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1.
Segner H Sundh H Buchmann K Douxfils J Sundell KS Mathieu C Ruane N Jutfelt F Toften H Vaughan L 《Fish physiology and biochemistry》2012,38(1):85-105
This brief review focuses on health and biological function as cornerstones of fish welfare. From the function-based point
of view, good welfare is reflected in the ability of the animal to cope with infectious and non-infectious stressors, thereby
maintaining homeostasis and good health, whereas stressful husbandry conditions and protracted suffering will lead to the
loss of the coping ability and, thus, to impaired health. In the first part of the review, the physiological processes through
which stressful husbandry conditions modulate health of farmed fish are examined. If fish are subjected to unfavourable husbandry
conditions, the resulting disruption of internal homeostasis necessitates energy-demanding physiological adjustments (allostasis/acclimation).
The ensuing energy drain leads to trade-offs with other energy-demanding processes such as the functioning of the primary
epithelial barriers (gut, skin, gills) and the immune system. Understanding of the relation between husbandry conditions,
allostatic responses and fish health provides the basis for the second theme developed in this review, the potential use of
biological function and health parameters as operational welfare indicators (OWIs). Advantages of function- and health-related
parameters are that they are relatively straightforward to recognize and to measure and are routinely monitored in most aquaculture
units, thereby providing feasible tools to assess fish welfare under practical farming conditions. As the efforts to improve
fish welfare and environmental sustainability lead to increasingly diverse solutions, in particular integrated production,
it is imperative that we have objective OWIs to compare with other production forms, such as high-density aquaculture. However,
to receive the necessary acceptance for legislation, more robust scientific backing of the health- and function-related OWIs
is urgently needed. 相似文献
2.
Ellis T Berrill I Lines J Turnbull JF Knowles TG 《Fish physiology and biochemistry》2012,38(1):189-199
Mortality has received insufficient attention as a fish welfare topic. Here, we aim to prompt fish farming stakeholders to
discuss fish mortalities in relation to welfare. Mortality in farmed fish populations is due to a variety of biotic and abiotic
causes, although it is often difficult to differentiate between underlying and immediate causes of mortality. Most mortality
appears to occur during episodes associated with disease outbreaks and critical periods (in development or production). Most
causes of mortality can be assumed to be associated with suffering prior to death. As mortality rates in farmed fish populations
are suspected to rank amongst the highest in commonly farmed vertebrate species, mortality should be a principal fish welfare
issue. Long-term mortality rates can be used as a retrospective welfare performance indicator and short-term mortality rates
as an operational welfare indicator. Scrutiny of mortality records and determining causes of death will enable action to be
taken to avoid further preventable mortality. The welfare performance of fish farms should only be judged on levels of predictable
and preventable mortality. Fish farmers will already be monitoring mortality due to commercial and legal requirements. As
profitability in fish farming is directly linked to survival, confronting mortality should ultimately benefit both fish and
farmers. 相似文献
3.
I. K. Berrill T. Cooper C. M. MacIntyre T. Ellis T. G. Knowles E. K. M. Jones J. F. Turnbull 《Fish physiology and biochemistry》2012,38(1):219-229
The welfare of farmed fish has attracted attention in recent years, which has resulted in notable changes within the aquaculture
industry. However, a lack of communication between stakeholders and opposing ethical views are perceived as barriers to achieving
consensus on how to improve farmed fish welfare. To address these issues, we developed an interactive approach that could
be used during stakeholder meetings to (1) improve communication between different stakeholder groups, (2) build consensus
on priorities for farmed fish welfare and (3) establish mechanisms to address welfare priorities. We then applied this approach
during a meeting of stakeholders to identify current and future priorities for farmed fish welfare in the UK. During the meeting
in the UK, stakeholders initially identified 32 areas that they felt were in need of development for future improvements in
farmed fish welfare. These were further refined via peer review and discussion to the seven most important “priority” areas.
Establishing a “better understanding of what good fish welfare is” emerged as the highest priority area for farmed fish welfare. The second highest priority area was “the need for welfare monitoring and documentation systems”, with mortality recording proposed as an example. The other five priority areas were “[improved understanding of] the role of genetic selection in producing fish suited to the farming environment”, “a need for integration and application of behavioural and physiological measures”, “the need for a more liberal regime in Europe for introducing new medicines”, “a need to address the issues of training existing and new workers within the industry”, and “ensuring best practise in aquaculture is followed by individual businesses”. Feedback from attendees, and the meeting outputs, indicated that the approach had been successful in improving communication
between stakeholders and in achieving consensus on the priorities for farmed fish welfare. The approach therefore proved highly
beneficial for future improvements in fish welfare in the UK. 相似文献
4.
