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1.
【目的】研究威氏海链藻在不同盐度条件下的生长和生化组分变化。【方法】设置盐度梯度为5、15、25、35、45,采用血细胞计数板计数法、热乙醇提取法、尼罗红染色法、苯酚硫酸法和考马斯亮蓝法,分别测定威氏海链藻在不同盐度下的生物量、叶绿素a、类胡萝卜素、中性脂质、总糖和蛋白质含量。【结果】盐度对威氏海链藻细胞密度影响显著(P<0.05),当盐度25和盐度35时,培养8 d细胞密度最高,均为2.0×106 mL-1;盐度对威氏海链藻叶绿素a和类胡萝卜素含量有显著影响(P<0.05),当盐度15时,细胞叶绿素a和类胡萝卜素含量均最高,分别为3.4814μg/mL(4 d)、2.3549μg/mL(8 d)。盐度对威氏海链藻可溶性总糖含量有显著影响(P<0.05),当盐度15时,8 d时可溶性总糖积累含量最高,为123μg/mL。当盐度35时,6 d时可溶性蛋白积累含量最高,为142.9μg/mL,且显著高于其他实验组(P<0.05)。盐度45时,8 d时中性脂含量最高,显著高于其他实验组(P<0.05)。【结论】盐度为15~35时,威氏海链藻生长速度较快,生化组成较为稳定,盐度15时最有利于藻细胞叶绿素a和类胡萝卜素、总糖的合成;盐度25和盐度35时,藻细胞平均增长速度较快,盐度35时最有利于藻细胞可溶性蛋白积累。  相似文献   

2.
在水温(28±1)℃,以配合饲料及最大摄食量的条件下,研究卵形鲳鲹(Trachinotus ovatus)幼鱼[初始体重(5.77±0.45)g]在盐度10、15、20、25、30和35下的生长及能量收支。结果表明:在盐度25时,湿重、干重、蛋白质及能量指标的特定生长率均达到最大值,分别为3.21%、2.06%、4.76%和4.66%;干重、蛋白质和能量指标的摄食率也达最大,分别为20.31%、13.57%和12.21%;干重、蛋白质和能量指标的转化效率也达最大,分别为35.61%、46.60%和52.78%。可见,盐度对卵形鲳鲹幼鱼的特定生长率、摄食率、转化效率及能量收支有显著影响。盐度对吸收效率则无显著影响,蛋白质和能量的平均吸收效率分别为94.91%和92.45%;在盐度25,卵形鲳鲹幼鱼得到最佳的能量分配模式,其收支方程为:100.00C=7.30F+10.13U+29.80R+52.77G。  相似文献   

3.
4.
The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot(Scophthalmus maximus) reared at five salinities(12,18,24,30,and 36).The fish were fed three isocaloric and isolipidic diets for 60 days.The results show that specific growth rate(SGR)and feed conversion efficiency(FCE) were higher in fish reared at salinities of 18 and 36,but lower at 12.Fish fed with diet C25P40(25%carbohydrate and 40%protein) had lower SGR and FCE values compared with those fed with the C5P52(5%carbohydrate and 52%protein) and C15P46(15%carbohydrate and 46%protein) diets;however,there was no statistical difference between diet C5P52 and C15P46.SGR and FCE values were unaffected by diet composition in fish reared at salinity 36.Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36,but lower at 12,while glucokinase(GK) activity was higher in fish reared at 12,and lower at 18 and 36.Dietary starch enhanced GK activity while depressing lipogenic enzyme activity.However,lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36.It is recommended that salinity should be maintained 12 in the farming of juvenile turbot.In addition,an increase in gelatinized starch from 5%to 15%could spare 6%dietary protein in fish reared at salinities of 18-30,while higher salinity(36) could improve dietary carbohydrate use and enhance the protein-sparing effect,which is linked with the induction of lipogenic capacities.  相似文献   

5.
Calculation and comparative study of the chlorophyll fluorescence ratio F685/F735 in brown algae (Laminaria japonica, Underia pinnatifida and Padina crassa) excited by blue and green light showed that the fluorescence ratios were higher when the algae were excited by blue light (440 nm), but reduced obviously under green light (540 nm) excitation. The values also reduced under dehydration but could recover during rehydration if the stress was not serious. The variation of the fluorescence ratio under dehydration was mainly because changes in fluorescence emission at 735 nm were always sharper than those at 685 nm. The ratio was sensitive to stress and has potential as a stress indicator in phycological research. Measurement of the fluorescence excitation spectra showed that the only peak at 540 hm changed apparently during dehydration. It meant that the function of the Chl a /Fucoxanthin protein complex for energy transfer was easily inhibited by water stress. However, no variation of the ratio was foun  相似文献   

