Abstract
The ability of the apple snail, Pomacea canaliculata (Lamarck) (Gastropoda: Ampullariidae), to learn either to avoid a trap or to come to obtain the bait was studied. The trap was made from a soft-drink bottle and included 10 g bait inside. Thirty snails, painted individually with different numbers, were released in a tank placed outdoors. Collection of the snails by the trap was performed 17 times during the period 17 June to 30 July 1998. The proportion of individual snails trapped showed a significant normal distribution around a mean of 0.533 ± 0.034 SEM. The mean interval between snails being trapped was 4.11 ± 0.26 days and this did not differ significantly between individual snails. Neither the size, represented by shell length, nor the sex showed significant correlation with the interval. This interval was independent of how many times the snail had been trapped until the penultimate collection. These results indicate that whether or not a snail is trapped is determined by probability, and not by size or sex, nor how many times the snail has been trapped previously.
