乐清湾泥蚶肉营养成分的分析及评价   总被引：2，自引：1，他引：1  

吴洪喜  柴雪良  李元中 《海洋科学》2004,28(8):19-22

对乐清湾泥蚶(Tegillarca granosa)肉营养成分进行了分析。结果表明,乐清湾泥蚶肉(干基)粗蛋白含量为67．75％;蛋白质氨基酸评价为85．4分,色氨基酸是惟一的限制性氨基酸。在蛋白质氨基酸组成中。以呈鲜味、甘味或与之有关的谷氨酸、冬氨酸、丙氨酸、甘氨酸、脯氨酸、丝氨酸6种氨基酸含量最高,占氨基酸总量的46．71％;不饱和脂肪酸含量也相当高．尤其是高度不饱和脂肪酸C20：5(EPA)和C22：6(DHA),占脂肪酸总含量的31．62％;此外还含有多种人体必需的维生素、无机盐、微量元素等多种成分。  相似文献   

辽河流域生态需水估算   总被引：13，自引：0，他引：13  

王西琴  张远  刘昌明 《地理研究》2007,26(1):22-28

从辽河流域存在的环境问题出发,在确定主要生态需水类型的基础上,基于水资源分区,分别估算各水资源分区的不同类型的生态需水,包括枯季河道生态需水、汛期输沙需水、入海需水、地下水恢复需补充的水量、河口湿地生态需水等。针对辽河流域季节性河流的特点,提出了枯水季节最小流量法的枯季河道生态需水计算方法。计算结果表明,辽河流域生态需水总量为130.44×10⁸m³,占地表径流的48.3%,其中浑太河、东辽河2个水资源分区的生态需水量占地表径流的比例在60%以上,辽河干流生态需水量占地表径流的53.5%,其余水资源分区生态需水量占地表径流的比例均在50%以下。研究结果为流域水资源配置及水环境保护与恢复提供科学依据。  相似文献   

环境变化对造礁石珊瑚营养方式的影响及其适应性          下载免费PDF全文

黄晖  俞晓磊  雷新明  张芳  练健生 《海洋科学进展》2020,38(2):189-198

造礁石珊瑚是珊瑚礁生态系统的框架生物,它们既能够通过共生藻的光合作用进行自养,也能够通过触手捕获和黏液吸附等方式进行异养。通过研究造礁石珊瑚光合自养以及异养营养的机理和过程,系统分析了光照、温度、营养盐、潮汐、水流、CO2质量浓度以及食物的可获得性等因素对造礁石珊瑚光合自养和异养营养产生的影响,并讨论了珊瑚的这2种营养方式对环境变化的适应性。在环境适宜的条件下,光合自养是健康造礁石珊瑚的主要营养方式;当珊瑚自养营养的供给受到限制时,异养营养能够在一定程度上弥补其营养缺失,甚至可能成为珊瑚的主要营养方式。造礁石珊瑚的2种营养方式能够对不同环境因素的变化做出不同响应,并通过两者之间的互补以适应环境变化。今后研究的重点应放在归纳各类因素对造礁石珊瑚2种营养方式的影响;深入研究造礁石珊瑚异养营养方式的规律与环境适应性;厘清造礁石珊瑚光合自养与异养营养之间的关系和协调模式。  相似文献   

Assessment of nitrogen maintenance requirement in juvenile Black Porgy <Emphasis Type="Italic">Acanthopagrus schlegeli</Emphasis>     

朱秋华  钱国英  高有领  汪财生 《中国海洋湖沼学报》2009,27(1):63-68

Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM′) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW per day, accounting for 12.2% to 21.1% of nitrogen intake. The amount of fecal nitrogen excretion varied from 0.21 to 0.32 mg/g BW per day, accounting for 16.3% to 21.6% of nitrogen intake. The endogenous nitrogen excretion, a main part of nitrogen consumption varied from 0.79 to 0.97 mg/g BW per day, accounting for 63.3 % to 68.0% of nitrogen intake. Positive correlation was found between NM and body weight, while a negative correlation was found between NM of unit body weight and the growth duration. No significant differences (p>0.05) were found in NM′ among different growth stages. The average of NM′ was 0.485 7mg/g per day. The results from nitrogen-free diet experiment showed that a negative correlation between NM and feed intake of nitrogen-free diet. NM increased with the decrease of feed intake of fish. The average of NM was 0.482 9 mg/g BW per day that was close to 0.483 8 mg/g BW obtained from fish with 120 g BW in nitrogen balance experiment. The nitrogen balance method is recommended to be a better method for determining NM in consideration of fish stress and result stability. This study also provides a calculated result of the protein content in diets, which is necessary for maintaining fish body protein at different growth stages. The calculation was based on the amount of nitrogen required for maintaining body protein per kg BW. Supported by Scientific Research Project Grant (No.2004C100059) from the city government of Ningbo, China.  相似文献   

