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1.
为探究大西洋鲑(Salmo salar)幼鱼的适宜投喂频率和胃排空规律,进行了养殖实验和胃排空实验.养殖实验设置了1次/天(F1组)、2次/天(F2组)、3次/天(F3组)、4次/天(F4组)和连续投喂(C F组)共5种投喂频率.胃排空实验采用连续测定胃含物的方法,用数学模型对胃含物数据进行拟合.研究表明:F1组日摄食... 相似文献
2.
The food consumption (recorded in kg of individual fish species), body length and mass of 11 Atlantic bottlenose dolphins kept first at Windsor Safari Park, UK (1979-1993/1994), and later at Harderwijk Marine Mammal Park, The Netherlands (1993/1994-1995) are reported. This broad-scale, longitudinal study is based on historical data that were originally recorded for short-term husbandry purposes. The chemical composition and caloric value of the diet were variable and were not recorded. The food intake quantities should therefore be viewed as rough weight estimates of what wild conspecifics might eat (depending on their diet). The average annual food consumption of adult males and non-pregnant, non-lactating females was approximately 2000 kg of fish (estimated at 176 x 10(5) kJ). Food consumption showed little increase during gestation, but was 58-97% higher during lactation than during similar periods in non-reproductive years. All six calves began to eat solid food within a year of birth although suckling continued for 14-37 months after birth. The pattern of food intake of mothers and calves varied substantially between suckling periods. No seasonal changes in food consumption were detected, although there were small seasonal changes in water temperature. Births occurred at various times of year, since the timing of mating varied between years. The animals' body length increased rapidly during the first 3 years of life after which the growth rate decreased. Body length reached asymptote at approximately 270 cm. Adults of both sexes weighed around 260 kg. The relationship between standard body length (in cm) and body mass (in kg), although based on a small sample size (n = 16), can be expressed as body mass = 17.261e(0.0156(body length-100)). Animals weighing 155-225 kg consumed between 2 and 4% of their body mass per day. 相似文献
3.
海蟑螂在中国沿海从南到北均有分布,为半陆生甲壳类生物,常栖息于近海岩礁的石缝中。海蟑螂野生资源量巨大,饲用与药用效果明显,且适应能力强,有很高的科研和实用价值。实验评估了奇异海蟑螂(Ligia exotica)幼体从出生到60日龄的生长表现,发现在45日龄后,个体体重增加开始明显加快。60日实验期间幼体增重率为7 746.51%,特定生长率为7.27%,高于其他甲壳类生物。幼体体长和体宽呈现相近的增长趋势,且体长的增长快于体宽。回归分析显示海蟑螂幼体体重与体长、体宽均具有较好的正相关性,决定系数R2分别为0.90和0.87,故可以通过体长和体宽估算其体重。实验首次实现了海蟑螂幼体的全人工培育,为其成为经济虾蟹类研究的模式动物打下了基础。且实验证实海蟑螂幼体生长速度非常快,有利于人们对其种群的开发利用。 相似文献
4.
