Gender-based differences in Florida apple snail (Pomacea paludosa) movements

Gastropod movements have been studied in the context of habitat selection, finding food and mates, and avoiding predation. Many of these studies were conducted in the laboratory, where constraints on spatial scale influence behavior. We conducted a field study of Florida apple snail (Pomacea paludosa) movements using telemetry. We hypothesized that Florida apple snail movements were driven by reproductive activity, and that gender differences would be evident. We documented male and female directions and distances traveled. We also conducted a trapping study that included conspecific bait to test if the presence of females attracted more males as measured by M:F ratios in traps. The greatest distances traveled were by males, and males were more likely to maintain a consistent bearing compared to females. Male distances peaked in what typically corresponds to peak breeding season. M:F ratios in traps were positively associated with reproductive activity in the study population as measured by egg cluster counts. Conspecific bait had no effect on the number of males or females captured. However, if a female crawled into the trap, we observed greater numbers of males compared to those with no trapped females. Males may have tracked females to increase mating encounters, following slime trails, as seen in other aquatic (including other Pomacea) snails. The capacity for mate finding has implications for reproductive success in the relatively low density populations often seen for Pomacea paludosa.