Developmental plasticity of muscle cellularity and swim performance of juvenile Chinook salmon in response to temperature

I investigated the influence of incubation temperature on muscle development and swim performance in juvenile Chinook salmon (Oncorhynchus tshawytscha). In 2011 and 2012, embryos were incubated at different combinations of temperature (7, 9, 15 °C), before and after the onset of free swimming. High-intensity fixed velocity swim tests were performed to assess anaerobic capacity of juveniles. In 2012, these tests were done at a standardized body size (~40 mm). The mean (least-squares) logged times to fatigue of the 15 °C-incubated fish was higher (0.623 ± 0.049 SE) than the 7 °C-incubated fish (0.435 ± 0.048 SE) even after acclimation at a common temperature (9 °C). This indicates a carry-over effect of incubation temperature on swim performance. However, cross-sectional fibre area and number did not correlate with individual swim performance. My study shows the importance of controlling for body size in studies linking muscle cellularity to swim performance