Lny Mercier Jacques Panfili Christelle Paillon Awa N'diaye David Mouillot Audrey M. Darnaude 《Estuarine, Coastal and Shelf Science》2011,92(4):534-545
Accurate knowledge of fish age and growth is crucial for species conservation and management of exploited marine stocks. In exploited species, age estimation based on otolith reading is routinely used for building growth curves that are used to implement fishery management models. However, the universal fit of the von Bertalanffy growth function (VBGF) on data from commercial landings can lead to uncertainty in growth parameter inference, preventing accurate comparison of growth-based history traits between fish populations. In the present paper, we used a comprehensive annual sample of wild gilthead seabream (Sparus aurata L.) in the Gulf of Lions (France, NW Mediterranean) to test a methodology improving growth modelling for exploited fish populations. After validating the timing for otolith annual increment formation for all life stages, a comprehensive set of growth models (including VBGF) were fitted to the obtained age–length data, used as a whole or sub-divided between group 0 individuals and those coming from commercial landings (ages 1–6). Comparisons in growth model accuracy based on Akaike Information Criterion allowed assessment of the best model for each dataset and, when no model correctly fitted the data, a multi-model inference (MMI) based on model averaging was carried out. The results provided evidence that growth parameters inferred with VBGF must be used with high caution. Hence, VBGF turned to be among the less accurate for growth prediction irrespective of the dataset and its fit to the whole population, the juvenile or the adult datasets provided different growth parameters. The best models for growth prediction were the Tanaka model, for group 0 juveniles, and the MMI, for the older fish, confirming that growth differs substantially between juveniles and adults. All asymptotic models failed to correctly describe the growth of adult S. aurata, probably because of the poor representation of old individuals in the dataset. Multi-model inference associated with separate analysis of juveniles and adult fish is then advised to obtain objective estimations of growth parameters when sampling cannot be corrected towards older fish. 相似文献
5.
Markus Pahlow Alain F. Vézina Heidi Maass Daniel G. Wright 《Progress in Oceanography》2008,76(2):151-191
Plankton ecosystems in the North Atlantic display strong regional and interannual variability in productivity and trophic structure, which cannot be captured by simple plankton models. Additional compartments subdividing functional groups can increase predictive power, but the high number of parameters tends to compromise portability and robustness of model predictions. An alternative strategy is to use property state variables, such as cell size, normally considered constant parameters in ecosystem models, to define the structure of functional groups in terms of both behaviour and response to physical forcing. This strategy may allow us to simulate realistically regional and temporal differences among plankton communities while keeping model complexity at a minimum.We fit a model of plankton and DOM dynamics globally and individually to observed climatologies at three diverse locations in the North Atlantic. Introducing additional property state variables is shown to improve the model fit both locally and globally, make the model more portable, and help identify model deficiencies. The zooplankton formulation exerts strong control on model performance. Our results suggest that the current paradigm on zooplankton allometric functional relationships might be at odds with observed plankton dynamics. Our parameter estimation resulted in more realistic estimates of parameters important for primary production than previous data assimilation studies.Property state variables generate complex emergent functional relationships, and might be used like tracers to differentiate between locally produced and advected biomass. The model results suggest that the observed temperature dependence of heterotrophic growth efficiency [Rivkin, R.B., Legendre, L., 2001. Biogenic carbon cycling in the upper ocean: effects of microbial respiration. Science 291 (5512) 2398-2400] could be an emergent relation due to intercorrelations among temperature, nutrient concentration and growth efficiency. A major advantage of using property state variables is that no additional parameters are required, such that differences in model performance can be directly related to model structure rather than parameter tuning. 相似文献
6.
The recent moratorium on the commercial at-sea driftnet fishery for wild Irish Atlantic salmon (Salmo salar L.) attempts to halt the decline witnessed in these stocks over the past three decades. The research investigated stakeholder attitudes to the perceived effects on stock recovery, in Irish rivers and estuaries, of seal predation and seal culling. Structured interviews conducted with 10 key stakeholders during June 2007 revealed divisive attitudes and a feeling of powerlessness in relation to stock recovery, which are impeding successful management of salmon stocks. However, areas of common ground exist between stakeholders, which lay the foundation for a sustainable way forward. 相似文献
7.
Ages of redeye round herring Etrumeus whiteheadi were estimated with associated errors and used to infer life-history information, such as age composition, age-at-maturity and instantaneous mortality rate. Samples were collected in November 2005 during a research survey aimed at estimating the biomass of spawning pelagic fish off South Africa’s west and south coasts. Replicate age estimates obtained from sagittal otoliths were collected with slight bias and relatively high precision. A von Bertalanffy model describing growth of the combined sexes, including juveniles, was Lt = 20.41(1 ? e?0.41(t ? 1.92)). Kimura’s likelihood ratio test revealed no statistically significant differences between growth parameters of males and females. Results suggested that otolith length is a better predictor of age than otolith weight. Maturity estimates for E. whiteheadi were similar to those previously documented. 相似文献
8.
