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本文通过延时摄影技术探究了不同刺参规格(小规格、中规格和大规格)及饥饿状态(饥饿0 d、5 d、10 d和15 d)对其集群行为的影响。研究发现:不同规格刺参的聚集率和标准聚集规模之间存在显著差异(P<0.05),且呈现出随刺参规格增大而升高的趋势,表明大规格刺参更倾向于聚集,且形成的集群规模更大;除饥饿10 d和饥饿15 d的组外,各处理组之间刺参聚集率和标准聚集规模都具有显著差异(P<0.05),随着饥饿时间的延长,刺参聚集率和标准聚集规模呈先降低,后升高,再保持稳定的规律。上述结果查明了规格和饥饿对刺参集群行为的影响,可为丰富刺参行为学研究及优化刺参增养殖管理策略提供理论依据。 相似文献
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实验设置了一直投喂、周期性饥饿1,2,3,4d和一直饥饿6个处理组,采用轮虫单个体培养,检验周期性饥饿对褶皱臂尾轮虫(Brachionus plicatilis)实验种群特征参数的影响.结果表明:一直投喂组的生殖价最高,对轮虫种群的潜在增长最有利,随饥饿强度的增大,生殖价减小.不同处理下,轮虫个体寿命与其生殖期之间存在显著的正相关(r=0.747).轮虫在受到饥饿后,寿命略有增长,但不同处理对轮虫的平均寿命(10.8~13.1d)和生殖期(6.3~8.3d)均未达到显著差异(P>0.05).饥饿强度增大时,轮虫个体的总产幼数、总产卵量显著下降(P<0.05),产第1幼、最后1幼、第1卵、最后1卵时间显著延长(P<0.05);同时,种群参数的世代时间(T)随饥饿强度增加而增大,内禀增长率(rm)、周限增长率(λ)和净生殖率(R0)却明显下降. 相似文献
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Temir A. Britayev Daniel Martin Elena M. Krylova Rudo von Cosel & Tatiana S. Aksiuk 《Marine Ecology》2007,28(1):36-48
Associations between scale‐worms and giant mussels are common constituents of hydrothermal vent and cold seep ecosystems, but very little is known about their nature and ecology. Here, we analyze the ecological characteristics of the associations between Branchipolynoe seepensis, an obligate symbiotic polychaete, and their host mytilid mussels Bathymodiolus puteoserpentis and B. azoricus inhabiting hydrothermal vent fields on the Mid‐Atlantic Ridge. Infested mussels generally harbored a single symbiont (<4% had two to six worms). Infestation rate varied from 7.2% to 76.5%, increasing with mussel size, and was significantly lower for B. puteoserpentis. Symbiont density at Lucky Strike ranged between 1071 and 1191 individuals m−2. Female symbiont size was always positively correlated with host size, while only males and juveniles from small mussels showed the same trend. This suggested a relatively long‐lasting host/symbiont association for females and short‐lasting association with successive reproductive migrations for adult males. The sex ratio of symbionts was always biased in favor of females. Males were smaller and more slender than females and had one mode in their size distributions, whereas females typically had three or more modes, suggestive of a longer life span in females. Between 59.1% and 72.2% of mussels had damaged soft tissues with substantially higher incidence of trauma in infested ones, suggesting that symbionts may cause trauma. The symbionts also induce tunnel‐like