Fish welfare at harvest is easily compromised by poor choice of handling and slaughter methods, lack of attention to detail
and by unnecessary adherence to fish farming traditions. The harvest process comprises fasting the fish to empty the gut,
crowding the fish, gathering and moving the fish using brails, fish pumps, and sometimes also road or boat transport and finally
stunning and killing the fish. The harvesting processes commonly used for bass, bream, carp, catfish, cod, eel, halibut, pangasius,
salmon, tilapia, trout, tuna and turbot are outlined. These harvesting processes are discussed; the consequences for fish
welfare identified and practical tests which can be made at the harvest site highlighted. Welfare at harvest for the majority
of farmed fish species can be improved by adopting and adapting existing procedures already known to be beneficial for fish
welfare through their use in other fish farming systems or with other species. It is seldom necessary to develop completely
new concepts or methods. 相似文献
5.
Müller-Graf C Berthe F Grudnik T Peeler E Afonso A 《Fish physiology and biochemistry》2012,38(1):231-241
The Treaty of Amsterdam, in force since 1 May 1999, has established new ground rules for the actions of the European Union
(EU) on animal welfare. It recognizes that animals are sentient beings and obliges the European Institutions to pay full regard
to the welfare requirements of animals when formulating and implementing Community legislation. In order to properly address
welfare issues, these need to be assessed in a scientific and transparent way. The principles of risk assessment in terms
of transparency and use of available scientific data are probably well suited for this area. The application of risk assessment
for terrestrial and aquatic animal welfare is a relatively new area. This paper describes the work developed in the context
of the European Food Safety Authority (EFSA) opinions on the application of a risk assessment methodology to fish welfare.
Risk assessment is a scientifically based process that seeks to determine the likelihood and consequences of an adverse event,
which is referred to as a hazard. It generally consists of the following steps: (i) hazard identification, (ii) hazard characterisation,
(iii) exposure assessment and (iv) risk characterisation. Different approaches can be used for risk assessments, such as qualitative,
semi-quantitative and quantitative approaches. These are discussed in the context of fish welfare, using examples from assessments
done to aquaculture husbandry systems and stunning/killing methods for farmed fish. A critical review of the applications
and limitations of the risk methodology in fish welfare is given. There is a need to develop appropriate indicators of fish
welfare. Yet, risk assessment methodology provides a transparent approach to identify significant hazards and support recommendations
for improved welfare. 相似文献
6.
7.
Martins CI Galhardo L Noble C Damsgård B Spedicato MT Zupa W Beauchaud M Kulczykowska E Massabuau JC Carter T Planellas SR Kristiansen T 《Fish physiology and biochemistry》2012,38(1):17-41
Behaviour represents a reaction to the environment as fish perceive it and is therefore a key element of fish welfare. This review summarises the main findings on how behavioural changes have been used to assess welfare in farmed fish, using both functional and feeling-based approaches. Changes in foraging behaviour, ventilatory activity, aggression, individual and group swimming behaviour, stereotypic and abnormal behaviour have been linked with acute and chronic stressors in aquaculture and can therefore be regarded as likely indicators of poor welfare. On the contrary, measurements of exploratory behaviour, feed anticipatory activity and reward-related operant behaviour are beginning to be considered as indicators of positive emotions and welfare in fish. Despite the lack of scientific agreement about the existence of sentience in fish, the possibility that they are capable of both positive and negative emotions may contribute to the development of new strategies (e.g. environmental enrichment) to promote good welfare. Numerous studies that use behavioural indicators of welfare show that behavioural changes can be interpreted as either good or poor welfare depending on the fish species. It is therefore essential to understand the species-specific biology before drawing any conclusions in relation to welfare. In addition, different individuals within the same species may exhibit divergent coping strategies towards stressors, and what is tolerated by some individuals may be detrimental to others. Therefore, the assessment of welfare in a few individuals may not represent the average welfare of a group and vice versa. This underlines the need to develop on-farm, operational behavioural welfare indicators that can be easily used to assess not only the individual welfare but also the welfare of the whole group (e.g. spatial distribution). With the ongoing development of video technology and image processing, the on-farm surveillance of behaviour may in the near future represent a low-cost, noninvasive tool to assess the welfare of farmed fish. 相似文献
8.
