ALLELIC AND GENOTYPIC VARIATION OF LEUCINE-AMINOPEPTIDASE (LAP-2) ANDPHOSPHOGLUCOMUTASE (PGM) IN PROCAMBARUS-CLARKII (DECAPODA, CAMBARIDAE), ACCLIMATED AT DIFFERENT TEMPERATURES AND EXPOSED TO THERMAL HARDENING

In this study, the allozymic and genotypic variation of leucine-aminop eptidase (Lap-2) and phosphoglucomutase (Pgm) in Procambarus clarkii f rom Baja California is analyzed, under different thermic conditions. T he repeated exposure of the organisms to the critical thermal maximum (CTMax) did not show a hardening response. However, there are differen ces in the allelic and genotypic frequencies of Lap-2 and Pgm among th e organisms acclimated at 20 and 33 degrees C, and the field populatio n. On the other hand, the frequencies of the heterozygote genotypes of Lap-2 and Pgm are higher in the final CTMax of 20 and 33 degrees C, c ompared to the field population. These results show a variation in the allozymic and genotypic frequencies which are determined by the effec t of temperature on P. clarkii. Also observed is a selection in favor of the heterozygote organisms in the CTMax.