Status assessment and opportunities for improving fish welfare in animal experimental research according to the 3R-Guidelines

Abstract

In mammalian research, the implementation of the 3Rs is ubiquitous. However, the adaptation of procedures for experimental work on fish seems less extensive in comparison, even though fish model organisms are common in a broad range of research fields already. To strengthen animal welfare in experimental research, we provide an overview of current research results, including studies on the nociception of fishes. Furthermore, we describe the potential of implementing the 3Rs in fish experimental research. In the context of "Reduction", we show alternative research methods to lethal sampling. Considering "Refinement", we point out possibilities to improve fish handling and indicate that adaptations to the individual species ecology are necessary. Under the aspect of "Replacement", we describe the high potential of cell cultures that can be obtained from fish tissue and give an overview of the already extensive use in ecotoxicology and virology. In addition, we illustrate that cell cultures could also be increasingly used for basic research. Graphical abstract

Perspective Chapter: In Vitro Contracting Cardiomyogenic Models from Whole Fish Embryos and Larvae – Method, Properties, and Applications

“…The changes in the heart usually primarily affect contractile activity and metabolism. Fish living in temperate climates are particularly susceptible to significant and long-term seasonal temperature changes [45][46][47]. Among these fish species, salmonids like rainbow trout can remain active between 4 and 24°C [42,48].…”

“…Outbreaks of fish diseases can have severe economic and social impacts. For instance, in Chile, outbreaks of infectious salmon anemia virus (ISAV) between 2007 and 2009 resulted in losses of approximately 2 billion US dollars and 15,000 jobs in the aquaculture industry [45,60].…”

“…Understanding these host-virus interactions at the cellular level is crucial for effective fish virology research and the development of targeted control measures. In this research area as well, there is an effort to transition to in vitro models in order to reduce the use of a high number of experimental animals [45].…”

Multiple faces of stress in the zebrafish (Danio rerio) brain

“…Fish in aquaculture and research facilities are often subjected to distress not only for short time periods (acute stress) but also for longer ones (chronic stress). However, rearing fish under conditions that respect the species-specific needs of the animals improves their well-being and performance in fish farms ( Macaulay et al, 2022 ) and under experimental conditions ( Grunow and Strauch, 2023 ). The main question of the present work is to identify which set of genes in which brain region is characteristic of specific stress situations and should therefore be focused on in future fish welfare assessments.…”

Editorial: Methodological approaches for fish reproduction management

“…Animal welfare is becoming increasingly important in both laboratory research and aquaculture, and the ethical treatment of laboratory animals requires special committees to monitor research protocols involving fish ( Toni et al, 2019 ). Fish welfare is an important and neglected aspect of animal care that encompasses the wellbeing and ethical treatment of fish species ( Grunow and Strauch, 2023 ). Over the past decade, interest has increased in developing non-lethal and less invasive methods to study fish reproduction.…”