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水温 饵料 投饵率对河蟹生长和饵料转化率的影响 总被引：3，自引：0，他引：3
在实验室条件下研究了水温、饵料和投饵率对河蟹生长的影响。结果表明,在10～26℃水温范围内,河蟹对不同饵料的摄饵率和特定生长率均与水温呈正相关关系;相比之下,用配饵投喂,河蟹对温度的变化较为敏感,但配饵的饲养效果明显次于螺蛳。随着水温的升高,当螺蛳的投饵率由半饱增至全饱时,河蟹的湿重生长率增长不明显,而体蛋白量则增加了13%～28%。在适温范围内,适当降低投饵率可提高饵料转化率和蛋白质利用率,可是蟹体蛋白量的增加则明显下降。 相似文献
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中华绒螯蟹的摄食量和胃容量研究 总被引：3，自引：1，他引：3
在实验室水族箱控温条件下,以个体重3—50g的河蟹为试验对象,探讨了河蟹日摄饵率与不同饵料,水温和蟹体规格之间的相关关系,并测定了不同规格河蟹胃的物理最大容纳量(胃容量)。研究结果表明,在15—25℃范围内,河蟹的日摄饵率与水温呈指数式递增.25℃时,河蟹对小鱼、配合饵料和熟黄豆的日摄饵率分别是15℃时的1.77、1.68和2.33倍;而在同一水温条件下,河蟹对黄豆的摄饵率最低、小鱼最高,表现出对小鱼有较好的嗜食性。20℃条件下,河蟹的日摄饵率与规格呈负相关关系.统计结果表明,三种饵料中,不同规格的河蟹对配合饵料的摄食随意性较大;河蟹的胃容量与体重呈明显正相关关系.结合体重与摄饵率、胃容量之相关方程,推算了一定水温条件下不同规格河蟹的日投饵次数. 相似文献
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蜕壳素在池塘养蟹中的应用及注意事项众所周知，河蟹蜕壳与生长是成正比例关系，在天然环境下，河蟹蜕壳不为人们所注意，然而在人工饲养条件下，饲养成活率和生长率直接与河蟹蜕壳有关，同时也直接影响经济效益。现就如何应用蜕壳素，提高蜕壳频率，浅谈一点体会；一、蜕... 相似文献
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河蟹人工养殖技术的能学探讨 总被引：5，自引：0，他引：5
本文从能学的角度探讨温度，饵料与河蟹生长，蜕壳，性成熟的关系；阐明了河蟹养殖中温度效应；指出应注意温度控制，防止有效积温引发的早熟；详细讨论了饵料的种类配比以及蛋白质含量对河蟹生长，蜕壳，性成熟的影响；为推广和提高福建河蟹人工养殖技术提供参考。 相似文献
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河蟹食性杂，偏动物性饵料，且生性贪食，在饵料投喂上，既要满足河蟹营养需求，加快蜕壳生长，又要降低养殖成本，提高养殖效益。可因地制宜，多 相似文献
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1 饵料多样性河蟹食性杂，偏动物性饵料，且生性贪食，在饵料投喂上，即要满足河蟹营养需求，加快脱壳生长，又要降低养殖成本，提高养殖效益。可因地制宜，多种渠道落实饵料来源。一是蟹池移栽足够的水草，覆盖率在40％以上，水草既是河蟹喜食的植物性饵料，又可净化水质。蟹池水草多，有利于小杂鱼、虾、螺、蚬等天然饵料生物的生长繁殖。蟹池水草以沉水植物为主，漂浮植物，挺水植物为辅。二是投放螺蛳，让其自然繁殖，供河蟹自由摄食。螺蛳肉营养丰富，脂肪含量高，口味好，河蟹非常喜欢摄食。蟹池投放螺蛳，不仅提供了优质天然饵料，降… 相似文献
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１培育体质健壮的优良鱼种越冬前期就应加强对池塘鱼种的饲养管理工作。对吃食性鱼投喂高质量的饵料，如谷芽、麦芽、营养全面的商品饵料；而滤食性鱼种应通过培肥水质，使池塘水体中有丰富的饵料生长，以满足鱼种摄食的需要。其次是调节好池塘水质，使水体有充足的溶氧，以达到提高鱼种的规格和肥满度。生产实践证明，在相同的水体条件，肥满度相同的鱼种，规格越大，成活率越高；相同条件下，鱼种规格相同时，肥满度大即鱼种体肥膘壮，越冬成活率也高。２为越冬鱼种创造良好的环境条件２．１鱼塘条件选择用作鱼种越冬的池塘，应具备水源充… 相似文献
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Effects of environmental factors on size-related growth efficiency of perch, Perca fluviatilis 总被引：1，自引：1，他引：0
Abstract – Two aspects of size-dependent growth were addressed using perch, Perca fluviatilis L, from 22 Swedish lakes. Firstly, maximum annual growth decreased linearly with length after the previous year. Secondly, median or realized growth showed a non-linear pattern, with minimum growth efficiency at intermediate length, probably related to the shift from invertebrate to fish diet. Between-lake variation in size-related growth efficiency was better explained by fish community characteristics than by abiotic factors. The growth of most size classes was negatively related to fish biomass, especially to biomass of 100 to 199-mm perch. Growth efficiency of perch >200 mm was positively related to the proportion of large perch in the community. These size- and density-dependent growth responses suggest that effects of competitive and predatory interactions will often mask the controlling or limiting effects of abiotic factors, such that realized growth of individuals and populations are poorly described by deterministic asymptotic growth models. 相似文献
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牙鲆不同家系生长性能比较及优良亲本选择 总被引：7，自引：2，他引：5
针对牙鲆生长慢的问题,实验室建立了63个牙鲆家系生长性能进行了测定和比较分析。对日龄80～230 d的不同家系鱼苗的体长和体重进行了测量,发现家系之间存在明显的生长差异,生长最快家系平均体重是最慢家系的3.08倍,最大体长是最小体长的1.47倍。家系的绝对增重率分布在0.138～0.478。利用多元方差分析（MANOVA）对家系因子进行分析表明,牙鲆家系生长日龄对家系体长和体重未达显著影响（P>0.05）;利用单因素方差（one-way ANOVA）分析和多重比较法（SNK）对63个家系的生长指标进行分析比较后表明,所有家系可分为生长快速、生长较快、生长一般、生长较慢和生长最慢5个组,5组之间具有显著性差异（P<0.01）,筛选出19、36、51、21、69、61、64和81号8个生长快速家系。利用多重比较法对RS♂×JS♀、RS♂×RS♀、RS♂×YS♀、JS♂×RS♀、JS♂×JS♀、YS♂×RS♀、YS♂×JS♀ 7个杂交组合产生的后代生长性状进行综合分析,发现JS♂×RS♀杂交产生的家系生长最快（P<0.05）,不同群体间与群体内杂交产生家系在生长上存在着明显的差异（P<0.05）。利用半同胞家系进行后裔性状测定和分析,对牙鲆3个群体中14个父本和12个母本的生长遗传性状进行鉴定,发现JS29、JS12 和RS41 3个父本及 RS75、RS28、RS86、JS21和JS22 5个母本产生的家系生长较快（P<0.05）。利用生长最快家系和生长最慢家系的体长和体重数据,建立了体长和体重关系式,决定系数R2>0.5、a值相近、b<3,表明家系个体的体长和体重密切相关,家系生长环境较稳定,两家系都处于异速生长阶段。 相似文献
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Stepwise function of natural growth for Scylla serrata in East Africa: a valuable tool for assessing growth of mud crabs in aquaculture 