structures among the ctenidia, indicating fidelity to a particular location inside the host. Based on our data, together with the fact that infested mussels became relatively wider than non‐infested ones, this association is considered parasitic (likely kleptoparasitic). Our data, together with those from previous studies, allowed us to define the main life‐history traits of B. seepensis: (i) the relationship with their host is parasitic, (ii) the association begins at the smallest mytilid size classes, (iii) there is sexual dimorphism in body size, (iv) sex ratio deviates from 1:1 in favor of females, (v) fertilization occurs through temporal pairing and pseudocopulation, (vi) sperm are stored by females, (vii) eggs are large (likely lecithotrophic or with direct development), (viii) females have a longer life span than males, (ix) adult males may be semalparous, undertaking reproductive migrations followed by a short period of pairing and then death, and (x) females have a semi‐continuous iteroparous reproductive cycle. 相似文献
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The deep‐sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid‐rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen‐deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep‐sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought. 相似文献
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文章研究了温度升高对一种造礁石珊瑚——丛生盔形珊瑚(Galaxea fascicularis)的两种形态型(H和S型)代谢和共生藻光合生理的影响。研究显示H型和S型对升温的生理响应差异明显:在虫黄藻水平上, H型丢失了大量的虫黄藻,减轻了共生体呼吸代谢的负荷; S型中虫黄藻数目尚可维持共生体呼吸代谢的需求,同时提高叶绿素b含量增强光的吸收。在宿主水平上,H型充分利用虫黄藻输送的营养物质,并通过异养摄食补偿能量消耗;S型宿主所储存的营养物质可以协助共生体适应热环境。结果表明,丛生盔形珊瑚两种形态型通过不同的能量利用方式适应环境的变化, H型倾向于维持共生体的代谢平衡,而S型倾向于提高共生藻的能量分配。 相似文献
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海面电磁回波频谱宽度与海浪波高密切相关,可应用频谱宽度进行海浪有效波高反演。本文应用线性滤波法仿真出了海表散射面元在雷达视向上的投影速度,建立了回波谱宽模型,分析了雷达空间分辨率、回波时间序列长度及海洋环境参数等因素对频谱宽度的影响,同时还针对如何在实际观测过程中选择回波时间序列长度、观测方位角等参数进行了讨论。最后还将理论结果与CSIR-X波段雷达实测数据谱宽估计结果进行了比较。结果表明,剔除雷达噪声以及频率泄露的影响后,基于高斯分布标准偏差的谱宽估计方法所得结果与理论结果吻合很好,这从而证明了理论结果的可靠性。本文所得结果对海浪有效波高反演具有一定参考价值。 相似文献
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对斜带石斑鱼(Epinephelus coioides)稚鱼在摄食和饥饿2种营养条件下胃肠道中5种内分泌细胞的形态、定位和分布密度进行比较研究.采用免疫细胞化学方法和5-羟色胺(5-hydroxytryptamine,5-HT)、生长抑素(somatostain,Som)、胃泌素(gastrin,Gas)、P物质(substance P,SP)及神经肽Y(neuropeptide,NPY)的特异性抗血清进行胃肠道免疫活性细胞的检测.结果显示,5种胃肠激素内分泌细胞在斜带石斑鱼稚鱼胃肠各部位均有开放型和封闭型2种,饥饿对细胞的形态有所影响但不明显.统计分析结果显示5种内分泌细胞在摄食组和饥饿组的斜带石斑鱼稚鱼胃肠各部位的分布密度存在明显差异.在贲门胃,饥饿组5-羟色胺和生长抑素免疫活性细胞数量上升,为正常摄食组的2.2倍和12.4倍,而在胃体和幽门胃则下降了1/3~5/6;饥饿组的胃泌素和P物质免疫阳性细胞数量在幽门胃下降为1/2,在肠道则有升有降;唯有神经肽Y免疫活性细胞在摄食组和饥饿组2组间没有显著差异.这些结果表明,胃肠激素参与调控斜带石斑鱼稚鱼胃肠的消化和吸收功能.一旦发生饥饿,斜带石斑鱼稚鱼胃肠激素细胞的分泌活性发生相应改变,最终可能会导致细胞功能失调,成为幼体死亡的因素之一. 相似文献