中华绒螯蟹幼蟹维生素C营养需求研究   总被引：9，自引：0，他引：9  

陈立侨  艾春香  温小波  刘晓玲  江洪波 《海洋学报》2005,27(1):130-136

在每100g等氮、等能纯化饲料中分别添加0,100,200,400,800,1 000mg维生素C(Vc)多聚磷酸酯(LAPP),用这样配制成的试验饲料饲喂已淡化5d的河蟹大眼幼体及后续幼蟹25d,探讨Vc对大眼幼体和幼蟹生长、存活、蜕壳频率及抗逆性的影响,同时探明幼蟹对Vc的适宜需求量,结果表明,饲料Vc添加量为100~400mg/100g时,可以保证幼蟹正常生长、存活和蜕皮,尤其以投喂添加Vc200mg/100g(C₂组)和400mg/100g(C₃组)饲料的Ⅲ期幼蟹增重率、存活率和平均蜕皮频率较高,其中C₂组(上述各指标值)分别为516.18%,62.83%,2.58,C₃组分别为458.89%,66.17%,2.61;饲料中缺少Vc时(如C₀组),Ⅲ期幼蟹的增重率、存活率和平均蜕皮频率最低,分别为265.31%,26.67%和2.26.饲料中Vc的添加量达到800mg/100g(C₄)和1 000mg/100g(C₅)时,幼蟹的蜕皮反而受到抑制,平均蜕皮频率降低,蜕皮周期延长,且存活率降低,到Ⅲ期幼蟹的增重率、存活率和平均蜕皮频率在C₄组分别为355.7%,31.33%,2.39,在C₅组分别为307.53%,28.56%,2.19.此外,各处理组幼蟹对抗逆性影响的试验表明,在一定的范围内,饲料中添加Vc能提高幼蟹的耐低氧能力和耐pH突变能力,而对耐盐度突变能力没有明显的影响.综合上述结果可以得出,为保持幼蟹良好生产性能,饲料中添加的Vc?  相似文献   

新疆孔雀河流域生态基流与天然植被需水量研究     

李肖杨  朱成刚  马玉其  王新友  王军政  陈亚宁 《干旱区地理》2021,44(2):337-345

研究和确定流域生态基流及天然植被需水量是为了遏制因河道断流或流量减少而造成的生态环境退化,以确保流域生态系统健康发展.根据孔雀河流域植被类型分布及多年径流状况,将河道分为A、B两部分,A段为孔雀河上游塔什店至第三分水枢纽常年未断流河道;B段为第三分水枢纽以下天然植被主要分布区.基于塔什店水文站近50 a水文数据,结合T...  相似文献   

几种缢蛏的营养性和健康性分析评价   总被引：11，自引：0，他引：11  

安贤惠 《海洋湖沼通报》2005,(4):99-103

缢蛏作为我国四大经济贝类之一,其养殖业已经兴起,并有从南向北推移的趋势,市场前景看好。但目前缢蛏养殖更多的是追求高产,而对其营养性、美味性和健康性等因素考虑较少。本研究以连云港及周边海区采集的缢蛏为研究对象,如连云港市场销售的养殖缢蛏,赣榆县海区、射阳县海区和如东县海区征集的野生缢蛏,以及连云港市场销售的竹蛏、美人蛏等,通过常规品质分析技术分析和利用火焰原子吸收光谱法(Atomic Absorption Spectrome-try简称AAS)和测汞仪等分析其Fe,Zn,Ca,Cu以及Hg,Cr,Pb等微量元素。结果表明参试材料具有不同的营养性,如美人蛏的出肉率、蛋白质含量和粗脂肪含量分别为56.88%、3.60%和58.761%,均居参试缢蛏之首,其它如缢蛏1、缢蛏2、缢蛏3、缢蛏4和竹蛏中的粗脂肪含量分别占肉干重的3.007%,3.096%,2.075%,2.061%和2.349%;蛋白质占肉干重的51.506%,48.924%,53.137%,42.709%和51.418%;每100g肉干重中总糖含量分别为142,122,114,138和69mg。微量元素在除缢蛏4的其它参试材料中表现为铁3.66,11.95,7.26和7.41,3.71mg.g-1;锌0.68,0.87,0.61和0.49,0.33 mg.g-1;钙1.95,4.86,2.90和3.46,2.97 mg.g-1,表现出丰富的矿物成分;所有参试材料中未检测到汞,铬也不高,符合国家卫生标准。而铜、铅普遍超标,说明海洋环境的恶化已经影响到了海产品的品质,缢蛏等海产品的健康性问题值得注意。  相似文献   