Evaluation of GEV model for frequency analysis of annual maximum water levels in the coast of United States 总被引：3，自引：0，他引：3
The three-parameter generalized-extreme-value (GEV) model has been recommended by FEMA [FEMA (Federal Emergency Management Agency of the United States), 2004. Final Draft Guidelines for Coastal Flood Hazard Analysis and Mapping for the Pacific Coast of the United States. http://www.fema.gov/library/viewRecord.do?id=2188] for frequency analysis of annual maximum water levels in the Pacific coast of the United States. Yet, the GEV model's performance in other coastal areas still needs to be evaluated. The GEV model combines three types of probability distributions into one expression. The probability distributions can be defined by one of the three parameters of the GEV model. In this study, annual maximum water levels at nine water-level stations with long history data (more than 70 years) were chosen for analysis in five coastal areas: Pacific, Northeast Atlantic, East Atlantic, Southeast Atlantic, and Gulf of Mexico coasts. Parameters of the GEV model are estimated by the maximum likelihood estimation (MLE) method. Results indicate that probability distributions are characterized by the GEV Type III model at stations in the Pacific, Northeast, and East Atlantic coastal areas, while they are described by GEV Type II in stations of the Southeast Atlantic and Gulf of Mexico coastal areas. GEV model predictions of extreme water levels show good correlation to observations with correlation coefficients of 0.89 to 0.99. For predictions of 10% annual maximum water levels, the GEV model predictions are very good with errors equal to or less than 5% for all nine stations. Comparison of observations and GEV model estimations of annual maximum water levels for the longest recorded return periods, close to 100 years, revealed errors equal to or less than 5% for stations in the Pacific and Northeast Atlantic coastal areas. However, the errors range from 10% to 28% for other stations located in the East and Southeast Atlantic coasts as well as Gulf of Mexico coastal areas. Findings from this study suggest caution regarding the magnitudes of errors in applying the GEV model to the East and Southeast Atlantic coasts and Gulf of Mexico coast for estimating 100-year annual maximum water levels for coastal flood analysis. 相似文献
9.
Variability in scale growth rates of chum salmon (Oncorhynchus keta) in relation to climate changes in the late 1980s 总被引：2，自引：1，他引：2
Fish scales were used to investigate the interannual variability in chum salmon growth rates at specific ages in relation to climatic/environmental changes during the 1980s–1990s. Scales were obtained from adult salmon returning to the east coast of Korea between 1984 and 1998. Assuming proportionality between scale size increments and fish length, distances between scale annuli were regarded as the growth conditions in different habitat areas with respect to the life stages of chum salmon. In estuarine and coastal areas, growth rates of fingerling salmon were higher in the 1990s than in the 1980s. Zooplankton abundance off the east coast of Korea increased after the late 1980s, which may have provided favorable growth conditions for young salmon in the 1990s. Growth of juvenile chum salmon during the first summer (Okhotsk Sea) was relatively stable, and neither SST nor zooplankton biomass fluctuated significantly during the study period. However, in the Bering Sea, salmon growth rates between age-2 and age-4 (i.e. ocean-phase immature salmon) were higher in the 1980s than in the 1990s. Variability in salmon growth in the Bering Sea was correlated to zooplankton biomass. These results suggest that the climate regime shift of 1988/1989 in the subarctic North Pacific affected salmon growth mediated by changes of zooplankton biomass, revealing a bottom-up process. 相似文献
10.
