stability constants (K′) calculated for 1 : 1 associations of the ligands with zinc. Values of log K′1 decreased from 6.6 to 5.8, and those of log K′2 from 7.2 to 6.2. The presence of the second ligand assemblage may be related to the release of intracellular material during senescence. 相似文献
16.
《Marine Chemistry》2007,103(1-2):122-130
Phosphomolybdenum blue (PMB) paired with cetyltrimethylammonium bromide (CTAB) can be extracted using a solid phase extraction technique on C18 sorbent. Based on this, a novel on-line solid phase extraction method coupled with flow injection (FI) analysis and colorimetric detection has been established to determine nanomolar level orthophosphate in seawater. A stopped flow technique was employed to assure the complete formation of the PMB–CTAB compound, which was sequentially extracted on an in-line Sep-Pak C18 cartridge. The adsorbed PMB–CTAB can be rapidly eluted by 0.56 mol/L H2SO4 in ethanol, and determined with a spectrophotometer at 700 nm. Experimental parameters, including reaction temperature, sample loading flow rate, stopped time and eluting flow rate, were optimized throughout the experiments based on univariate experimental design. The results show that reaction temperature and stopped time were the major factors affecting the formation of PMB–CTAB. Silicate concentration up to 5000 times higher than that of orthophosphate would not interfere with the determination of orthophosphate. Using artificial seawater with salinity of 35 as a matrix under the optimized conditions, the standard curve shows a linear range between 3.2 and 48.5 nmol/L, and the recovery and the detection limit of the proposed method are 96.4% and 1.57 nmol/L, respectively. The relative standard deviation (RSD) (n = 8), which was determined daily for 8 days, was 4.52% for the artificial seawater at a concentration of 32.4 nmol/L orthophosphate. Two typical seawater samples were analyzed using both the proposed method and the MAGnesium hydroxide-Induced Coprecipitation (MAGIC) method. The results of the two methods show no significant difference using the t test. Compared to the MAGIC method, the proposed method has the advantage of being more sensitive, faster, sample saving and easy for on-line analysis. 相似文献
17.
The northern part of Okinawa Island suffers from red soil pollution—runoff of red soil into coastal seawater—which damages coastal ecosystems and scenery. To elucidate the impacts of red soil pollution on the oxidizing power of seawater, hydrogen peroxide (HOOH) and iron species including Fe(II) and total iron (Fe(tot), defined as the sum of Fe(II) and Fe(III)) were measured simultaneously in seawater from Taira Bay (red-soil-polluted sea) and Sesoko Island (unpolluted sea), off the northern part of Okinawa Island, Japan. We performed simultaneous measurements of HOOH and Fe(II) because the reaction between HOOH and Fe(II) forms hydroxyl radical (•OH), the most potent environmental oxidant. Gas-phase HOOH concentrations were also measured to better understand the sources of HOOH in seawater. Both HOOH and Fe(II) in seawater showed a clear diurnal variation, i.e. higher in the daytime and lower at night, while Fe(tot) concentrations were relatively constant throughout the sampling period. Fe(II) and Fe(tot) concentrations were approximately 58% and 19% higher in red-soil-polluted seawater than in unpolluted seawater. Gas-phase HOOH and seawater HOOH concentrations were comparable at both sampling sites, ranging from 1.4 to 5.4 ppbv in air and 30 to 160 nM in seawater. Since Fe(II) concentrations were higher in red-soil-polluted seawater while concentrations of HOOH were similar, •OH would form faster in red-soil-polluted seawater than in unpolluted seawater. Since the major scavenger of •OH, Br−, is expected to have similar concentrations at both sites, red-soil-polluted seawater is expected to have higher steady-state •OH concentrations. 相似文献
18.
The thermal phase transformation of the iron-manganese phase of the Pacific Ocean manganese nodules were studied by the differential thermal and X-ray diffraction methods. X-ray powder patterns of the heated samples at the temperature of 600°C to 1000°C show the occurrence of hematite, bixbyite and cubic and tetragonal (Fe, Mn)3O4. Bixbyite produced by the heat treatment of the iron-manganese phase gives an abnormal X-ray pattern in comparison with the standard sample of bixbyite. Cubic (Fe, Mn)3O4 is produced not only by the reaction of bixbyite with hematite over 900°C, but also at the lower temperature, such as 600°C. While, tetragonal (Fe, Mn)3O4 is a reaction product of cubic (Fe, Mn)3O4 with bixbyite over 900°C in the case of manganese rich nodules. The species and quantities of the products after the heat treatment are assumed to be mostly influenced by the relative contents of iron and manganese in the manganese nodule. 相似文献
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采用过氧化氢法降解了相对分子质量约为141万±8.3万的海藻异枝麒麟菜(Eucheuma striatum Schmitz)硫酸多糖(ESPS),降解产物平均相对分子质量为4 819±440.降解后多糖的硫酸基(OSO2-3)质量分数稍有下降,由16.03%降至15.20%左右.同时,用体外模拟方法研究了降解前后ESPS对草酸钙(CaOxa)晶体生长的抑制作用,降解后的ESPS明显优于未降解多糖,其诱导生成的一水草酸钙(COM)晶体尺寸进一步减小,晶体数量减少,且棱角更为圆钝.表明低分子质量ESPS更能抑制CaOxa晶体的成核和生长. 相似文献