Osmotic pressure in vitreous fluid in cold versus warm fish. A: Osmotic pressure in vitreous fluid in smelt at warm (8–10 °C) and cold (<0.5 °C) temperatures. B: Thermal hysteresis in vitreous fluid in smelt at warm (8–10 °C) and cold (<0.5 °C) temperatures. The values are presented as mean±SEM with n=3 for the warm group and n=5 for the cold group. * indicates a statistically significant difference.