Suzan S. Pool Richard D. Brodeur N. Lynn Goodman Elizabeth A. Daly 《Estuarine, Coastal and Shelf Science》2008
The Juan de Fuca Eddy is a seasonal, counter-clockwise gyre off the mouth of the Strait of Juan de Fuca between Washington, USA and British Columbia, Canada that may provide favorable feeding habitat for juvenile coho salmon (Oncorhynchus kisutch) during their early marine existence. In late September 2002, physical and biological sampling was conducted along two transects of the eddy region. Surface rope trawling was conducted to capture juvenile salmon and other nekton, along with bongo and neuston net tows to examine potential mesozooplanktonic salmon prey. Presence of the Juan de Fuca Eddy was confirmed with vertical water profiles. In addition, nutrient and chlorophyll a concentrations collected from 3-m depth were within the range observed in previous studies within the eddy region. In the mesozooplankton community, euphausiids, chaetognaths, and decapod megalopae were common. In the diet of juvenile coho salmon, euphausiids and decapod megalopae were dominant by percent number, and larval and juvenile fish were dominant by percent weight. Feeding intensity (percent body weight) based on stomach contents was variable, but not significantly different among stations. To compare the Juan de Fuca Eddy region with an upwelling area, we sampled along a transect off La Push (LP), Washington, USA which is south of the eddy. The eddy region was found to be less productive than the LP transect. Nutrients were lower, chlorophyll a concentrations were higher, and zooplankton abundance was generally higher along the LP transect than in the eddy region. In addition, more juvenile coho salmon were captured from the LP transect than the eddy region. Prey items in stomachs of salmon from the LP transect were heterogeneous compared to those from the eddy region. Feeding intensity along the LP transect was slightly lower and more variable than in the eddy region, and differences in feeding intensity among LP stations were significant. In addition, feeding intensities among stations nested within regions were significantly different. 相似文献
11.
We hypothesise that salmon year class strength is determined in two stages during the first year in the ocean. There is an early natural mortality that is mostly related to predation, which is followed by a physiologically-based mortality. Juvenile salmon that fail to reach a critical size by the end of their first marine summer do not survive the following winter. In this study we describe our initial tests of this critical size and critical period hypothesis using data from ocean surveys of juvenile salmon and from experimental feeding studies on coho. Conservative swept volume abundance estimates for juvenile coho, and possibly chinook, indicate that there is high mortality in fall and winter during their first year in the sea. Studies of otolith weight show that the length and otolith-weight relationship for young coho changes in the early fall of their first ocean year. Studies of growth and associated hormone levels in feeding studies show that slow growing juvenile coho are stunted and deficient in an insulin-like growth factor-I (IGF-I). Juvenile coho sampled in September had low IGF-I values, indicative of poor growth. The results of these studies provide evidence for the general hypothesis that growth-related mortality occurs late in the first marine year and may be important in determining the strength of the year class (brood year). The link between total mortality and climate could be operating via the availability of nutrients regulating the food supply and hence competition for food (i.e. bottom–up regulation). 相似文献
12.
以4种不同地理群体大菱鲆为亲本，采用巢式设计方法和人工采卵授精技术，按照1雄配2雌的原则，构建了28个父系半同胞家系和56个母系全同胞家系，分别测定了每个母系生长到6月龄的全同胞个体60个后代的体长、全长、体高、体重，应用数量遗传学原理，利用全同胞资料，采用方差、协方差分析的方法，研究了大菱鲆6月龄生长性状的遗传力及性状间的遗传相关和表型相关。对性状遗传力研究结果表明，雌性遗传方差组分均大于雄性遗传方差组分，雌性遗传方差组分存在显著的母性效应。基于父系半同胞组内相关法估计的遗传力是大菱鲆体长、全长、体高、体重遗传力的无偏估计值，估计的遗传力准确可靠，估计值分别为0．282、0．251、0．283、0．450，为中高等遗传力，显示对大菱鲆生长性状进行选择育种具有很大的潜力。对性状间相关性分析结果表明，依据父系半同胞遗传协方差组分和表型协方差分别估计体长．全长、体长一体高、体长．体重、全长。体高、全长一体重、体高一体重间的遗传相关和表型相关，遗传相关在0．888-0．985，表型相关在0．864—0．957，各性状间遗传相关和表型相关经t检验均达到极显著水平（P〈0．01）。 相似文献
13.
