水产动物补偿生长的研究概述

对补偿生长的类型,补偿生长的机理,影响补偿生长的因素,补偿生长过程中鱼类生理生化的变化以及补偿生长在水产养殖中的应用的研究进行了较全面的概述.影响补偿生长的因素有很多,水产养殖动物的体重,种类的不同会导致补偿生长的差异,限食程度,营养成分,性成熟程度和环境因子等因素也会影响到水产动物的补偿生长.提出了补偿生长过程中鱼类的脂肪,蛋白,RNA/DNA,蛋白酶、脂肪酶,淀粉酶和碱性磷酸酶,钙离子、胆固醇、甘油三脂、血红细胞、血红蛋白等成分也会发生相应的变化,但因种类差异而有所不同,并对补偿生长在水产动物养殖中应用前景进行了展望.     

羊栖菜的生长和生化组成的影响因素

综述了羊栖菜生长和生化组成的多种影响因素,包括非生物因素(温度、光照强度、营养盐、重金属)和生物因素(种质、生长阶段、敌害生物),以期为羊栖菜资源的保护和可持续利用以及提高羊栖菜的产量和品质提供理论依据。     

羊药浴技术及其注意事项

药浴是羊只饲养管理上必不可少的一项工作,是预防和治疗羊体外寄生虫病(如疥螨、羊虱等)的一种措施,可增进皮肤健康及促进羊毛生长,确保羊只机体健康。文章介绍了药浴液的使用、药浴方法,提出药浴的要点以及注意事项,以供养羊户参考。     

不同温度下饥饿对鲫鱼生长的影响

饥饿是影响鱼类生长、发育和生存的重要因素之一,许多鱼类都可以忍受一定程度的饥饿,但不同鱼类对饥饿的耐受力和适应性不同。本文通过对不同温度下,处于饥饿状态的鲫鱼的生长进行分析,以了解饥饿对其生长产生的影响。     

碳氮营养和培养条件对芽孢杆菌(Bacillus sp.) A4生长的影响

芽孢杆菌(Bacillus sp.) A4是一株具有溶甲藻能力的菌株,为探究营养条件与培养条件对A4生长的影响,明确在多因素共同作用下菌株的生长特性,先以单因素方法比较不同碳、氮营养因子对其生长的影响,再以Plackett-Burman方法综合比较碳源、氮源、pH、接种菌量、温度、转速、装液量等因子对其生长的协同影响效应。结果显示,A4菌对有机碳源玉米浆和有机氮源大豆蛋白利用效果最好,培养24 h后菌量分别达到3.58×108、3.19×108 CFU/ml。各因子的重要性排序依次为大豆蛋白、温度、玉米浆、转速、接种菌量、pH、装液量,且大豆蛋白和温度对A4菌的生长影响显著(P<0.05)。研究表明,培养条件对菌株生长调控也有重要意义,在评估相关因素对菌株生长或生态功能的影响时,须将营养条件和培养条件协同分析。     

氮、磷、铁对牟氏角毛藻生长速率的影响

通过单因子试验和正交试验方法研究N、P、Fe对牟氏角毛藻生长的影响。试验结果表明：在单因子试验中，N、P、Fe对牟氏角毛藻生长的影响显著，其中N因素的影响最为显著；在正交试验中，在N质量浓度为35mg/L和P质量浓度为1．5mg/L时，牟氏角毛藻生长最快，而此时受N的影响，Fe对牟氏角毛藻的生长影响不明显。     

强壮前沟藻生长的营养需求研究

以强壮前沟藻为材料,采用实验室内单种培养方法,以氮、磷、维生素和微量元素进行四因素三水平正交试验,研究强壮前沟藻生长的营养需求.试验结果表明,磷对强壮前沟藻生长的影响达到显著水平,氮元素对该藻生长的影响也较为显著,而微量元素及维生素对强壮前沟藻生长影响不显著,各因素对强壮前沟藻生长的影响依次为:磷>氮>微量元素>维生素;强壮前沟藻生长的最佳营养条件为氮元素880 μmol/L,磷元素108 μmol/L,微量元素21.0 μmol/L,维生素0.96 μmol/L.根据强壮前沟藻生长的营养需求,初步探讨了营养条件对该藻形成赤潮的影响.     

