Novel euthanasia technique for zebrafish using electric shock in standard group housing aquaria.

Zebrafish are widely used in research, accounting for approximately 50% of all laboratory fish across Europe. Due to their rapid reproduction and aging, effective and practical euthanasia methods are necessary for managing large stocks. This study investigated whether adult zebrafish can be euthanised by delivering an electrical current directly via the water in their housing aquaria.

Putative Nociceptive Responses in a Decapod Crustacean: The Shore Crab ().

Nociceptors are receptors that detect injurious stimuli and are necessary to convey such information from the periphery to the central nervous system. While nociception has been extensively studied in various taxa, there is relatively little electrophysiological evidence for the existence of nociceptors in decapod crustaceans. This study investigated putative nociceptive responses in the shore crabs, specifically their response to mechanical and noxious chemical stimuli.

The behavior and welfare of neglected species: some examples from fish and mammals.

Animal welfare is the state of an animal's body and mind and the level to which its requirements are satisfied. Animal welfare is affected by human decisions and actions. Numerous decisions concerning animals are driven by human desires to enhance their own lives, and some of these decisions may be influenced by self-interest or a strong emphasis on economic factors.

Differential metabolic responses in bold and shy sea anemones during a simulated heatwave.

As climate change-induced heatwaves become more common, phenotypic plasticity at multiple levels is a key mitigation strategy by which organisms can optimise selective outcomes. In ectotherms, changes to both metabolism and behaviour can help alleviate thermal stress. Nonetheless, no study in any ectotherm has yet empirically investigated how changing temperatures affect among-individual differences in the associations between these traits.

Pain management in zebrafish : Report from a FELASA Working Group.

Empirical evidence suggests fishes meet the criteria for experiencing pain beyond a reasonable doubt and zebrafish are being increasingly used in studies of pain and nociception. Zebrafish are adopted across a wide range of experimental fields and their use is growing particularly in biomedical studies. Many laboratory procedures in zebrafish involve tissue damage and this may give rise to pain.

Acetic acid-induced pain elicits stress-, and camouflage-related responses in zebrafish: Modulatory effects of opioidergic drugs on neurobehavioral phenotypes.

While pain results from the activation of nociceptors following noxious stimuli, mounting evidence links pain- and stress-related responses in mammals. In zebrafish, the activation of hypothalamic-pituitary-interrenal (HPI) axis may also regulate body pigmentation (the camouflage response). Here, we aimed to investigate a putative relationship between pain-, stress-, and camouflage-related parameters in adult zebrafish.

Methods to Induce Analgesia and Anesthesia in Crustaceans: A Supportive Decision Tool.

Methods to induce analgesia and anesthesia for research purposes, handling, transport, or stunning have been used in 71 species of crustaceans. A non-systematic literature search was conducted on crustacean anesthetic methods. This review presents a comprehensive evaluation of drugs and non-chemical methods used to provide analgesia and anesthesia in many crustacean species rather than just decapod crustaceans.

Pain Recognition in Fish.

Empirical evidence has demonstrated that fish experience pain, and so to ensure their good welfare, it is vital that we can recognize and assess pain. A range of general, behavioral, and physiologic indicators can be used when assessing pain in fish. Many of these can be used at the tank side and are termed operational welfare indicators, whereas some require further computer or laboratory analysis.

Impact of Lidocaine on Pain-Related Grooming in Cuttlefish.

Nociception is the neural process of encoding noxious stimuli and is typically accompanied by a reflex withdrawal response away from the potentially injurious stimulus. Studies on nociception in cephalopods have so far focused on octopus and squid, with no investigations to our knowledge on cuttlefish. Yet, these are an important species both in scientific and commercial use.

Impact of intraspecific variation in teleost fishes: aggression, dominance status and stress physiology.

Dominance-based social hierarchies are common among teleost fishes. The rank of an animal greatly affects its behaviour, physiology and development. The outcome of fights for social dominance is affected by heritable factors and previous social experience.

Understanding early-life pain and its effects on adult human and animal emotionality: Translational lessons from rodent and zebrafish models.

Critical for organismal survival, pain evokes strong physiological and behavioral responses in various sentient species. Clinical and preclinical (animal) studies markedly increase our understanding of biological consequences of developmental (early-life) adversity, as well as acute and chronic pain. However, the long-term effects of early-life pain exposure on human and animal emotional responses remain poorly understood.

The Use of Zebrafish as a Non-traditional Model Organism in Translational Pain Research: The Knowns and the Unknowns.

The ability of the nervous system to detect a wide range of noxious stimuli is crucial to avoid life-threatening injury and to trigger protective behavioral and physiological responses. Pain represents a complex phenomenon, including nociception associated with cognitive and emotional processing. Animal experimental models have been developed to understand the mechanisms involved in pain response, as well as to discover novel pharmacological and non-pharmacological anti-pain therapies.

