共查询到20条相似文献，搜索用时 62 毫秒
1.
在实验室大型玻璃钢水槽中,流水条件下投喂两种不同颗粒大小的卤虫,采用Eggers模型比较了黄海、渤海主要中上层小型鱼类玉筋鱼的摄食、生长和生态转换效率等生态能量学特征.结果表明:投喂颗粒小的幼体卤虫的排空率比投喂颗粒大的成体卤虫的大,分别为0.2136,0.1887.摄食小颗粒幼体卤虫的玉筋鱼的摄食率、生长率和生态转换效率分别为22.53g/(100g·d)(湿质量)或60.14kJ/(100g·d),3.63g/(100g·d)(湿质量)或14.86kJ/(100g·d),16.12%(以湿质量计)或24.70%(以能量计);而摄食大颗粒成体卤虫的玉筋鱼的摄食率、生长率和生态转换效率分别为27.54g/(100g·d)(湿质量)或51.69kJ/(100g·d),4.77g/(100g·d)(湿质量)或19.50(kJ/100g·d),17.31%(以湿质量计)或37.69%(以能量计).摄食成体卤虫的湿重比摄食幼体卤虫的多,而摄食幼体卤虫所含能量比成体卤虫的高;从玉筋鱼的生长情况来看,成体卤虫投喂的效果明显优于幼体卤虫,不管是用湿重还是用能含量来表示,摄食成体卤虫的生长都比摄食幼体的快,摄食成体的生态转化效率也都比摄食幼体的要高. 相似文献
2.
南麂列岛岛礁区域鱼类种类组成和数量分布 总被引：3，自引：0，他引：3
采用底层拖网方法,以渔获率作为鱼类资源分布的数量指标,进行了南麂列岛岛礁区域2011年4月、8月、11月和2012年3月4个季节的鱼类种类组成、数量分布以及时空变化研究。结果表明:(1)调查海域鱼类有69种,鱼类种数夏季>秋季>冬季>春季;(2)六指马鲅、海鳗、棘头梅童鱼、龙头鱼、赤鼻棱鳀、白姑鱼、、中颌棱鳀、六丝钝尾虎鱼等15种鱼占鱼类总渔获量的89.13%,是调查海域底层拖网的主要捕捞鱼类;(3)不同季节的鱼类渔获量组成相差较大,优势种季节演替现象明显;(4)渔获率的季节变化明显,渔获率夏秋季明显高于冬春季,夏秋季渔获率较高的区域一般在调查海域西北方向的开阔海域。 相似文献
3.
《中国海洋大学学报(自然科学版)》2017,(7)
本文旨在查明目前黄河口水域鱼类浮游生物的种类组成和数量变化,为进一步研究鱼类资源早期补充、种群动态以及制定合理的渔业资源养护措施提供基础资料。根据2013年8月、2014年5月在黄河口及其邻近水域进行的鱼卵、仔稚鱼的调查数据,研究了该水域5、8月鱼卵、仔稚鱼的种类组成、数量分布,分析了鱼卵、仔稚鱼优势种数量分布与水温、盐度等环境因子的关系。研究表明,本次调查获得鱼卵25 613粒,隶属于12科13属15种(未定种1种);仔稚鱼369尾,隶属于4科7属9种(未定种1种)。5月鱼卵优势种为日本鳀(Engraulis japonicus)、赤鼻棱鳀(Thryssa chefuensis)和斑鰶(Konosirus punctatus),密集区分布在黄河口北部近岸海域,分布在密集区的种类以日本鳀和赤鼻棱鳀为主;8月鱼卵优势种为短吻红舌鳎(Cynoglossus joyneri)和多鳞鱚(Sillago sihama),其鱼卵主要集中分布于北部近岸海域,南部水域的部分站位也有鱼卵密集,密集区内的种类以短吻红舌鳎和多鳞鱚为主。5月仔稚鱼优势种为矛尾虾虎鱼(Chaeturichthys stigmatias)和赤鼻棱鳀等,仔稚鱼主要集中分布于黄河口南部海域,密集区以赤鼻棱鳀和矛尾虾虎鱼为主;8月仔稚鱼数量极少,无明显优势种。Pearson相关分析表明,除5月赤鼻棱鳀鱼卵数量与表层水温呈显著正相关外,其他优势种鱼卵、仔稚鱼数量与表层水温、表层盐度均无显著相关性。与历史同期调查结果相比,该水域5、8月鱼卵、仔稚鱼的种类组成和数量分布均发生了一定的变化。带鱼(Trichiurus lepturus)、小黄鱼(Larimichthys polyactis)、蓝点马鲛(Scomberomorus niphonius)和鳓(Ilisha elongate)等传统经济鱼类的鱼卵、仔稚鱼少见,以日本鳀、赤鼻棱鳀和斑鰶等小型中上层鱼类为主要优势种;黄姑鱼(Nibea albiflora)、皮氏叫姑鱼(Johnius belangeri)等鱼卵、仔稚鱼密度低。 相似文献
4.
