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1.
对多种经济双壳贝类和养殖中的污损动物的N和P排泄进行了测定 ,包括排泄成分和排泄速率。在这些动物的N排泄中 ,NH4 N占主要部分 ,如笼式养殖的双壳贝类NH4 N占总N排泄的平均值范围为 70 8%— 80 1 % ;氨基酸是第二大排泄成分 ,平均占总N排泄的 1 0 %—2 5 %。其他形态的N ,如尿素、亚硝酸盐和硝酸盐也有检出。在P排泄中 ,有机磷 (DOP)约占总溶解磷 (TDP)排泄的 1 5 %— 2 7%。据估算 ,整个四十里湾所养殖的双壳贝类在夏季每天将排泄4 5 4t总溶解氮 ,其中NH4 N 3 36t、Amino N 0 69t、Urea N 0 2t。同时每天磷的排泄为 0 5 7tTDP ,其中DOP 0 1 5t。对面积为 1 3× 1 0 4 hm2 的海区而言 ,贝类的N、P排泄分别能满足浮游植物生产所需N、P的 44%和 40 %。高密度的贝类养殖对养殖生态系统营养循环的影响是很显著的。附着动物 (柄海鞘等 )的N、P排泄及其对营养循环的影响也不容忽视。  相似文献   
2.
The effect of light intensity on the release of dissolved organic carbon during photosynthesis on NaH14CO3 was investigated using the phytoplanktonic CyanobacteriumOscillatoria rubescens. The released products were fractionated by molecular size and chemical identifications attempted using combined thin-layer electrophoresis and chromatography, and high pressure liquid chromatography.Within the range of irradiances tested (from 6 to 60 µmole m–2 sec–1), though the upper one inhibited photosynthesis ofO. rubescens, light had little effect on the quantity and composition of the excreted products. The released carbon was always lower than 3% of the incorporated carbon, and mainly composed (62 to 86%) by small molecular weight compounds. The prevailing identified compounds were amino acids which represented more than 20% of the excreted carbon. Among organic acids, glycolic acid accounted for less than 2% of the recovered radioactivity. Glucose was the only identified sugar.Abbreviations EOC excreted organic carbon - DOC dissolved organic carbon - PER percent extracellular release - LMW low molecular weight - HMW high molecular weight - AA amino acids - µmoles m–2 sec–1 = µEinsteins m–2 sec–1  相似文献   
3.
In the oyster Ostrea chilensis the adult female broods the young for almost the entire developmental period, releasing a large pediveliger larva (450 μm shell length) with an extremely short pelagic phase. In this study of the larval physiology, the dry weight of the embryo or larva remained constant during the early developmental stages (as far as, and including, the trochophore), but the veliger grew steadily to reach 8 μg at 450 μm shell length, the stage at which it was ready for release. During this growth period the veliger consumed metabolic reserves (62% protein and 38% lipid). Carbohydrate levels were negligible. Chilean oyster veligers larger than 275 μm shell length were able to remove particles from suspension, but clearance rate (2 μl h 1 larva 1 at 450 μm shell length) was much lower than published values for planktotrophic veligers. Low clearance rate in the veliger of O. chilensis is probably attributable to the absence of the postoral ciliary band. Oxygen uptake increased from 19 – 22 nl O2 h 1 ind 1 for pre-veliger stages to 32 nl O2 h 1 ind 1 for a veliger 450 μm long, which is consistent with published values for veligers in general when corrected for body weight. Excretion rate was low, increasing from 0.04 ng NH4-N h 1 larva 1 in the trochophore to 0.13 ng NH4-N h 1 larva 1 in a pediveliger of shell length 450 μm. Biochemical energy reserves were insufficient to meet the metabolic demands of the developing larva, suggesting that uptake of particles and/or dissolved organic matter from the mantle cavity of the female is necessary for successful development.  相似文献   
4.