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MU Lin CHI Yong-xiang LIU Shou-hua SONG Jun LIN Xiao-pei LI Yan ZHANG Jian-li 《海洋通报(英文版)》2013,(2):26-36
应用ROMS数值模式配置基本实验模拟了2004年到2006年中国东部海域海平面的季节变化。模拟结果与TOPEX/Poseidon(T/P)卫星高度计观测结果基本一致,海平面年较差从中国沿岸到黑潮路径逐渐变小。将数值模式的风应力项去掉,配置对比实验。与基本实验结果对比发现,对比实验海平面仍然具有季节变化,但是闽浙沿岸和苏北沿岸海平面春夏季异常偏低、秋冬季异常偏高现象消失,中国沿岸向太平洋的海平面变化减弱。春季和秋季,渤、黄海和黑潮附近海平面异于东海的现象减弱。对比实验海平面的年较差的数值明显减小,从近岸向黑潮海平面年较差渐变的过程消失。整个渤黄海的海平面年较差近似。对比实验海平面年较差占基本实验海平面年较差比率从近岸向黑潮路径逐渐增大。 相似文献
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采用室内实验的方法研究了饥饿对二倍体 (2n)和三倍体(3n)长牡蛎(Crassostreagigas)呼吸和排泄的影响。实验饥饿的时间为2,5,8,11,14,23,32d,实验牡蛎的软体部干质量为M2n=0.347g±0.071g;M3n =0.301g±0.099g。实验结果表明 :(1)二倍体长牡蛎在饥饿2~14d内 ,随着饥饿时间的延长 ,个体的耗氧率增大 ,当饥饿14d以后 ,随着饥饿时间的延长 ,个体的耗氧率下降 ;三倍体长牡蛎则表现出饥饿5d以后 ,随着饥饿时间的延长 ,个体的耗氧率下降。耗氧率与饥饿时间的关系为:Ro ,2n(mg/(个·h))= -0.08 +0.21T-0.01T2-0.01T3,Ro ,3n(mg/(个·h))= -1.97+0.45T-0.12T2+0.01T3;在饥饿2~5d内 ,二倍体和三倍体长牡蛎的耗氧率差异不显著(P>0.05) ,而饥饿5d以后 ,耗氧率的差异达到显著水平(P<0.05) ;(2)二倍体长牡蛎在饥饿2~8d内 ,随着饥饿时间的延长 ,其排氨率增加 ,当饥饿8d以后 ,排氨率则逐渐下降 ;三倍体长牡蛎则表现出饥饿5d以后 ,随着饥饿时间的延长 ,个体的排氨率下降。排氨率与饥饿时间的关系为 :RA ,2n(μg/(个·h))= -16.09 +32.65T-8.11T2 +0.57T3 ,RA ,3n(μg/(个·h))=4.57 +16.07T-5.42T2 +0.44T3 ;在实验的时间范围内 ,二倍体和三倍体长牡蛎排氨率的差异达到显著水平 (P<0.05)。 相似文献
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为了确定条纹锯(Centropristis striata)仔鱼的不可逆点(PNR),作者在温度(22.9±0.8)℃、盐度30~32、DO≥5.0mg/L、pH7.8~8.2,光照强度40~100 Lx条件下,对人工孵化的条纹锯仔鱼开展饥饿胁迫对其存活、摄食、生长的变化规律的试验研究及影响。结果显示,仔鱼在孵化后2 d开口摄食,仔鱼体长开始下降,从内源营养期转入混合营养期,持续1 d;3 d时卵黄囊、油球消失,仔鱼体长增加,进入外源营养期,初次摄食率可达到68.25%。3.5 d时初次摄食率最高达到88.24%,之后初次摄食率逐渐下降,5 d时初次摄食率下降为37.5%,可知条纹锯PNR=5 d。6.5 d时试验组仔鱼全部死亡。结果表明,内源营养期对照组与试验组无显著差异,对卵黄囊与油球的利用率相似。混合营养期,仔鱼体长出现负增长,且试验组负增长速率明显高于对照组。外源营养期,试验组仔鱼体长持续下降,至PNR时体长负增长速率加快死亡率增加,直至全部死亡;对照组仔鱼体长开始增长,死亡率逐渐下降并趋于稳定。条纹锯仔鱼孵出后2~5 d为摄食的关键时期。 相似文献
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饥饿对中国龙虾叶状幼体Ⅰ期发育、摄食及存活的影响 总被引:6,自引:1,他引:6
中国龙虾叶状幼体Ⅰ期在饥饿条件下的生长发育、变态、存活的研究结果表明:初孵叶状幼体耐饥饿能力较强,完全饥饿144h,成活率为100%,饥饿192~216h,成活率为76%~68%.由生长和变态来看,推迟24~36h投饵,对叶状幼体Ⅰ期的生长没有明显影响.在摄食饵料方面,初孵幼体饥饿144h,仍然有55%的幼体具有摄食能力.饥饿24~120h的初期叶状幼体摄食卤虫幼体的大小(体长为349.5~604.9μm)可达到自身体长的1/2~1/3.当叶状幼体连续摄饵时间达60h,体内储存一定的营养后,即使不再喂食,幼体也能变态,但变态率较低.由间隔投饵效果来看,每隔8,16,24h投饵,幼体的发育变态差异不大.这些研究结果对开展龙虾基础生物学与人工育苗技术研究,提高育苗成活率将有一定的参考意义. 相似文献
