Several studies have reported the neurophysiological and behavioural mechanisms that enable fish to experience several types of affective states, such as fear, pain and joy. This is crucial for the welfare feelings-based approach, as conditions that bring positive or negative valence to fish influence their affective state. A method to understand to what extent fish ‘like’ or ‘dislike’ their surrounding features is by evaluating their consistent choices (preferences) and propensity to reach environmental resources or traits (motivation). In this review, we propose how to assess preference and motivation tests in fish and discuss the limitations and potential biases that may affect such tests. Furthermore, we emphasize that understanding the avoidance responses of fish under a welfare context is a complementary method to improve the quality of life of fish in any type of rearing environment. Although there are other reviews about animal preference and motivation, this is the first one exclusively dedicated to the application of fish welfare.

中文翻译：

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偏好、回避、动机及其对鱼类福利的重要性

几项研究报告了使鱼类能够体验几种情感状态的神经生理学和行为机制，例如恐惧、疼痛和快乐。这对于基于福利情感的方法至关重要，因为给鱼带来正价或负价的条件会影响它们的情感状态。了解鱼类“喜欢”或“不喜欢”周围特征的程度的一种方法是评估它们的一致选择（偏好）和接触环境资源或特征的倾向（动机）。在这篇综述中，我们提出了如何评估鱼类的偏好和动机测试，并讨论可能影响此类测试的局限性和潜在偏差。此外，我们强调，了解鱼类在福利背景下的回避反应是提高任何类型饲养环境中鱼类生活质量的补充方法。尽管还有其他关于动物偏好和动机的评论，但这是第一篇专门致力于鱼类福利应用的评论。