Impact of temperature-dependent developmental plasticity on immune response and cardiac health to Yersinia ruckeri infection, in Atlantic salmon parr

Abstract

Heart injuries and diseases are one of the largest challenges in Atlantic salmon aquaculture. Presently, salmon experience intensive farming conditions and feeding regimes, and different viral and bacterial pathogens flourish and create cardiac health risks. Many have suggested how early life history plays a greater role in performance than previously assumed. The RCN-NFR funded project COOLFISH (PNO: 325571) led by Nofima has supported this thesis which aims at improving Atlantic salmon cardiac health and welfare by exploring the impact of temperature-dependent developmental plasticity. By comparing two different incubation temperature regimes, 4 °C and 8 °C at the embryonic stage, this study has provided increased knowledge on how incubation temperature affects heart morphology and immune response at the parr stage using a Y. ruckeri infection model, which has also increased general knowledge of bacterial infection in cardiac tissue. Gene expression analysis and observations revealed differences in immune and stress responses, as well as muscle metabolism and growth. Most of the results indicate improved performance in the hearts of 4 °C incubated fish, in contrast to observations of cardiac pathology markers in the 8 °C incubated fish.