Pierluigi Carbonara Sbastien Alfonso Francesco Gai Laura Gasco Giovanni Palmegiano Maria Teresa Spedicato Walter Zupa Giuseppe Lembo 《Aquaculture Research》2020,51(7):3007-3016
Welfare in farmed fish got particular attention during the last decades from both governmental and public sides. In aquaculture context, welfare concerns are mainly related to handling procedures, water quality and stoking densities. In Europe, authorities had to clarify the threshold limits of stocking densities to maintain fish good welfare, including for organics aquaculture through the EC regulation 710/2009. However, effects of stocking density on fish welfare are complex and sometimes contradictory. Moreover, there is a lack of knowledge about the impact of density on fish welfare in organic aquaculture. Thus, the aim of the study is to asses welfare state of rainbow trout (Oncorhynchus mykiss) at two initial stocking densities (low density, LD: 12 kg/m3 and high density, HD: 17 kg/m3) fed using organic feed by combining the monitoring of growth performances, behaviour (swimming activity) and physiological indicators (i.e. cortisol, glucose, lactate, hematocrit, red blood cellule count and lysozyme). At the end of experiment, the stocking density reached 21 kg/m3 and 30 kg/m3 for the LD and HD respectively. Overall, growth performances, swimming activity and level of physiological indicators of stress and welfare were similar between HD and LD over the experiment duration. To conclude, we observed no alteration of fish welfare between the two stocking densities monitored. This study suggests that a final stocking density of 30 kg/m3 can be considered for organic aquaculture of rainbow trout respecting welfare. 相似文献
9.
冰鲜大黄鱼加工过程中的细菌学分析及关键控制点 总被引：2，自引：1，他引：2
探讨了冰鲜大黄鱼加工过程中鱼体温度变化及细菌总数和主要腐败菌假单胞菌的变化,分析了加工中的关键控制点。活鱼、加工结束后中心温度超过8℃的鱼的细菌总数、假单胞菌数分别为5.5×104、4.5×104cfu/g和3.3×104、1.4×103cfu/g;加工结束后中心温度未超过8℃的鱼,细菌总数和假单胞菌数分别为9.6×103、3.8×103cfu/g;冰藏2d、5d后鱼的细菌总数、假单胞菌数分别为1.1×104、8.6×103cfu/g和2.4×103、5.6×103cfu/g。并从细菌学角度确定了原料鱼、冰、预冷却、运输、加工是冰鲜大黄鱼加工过程中的关键控制点。 相似文献
10.
Increased aquaculture production has raised concerns about managing protocols to safeguard the welfare of farmed fish, as
consumers demand responsible aquaculture practices to provide ‘welfare friendly’ products. Feeding is one of the largest production
cost in a fish farm and can be one of the biggest stressors for fish. Under farming conditions, fish are challenged with artificial
diets and feeding regimes, and inadequate feeding conditions cause stress, alteration of normal behavioural patterns, poor
performance and eventually diseases and death, which are by no means acceptable neither economically nor ethically. This review
aims to highlight the impact of feeding rhythms and feeding time upon physiological and behavioural welfare indicators, which
show circadian rhythms as well. Therefore, all these variables should be considered when designing feeding strategies in farming
conditions and assessing the welfare state of cultured fish. 相似文献
11.
Attia J Millot S Di-Poï C Bégout ML Noble C Sanchez-Vazquez FJ Terova G Saroglia M Damsgård B 《Fish physiology and biochemistry》2012,38(1):107-118
Following the development of demand-feeding systems, many experiments have been conducted to explore feeding motivation and
feed intake in farmed fish. This work aims to review a selection of studies in the field, focusing on three key factors, related
to demand feeding and fish welfare. Firstly, we outline how demand feeders should be considered when developing feed management
strategies for improving welfare in production conditions. Secondly, via laboratory demand-feeding experiments, we show self-feeding
activities depend not only on feeding motivation and social organisation, but also on individual learning capacity and risk-taking
behaviour. Thirdly, we report encouraging results demonstrating that when presented with two or more self-feeders containing
complementary foods, fish select a diet according to their specific nutritional requirements, suggesting that demand feeders
could be used to improve welfare by allowing fish to meet their nutritional needs. 相似文献
12.
