13 – Stress in Fish as Model Organisms

1. Introduction 2. Indicators of Stress in Laboratory Fish 3. Factors Impacting Stress in Laboratory Fish Handling 4. Housing 4.1. Density 4.2. Enrichment 4.3. Light/Dark Cycle 5. Feeding and Stress 6. Sex and Hierarchies 7. Sex Determination and Reversal 8. Stress, Cortisol, and Reproduction 9. Anesthetics 10. Underlying Diseases 11. Consistency 12. Conclusion and Key Unknowns With the advent of the zebrafish, the three-spined stickleback, and the medaka as laboratory animals, the emergence of fish as model organisms has provided a wide variety of potential experimental subjects, simultaneously introducing new challenges to both researchers and aquaculturists. With regard to stress in these fishes, we must shift the emphasis beyond the traditional definitions of production in terms of fecundity and growth and toward the goals of experimental consistency, animal welfare, and model robustness. In order to improve fish as model organisms, aquaculturists and researchers must use each organism's natural history as a template for developing appropriate husbandry practices. In this chapter, we review published data regarding stress in laboratory fishes in order to provide a foundation for building better husbandry protocols for the purposes of improving fish as model organisms.