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下载免费PDF全文 Per‐Olav Moksnes David Oersted Mirera Emma Björkvik Muumin Iddi Hamad Humphrey Matalu Mahudi Daniel Nyqvist Narriman Jiddawi Max Troell 《Aquaculture Research》2015,46(12):2938-2953
Predicting growth is critical in aquaculture, but models of growth are largely missing for mud crab species. Here, we present the first model of natural growth in juvenile and adult mud crabs Scylla serrata from East Africa using a stepwise growth function based on data on intermoult periods and growth at moult from field mark‐recapture, pond and laboratory studies. The results showed a sigmoid growth pattern in carapace width and suggest that S. serrata in East Africa will reach 300 g and sexual maturity ~9.9 months after settlement, and a commercial size of 500 g after 12.4 months. Analyses of the literature identified several issues with the common praxis to compare standard growth measures between aquaculture studies with different initial size or growing periods. Using the new growth function to estimate the proportional difference between modelled and obtained growth as an alternative method, we show that growth rates of S. serrata cultured in cage systems, which are dominant in East Africa, was <40% of the estimated natural growth and growth obtained in pond systems. The analysis also indicated that growth rates of S. serrata in Southeast Asia was over 50% higher compared with similar culture systems in East Africa, and that different species of mud crabs had large differences in growth rates. This study shows that growth in the present mud crab aquaculture systems in East Africa is below their expected potential. Further work is needed to identify the factors behind this observation. 相似文献
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Abstract – Spatial models of fish growth rate potential have been used to characterize a variety of environments including estuaries, the North American Great Lakes, small lakes and rivers. Growth rate potential models capture a snapshot of the environment but do not include the effects of habitat selection or competition for food in their measures of environment quality. Here, we test the ability of spatial models of fish growth rate potential to describe the quality of an environment for a fish population in which individual fish may select habitats and local competition may affect per capita intake. We compare growth rate potential measurements to simulated fish growth and distributions of model fish from a spatially explicit individual-based model of fish foraging in the same model environment. We base the model environment on data from Lake Ontario and base the model fish population on alewife in the lake. The results from a simulation experiment show that changes in the model environment that caused changes in the average growth rate potential correlated extremely highly ( r 2 ≥0.97) with changes in simulated fish growth. Unfortunately, growth rate potential was not a reliable quantitative predictor of simulated fish growth nor of the fish spatial distribution. The inability of the growth rate potential model to quantitatively predict simulated fish growth and fish distributions results from the fact that growth rate potential does not consider the effects of habitat selection or of competition on fish growth or distribution, processes that operate in our individual-based model and presumably also operate in nature. The results, however, do support the use of growth rate potential models to describe the relative quality of habitats and environments for fish populations. 相似文献
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Andrew L. Rypel 《Ecology of Freshwater Fish》2012,21(4):521-532