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本文研究了具有克服肿瘤耐药活性的软珊瑚共附生真菌Aspergillus sp. EGF 15-0-3苯甲醛类化学成分。采用硅胶柱层析、十八烷基硅烷键合硅胶层析、Sephadex LH-20层析、高效液相色谱(high performance liquid chromatography, HPLC)等多种方法进行分离纯化; 通过核磁共振波谱(nuclear magnetic resonance, NMR)、质谱(mass spectrometry, MS)等现代波谱分析及物理常数对照等方法进行结构鉴定; 采用MTT法对苯甲醛部位和单体化合物进行克服肿瘤耐药活性研究。从EGF15-0-3的苯甲醛部位共得到9个苯甲醛类化合物, 结构依次为flavoglaucin (1)、tetrahydroauroglaucin (2)、isoaspergin (3)、 isotetrahydroauro-glaucin (4)、dihydroauroglaucin (5)、isodihydroauroglaucin (6)、2-(1',5'-heptadienyl)-3, 6-dihydroxy-5-(3'-methyl-2'-butenyl) benzaldehyde (7)、auro-glaucin (8)和2-(2',3-epoxy-1'-heptenyl)-6-hydroxy-5- (3'methyl-2'-butenyl) benzaldehyde (9)。体外克服肿瘤耐药活性研究表明, 苯甲醛类化合物9具有较强的克服肿瘤耐药活性, 可能是由于其结构2位烷基侧链与3羟基形成吡喃环所致。 相似文献
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海水盐度对沉降泥沙固结过程影响研究 总被引:1,自引:0,他引:1
黄河每年输送上亿吨泥沙入海,其中80%以上沉积在河口附近水下三角洲。受黄河入海径流量、气候及海洋动力条件影响,黄河口海域海水盐度变化显著。目前,不同盐度海水环境下入海泥沙沉降形成的海床土,固结过程有何差异尚不清楚。本文在黄河水下三角洲潮坪配制不同盐度的流态沉积物,模拟不同沉积环境下新沉积土的固结过程,利用轻型贯入测试、十字板剪切测试等现场原位试验,实时观测沉积环境盐度对沉降泥沙固结过程的影响。研究发现:随着海水盐度增加,沉积物固结强度增大,沉积环境盐度每增高1‰,沉积物固结后强度可增加0.15倍;海水盐度对沉积物固结速率的影响,在初始阶段表现不明显,在沉积物固结后期,盐度每增高1‰,固结速率可增长1.23倍;海水盐度的增高,还加剧了沉积物固结强度的空间非均匀性。本研究的发现,促进了对河口区海底工程环境的认识。 相似文献
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The effects of biological heating on the upper-ocean temperature of the global ocean are investigated using two ocean-only experiments forced by prescribed atmospheric fields during 1990–2007, on with fixed constant chlorophyll concentration, and the other with seasonally varying chlorophyll concentration. Although the existence of high chlorophyll concentrations can trap solar radiation in the upper layer and warm the surface, cooling sea surface temperature (SST) can be seen in some regions and seasons. Seventeen regions are selected and classified according to their dynamic processes, and the cooling mechanisms are investigated through heat budget analysis. The chlorophyll-induced SST variation is dependent on the variation in chlorophyll concentration and net surface heat flux and on such dynamic ocean processes as mixing, upwelling and advection. The mixed layer depth is also an important factor determining the effect. The chlorophyll-induced SST warming appears in most regions during the local spring to autumn when the mixed layer is shallow, e.g., low latitudes without upwelling and the mid-latitudes. Chlorophyll-induced SST cooling appears in regions experiencing strong upwelling, e.g., the western Arabian Sea, west coast of North Africa, South Africa and South America, the eastern tropical Pacific Ocean and the Atlantic Ocean, and strong mixing (with deep mixed layer depth), e.g., the mid-latitudes in winter. 相似文献