《Deep Sea Research Part II: Topical Studies in Oceanography》2009,56(24):2553-2559
A bioenergetic model of juvenile pink salmon (Oncorhynchus gorbuscha) was used to estimate daily prey consumption and growth potential of four ocean habitats in the Gulf of Alaska during 2001 and 2002. Growth potential was not significantly higher in 2002 than in 2001 at an alpha level of 0.05 (P=0.073). Average differences in growth potential across habitats were minimal (slope habitat=0.844 g d−1, shelf habitat=0.806 g d−1, offshore habitat=0.820 g d−1, and nearshore habitat=0.703 g d−1) and not significantly different (P=0.630). Consumption demand differed significantly between hatchery and wild stocks (P=0.035) when examined within year due to the interaction between hatchery verses wild origin and year. However, the overall effect of origin across years was not significant (P=0.705) due to similar total amounts of prey consumed by all juvenile pink salmon in both study years. We anticipated that years in which ocean survival was high would have had high growth potential, but this relationship did not prove to be true. Therefore, modeled growth potential may not be useful as a tool for forecasting survival of Prince William Sound hatchery pink salmon stocks. Significant differences in consumption demand and a two-fold difference in nearshore abundance during 2001 of hatchery and wild pink salmon confirmed the existence of strong and variable interannual competition and the importance of the nearshore region as being a potential competitive bottleneck. 相似文献
14.
G.T. Ruggerone J.L. Nielsen J. Bumgarner 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2776
We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976–1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976–1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean. 相似文献
15.
本文以平均体重为(388.00±41.11)g的大西洋鲑(Salmosalar)为实验对象,探究了改性粘土絮凝过程对养殖水体水质以及大西洋鲑存活、组织形态和氧化应激反应的影响。在本实验条件下,添加改性粘土的实验组水质得到一定程度的改善,其中磷酸盐、铵盐、亚硝酸盐浓度相较于对照组有明显降低的趋势(P0.05)。添加远高于现场可有效去除赤潮生物用量(4—10g/m~2)的改性粘土并没有导致大西洋鲑出现死亡现象,显微观察结果显示,实验组与对照组中大西洋鲑鱼鳃、消化道组织特征无明显差别。对大西洋鲑鳃、肝脏、消化道的丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性测定结果表明,改性粘土未对大西洋鲑造成显著的氧化胁迫(P0.05)。本研究结果说明,在远高于现场有效用量条件下,改性粘土未对大西洋鲑产生不良影响,该研究结果将为改性粘土治理有害藻华技术在国内外养殖海域的应用提供科学依据。 相似文献
16.
An introduced turbot population was used to establish families and to estimate genetic parameters of the offspring. However, there is a lack of pedigree information, and common environmental effects can be introduced when each full-sib family is raised in a single tank. Therefore, in the genetic evaluation, SSRs(simple sequence repeats) were used to reconstruct the pedigree and to calculate molecular relatedness between individuals, and the early mixed-family culture model was used to remove the impact of the common environmental effects. After100 d of early mixed culture, twenty SSRs were used to cluster 20 families and to calculate paired molecular relationships(n=880). Additive genetic matrices were constructed using molecular relatedness(MR) and pedigree reconstruction(PR) and were then applied to the same animal model to estimate genetic parameters. Based on PR, the heritabilities for body weight and body length were 0.214±0.124 and 0.117±0.141, and based on MR they were 0.101±0.031 and 0.102±0.034, respectively. Cross validation showed that the accuracies of the estimated breeding values based on MR(body weight and body length of 0.717±0.045 and 0.629±0.141, respectively) were higher than those of PR(body weight and body length of 0.692±0.052 and 0.615±0.060, respectively). The MR method ensure availability of all genotyped selection candidates, thereby improving the accuracy of the breeding value estimation. 相似文献
17.
