Enhancement of habituation during escape swimming in starved crayfish.

Feeding is important to supply the immediate energy needs of animals and starved animals must expend energy in attempting to acquire foods irrespective of the danger of predation risk. Crayfish escape from attack of predators by tailflipping and in response to rostral stimuli crayfish show backward escape swimming following an initial rapid flexion of the abdomen. Since the tailflip is an energetically costly behaviour, the occurrence of a tailflip diminishes if a stimulus is repeatedly applied through habituation. In this study, we have compared the process of this habituation between fed and starved crayfish. We found that in starved animals habituation was enhanced compared to fed animals. The presence of food in the experimental tanks further enhanced habituation of starved animals. Starved crayfish thus showed trade-offs between energy saving and predation risk.