R. Gornati S. Gualdoni R. Cavaliere G. Terova M. Saroglia G. Bernardini 《Aquaculture International》2005,13(1-2):51-55
The issue of animal welfare in aquaculture is of growing interest and there is an increasing consumer demand for documentation of safe and ethically defendable food production. In this context, we have looked for molecular markers among those genes whose expression is modified by the different farming conditions. We have compared gene expression of sea bass farmed at different population densities by differential display, and we have obtained six bands differentially expressed whose sequences have been deposited in the public databases; two of them were suppressed by high population density, while four were induced by the treatment. These genes can be used as biomarkers, and together with a panel of stress-related genes of sea bass (D. labrax) that we have already obtained, could allow the rapid diagnosis of the welfare status of a fish using RT-PCR. We are certain that the new molecular techniques will find their place in the everyday management of fish farming. On the other hand, we are also aware that the scarcity of genomic resources for some fish species, in spite of their economical interest, will retard the beneficial effects that modern biotechnology could bring to aquaculture industry. Therefore, an effort should be made to reduce, as far genomic resources are concerned, the gap that separates farmed species from model organisms such as Danio rerio and Fugu rubripes. 相似文献
13.
日本鳀（Engraulis japonius）是一种离水极易腐败的小型中上层鱼类,广泛分布于中国的渤海、黄海和东海。文章利用危害分析和关键控制点（hazard analysis and critical control point,HACCP）体系原理分析了海上加工船加工日本鳀鱼干的原料、加工工艺条件和贮藏运输等方面对产品可能带来的危害,指出了船上加工日本鳀鱼干生产过程的关键控制点,制定了HACCP工作计划表,提出了日本鳀鱼干加工中原料及各加工工序的危害因素、卫生操作程序、监控测定方法和纠偏措施,构建了船上加工日本鳀鱼干生产的HACCP质量安全管理体系模式。 相似文献
14.
在江西峡江和赣州进行了HACCP(Hazard Analysis and Critical Control Point)体系在斑点叉尾(Ictaluruspunctatus)人工繁殖中的应用研究。应用HACCP的基本原理,对整个斑点叉尾人工繁殖过程进行危害分析,确立了亲鱼培育池的选择、亲鱼种质选择、亲鱼产卵池的选择、受精卵孵化、苗种培育、水质监测、饲料供应、日常管理等8个关键控制点,提出了相应的预防措施、关键限值、监控措施以及超过关键限值时的纠正措施,使各关键控制点处于人为控制之下。实现了斑点叉尾人工繁殖按无公害化、规范化、标准化生产。 相似文献
15.
《Aquaculture (Amsterdam, Netherlands)》2005,243(1-4):121-132
The welfare of fish is receiving increasing attention and attempts have been made to control welfare in farmed fish through regulation of management practices, including stocking density. However, there is little published information on the influence of stocking density on welfare of fish in marine cages. This present study examined welfare in Atlantic salmon (Salmo salar) in cages on a commercial marine farm, exposed to densities ranging from 9.7 to 34 kg m−3. On three occasions over a period of 10 months, fish were sampled from each cage, weighed and measured; their fin condition assessed and blood samples taken for measurement of glucose and cortisol. A multivariate analysis was used to combine four commonly used measures of fish welfare (condition of body and fins and plasma concentrations of glucose and cortisol) into a single welfare score. As well as objectively reflecting a coherence within the data, this score was consistent with the evaluation of welfare by experienced farmers. A generalized linear model indicated that the median welfare score for each cage was significantly related to sampling period, to stocking density (mean over the previous 3 months) and to location of the cage. A model with all the data from individual fish proved to be more robust and also identified sample period, stocking density (mean over 3 months) and position of the cage as significant predictors of the welfare score. There was no significant association between the welfare score and the length of time since grading or lice treatment. Further analysis of the relationship between stocking density and the welfare score suggested that there was no trend up to an inflection point ca. 22 kg m−3, after which increasing stocking density was associated with lower welfare scores. This study suggests that, while stocking density can influence the welfare of Atlantic salmon in production cages, this is only one influence on their welfare and on its own cannot be used to accurately predict or to control welfare. 相似文献
16.