黄鳍刺(鱼叚)虎鱼(Acanthogobius flavimanu)前期幼鱼摄食习性和摄食率的初步研究 总被引：1，自引：0，他引：1
对 1997年 5月莱州湾潍河口采集的黄鳍刺虎鱼前期幼鱼进行消化道内含物分析。结果表明黄鳍刺虎鱼前期幼鱼为浮游动物食性 ,主要摄食镖蚤类、短尾类幼体、猛蚤类和甲壳类的六肢幼体。摄食有明显的节律 ,清晨消化道内含物最多 ,傍晚最少。摄食的种类随昼夜不同时间有一定的变化。摄食率 :C=9.2 52 8g/ (10 0 g· BW· d) ;日摄食量 :FD=0 .0 0 4 7g/ d。 相似文献
5.
不同大小玉筋鱼摄食、生长和生态转换效率的比较 总被引：4，自引：0，他引：4
本研究将Eggers模型移入实验室大型玻璃钢水槽中，以细脚长蜮为饵料，在流水条件下，比较了黄渤海主要中上层小型鱼类玉筋鱼大小两种体重组的摄食、生长和生态转换效率等生态能量学特征。结果表明：小个体的摄食率、生长率和生态转换效率分别为12．36gW．W．／100g／d或12．44kJ／100g／d，2．22gW．W．／100g／d或9．09kJ／100g／d，0．18％W．W．或0．73％kJ；大个体的摄食率、生长率和生态转换效率分别为9．16gW．W．／100g／d或9．22kJ／100g／d，0．83gW，W．／100g／d或3．41kJ／100g／d，0．09％W．W．或0．37％kJ。不管是以湿重还是以能量计算，小个体的都比大个体的要高。 相似文献
6.
温度和流速对细鳞鲑(Brachymystax lenok)幼鱼游泳能力的影响及其与呼吸代谢的关系 总被引：1，自引：0，他引：1
通过鱼类游泳代谢测定装置,研究了5个温度(4、8、12、16和20°C)水平下细鳞鲑(Brachymystax lenok)幼鱼的爆发游泳速度(BS)、临界游泳速度(UCrit)及其测定过程中的呼吸代谢率和不同恒定流速临条件下的最大续航游泳时间,并分析比较了幼鱼摄食与空腹状态下相关测试指标的差异,探讨了温度和流速对细鳞鲑幼鱼游泳能力的影响。结果表明,5个温度水平下摄食组和空腹组细鳞鲑幼鱼的BS不存在显著差异(P0.05),且各实验组的BS对温度均无依赖关系,其摄食组和空腹组的线性拟合方程分别为Y摄食=–0.0336x2+0.2424x+0.27(R2=0.929)和Y空腹=–0.045x2+0.317x+0.192(R2=0.9158);5个温度水平下,摄食组和空腹组细鳞鲑幼鱼的UCrit分别为:(0.42±0.0038)和(0.43±0.001)、(0.42±0.0038)和(0.46±0.0099)、(0.46±0.0025)和(0.47±0.0076)、(0.43±0.0081)和(0.43±0.0010)、0.47±0.0014和(0.48±0.0012)m/s,且随着温度升高和流速增大,摄食组较空腹组的呼吸耗氧率分别增加了17.80%(4°C)、32.24%(8°C)、19.39%(12°C)、39.39%(16°C)和19.48%(20°C);在最适温度条件下(16°C),不同测试流速对摄食组和空腹组细鳞鲑幼鱼的最大续航游泳时间存在显著性差异(P0.05),采用非线性拟合得到了8个测试流速与最大续航游泳关系的幂函数模型,由幂函数方程可知,最大续航游泳时间与测试流速呈负相关性,摄食组与空腹组存在显著性差异(P0.05),且随着流速增大,其最大续航游泳时间缩减剧烈。本研究认为,在设计大坝鱼道过程中应充分考虑不同温度条件和摄食条件下鱼类的爆发游泳速度和临界游泳速度参数,且如果考虑春秋季节细鳞鲑幼鱼上溯的有效通过率,那么鱼道的入口流速应小于0.65m/s,鱼孔处流速小于0.42 m/s。 相似文献
7.
