Meeting Abstract
Rainbow smelt (Osmerus mordax), a eurythermal fish, swim in environments from -1.8°C to 20°C. These different temperature regimes pose distinct challenges to feeding and locomotion by smelt. The acclimation to cold by the red muscle of the smelt can be studied with the goal of understanding how these fish can swim in such different thermal environments. Swimming performance in warm vs. cold acclimated smelt was tested and a video analysis of the swimming was examined to determine average tailbeat frequency. The cold acclimated smelt had a faster maximum steady swimming speed and swam with a higher tailbeat frequency than the warm acclimated smelt. Muscle mechanics experiments demonstrated faster contractile properties in the cold acclimated fish. Histology, dot blot analysis, and RNA-SEQ indicate that there is a change in the myosin heavy chain composition and other muscle proteins of muscle with cold acclimation. In addition, increased expression of antifreeze proteins in cold acclimated smelt confirm that thermal acclimation has occurred.