船载南极磷虾智能化捕捞加工生产线在食品安全体系中的特征分析 总被引：1，自引：0，他引：1
在近年来快速发展的南极磷虾产业中,南极磷虾捕捞加工船上的捕捞加工生产是其产业链中的一个重要环节。由于南极磷虾的生物特性,船载捕捞加工线直接影响产品质量,进而影响后端陆基深加工产品的质量等级。以“深蓝”号南极磷虾捕捞加工船智能化捕捞加工的冻虾、虾肉和虾粉3种磷虾产品生产线为研究对象,比较其与传统船载加工的差异,基于HACCP体系对3条生产线的工艺流程进行分解和危害分析,并确定关键控制点;通过初步建立控制体系的过程,研究船载南极磷虾捕捞加工生产线在体系中的特征。研究表明,捕捞加工系统由于自动化、整体连贯性和封闭性较高,减少了人为和环境危害概率,关键控制点更为清晰,所有外部输入环节、控制系统参数设置和金属探测都为关键控制点,并对GMP和SSOP的实施要求更为严格,对设备的维护保养和日常清洁要求更高。分析结果可为其他同类船舶的船载加工线设计和建立标准提供参考。 相似文献
17.
Felicity Huntingford Colin Adams Victoria A. Braithwaite Sunil Kadri Tom G. Pottinger Peter Sandoe & James F. Turnbull 《Fish and Fisheries》2007,8(3):277-280
The welfare of fish is a topic of increasing debate touching on a number of complex scientific and ethical issues and constructive dialogue between groups with differing approaches to the topic requires mutual understanding from both perspectives. In a recent review aimed at stimulating debate on this topic, Arlinghaus et al. (2007) explore the question of fish welfare in the particular context of recreational angling, by means of a critique of a review of fish welfare in general written by ourselves ( Huntingford et al. 2006 ). We entirely agree with the desirability of debate on this topic and recognize a number of valuable qualities in the commentary by Arlinghaus et al. However, we argue that the critique has some serious flaws. In the first place, by rejecting a feelings‐based approach to welfare, it fails to address the aspect of welfare that is at the heart of much legitimate public concern. Secondly, while advocating an objective, scientific approach to fish welfare, Arlinghaus et al. fail to present their own agenda (that recreational angling is morally acceptable) in a transparent way. Thirdly, they seriously misrepresent the position taken in Huntingford et al. (2006) on a number of important issues. In this reply, we address these points and then discuss briefly the areas of agreement and constructive disagreement between the two reviews. 相似文献
18.
Cortisol and finfish welfare 总被引：1，自引：0，他引：1
Ellis T Yildiz HY López-Olmeda J Spedicato MT Tort L Øverli Ø Martins CI 《Fish physiology and biochemistry》2012,38(1):163-188
Previous reviews of stress, and the stress hormone cortisol, in fish have focussed on physiology, due to interest in impacts
on aquaculture production. Here, we discuss cortisol in relation to fish welfare. Cortisol is a readily measured component
of the primary (neuroendocrine) stress response and is relevant to fish welfare as it affects physiological and brain functions
and modifies behaviour. However, we argue that cortisol has little value if welfare is viewed purely from a functional (or
behavioural) perspective—the cortisol response itself is a natural, adaptive response and is not predictive of coping as downstream
impacts on function and behaviour are dose-, time- and context-dependent and not predictable. Nevertheless, we argue that
welfare should be considered in terms of mental health and feelings, and that stress in relation to welfare should be viewed
as psychological, rather than physiological. We contend that cortisol can be used (with caution) as a tractable indicator
of how fish perceive (and feel about) their environment, psychological stress and feelings in fish. Cortisol responses are
directly triggered by the brain and fish studies do indicate cortisol responses to psychological stressors, i.e., those with
no direct physicochemical action. We discuss the practicalities of using cortisol to ask the fish themselves how they feel
about husbandry practices and the culture environment. Single time point measurements of cortisol are of little value in assessing
the stress level of fish as studies need to account for diurnal and seasonal variations, and environmental and genetic factors.
Areas in need of greater clarity for the use of cortisol as an indicator of fish feelings are the separation of (physiological)
stress from (psychological) distress, the separation of chronic stress from acclimation, and the interactions between feelings,
cortisol, mood and behaviour. 相似文献
19.
