Abstract:
1. Selected and avoided temperatures of acclimated Procambarus clarkii, juveniles, preadults and adults, were determined. 2. Neither the different development stages nor the acclimation temperatures (20, 23, 26 and 29-degrees-C) had any effect upon the acute preferenda of crawfish. 3. Procambarus clarkii final preferendum was 23.4-degrees-C. 4. Avoidance thermal behavior was not influenced by size but acclimation temperatures did have a significant influence. The relative change of avoided temperature in respect to acclimation was narrower at high than at cold temperatures. 5. The performance of crawfish from Baja California is closely related to higher latitudinal species as far as temperature is concerned.