6.
INTRODUCTIONFrequentoccurrenceofHAB (HarmfulAlgalBlooms)hasbeenobservedinChinasincethe1 970’s .ThegreatharmtothemarineecosystemandpotentialthreattohumanhealthcausedbyHABhavebecomeamajorconcern .However ,themechanismofHABformationisstillpoorlyunderstood .BothphysicalandchemicalfactorsareconsideredasmaincausesforHABformation ,becauseunderoptimaltemperature ,salinityandnutrientconditions,HABspeciesgrowfastandaremorelikelytoformblooms .Changesintheseenvironmentalfactorsmayleadtoashif…  相似文献   

7.
The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio. Th effects of DCMU on F685/F735 of marine red, brown and green algae under excitationlight of different wavelengths were investigted. In the brown algae, Laminaria japonica and Undariapinnatifida,DCMU did not increase this ratio under blue light excitation but increased the ratio slightlyunder excitation by green light. For the red algea, Halymenia sinensis, DCMU increased the ratiomarkedly under both blue and green ligh excitation. The percentage increase could reach 50% (undergreen light excitation) and was due to unequal enhancement at the two emission maxima by DCMU. Afraction of chlorophyll which contributed to fluorescence in the 735 nm region was less sensitive toDCMU and was likely from photosystem I of red algae. In the green alga, Ulva pertusa, DCMU causeda slight increase in F685  相似文献   

8.
Competition among HAB (Harmful Algal Bloom) species Dinoflagellate Alexandrium tamarense, Raphidophyte Heterosigma carterae, and Diatom Skeletonema costatum was studied in the laboratory. Experiments with these three major HAB species under combinations of different salinities (10, 18, 25, 30, 35) and temperatures (19℃, 25℃) were carried out. The results showed that S. costatum successfully competed with the other two species at salinities of 18, 25,30, and 35 at temperatures of 19℃ and 25℃. However, H. carterae showed its advantage at low salinity of 10 and became the single dominant species at salinity 10 and 25℃. A. tamarense could not compete successfully with the other two species especially at low salinities. However, it could remain at low density in the presence of higher densities of other algae.  相似文献   

9.
1 INTRODUCTION Heavy metal pollution in marine environment has always been a serious problem over the last several decades, because most of the heavy metal species that enter marine environment accumulated there without decomposition. Strontium is a minor…  相似文献   

10.
文昌鱼对几种环境因子及污染物的耐受极限初步研究   总被引:1,自引:0,他引:1  
<正>文昌鱼(Branchiostoma belcheri)隶属脊索动物门头索动物亚门,是全世界现存动物中与脊椎动物关系最近的一类非脊椎动物[1],被称为生物进化的“活化石”。它营养丰富,干品蛋白质含量约达70%左右,还含有较高的磷和碘,脂肪含量低,具有较高的  相似文献   

11.
Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/PO4^3- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH4-N concentration in water at shaking rate of 60 r/min decreased gradually, while at 120 r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse- and fine-grained sediments. The PO4^3- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium- and coarse-grained sediments.  相似文献   

12.
Sediments and surface water were sampled in a tide flat in the Huiquan Bay, Qingdao, China in January 2004 to simulate the exchange of NH4-N/NO3-N/ PO 43- between sediments and surface water. A working system was designed with which samples were shaken at 60, 120 and 150 revolutions per minute (r/min). Experiment results show that NH4-N concentration in water at shaking rate of 60r/min decreased gradually, while at 120r/min increased gradually. In resuspension, fine-grained sediments contributed most NH4-N to the seawater, followed by medium-grained and coarse-grained sediments. The NO3-N concentration in water had a negative relation with the shaking rate; the medium-grained sediments contributed more NO3-N to seawater than the coarse-and fine-grained sediments. The PO 43- concentration is positively related with the shaking rate, the fine-grained sediments were the main N and P contributor to the seawater, followed by medium-and coarse-grained sediments.  相似文献   