碳氮营养和培养条件对芽孢杆菌(Bacillus sp.)A4生长的影响

芽孢杆菌(Bacillus sp.)A4是一株具有溶甲藻能力的菌株,为探究营养条件与培养条件对A4生长的影响,明确在多因素共同作用下菌株的生长特性,先以单因素方法比较不同碳、氮营养因子对其生长的影响,再以Plackett-Burman方法综合比较碳源、氮源、pH、接种菌量、温度、转速、装液量等因子对其生长的协同影响效应。结果显示,A4菌对有机碳源玉米浆和有机氮源大豆蛋白利用效果最好,培养24 h后菌量分别达到3.58×10~8、3.19×10~8 CFU/ml。各因子的重要性排序依次为大豆蛋白、温度、玉米浆、转速、接种菌量、pH、装液量,且大豆蛋白和温度对A4菌的生长影响显著(P0.05)。研究表明,培养条件对菌株生长调控也有重要意义,在评估相关因素对菌株生长或生态功能的影响时,须将营养条件和培养条件协同分析。     

鱼类补偿性生长的研究进展

本文综述了鱼类补偿生长的研究进展,对鱼类补偿生长的定义、类型、影响因素、试验设计、生理机制进行了分析。初步探讨了补偿生长的理论意义以及在水产养殖实践中的应用前景和存在的问题。     

浅析影响养殖鱼类水体的生态因素

"养鱼先养水",良好的水质对养殖鱼类的生存和生长是十分重要的。本文就影响养殖鱼类水体生态环境的理化因素和生物因素进行分析。     

Potential applications of biological filtration media in changing water properties and subsequent effects on common carp (Cyprinus carpio) in recirculating aquaculture systems

This work aims to develop a suitable aquaculture system to solve issues pertaining to water quality in recirculating aquaculture systems (RAS) thereby improving fish growth performance and their feed conversion ratio (FCR). It is known that the efficiency of nutrient decomposition depends on the amount and species of bacteria present in the filter, and these can in turn be regulated by the pH. Our study shows that the significant increase in pH from 7.45 to 7.51 and 7.47 is achieved after the water was filtered through sawdust and wood wool respectively. At the same time, nitrite concentrations were found to have significantly decreased from 0.06 ppm in the control to 0.01 ppm in the sawdust treatment. Changes in the physical–chemical properties of treated water affect the biological properties of the organisms. It was found that the average final body weight for fish in the wood wool treatment 30.96 g and fish in the sawdust treatment 31.44 g was significantly higher compared to that for the fish in the control treatment 28.42 g. The use of sponge, wood wool or sawdust resulted in significantly lower FCR and therefore better fish productivity in RAS. At the same time, the red blood cell count, plasma urea, plasma creatinine, plasma albumin, and GOT and GPT were significantly higher in fish in the plastic, sponge, wood wool or sawdust treatment compared to the control treatment. In summary, this study demonstrates the benefits of using sponge, wood, wool and sawdust as biofilter media for aquaculture.     

A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture

This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O₂ (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal.     

农牧户对草原生态保护补奖政策的评价与期望——基于内蒙古等6省区绒毛用羊养殖户问卷调查数据的分析

基于内蒙古等6省区绒毛用羊养殖户问卷调查数据,应用统计性描述分析方法,分析农牧户对草原生态保护补奖政策的认知情况和满意度评价。研究结果表明,仅有半数的农牧户对政策有所了解,相关扶持政策的获得比例不高,但是获得奖励的农牧户对政策的满意度较高。根据农牧户目前的养殖困难及政策期望,提出继续加大补奖政策宣传力度和执行力度,提高种公羊补贴水平并扩大政策覆盖面,研究制定绒毛最低保护价格政策,加大金融扶持力度等对策建议。     

Insulin-like growth factor signalling and its significance as a biomarker in fish and shellfish research

The insulin-like growth factor signalling system comprises insulin-like growth factors, insulin-like growth factor receptors and insulin-like growth factor-binding proteins. Along with the growth hormones, insulin-like growth factor signalling is very pivotal in the growth and development of all vertebrates. In fishes, insulin-like growth factors play an important role in osmoregulation, besides the neuroendocrine regulation of growth. Insulin-like growth factor concentration in plasma can assess the growth in fishes and shellfishes and therefore widely applied in nutritional research as an indicator to evaluate the performance of selected nutrients. The present review summarizes the role of insulin-like growth factor signalling in fishes and shellfishes, its significance in aquaculture and in evaluating growth, reproduction and development, and discusses the utility of this system as biomarkers for early indication of growth in aquaculture.

