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为了评估浒苔(Ulva prolifera)对养殖废水的净化效果,本文研究了4个温度水平(22.5℃、25.5℃、28.5℃和31.5℃)和3种氮源(NH4Cl、NaNO2和NaNO3)下,浒苔对工厂化养殖水环境的适应能力及其净化效果。结果显示,96 h内4个温度处理组浒苔对总氨氮(TAN,包括NH4+-N和NH3)的平均吸收速率分别为14.65、14.88、14.48和13.53 μmol/(g?h),144 h内温度各处理组对亚硝态氮(NO2–-N)的平均吸收速率分别为11.28、10.48、9.11和8.38 μmol/(g?h),144 h内各温度处理组对硝态氮(NO3–-N)的平均吸收速率分别为9.41、8.62、8.80和7.35 μmol/(g?h);温度对浒苔的生长速率有极显著的影响(P<0.01),而氮源对浒苔的生长速率有显著影响(P<0.05);在相同氮源条件下,浒苔的生长速率随着温度的升高而逐渐降低;在相同温度条件下,氮源为氨氮(NH4+-N)时,浒苔的生长速率大于氮源为NO2–-N和NO3–-N的生长速率;温度和氮源对浒苔叶绿素a的含量影响不显著(P>0.05),氮源为NH4+-N和NO2–-N时,随着温度的升高,浒苔中叶绿素a的含量均有升高的趋势,而氮源为NO3–-N时,浒苔中叶绿素a的含量呈先降低再升高的趋势;温度和氮源对浒苔中类胡萝卜素的含量均有极显著影响(P<0.01)。随着温度的升高,各处理组浒苔中类胡萝卜素的含量均呈升高的趋势,其中,在28.5℃和31.5℃条件下,NO3–-N处理组浒苔类胡萝卜素的含量明显高于其他各处理组(P<0.05)。研究表明,温度在22.5℃~31.5℃范围内,浒苔可以有效吸收TAN、NO2–-N和NO3–-N等对虾工厂化养殖废水中的营养盐,浒苔对NH4+-N的吸收速率最大,但随着水温的升高,浒苔对NH4+-N、NO2–-N和NO3–-N的吸收速率均呈降低的趋势。 相似文献
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测定了江苏滨海县海域漂浮浒苔(Ulva prolifera)的光合生理特性(叶绿素荧光参数、叶绿素含量、Rubisco活性、光合速率)和组织含碳量,并分析了浒苔暴发海区水体溶解性无机碳(dissolved inorganic carbon,DIC)浓度及pH值变化特征。结果表明:1)浒苔漂到滨海海域时藻体状态良好,藻体Fv/Fm达到0.67,Yield为0.57,总光合速率为66.99μmol(C)·g-1(FW)·h-1,叶绿素a和b的含量分别为0.91 mg·g-1和0.65mg·g-1,Rubisco活性达到11.39μmol(CO2)·g-1(FW)·min-1;2)覆盖区域不同位点海水无机碳体系各参数均出现不同程度的变化,从浒苔覆盖区边缘到中心,海水中DIC和HCO3-浓度逐步降低(P0.05),而海水pH值却逐渐升高(P0.05)。3)2008~2013连续6年暴发的绿潮藻生物量累计约达9 832.8×104t湿重,可固定CO2量达1 843.67×104t,说明浒苔对DIC的吸收能力较强,能促进海水无机碳体系循环,提高海水pH值,能一定程度上增加海洋碳汇强度。 相似文献
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变温对孔石莼生长和生化组成的影响 总被引:2,自引:0,他引:2
在光照培养箱中研究了变温(23±3)℃、(26±3)℃、(29±3)℃及相应的恒温对照23、26、29℃共6个温度处理对孔石莼生长、叶绿素含量、可溶性糖和蛋白质含量的影响。试验结果表明,与相应的恒温相比,变温对孔石莼的生长有促进作用,且随变温持续时间发生变化。(26±3)℃变温的促生长作用最强,其次为(23±3)℃、(29±3)℃。变温处理下孔石莼的叶绿素a、b含量降低,蛋白质含量减少。可溶性糖含量除在(26±3)℃变温处理下略有升高,其余变温处理下降低。变温虽然对孔石莼的生长有不同程度的促进作用,但不利于其叶绿素a、b合成及可溶性糖积累和蛋白质合成。这可能是藻类为适应环境因子变化而做出的积极生理调节。 相似文献
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为测试浒苔(Enteromorpha prolifera)对于有机高分子絮凝剂阴离子聚丙烯酰胺AP120的助凝效果,通过絮凝试验比较了浒苔投加量对于泥浆沉降比、pH值的影响,以及浒苔不同投加量情况下絮凝剂AP120投加量与浊度去除率的关系。结果表明,随浒苔投加量的增加,泥浆同一时间的沉降比呈现先降低后增大的趋势,浒苔投加量为1.0 g/L时较2.0 g/L、3.0 g/L同一时间泥浆沉降比低。泥浆的pH值随着浒苔投加量的增加而降低,当浒苔投加量为2.0 g/L时,泥浆液的pH值近似于7.0。浒苔作为AP120的助凝剂对提高泥浆絮凝后的浊度去除率有作用,浒苔投加量为2.0 g/L对AP120的助凝效果较好,AP120投加量为5.0 mg/L时,浊度去除率达到97.8%;浊度去除率达到95%时,絮凝剂AP120投加量可减少40%。 相似文献
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以条浒苔为研究对象,以蛋白质提取率为指标,通过单因素试验确定提取条件,后采用均匀设计确定纤维素酶辅助提取工艺条件。结果表明,条浒苔蛋白质的提取条件为pH 11.0,温度60℃,时间5h;纤维素酶辅助提取条件为料液比1∶50,温度30℃,pH 5.5,时间5.5h,加酶量5.0%,纤维素酶处理后再经水提取5h,在此条件下蛋白质的提取率为30.22%~35.74%。为浒苔深加工及资源化利用,测定浒苔蛋白质的功能特性,结果表明,条浒苔蛋白质的等电点pI=3.0,在pH 7时起泡性最好,起泡性随着蛋白质溶液的浓度增加而增强,泡沫稳定性在pH 3和质量浓度2mg/ml时最好,乳化性在4mg/ml时最好,乳化稳定性在2mg/ml时最好,条浒苔蛋白质的吸油性为131.6%,60℃时溶解性最大。 相似文献
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浒苔对海水中重金属的富集研究及食用安全风险评估 总被引:3,自引:0,他引:3
研究了浒苔(Enteromorpha prolifera)分别在镉(Cd2+,浓度分别为5、20、80μg/L)和铅(Pb2+,浓度分别为5、20、80μg/L)及对照组的海水中培养时,2种重金属在其体内的积累规律。结果表明,浒苔对Cd和Pb具有较强的富集能力,对Cd的富集倍数范围为558~1882倍,对Pb的富集倍数范围为6295~11080倍。本研究并对富集Pb和Cd后浒苔的食用安全进行风险评估。 相似文献
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Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean
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The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna. 相似文献
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In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg. 相似文献
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Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
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Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus. 相似文献
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Growth hormone (GH) and reproduction: a review 总被引:5,自引:0,他引:5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
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Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
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Qin-Cheng Huang Di‐Gen Qin Bei‐Ping Tan Tao Du Yuan-Zhi Yang Qi-hui Yang Shu‐Yan Chi Xiao-hui Dong 《Aquaculture Research》2020,51(2):816-827
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg. 相似文献