Fish welfare: a challenge to the feelings-based approach, with implications for recreational fishing
Robert Arlinghaus Steven J. Cooke Alexander Schwab & Ian G. Cowx 《Fish and Fisheries》2007,8(1):57-71
Fish welfare issues are increasingly appearing on social and political agendas and have recently gained prominence in fisheries literature. By focusing on examples from recreational fishing, this paper challenges some of the previous accounts of fish welfare. Issues of concern encompass: (1) the feelings‐based approach to fish welfare; (2) the artificial divide between human beings and nature; and (3) ways in which stakeholders can address fish welfare issues. The different approaches to characterizing the interaction of humans with animals are animal welfare, animal liberation and animal rights. We show that the suffering‐centred approaches to fish welfare and the extension of the moral domain to fish – characteristic of the concepts of animal liberation and animal rights – are not the cornerstone of animal welfare. This, however, does not question the need of fisheries stakeholders to consider the well‐being of fish when interacting with them. There are many ways in which recreational fishing stakeholders can modify standard practices to improve the welfare of fish, without questioning fishing as an activity per se. Examples are choice of gear and handling techniques. Previous accounts have failed to include discussions of the many efforts – voluntary or mandated – pursued by fisheries stakeholders to reduce fish stress, injury and mortality. Progress towards addressing fish welfare issues will be enhanced by avoiding the viewing of humans as ‘non‐natural’ disturbance to fishes and keeping three types of crucial question in separate compartments. The three questions cover the symptoms of good and poor welfare, the conscious experience of suffering, and the ethical attitudes towards animals. Fish biologists should focus on the first question – objective measurement of biochemical, physiological and behavioural indicators – to evaluate whether human interactions with fish impair the latters’ health or prevent them from receiving what they need, if held in captivity. 相似文献
20.
Anaesthesia of farmed fish: implications for welfare 总被引：1，自引：0，他引：1
During their life cycle as farmed animals, there are several situations in which fish are subjected to handling and confinement.
Netting, weighing, sorting, vaccination, transport and, at the end, slaughter are frequent events under farming conditions.
As research subjects, fish may also undergo surgical procedures that range from tagging, sampling and small incisions to invasive
procedures. In these situations, treatment with anaesthetic agents may be necessary in order to ensure the welfare of the
fish. The main objective of this paper is to review our knowledge of the effects of anaesthetic agents in farmed fish and
their possible implications for welfare. As wide variations in response to anaesthesia have been observed both between and
within species, special attention has been paid to the importance of secondary factors such as body weight, water temperature
and acute stress. In this review, we have limited ourselves to the anaesthetic agents such as benzocaine, metacaine (MS-222),
metomidate hydrochloride, isoeugenol, 2-phenoxyethanol and quinaldine. Anaesthetic protocols of fish usually refer to one
single agent, whereas protocols of human and veterinary medicine cover combinations of several drugs, each contributing to
the effects needed in the anaesthesia. As stress prior to anaesthesia may result in abnormal reactions, pre-anaesthetic sedation
is regularly used in order to reduce or avoid stress and is an integral part of the veterinary protocols of higher vertebrates.
Furthermore, the anaesthetic agents that are used in order to obtain general anaesthesia are combined with analgesic agents
that target nociception. The increased use of such combinations in fish is therefore included as a special section. Anaesthetic
agents are widely used to avoid stress during various farming procedures. While several studies report that anaesthetics are
effective in reducing the stress associated with confinement and handling, there are indications that anaesthesia may in itself
induce a stress response, measured by elevated levels of cortisol. MS-222 has been reported to elicit high cortisol release
rates immediately following exposure, while benzocaine causes a bimodal response. Metomidate has an inhibitory effect on cortisol
in fish and seems to induce the lowest release of cortisol of the agents reported in the literature. Compared to what is observed
following severe stressors such as handling and confinement, the amount of cortisol released in response to anaesthesia appears
to be low but may represent an extra load under otherwise stressful circumstances. Furthermore, anaesthetics may cause secondary
adverse reactions such as acidosis and osmotic stress due to respiratory arrest and insufficient exchange of gas and ions
between the blood and the water. All in all, anaesthetics may reduce stress and thereby improve welfare but can also have
unwanted side effects that reduce the welfare of the fish and should therefore always be used with caution. Finally, on the
basis of the data reported in the literature and our own experience, we recommend that anaesthetic protocols should always
be tested on a few fish under prevailing conditions in order to ensure an adequate depth of anaesthesia. This recommendation
applies whether a single agent or a combination of agents is used, although it appears that protocols comprising combinations
of agents provide wider safety margins. The analgesic effects of currently used agents, in spite of their proven local effects,
are currently being debated as the agents are administrated to fish via inhalation rather than locally at the target site.
We therefore recommend that all protocols of procedures requiring general anaesthesia should be complemented by administration
of agents with analgesic effect at the site of tissue trauma. 相似文献