温度和体重对刺参呼吸和排泄的影响   总被引:25,自引:0,他引:25  
于 2 0 0 0年 2月 2 8日— 4月 1 1日 ,采用实验生态学的方法 ,研究了温度对刺参呼吸和排泄的影响。按海参个体大小分别设立大 [(1 49 9± 2 8 0 )g]、中 [(5 2 1± 1 2 9)g]、小 [(1 7 3± 5 5 )g]3个组别 ,以及 1 0℃、1 5℃、2 0℃、2 5℃、3 0℃ 5个梯度。主要实验结果为 :(1 )大、中规格刺参夏眠前后其耗氧率 (OCR)和排泄率 (AER)变化明显 ,而小规格刺参的耗氧率和排泄率受夏眠的影响较小 ;(2 )在 1 5— 3 0℃条件下 ,刺参的体重 (W)与耗氧量 (R)之间的回归关系符合幂函数方程 R =aWb ,其 a值范围为 0 0 1 1 6— 0 0 4 3 6 ,b值为 0 9475— 1 3 1 2 3。在一定范围内 ,三组刺参的耗氧率都随温度的升高而增大并出现一个峰值 ,但温度变化对小规格刺参的耗氧率影响较小 ,对大、中规格刺参则影响较大 ;(3 )实验温度下 ,刺参的体重 (W )与排泄量 (A )也可用回归方程A =aWb 表示 ,a、b平均值分别为 4 941 0和 0 772 4。在一定范围内 ,随温度的升高刺参的排泄率也呈上升趋势 ,在 2 0℃时大、中规格刺参排泄率出现最高值 ,而小规格刺参排泄率在 2 5℃达到最高  相似文献   
5.
盐度对刺参(Apostichopus japonicus)呼吸和排泄的影响   总被引:17,自引:1,他引:17  
采用封闭式呼吸器法研究了(15±0.5)℃水温条件下不同盐度(22、27、31.5、36)对四种规格刺参{S[(39.60±8.77)g]、M[(71.80±14.04)g]、L[(128.30±19.69)g]和XL[(196.65±19.81)g]}呼吸和排泄的影响。结果表明,各规格组刺参单位体重耗氧率[Rwr,μg/(g·h)]和排氨率[(Rwe,μg/(g·h)]在盐度22—31.5范围内均随着盐度的升高而降低,当盐度升高至36时,二者都明显升高;各盐度下实验刺参的单位体重耗氧率分别为17.52、16.32、15.49和17.60μg/(g·h),单位体重排氨率分别为1.05、0.88、0.87和0.95μg/(g·h);在同一盐度下,刺参体重越大,其单位个体耗氧率[Rir,μg/(ind·h)]和排氨率[Rie,μg/(ind·h)]越高,二者呈幂函数关系,可用关系式Rir(或Rie)=aWb表示;关系式Rir=aWb中,a值的变动范围为40.6656—81.1900,b值为0.6432—0.8145;而关系式Rie=aWb中,a值的变动范围为2.0947—4.8489,b值为0.6507—0.8072;盐度对刺参O∶N比的影响不显著,各盐度条件下,不同规格的刺参,其O∶N比均在15左右,表明本实验条件下该参代谢所需要的能量主要由脂肪和碳水化合物提供。从呼吸和排泄的角度来看,刺参在其最适温度(15℃)条件下,具有一定的渗透压调节能力,能够适应较广的盐度变化范围(22—36)。  相似文献   
6.
用GDX 102树脂从海洋浮游植物三角褐指藻(Phaeodactylum tricornutum)的分解产物和代谢产物中分离提取腐植类物质(DHS,EHS)及乙醇可溶物(DES,EES),用~1H-NMR,IR和UV光谱进行结构分析,并同海水中腐植质(HS)和乙醇可溶物(ES)做了比较。结果表明,DHS,EHS和HS都以高支链烷烃、碳水化合物和氨基酸结构为主要组分,另有少量芳烃和杂环化合物。它们的化学结构很相似,说明DHS和EHS是海水腐植质的重要来源。  相似文献   
7.