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Effects of surface waves and sea spray on air–sea fluxes during the passage of Typhoon Hagupit 总被引:2,自引:1,他引:2
Air–sea exchange plays a vital role in the development and maintenance of tropical cyclones(TCs). Although studies have suggested the dependence of air–sea fluxes on surface waves and sea spray, how these processes modify those fluxes under TC conditions have not been sufficiently investigated based on in-situ observations.Using continuous meteorological and surface wave data from a moored buoy in the northern South China Sea,this study examines the effects of surface waves and sea spray on air–sea fluxes during the passage of Typhoon Hagupit. The mooring was within about 40 km of the center of Hagupit. Surface waves could increase momentum flux to the ocean by about 15%, and sea spray enhanced both sensible and latent heat fluxes to the atmosphere,causing Hagupit to absorb 500 W/m~2 more heat flux from the ocean. These results have powerful implications for understanding TC–ocean interaction and improving TC intensity forecasting. 相似文献
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北极海冰作为一个巨大的淡水资源库, 每年向全球输送大量淡水资源, 从北极输出的海冰在向南输送的过程中融化, 对海洋水循环与水环境产生影响, 进而影响全球气候变化, 弗雷姆海峡作为北极海冰输出的主要通道, 对其研究显得尤为重要。为了解弗雷姆海峡海冰长期输出量, 利用美国冰雪数据中心(NSIDC)发布的海冰密集度、海冰厚度与海冰漂移速度数据, 计算得到 1979 年至 2019 年弗雷姆海峡海冰输出面积通量与 2010 至 2019 年弗雷姆海峡海冰输出体积通量, 并在此基础上分析弗雷姆海峡近 40 a 海冰输出量的变化状况以及弗雷姆海峡海冰输出的年际变化、季节变化, 并分析了影响弗雷姆海峡海冰输出量的可能原因。结果表明: 近 40 a 弗雷姆海峡年均海冰输出面积通量为 7.83×105 km2,近 10 a 弗雷姆海峡海冰年均输出体积通量为 1.34×106 km3, 从长期来看, 弗雷姆海峡海冰输出面积通量呈略微增加趋势, 弗雷姆海峡海冰输出体积通量在 2010—20... 相似文献
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使用卫星测高、海表温度以及中国沿海台站水位等数据,分析研究了ENSO对中国近海海平面影响的区域特征。结果表明:(1)赤道东太平洋海表温度与我国近海海平面存在显著的遥相关关系。相关系数自北至南呈梯度递增,分为3个影响明显的区域,分别是渤、黄海、东海和南海海域。南海海平面异常与赤道东太平洋区域的海表温度异常相关性最强,大部分区域的相关系数超过了0.6;东海海域海平面异常与赤道东太平洋海表温度的遥相关系数弱于南海,强于渤、黄海,大部分海域的遥相关系数超过了0.4;渤、黄海海域海平面异常与赤道东太平洋海表温度的遥相关系数最弱,但是大部分海域的遥相关系数超过了0.3,通过了显著性检验。(2)中国沿海海平面的季节变化与ENSO有明显的相关关系,且影响范围具有明显的区域特征,以长江口和台湾海峡为分界线分为长江口以北、长江口到台湾海峡以及台湾海峡以南3个区域。海平面的年振幅在厄尔尼诺年均出现偏低的现象,并且年振幅的极小值均出现在厄尔尼诺年。另外,海平面的年振幅对厄尔尼诺事件的响应与其强弱有关,在强厄尔尼诺事件中,响应区域和幅度较大,弱事件中,响应区域和幅度偏小。(3)南海、东海和渤、黄海这3个区域沿海的海平面变化均存在4~7 a的显著振荡周期,说明这3个区域的海平面均受ENSO的影响。其中,南海7 a周期的振荡幅度最大,约为1.5 cm;东海7 a周期的振荡幅度次之,约为1.3 cm;渤、黄海6 a周期的振荡幅度最小,不到1 cm。 相似文献