This minireview talks about how environmental perturbations are affecting fish development and reproductive physiology. It highlights interactions between hormones, growth factors with particular emphasis on the growth hormone (GH)-insulin-like growth factor (IGF)-axis, and selected cytokines involved in the complex orchestration of reproduction, growth, metabolism and health in teleost fish. Focus is placed on challenges posed by changing water temperature and salinities on fish reproduction and growth, and how these factors influence the GH-IGF-system and immune genes during environmental adaptation. Another focus is placed on chemical pollutants including endocrine disrupting compounds (EDCs) and on mechanistic links with the GH/IGF-immune axis. Finally, we highlight some synergistic effects of EDCs with physical and natural stressors, including pathogens and recent attempts to optimise fish health by dietary additives. This minireview concludes with a discussion of the One Health concept.