13.
Growth and biochemical responses of the coenobial green alga Scenedesmus obliquus to salinity stress were monitored across different phases of growth. The alga was cultured on BG11 growth medium and subjected to 0, 30, 100, and 200 mmol/L NaCl for a period of 20 d, during which algal cultures were harvested at 4-d intervals. The salinity-induced inhibition of algal growth was accompanied with prolongation of timing of the different growth phases. The sharp and progressive salinity-induced inhibition of algal growth rate during the early phase of growth points to salt shock but moderation of inhibition at the subsequent stages of growth means algal acclimation to salinity. The concentrations of chlorophylls a and b, soluble sugars, proteins as well as those of K+ and Na+ in the alga exhibited peaks at the initiation of the exponential phase of growth, with increasing magnitude in proportion to the increase in the level of salinity. Nevertheless, whereas soluble sugars of the alga peaked at initiation of the exponential phase, starch concentration progressively increased with culture age, reaching saturation towards the stationary phase. Whereas the salinity-induced increase in soluble sugars was most evident at the early stages of growth the reverse was true for starch. The present results point to fast acclimation of S. obliquus to salt stress post a brief salt shock, utilizing soluble sugars, K+ and Na+ for osmotic adjustment. Increasing salinity from 0 to 200 mmol/L NaCl led to progressive increase in soluble sugars, proteins, K + and Na + concentrations of the algal cells, particularly at the early stages of growth. However, the salinity-induced increase in chlorophyll concentration approached a limit at 100 mmol/L NaCl whereas that in starch concentration was more evident at the later stages of growth.  相似文献   

14.
光合细菌对养殖水质及凡纳滨对虾抗病力的影响   总被引:1,自引:0,他引:1  
在凡纳滨对虾养殖环境中人工引入不同浓度的光合细菌,监测氨氮、亚硝酸氮、化学需氧量的变化,15d后测定凡纳滨对虾的AKP、POD、PO、SOD、抗菌、溶菌活力,以及不同光合细菌浓度下凡纳滨对虾的成活率与体重增长率,研究光合细菌对水质和凡纳滨对虾抗病力的影响。结果表明,引入光合细菌可显著降低水体化学需氧量、氨氮含量,并抑制亚硝酸盐氮的产生,提高凡纳滨对虾的抗病力。当光合细菌投放浓度为3×103/mL时,水体中化学需氧量、氨态氮、亚硝酸盐氮含量的均值分别比对照组降低31.59%、43.42%、52.20%,差异显著(P<0.05);对虾的AKP、POD、PO、SOD、抗菌、溶菌活力分别比照组提高31.92%、72.29%、55.56%、31.61%、39.07%、69.51%,差异显著(P<0.05);成活率,体重增长率分别比对照组提高18.67%、34.03%,差异显著(P<0.05)。  相似文献   

15.
The study on the effect of NO on the growth of Chaetoceros curvisetus   总被引:1,自引:0,他引:1  
1 INTRODUCTION As a recently recognized information molecule in campaign of the “Molecule of the Year” by Sci- ence magazine, nitric oxide (NO) has attracted much attention from biologists and many other field scien- tists, for its very important physio…  相似文献   

16.
The capability ofScenedesmus obliquus to remove cations (K^+, Na^+, Ca^2+, Mg^2+) from saline- alkaline water was investigated at different salinities (0, 5, 10, 15, 20, 25) and carbonate alkalinities (0, 5, 10, 15, 20, 25, 30, 35 mmol/L). K^+, Na^+, Ca^2+, and Mg^2+ in saline-alkaline water were efficiently removed by S. obliquus. The maximum removal of the cations (29.37 mg for K^+, 185.85 mg for Na^+, 23.07 mg for Ca^2+, 66.14 mg for Mg^2+) occurred at salinity 25. The maximum removal of K^+ (2.28 mg), Na+ (6.62 mg), Ca^2+ (1.01 mg), and Mg2+ (0.62 mg) occurred at carbonate alkalinities of 25 mmol/L for K*, 35 mmol/L for Na+, 20 mmol/L for Ca2+, and 25 mmol/L for Mf+, respectively. Under a salinity stress, the concentration of Na' in S. obliquus increased significantly, while that of K~ decreased significantly. The concentrations of Ca^2+ and Mg2+ decreased as well. The ratios of K+/Na~, Ca2+/Na^+, and Mg^2+/Na^+ were significantly lower in all salinity treatments than those of the control. Under alkaline stress, the concentrations of Nan and K+ in S. obliquus decreased significantly and the ratios of K^+/Na^+, Ca2+/Na^+, and Mg^2+/Na^+ were significantly higher in all treatments than in the control. Moreover, the concentrations of Ca2+ and Mg2+ in S. obliquus at alkalinities of 5-10 mmol/L were significantly higher than those of the other treatments. The removal of Na+ by S. obliquus mainly occurs through biosorption, and Mg^2+ and Ca^2 + were removed through both biosorption and bioaccumulation.  相似文献   