《中国海洋大学学报(自然科学版)》2010,(Z1)
研究了投喂新鲜、冷冻、烘干的菲律宾蛤仔(Ruditapes philippinarum)肉对三疣梭子蟹(Portunus tritubercula-tus)摄食、代谢及生长的影响。实验结果表明:用干重表示的摄食不同蛤肉的三疣梭子蟹日平均摄食率、特定生长率、饵料转化效率有显著差异:投喂新鲜蛤肉、冷冻蛤肉、烘干蛤肉的蟹日平均摄食率分别为6.15%±0.98%,6.33%±0.91%,10.72%±1.18%,烘干蛤肉组显著高于其他两组(P0.05);日特定生长率分别为2.90%±0.37%,2.23%±0.46%,1.97%±0.30%,新鲜蛤肉组显著高于其他2组(P0.05);饵料转化效率分别为41.57%±5.67%,32.72%±6.60%,17.52%±1.04%,新鲜蛤肉组冷冻蛤肉组烘干蛤肉组(P0.05)。蜕壳率分别为169.23%,160.00%,166.67%。摄食代谢中,饱食后2~4 h内代谢率达到高峰,4~6 h代谢率仍较高但有下降趋势。摄食不同蛤肉的三疣梭子蟹在饱食后0~2 h和2~4 h内新鲜蛤肉组亚硝氮排泄率分别为(0.133±0.008)μg.g-1.h-1和(0.287±0.006)μg.g-1.h-1,显著低于冷冻蛤肉组[(0.180±0.013)μg.g-1.h-1,(0.334±0.007)μg.g-1.h-1]和烘干蛤肉组[(0.197±0.009)μg.g-1.h-1,(0.347±0.034)μg.g-1.h-1],而4~6 h内各组间差异不显著。各处理组氨氮排泄率、耗氧率在饱食后0~2h,2~4 h,4~6 h都有显著差异,冷冻蛤肉组烘干蛤肉组新鲜蛤肉组(P0.05)。新鲜蛤肉组蟹饱食后0~2 h,2~4h,和4~6 h内氨氮排泄率分别为平均每小时(0.689±0.007)μg.g-1,(0.959±0.048)μg.g-1,(0.752±0.028)μg.g-1;耗氧率分别为(0.073±0.003)mg.g-1,(0.099±0.005)mg.g-1,(0.072±0.006)mg.g-1。综合考虑,投喂新鲜蛤肉三疣梭子蟹特定生长率、饵料转化效率最高,氨氮排泄率最低,既有利于提高蟹产量,又有利于清洁生产。 相似文献
8.
