Repair process and enzymatic activity associated with induction of shell regeneration in the invasive species Pomacea canaliculata

This study investigated the repair process and enzymatic activity responses after induction of shell regeneration in Pomacea canaliculata. The survival rates, height of regenerated shell, and activities of alkaline phosphatase (ALP) and carbonic anhydrase (CA) were investigated and recorded for 15days. A triangular piece of shell about 8mm wide was excised from the ventral region of the shell. On the basis of photographs and enzyme assay, it was concluded both yellow-shell apple snails and black-shell apple snails had high survival rates (100%). The regenerated new shell was initially thin, with the wound sealed 5days after induction of shell regeneration; after that the regenerated shell thickened. Three snails were sampled at 0, 0.5, 1, 2, 3, 5, 10 and 15 days after shell excision for analysis of enzymatic activity of ALP and CA. Trends of the activity of ALP and CA in the mantle were similar. Initially they both showed a decline on the first day, then rose on following days. Activity of ALP declined to a minimum on the first day, and an activity peak in both colour forms appeared on the fifth day (P<0.05) and was maintained for the rest of the experiment. The minimum value of CA occurred after 0.5 days, and a significant increase was also observed on the fifth day (P<0.05). This study has revealed that apple snails have good shell regeneration abilities, and that ALP and CA probably play a crucial role in shell growth and regeneration.