For circumpolar species, little is known on how somatic growth rates can vary at large, transcontinental spatial scales. In this study, a meta‐analysis of growth rates was conducted for northern pike ( Esox lucius) across North America and Eurasia. Growth rates of northern pike did not differ between North American and ‘coastal Eurasian’ pike (e.g., UK, Ireland, Sweden), while growth rates for both of these groups were significantly higher compared to ‘inland Eurasian’ pike (mainly in Russia). There was no difference in growth between lentic and lotic habitats on either continent. In North America, pike growth was positively correlated with temperature, but in Eurasia, pike growth correlated poorly with most climatic variables. Similarly, maximum longevity in pike populations was significantly predicted by latitude in North America, but not in Eurasia. After standardising annual pike growth by the thermal opportunity for growth, a highly significant countergradient growth relationship was found for North American pike, while a significant, but considerably less predictive countergradient growth relationship was found for Eurasian pike. This study provides novel insights into the ecology of a circumpolar species and how populations function at extraordinarily large spatial scales. First, pike appear to be cosmopolitan across hydrologic habitats having fast or slow growth in either lentic or lotic environments. Secondly, continental‐scale differences in pike growth rates are suggestive of major genetic and life‐history differences. Finally, variable climate–growth relationships and countergradient growth patterns indicate that global climate change is likely to affect circumpolar fishes like pike in complex, nonlinear ways. 相似文献
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为了探讨不同营养盐对轮叶黑藻(Hydrilla verticillata)生长的影响,进行了6种营养因子在不同浓度下的轮叶黑藻室内栽种试验,通过与空白对照组比较栽种期间轮叶黑藻的生长情况及试验结束时轮叶黑藻的鲜重,了解其对不同营养盐的需求。结果表明,0.5 mg/L氯化铵对轮叶黑藻生长促进作用不大,1 mg/L、2 mg/L、4 mg/L氯化铵有明显的促生长作用,组间差距不大(P0.05),8 mg/L氯化铵组对轮叶黑藻的生长有抑制作用;随着磷酸氢钙浓度的增加,对轮叶黑藻的促生长作用增强,但各处理间差异不显著(P0.05);高浓度氯化钾(0.8 mg/L)对轮叶黑藻的生长有一定的抑制作用,中低浓度(0.1~0.4 mg/L)对轮叶黑藻的生长有促进作用;0.05 mg/L硫酸镁对轮叶黑藻的生长促进作用不大,高于0.1 mg/L时株高增长与浓度增加成正比;硫酸锌、硼酸钠在试验浓度下对轮叶黑藻的生长影响基本表现为正相关关系。 相似文献
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Abstract. In aquaculture experiments of only a few months'duration, fish can approach their asymptotic size and growth rates may change greatly. One objective of aquaculture is to obtain a maximum economic return, and a growth model is needed to relate rate of growth to food consumption and other costs to find the optimum duration of growth cycles. Von Bertalanffy's equation is an asymptotic growth model which can be used for this purpose. A variable growth rate model was developed to describe fish growth oscillations observed in aquaculture experiments. This growth model provides improved estimates of von Bertalanffy's equation in aquaculture and can be used for an efficient evaluation of fish production during production cycles. 相似文献
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中国明对虾眼柄微结构与其生长的关系 总被引：1，自引：0，他引：1
观察了采集于江苏南通近海的69只中国明对虾的眼柄微结构,分析了其体长和体质量的生长。结果显示,眼柄由表层、色素层、钙化层和膜层4个部分组成。眼柄内存在明显的生长宽带和细纹,其中宽带数0~1个,细纹数27~37个。最小AIC法拟合分析显示,中国明对虾体长、体质量的生长与眼柄细纹数都呈显著的Logistic关系。研究表明,中国明对虾眼柄中的宽带与其年龄相关,细纹可用来分析中国明对虾的生长,而细纹的形成周期是否与个体差异、生长环境差异等相关还需要进一步验证。 相似文献
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Abstract. A bioenergetic growth model was developed to examine the integrated effects of fertilization, stocking density, and spawning on the growth of tilapia, Oreochromis niloticus (L.), in pond aquaculture. The analyses showed that growth rates increase with higher levels of organic fertilization up to 500kg/ha/week. Growth rates increased with added food rations in ponds, reaching a maximum growth of 2-07g/day at about 44–48 days after stocking. Fish growth rates decreased with increased levels of stocking density. The stocking density for optimal growth is 1fish/m2 ; the optimal density for total harvesting weight and fish size is 2 fish/m2 . Model sensitivity analysis indicated that tilapia growth is most sensitive to catabolism (metabolism) and anabolism (synthesis) coefficients, both of which are geometrically related to the fish body weight. Food assimilation efficiency (b) and the food consumption coefficient (h) have a modest effect on fish growth. Spawning in grow-out ponds can have a major effect on fish growth. 相似文献