     

内陆碱性水域凡纳滨对虾生长与环境因子的关系

研究内陆碱性水域凡纳滨对虾体重生长速度分别与碱度、盐度、pH、离子系数、Ca2 、Mg2 、K 质量浓度、Ca2 Mg2 以及(1/2Ca2 )/(1/2Mg2 )、Na /K 等水环境因子的相关性。结果表明,这些因子对对虾体重生长速度的影响存在相互作用;它们与体重生长速度的简单相关性都受到其他因子的显著负效应影响;碱度、盐度、pH、离子系数、Ca2 Mg2 、(1/2Ca2 )/(1/2Mg2 )及Ca2 质量浓度对对虾生长的影响被弱化;Mg2 质量浓度的影响不明显。内陆碱性水域K 质量浓度和Na /K 很可能是影响对虾生长的主要环境因子;适当提高盐度及Ca2 、K 质量浓度,降低Na /K ,将有利于对虾生长。     

盐碱水域对虾体质量生长与环境因子的相关性

通过凡纳滨对虾生长试验,研究内陆碳酸盐类盐碱水域对虾生长与碱度、pH、K 浓度、Na /K 及(1/2Ca2 )/(1/2Mg2 )的相关性,为移殖提供技术依据.试验结果表明,幼虾体质量生长速度与5种环境因子的简单相关性均受到其他因子或因子组合的负效应影响,环境因子对幼虾生长的影响程度被削弱.幼虾的体质量生长速度与碱度、pH、K 浓度及(1/2Ca2 )/(1/2Mg2 )的相关性不明显,而与Na /K 显著相关.碱度、pH、K 浓度及(1/2Ca3 )/(1/2Mg2 )对驯化幼虾体质量生长的影响不明显,Na /K 可能是主要影响因子.提高驯化技术水平将有利于幼虾的生长与生存.     

Simultaneous effects of nutritional and environmental factors on growth and flesh quality of Perca fluviatilis using a fractional factorial design study

Fractional factorial design is a practical approach for studying multiple factors, with a minimum of experimental units. The objective of this work was to study the simultaneous effects of nutritional and environmental factors on both growth and flesh quality of common perch (Perca fluviatilis), a new inland aquaculture species. This study sought answering the two following questions: (i) which combinations of factors allow improving growth, food efficiency, and technological, sensorial and nutritional qualities? (ii) is it possible to simultaneously improve growth performances and flesh quality? In a first experiment, twelve factors (7 nutritional and 5 environmental factors) were each tested at 2 levels in a fractional factorial design in 24 independent recirculating 500 L tanks. The best 4 combinations identified in this first experiment were then validated in a second experiment. The first phase of the multifactorial approach used here allowed revealing emergent information: i) there is a combination of factors that allows reducing both the heterogeneity of the production and the losses of nitrates and phosphates, while preserving good characteristics of growth and quality of fillets; ii) it is possible to improve the quality of the aquatic production system, without decreasing significantly growth efficiency; iii) the effect of a given factor, even such an important one like diet, temperature or target biomass, depends on the levels of the other rearing factor levels, thus the usual reference optimum used for a given factor has no meaning theoretically and can be questioned according to the levels of the other factors which act altogether on the functioning of the rearing system.The input factor combinations resulting in a significant enhancement of single output variables or several output variables were identified (e.g. improvement of feed efficiency, and/or fillet docosahexanoic acid content). Our results clearly demonstrate a strong interdependence of input factors into the animal rearing system, particularly between nutritional and environmental ones.     

Variability in growth rates of freshwater eels (Anguilla spp.) in New Zealand

Abstract— Both species of New Zealand freshwater eels (the shortfinned eel Anguilla australis and the longfinned eel A. dieffenbachii ) are widespread and abundant, supporting important commercial and recreational fisheries. This article reviews growth studies from 35 widely distributed sites throughout New Zealand and discusses factors that influence growth rates. Length at given age is characterized by high intra- and inter-population variability; growth rates for eels >30 cm are typically slow (2–3 cm per year) and linear, with females generally growing faster than males. Water temperature affects the length of the growing season, although growth rates are not correlated with latitude. Other factors suggested as affecting growth rates are eel density, quantity and quality of food, and interactions between both eel species. Al though growth of some New Zealand eel populations is the slowest recorded for any species of Anguilla , growth in culture can be rapid, similar to that of other temperate eel species.     

Factors Affecting the Trout Fishery at Grafham Water

In this paper some of the controllable factors affecting angling catch at Grafham Water trout fishery are examined and an attempt made to relate them. There appears to be a close relationship between annual catch and annual stocking in the case of rainbow trout. The relation of the brown trout catch to other factors is rather different; the main reason is probably a higher frequency of survival into later seasons and slower growth. The effect of growth rates and other less quantifiable factors is discussed.