Turning up the heat on subzero fish: thermal dependence of sustained swimming in an Antarctic notothenioid

• Published in: Journal of thermal biology Vol. 27; no. 5; pp. 381 - 386
• Main Authors: Wilson, Robbie S., Kuchel, Louise J., Franklin, Craig E., Davison, William
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2002
• Subjects: Antarctic; Fish; Marine; Pagothenia borchgrevinki; Swimming performance; Thermal dependence; Fish; Pagothenia borchgrevinki; Antarctic; Thermal dependence; Swimming performance
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/S0306-4565(02)00006-2

We determined the maximum sustained swimming speed ( U crit), and resting and maximum ventilation rates of the Antarctic fish Pagothenia borchgrevinki at five temperatures between −1°C and 8°C. We also determined resting metabolic rate (VO 2) at −1°C, 2°C, and 4°C. U crit of P. borchgrevinki was highest at −1°C (2.7±0.1 BL s −1) and rapidly decreased with temperature, representing a thermal performance breadth of only 5°C. This narrow thermal performance supports our prediction that specialisation to the subzero Antarctic marine environment is associated with a physiological trade-off in performance at high temperatures. Resting oxygen consumption and ventilation rate increased by more than 200% across the temperature range, which most likely contribute to the decrease in aerobic swimming capabilities at higher temperatures.