Personality-specific carry-over effects on breeding.

Carry-over effects describe the phenomenon whereby an animal's previous conditions influence its subsequent performance. Carry-over effects are unlikely to affect individuals uniformly, but the factors modulating their strength are poorly known. Variation in the strength of carry-over effects may reflect individual differences in pace-of-life: slow-paced, shyly behaved individuals are thought to favour an allocation to self-maintenance over current reproduction, compared to their fast-paced, boldly behaved conspecifics (the pace-of-life syndrome hypothesis).

The impact of personality, morphotype and shore height on temperature-mediated behavioural responses in the beadlet anemone Actinia equina.

Between-individual variation in behavioural phenotype, termed personality, is an important determinant of how populations cope with acute environmental fluctuation related to climate change. Personality in the beadlet sea anemone Actinia equina is linked to genetically distinct morphotypes, which are associated with different heights on the shore. In the intertidal zone, high-shore environments experience more environmental fluctuation due to longer periods of exposure, and animals adapted to live in these environments are predicted to deal more effectively with environmental perturbation than their low-shore counterparts.

Acute and chronic stress prevents responses to pain in zebrafish: evidence for stress-induced analgesia.

The state of an animal prior to the application of a noxious stimulus can have a profound effect on their nociceptive threshold and subsequent behaviour. In mammals, the presence of acute stress preceding a painful event can have an analgesic effect whereas the presence of chronic stress can result in hyperalgesia. While considerable research has been conducted on the ability of stress to modulate mammalian responses to pain, relatively little is known about fish.

Evolution of nociception and pain: evidence from fish models.

In order to survive, animals must avoid injury and be able to detect potentially damaging stimuli via nociceptive mechanisms. If the injury is accompanied by a negative affective component, future behaviour should be altered and one can conclude the animal experienced the discomfort associated with pain. Fishes are the most successful vertebrate group when considering the number of species that have filled a variety of aquatic niches.

Personality predicts foraging site fidelity and trip repeatability in a marine predator.

Animal populations are often comprised of both foraging specialists and generalists. For instance, some individuals show higher foraging site fidelity (spatial specialization) than others. Such individual differences in degree of specialization can persist over time-scales of months or even years in long-lived animals, but the mechanisms leading to these different individual strategies are not fully understood.

Assessment of behaviour in groups of zebrafish (Danio rerio) using an intelligent software monitoring tool, the chromatic fish analyser.

Background: Zebrafish (Danio rerio) are an increasingly popular model species within a variety of biomedical and neurobiological contexts. Researchers are required to prevent any negative states, such as pain, when using experimental animals to optimise fish welfare but analysis tools for zebrafish are lacking.

New Method: The chromatic fish analyser (CFA) is a computer-based monitoring system that has the potential to identify changes in fish behaviour via spatial chromatic analysis of video images.

Automated monitoring of behaviour in zebrafish after invasive procedures.

Fish are used in a variety of experimental contexts often in high numbers. To maintain their welfare and ensure valid results during invasive procedures it is vital that we can detect subtle changes in behaviour that may allow us to intervene to provide pain-relief. Therefore, an automated method, the Fish Behaviour Index (FBI), was devised and used for testing the impact of laboratory procedures and efficacy of analgesic drugs in the model species, the zebrafish.

Ethical considerations in fish research.

Fishes are used in a wide range of scientific studies, from conservation research with potential benefits to the species used to biomedical research with potential human benefits. Fish research can take place in both laboratories and field environments and methods used represent a continuum from non-invasive observations, handling, through to experimental manipulation. While some countries have legislation or guidance regarding the use of fish in research, many do not and there exists a diversity of scientific opinions on the sentience of fish and how we determine welfare.

Where to draw the line? Should the age of protection for zebrafish be lowered?

Zebrafish are not protected by legislation in many countries until they reach the first feed stage, typically at five days post-fertilisation. If they exhibit similar responses to adults when responding to pain and other stimuli should they be given more protection?

An investigation on the impact of substrate type, temperature, and iodine on moon jellyfish production.

Jellyfish are a popular public aquarium species, however, their collection from natural populations is undesirable due to impact on species abundance and bycatch. Thus, a sustainable supply of jellyfish bred in-house would be highly desirable. Here we describe an investigation into developing a sustainable moon jellyfish, Aurelia aurita, breeding program by determining the impact of substrate type on reattachment of polyps and the influence of iodine and temperature on strobilation and ephyra production.

Comparative Physiology of Nociception and Pain.

The study of diverse animal groups allows us to discern the evolution of the neurobiology of nociception. Nociception functions as an important alarm system alerting the individual to potential and actual tissue damage. All animals possess nociceptors, and, in some animal groups, it has been demonstrated that there are consistent physiological mechanisms underpinning the nociceptive system.