17.
To determine the optimal salinity for growth and first sexual maturity of ExopaIaemon carinicauda, the effects of salinity on growth and reproductive performance of early juvenile prawns of E. carinicauda were evaluated under laboratory conditions. Postlarvae from the same female broodstock were reared at six salinity levels (5, 10, 15, 20, 25, and 30) for 12 weeks. The specific growth rate (SGR) and survival rate (SR) under different salinity levels in the first 6 weeks were calculated and compared. SGR was significantly influenced by salinity. Prawns reared in salinity of 10 grew significantly faster (P〈0.05) than those reared in salinities of 5, 20, 25, and 30. However, ANOVA confirmed that there was no significant effect among the six salinity levels on SR. For the next 6 weeks, the body length (BL), body weight (BW) at the first sexual maturity, and the age at median sexual maturity (As0) of females were measured and compared. Female prawns reared at salinity of 10 presented significantly shorter A50, but no significant differences among the six salinity levels for BL and BW at the first sexual maturity were observed. Based on the above information, the optimal salinity for growth and first sexual maturity of juvenile E. carinicauda is approximately 10.  相似文献   

18.
【目的】探索不同附着基质对长茎葡萄蕨藻(Caulerpalentillifera)直立枝生长及藻体附着效果的影响。【方法】对长茎葡萄蕨藻直立枝以垂直砂埋、水平砂埋、塑料网网夹、尼龙网网夹及无附着基质(对照组)五种附着方式进行实验,探究长茎葡萄蕨藻直立枝的生长、附着能力、光合特性参数及营养含量的变化。【结果】垂直砂埋处理下,藻体的新生直立枝质量、质量长度比及球状小枝的直径与其他各组相比最优(P <0.05),分别是0.313 3 g、0.086 6 g/mm和1.67 mm,是对照组的7.38、9.62、1.67倍;水平砂埋与对照组相比,藻体附着能力有显著增强(P <0.05),假根数为26,长度为30.77 mm及假根附着砂砾质量为0.566 0 g;除对照组外,各组最大光能转化效率(Fv/Fm)和实际光化学效率Y(II)值呈先下降后上升趋势,24 h后垂直沙埋藻体Fv/Fm和Y(II)最快恢复原始水平,为0.856μmol·m~(-2)·s~(-1)和0.851μmol·m~(-2)·s~(-1),显著高于其余组(P <0.05);垂直砂埋与水平砂埋处理后的藻体,其可溶性糖含量分别比对照组显著降低34.24%和33.93%(P<0.05),而网夹处理后,没有显著差异(P> 0.05)。垂直砂埋处理对藻体总蛋白含量增加有显著促进作用,是对照组的1.26倍(P <0.05)。【结论】长茎葡萄蕨藻直立枝以垂直砂埋附着方式生长最佳,以水平砂埋附着方式附着更牢固。  相似文献   

19.
This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.  相似文献   

20.
This study examined the effects of salinity on embryonic development, survival, and growth of the Hong Kong oyster Crassostrea hongkongensis. The embryos, larvae, and juveniles of C. hongkongensis were held in artificial seawater at three different salinities (low, 15; medium, 23; and high, 30) to determine the optimum hatchery and nursery conditions for mass production of the seeds. Results showed that the percentage production of straight-hinged larvae from fertilized eggs was significantly lower at the high salinity than at the low- and medium-salinities (P < 0.05). The survival rates of larvae and juveniles differed significantly among the three salinity trials, with the highest survival rate observed at the low salinity (P < 0.05). The shell height of larvae was significantly larger at the low salinity than at the high and medium salinities from days 9 to 15 (P < 0.05), whereas that of juveniles was significantly larger at the low salinity than at the high and medium salinities on day 70 (P < 0.05). These results indicate that the larvae and juveniles of C. hongkongensis are tolerant to a wide range of salinities (15 to 30), but show better growth and survival at relatively low salinities. Thus, it is recommended to use relatively low salinities in hatchery and nursery systems for improved yields of C. hongkongensis.  相似文献   

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