According to Hans Seyle’s classical definition, the stress response is a “non-specific result of any demand upon the body” to maintain or restore homeostasis . While the stress response is usually adaptive in the sense that allows animals to cope with perceived stressors to regain balance, prolonged or acute stressors can be mal-adaptive and detrimental to health and welfare, a state coined as “distress” by Seyle’s . Over the past years, it has become clear that the stress response is highly heterogenous, varying between individuals according to their genetic background, early-life experiences, and vertical epigenetic transmission. Stress research in fish is a relatively recent topic but it has been gaining attention, in particular because of the increasing use of fish in animal farming and the need to keep production performance while improving animal welfare.

In the context of domestication, fish have been brought from nature into captive environments for a number of reasons, including as sources of food and raw materials, for biomedical research, for the aquariology and exhibition industries, or for cultural reasons. Under captive conditions, animals are exposed to a set of factors that can act as stressors, including the physical conditions of the environment, dietary shifts, transport practices, handling, confinement, high-density, among others. In fish, like in other vertebrates, early-stages of domestication entail the adaptation of wild-animals to captive conditions by a progressive genetic and phenotypic transformation.

This project is funded by the Macao Science and Technology Development Fund (FDCT). Project reference: FDCT 0025/2020/A1