盐度对二倍体和三倍体长牡蛎呼吸和排泄的影响   总被引:6,自引:1,他引:6  
采用室内实验的方法研究了盐度对二倍体(2n)和三倍体(3n)长牡蛎(Crassostrea gi-gas)呼吸和排泄的影响。实验的盐度(S)梯度为15,20,25,30,35共5个梯度,实验牡蛎的规格为,2n:W(软体部干质量,单位为g)=0.347±0.071 g;3n:W=0.301±0.099g。实验结果表明:盐度对二倍体和三倍体长牡蛎的呼吸和排泄有显著影响。在实验的盐度范围内,随着盐度的升高,二倍体和三倍体长牡蛎的耗氧率逐渐增大,盐度与耗氧率的关系可表示为,2n:Ro[mg/(g·h)]=0.0142S~(1.219),3n:Ro[mg/(g·h)]=0.0085S~(1.391);随盐度的升高,排氨率逐渐增大,当S为35时,二倍体和三倍体长牡蛎的排氨率略有下降,在实验的盐度范围内,盐度与排氨率的关系可表示为,2n:RA[μg/(g·h)]=-12.25+2.902S-0.0573S~2;3n:RA[ug/(g·h )]=-39.39+3.882S-0.06S~2。在实验的盐度范围内,二倍体和三倍体长牡蛎耗氧率的差异未达到显著水平(P>0.05),而排氨率的差异则有所不同,当S为15~20时,二倍体和三倍体牡蛎的排氨率差异达到显著水平(P<0.05),而S为25~35时,其差异不显著(P>0.05)。  相似文献   
8.
In this study we examined the hypothesis that, under conditions of replete macronutrients and iron in the Southern Ocean, phytoplankton abundance and specific N uptake rates are influenced strongly by the processes of grazing and NH4 regeneration. NH4 and NO3 uptake rates by marine phytoplankton were measured to the northeast and northwest of the island of South Georgia during January-February 1998. Mean specific uptake rate for NO3 (vNO3) was 0.0026 h−1 (range 0.0013-0.0065 h−1) and for NH4 (vNH4) was 0.0097 h−1 (0.0014-0.0376 h−1). vNH4 was related positively with NH4 availability, which ranged from 0.1 to 1.5 mmol m−3 within the upper mixed layer. Ambient NH4 concentrations and vNH4 were both positively related to local krill biomass values, computed from mean values along acoustic transect segments within 2 km of the uptake measurement stations. These biomass values ranged from ∼1 g krill fresh mass m−2 in the northwest to >4 kg krill wet mass m−2 in the northeast. In contrast to the variability found with NH4 concentrations and uptake rates, vNO3 was more uniform across the sampling sites. Under these conditions, increasing NH4 concentration appeared to represent an additional N resource. However, high vNH4 tended to be found for stations with lower phytoplankton standing stocks, across a total range of 0.24-20 mg chlorophyll a m−3. These patterns suggest a coupling between phytoplankton biomass, vNH4 and krill in this region of variable but high krill biomass. Locally high concentrations of krill in parts of the study area appeared to have two opposing effects. On the one hand they could graze down phytoplankton stocks, but on the other hand, their NH4 excretion supported enhanced uptake rates by the remaining, ungrazed cells.  相似文献   
9.
This paper examines the potential availability to a demersal fish of cadmium and zinc associated with digested sewage sludge, via a food chain as well as directly from the sludge, and the tissue distribution and possible excretion of any accumulated cadmium and zinc. Radioactive tracer techniques were used in order to follow the food chain transfer of the metals. Flounder (Platichthys flesus) accumulated cadmium both directly from sludge (delivered in newly ingested unassimilated gutfuls in the amphipods) and in assimilated form from the tissues of the amphipod crustacean Corophium volutator that had been feeding on a sludge–sediment mixture. Cadmium from both sources could be excreted by the fish. The concentration of cadmium within the whole fish increased as the input of cadmium in the diet increased. Zinc, similarly, is available to the flounder both directly from sludge and from zinc accumulated in C. volutator. Only a limited increase in net accumulation of zinc by the flounder was observed upon increased inputs of zinc through the diet, perhaps indicating some regulation of body zinc concentration by the flounder.  相似文献   
10.
王琰  曹文达 《海洋与湖沼》1993,24(3):256-263
用GDX 102树脂从海洋浮游植物三角褐指藻(Phaeodactylum tricornutum)的分解产物和代谢产物中分离提取腐植类物质(DHS,EHS)及乙醇可溶物(DES,EES),用1H-NMR,IR和UV光谱进行结构分析,并同海水中腐植质(HS)和乙醇可溶物(ES)做了比较。结果表明,DHS,EHS和HS都以高支链烷烃、碳水化合物和氨基酸结构为主要组分,另有少量芳烃和杂环化合物。它们的化学结构很相似,说明DHS和EHS是海水腐植质的重要来源。  相似文献   
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