Effect of temperature on swimming performance in juvenile southern catfish ( Silurus meridionalis)

Abstract

The critical swimming speed ( U crit, aerobic swimming performance) and endurance (anaerobic swimming performance) of juvenile southern catfish Silurus meridionalis Chen (9.8 ± 0.1 cm body length and 8.09 ± 0.17 g body mass, n = 226) were investigated at 10, 15, 20, 25, and 30 °C. Both absolute U crit (cm s − 1 ) and relative critical swimming speed ( U r, BL s − 1 ) of juvenile southern catfish increased in the temperature zone from 10 to 25 °C ( p < 0.05) and plateaued between 25 and 30 °C. However, the relationship between endurance time (tested at 1.23, 1.59 and 1.79 U r-max) and temperature followed an approximate bell-shape curve as temperature rose ( p < 0.05). The optimum temperatures of maximal U crit (3.40 BL s − 1 ) of juvenile southern catfish was 28.4 °C. But that of experimental fish's endurance which was tested at velocity of 1.59 and 1.79 U r-max was 23.2 °C. These results show that temperature has a significant effect on swimming performance in juvenile southern catfish.