Ramos, J., Balasch, J. C., Tort, L. 2021. About welfare and stress in the early stages of fish. Frontiers in Veterinary Science 8, 634434.

In conclusion, the investigations carried out up to now demonstrate that during the early stages fish show high sensitivity to many types of stressors involving an array of responses to overcome alterations that could affect the animal and be transmitted to the progeny. Welfare in eggs and larvae is a continuous process that involve both parental experience and development, so environmental parameters have to be controlled during all the life time, especially during the gamete and organogenesis stages. Standard protocols should be developed including all environmental parameters by studying not just the zoothecnical indexes but also stress and welfare-related indicators such as behavioral traits, stress hormones, or the expression of genes associated to them. In our opinion, the results of the research on these early stages also points out a lack of adequate standards for reliable welfare results in relation with the procedures for maintenance, husbandry or transport (Table 1).