湿地缺水问题的研究展望   总被引：2，自引：0，他引：2  

王芳 《湿地科学与管理》2006,2(1):12-17

湿地是水循环的主体环节,从河流、湖泊、沼泽到河口以至近岸海区,都直接受水资源开发利用的影响。由于水资源传统的开发方式和过度利用,使湿地面临严重的缺水形势。为了保护湿地,维护流域水循环,我国已经开展了湿地生态需水研究,并取得一些成果。但是,如何保障湿地需水仍是摆在我们面前的重要课题。水权是水资源管理更加科学的分配制度,因此借助水权来探索生态需水的保障机制,使湿地生态需水得到可靠保证。  相似文献   

Soil seed flora, germination and regeneration pattern of woody species in an Acacia woodland of the Rift Valley in Ethiopia     

Mekuria Argaw  Demel Teketay  Mats Olsson 《Journal of Arid Environments》1999,43(4):411

The objectives of this study were to determine the composition, density and spatial distribution of the soil seed bank of woody species, as well as their regeneration pattern in two different land use systems, controlled (ranch) and open grazing, in an Acacia woodland of the Rift Valley in Ethiopia. We also compared the species composition of the soil seed bank and the above-ground vegetation to find out if differences exist in the soil seed bank and advance regeneration between the two land use systems. The germination requirements of seeds of the woody species were also investigated under laboratory conditions. Acacia senegal, Acacia seyal, Acacia tortilis, Dichrostacys cinerea and Balanites aegyptiaca were encountered in the above-ground vegetation in both systems. Seeds of only A. tortilis (90±32 seeds m⁻²) from the ranch, and A. senegal (5±3 seeds m⁻²) and A. tortilis (72±34 seeds m⁻²) from the open system were found in the soil seed bank along transects with patchy horizontal pattern. The two systems were not significantly different in density of soil seed banks of A. senegal andA. tortilis . Jaccard's similarity index showed that only a few woody species were common in the soil seed flora and above ground vegetation. However, all of the species accumulated seeds (58±43–331±130 seeds m⁻²) in/on the soil under the canopy. Very large numbers of seeds of A. tortilis (19382±9722 seeds m⁻²) and D. cinerea (1278±494 seeds m⁻²) were also found in barns. Most of the seeds recovered from the soil samples (60–80%) were found in the litter layer. Acid and mechanical scarification improved legume germination (36–99% and 60–99%, respectively) over boiling water (0–48%). Treatment means differed significantly for all the legumes (p<0·001) but not for Balanites. Height and diameter class distribution of regeneration of A. tortilis and D. cinerea in both systems and A. senegal in the open system had a negative exponential correlation (r_s=−0·5, −0·25 and −0·86, respectively). A. seyal and B. aegyptiaca showed poor regeneration. Horizontal distribution of advance regeneration of all the species was patchy. Advance regeneration of A. seyal, A. tortilis and B. aegyptiaca were not significantly different, while that of A. senegal and D. cinerea were significantly different between the two systems. Poor representation of species in the soil seed bank along transects and in the different height and diameter classes may be attributed to the low density of mature trees as well as the mode and strategy of seed dispersal. Ungulate and wind dispersed species (e.g. A. senegal, A. tortilis and D. cinerea) were highly favoured. Patchiness in the distribution of seeds and advance regeneration was also a result of endozoochory. Dispersal of non-ungulate dispersed seeds (A. senegal, A. seyal and B. aegyptiaca) was restricted to the canopy zone. Piles of seeds ofA. tortilis and D. cinerea that were found in barns were a result of consumption of their pods by cattle. High concentration of seeds in the litter layer may be due to low soil disturbance and larger size of seeds. The height and diameter class distribution of A. senegal (in the open system), A. tortilis and D. cinerea also indicated that the species have good regeneration. Results from the germination tests indicated that seeds of the legumes require pre-sowing treatments to give a rapid, uniform and improved germination. Intervention through artificial regeneration should be employed to improve the density and regeneration capacity of those species with hampered regeneration at both systems.  相似文献   

两种东风螺的营养成分分析与评估   总被引：2，自引：0，他引：2  

许贻斌  沈铭辉  魏永杰  王德祥  柯才焕 《台湾海峡》2008,27(1):26-32

本文对方斑东风螺和波部东风螺自身营养成分进行分析,测定其中的含肉率和腹足肌含有的基本营养成分,分析氨基酸种类及组成和脂肪酸种类及组成,对方斑东风螺和波部东风螺的营养价值进行综合评定以及对比分析.结果表明:方斑东风螺和波部东风螺含肉率分别为48.94%±2.01%和45.12%±2.29%,腹足肌中都含有高达70%左右的蛋白含量和5%左右低含量的脂肪,糖类含量接近10%,氨基酸种类齐全,必需氨基酸相对含量高,必需氨基酸指数在43以上,肉味鲜美,方斑东风螺的EPA和DHA相对含量总和为7.1%,波部东风螺为10.5%,方斑东风螺和波部东风螺的n-3系列不饱和脂肪酸相对含量分别高达6.4%和7.5%,n-6系列分别为13.4%和15.0%,属名贵滋补的海产品.  相似文献