Food aversion learning induced by lithium chloride in the crayfish Procambarus clarkii

The ability of the crayfish Procambarus clarkii to develop a food aversion learning was examined. For this purpose, in crayfishes fed with trout, a novel food (chicken) was associated in a single trial with a well-known toxic substance, lithium chloride (LiCl), and food intake was recorded for 10 days afterward using a two-choice protocol. All during the experimental period, a significant effect of treatment was observed that accounted for the lower chicken intake in the LiCl-treated group, compared with the control groups (NaCl-treated group and puncture group). In contrast, LiCl-treated animals had an increased trout intake during the entire period. In addition, it was observed that total food intake was similar among the three groups. These results indicate that the crayfish may develop a food aversion learning when illness is induced by LiCl after the animal accepts and eats a novel food.