在实验室内, 22. 5±0. 5℃条件下以去头去骨去鳞片去皮的金色小沙丁鱼的纯肉糜为饵料饲养斜带髭鲷幼鱼,测定体重范围在 4. 6~6. 5g的斜带髭鲷的体重、体长的生长曲线及其生态转换效率和特定生长率.实验结果表明,斜带髭鲷的体重、体长在实验期间直线增长,体重、体长的生长曲线分别为Wt(w.w.湿重,下同 ) =0. 391 7t 5. 766 2(R=0. 999 6)和Lt=0. 105t 6. 265(R=0. 989 9).用胃含物法测定斜带髭鲷的胃排空率、日摄食量、日生长量、生态转换效率和特定生长率.实验得到斜带髭鲷消化道的瞬时排空率Rt= 1. 23 4×10-3 (m/m) /h,日摄食量Cd= 1. 342 9g(w.w. ),生态转换效率Eg=29. 50% ±2. 77% [m/m(w.w. ) ],特定生长率SGR=4. 71%±0. 69% [m/m(w.w. ) ]. 相似文献
9.
东海、黄海不同生长时期鳀鱼的胃排空率 总被引：1，自引：0，他引：1
采用现场和室内模拟方法,测定了东海、黄海不同时期鳀鱼的胃排空率,比较了3种常用数学模型对其排空曲线的拟合程度.统计结果表明,3种数学模型均可较好地描述鳀鱼的胃排空曲线,其中当鳀鱼个体较小或实验温度接近于适温下限时,排空曲线较接近于一条直线,随个体增大和温度升高,则逐渐演变为典型的指数曲线;综合评价结果表明,指数模型最适于定量描述其胃排空曲线,平方根模型次之,直线模型较差.在本研究的生长期范围内,近岸觅食高温期的当年生鳀鱼个体较小,胃排空率相对较低;随后温度虽然降低,但个体有较大幅度增大,排空率明显增大;当温度继续降低至越冬温度时,个体继续增大引起的变化被温度效应所掩盖,排空率降低到最低点;越冬后洄游至近岸海域进行生殖之前,温度和体重与越冬阶段项比较,都有较大幅度增长,且测定时卵巢已发育至Ⅳ期,卵巢发育增大了体内能量消耗,故这一时期鳀鱼的胃排空率远大于其他各时期. 相似文献
10.
为研究曼氏无针乌贼(Sepiella japonica)在不同温度下(15oC、20oC和25oC)进食冰鲜葛氏长臂虾(Palaemon gravieri)后的胃内容物特性变化及胃排空规律,本实验将采用3种常用数学模型(线性、平方根及指数模型)对胃排空曲线进行拟合,比较进食后胃排空过程中胃内容物的水分、pH和消化酶的变化规律。结果表明,3种数学模型均能较好地描述曼氏无针乌贼胃排空曲线,但是平方根模型对曼氏无针乌贼胃内容物湿重和干重的数据拟合效果最优。根据平方根模型计算,在15oC、20oC和25oC水温时曼氏无针乌贼50%胃内容干重排出的理论时间分别为4.4h、3.7h和3.6h,而完全排空的时间分别为13.8h、12h和12h。在摄食后0—14h内,胃内容物水分含量表现为先逐渐下降后显著上升;pH值在摄食后0—8h内逐渐降低,8—14h缓慢上升;胃蛋白酶和胰蛋白酶均呈现先升高后降低的变化趋势,而淀粉酶则总体保持恒定。曼氏无针乌贼在15oC、20oC和25oC三个温度下进食冰鲜葛氏长臂虾,胃排空过程中的胃内容物水分含量、pH值和消化酶比活力均存在显著差异(P0.05)。综上所述,25oC水温条件更有利于曼氏无针乌贼的胃排空过程,同时建议在饲喂管理中按照3.6h的间隔进行投喂。 相似文献
11.
Chandralata Raghukumar G. Sheelu P. A. Loka Bharathi Shanta Nair C. Mohandass 《Marine Georesources & Geotechnology》2001,19(1):1-16
In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance. 相似文献
12.
Arne Schnack-Friedrichsen Angela M. Davis Jim D. Bennell Dei G. Huws 《Marine Georesources & Geotechnology》2001,19(4):221-243
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths. 相似文献
13.
海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。 相似文献
14.
Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification
An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm. 相似文献
15.
Shigehisa Nakamura 《Marine Geodesy》2000,23(1):55-61
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone. 相似文献
16.
17.
Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations. 相似文献
18.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics. 相似文献
19.
20.
Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans 总被引：1，自引：0，他引：1
A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level. 相似文献