Interspecies competition and growth response of Pomacea maculata and Pomacea paludosa

Biological invasions can alter species assemblages by shifting the interspecific competitive balance and altering habitats. Pomacea maculata is an exotic snail that has successfully invaded ecosystems in Florida that also have declining populations of the native snail Pomacea paludosa. There has been some uncertainty as to whether those declines may be associated with competition from P. maculata. To test interspecific interactions, we examined four different interaction mechanisms, neutralism, chemical amensalism (i.e. antibiosis), direct competition, and visual intimidation, to investigate their effects on growth relative to controls. No statistically significant differences were found between controls and P. maculata and P. paludosa growth rates for neutralism (P=0.163, P=0.340), chemical amensalism (P=0.396, P=0.556), direct competition (P=0.144, P=524), or native visual intimidation treatments (P=0.863). Analysis on P. maculata specimens