饲料脂肪水平对三疣梭子蟹(Portunus trituberculatus)幼蟹生长及体组成的影响 总被引：2，自引：1，他引：1
采用单因素试验设计方法, 进行了不同饲料脂肪水平对三疣梭子蟹(Portunus trituberculatus)幼蟹生长及体组成影响的研究。结果表明, 低饲料脂肪水平(1.8%)组的增重率和特定生长率最低, 饲料脂肪水平为4.2%组的增重率和特定生长率最高。不同饲料处理对三疣梭子蟹蟹体的水分、粗蛋白和灰分含量无显著影响, 饲料脂肪水平为9.01%组蟹体的脂肪含量最高, 饲料脂肪水平为1.8%组的蟹体脂肪含量最低。饲料处理显著影响各处理组的性腺指数, 饲料脂肪水平为13.76%组的性腺指数最低。而不同饲料处理对各组的肝胰腺指数、壳宽、壳长和壳高无显著影响。本实验结果显示, 4.2%—13.76%的饲料脂肪水平能满足三疣梭子蟹正常生长和发育所需。 相似文献
18.
以虹鳟(Oncorhynchus mykiss)优良品系选育第二世代群体作为试验群体,分别采用只含有加性效应和包括加性和显性效应的单性状动物模型估计了体质量、头长、体长、体宽、体厚等5个主要生长性状的加性遗传力和显性方差组分比率。只含有加性效应的模型结果显示,上述5个性状的遗传力在0.16—0.48之间,多为中等或较高遗传力;同时包括加性和显性效应的模型分析结果显示,上述5个性状的显性方差组分比率在0.24—0.67之间,均处于中等或较高水平。其中体长显性方差组分比率最低,为0.24,头长显性方差组分比率最高,为0.67。此外,与简单加性模型相比,同时包括加性和显性效应的模型估计的5个性状加性遗传力均有下降,在0.14—0.42之间,但是模型改变并没有影响到各性状加性遗传力大小数值的排序关系。本研究还发现,将显性效应纳入模型后,加性方差和随机残差都出现显著下降,提示只含有加性效应的混合模型中所期望的显性效应等非加性效应都可以简单地归入随机残差并不确切,如果将显性效应纳入育种规划,可以获得更大的遗传进展。 相似文献
19.
流速作为深远海养殖海区选址的重要依据,也是影响鱼类游泳能力的重要因素之一,为评价深远海养殖良种斑石鲷(Oplegnathus punctatus)的游泳能力,明确最适放养规格,分别以体重50、150、250、350g的斑石鲷为研究对象,利用鱼类游泳能力及运动消耗检测装置,在24℃条件下,解析了不同规格的斑石鲷在四种流速下的续航时间、暴发游泳速度(Uburst)、临界游泳速度(Ucrit)和运动耗氧率(MO2),并计算出其单位位移耗能(COT)和最适游泳速度(Uopt)。结果表明,鱼体规格和流速均会对实验鱼续航时间产生影响显著(P<0.001,F=25.401,df=1),50g斑石鲷在60cm/s流速下续航时间显著小于其他三种规格(P<0.05),在大于60cm/s流速下,四种规格斑石鲷续航时间均小于30min;250g和350g斑石鲷暴发游泳速度显著高于50g与150g(P<0.05);斑石鲷临界游泳速度与体重成正相关(R=0.96),不同规格下临界游泳速度存在显著差异(P<0.05);各规格实验鱼间最适游泳速度无显著差别(P>0.05)。以上结果表明,不同规格斑石鲷游泳能力存在显著差异,其中250g和350g斑石鲷耐流能力显著优于50g和150g。综上所述,斑石鲷在深远海海域进行陆海接力养殖时,建议放养250g以上规格,且养殖海域流速不超过60cm/s。 相似文献