The effects of starvation on fast-start escape and constant acceleration swimming performance in rose bitterling (Rhodeus ocellatus) at two acclimation temperatures.

Abstract

To investigate the effects of starvation and acclimation temperature on the escape ability of juvenile rose bitterling (Rhodeus ocellatus), we measured the fast-start escape and constant acceleration swimming performance of fish fasted for 0 (control), 1 and 2weeks and half-lethal periods (6 or 4weeks) at two temperatures (15 and 25°C). Fish acclimated at a high temperature exhibited shorter response latency (R), higher maximum linear velocity (V max) and longer escape distance during escape movement (D 120ms) than those at the low temperature. Starvation resulted in a significant decrease in V max and D 120ms at either low or high temperature and a significant increase in R at only the high temperature in the half-lethal period groups (P<0.05). The relationship between V max (Y, ms(-1)) and starvation time (X, week) was Y 15=-0.062X+1.568 (r=-0.665, n=36, P<0.001) at low temperature and Y 25=-0.091X+1.755 (r=-0.391, n=40, P=0.013) at high temperature. The relationship between U cat (Y, cms(-1)) and starvation time (X, week) was Y 15=-1.649X+55.418 (r=-0.398, n=34, P=0.020) at low temperature and Y 25=-4.917X+62.916 (r=-0.793, n=33, P<0.001) at high temperature. The slopes of equations showed a significant difference between low and high temperature (F 1,63=9.688, P=0.003), which may be due to the different energy substrate utilization when faced with food deprivation at different temperatures.