Feeding preference of exotic snails Pomacea canaliculata on macrophytes in constructed wetland: Implications for biological control of invasive species
Journal
Journal of Taiwan Agricultural Engineering
Journal Volume
60
Journal Issue
1
Date Issued
2014-03-01
Author(s)
Wang, Tzu Ting
Abstract
Constructed wetlands are widely developed in Taiwan to compensate the lost and degraded natural wetlands due to human impacts and simulate the natural wetlands to provide many different ecosystem services such as water purification, climate regulations, wildlife habitat, and human recreation. However, biological invasion has become a serious threat in constructed wetland ecosystems because of their relatively low habitat stability and complexity. Nowadays, exotic apple snails (Ampullariidae: Pomacea canaliculata) have invaded most of the constructed wetlands in Taiwan and caused serious problems to the ecosystem including lowering the wastewater purification efficiency by extensively feeding on the macrophytes, competing with the native gastropods, and causing visual impacts due to their over-dominance in the constructed wetland habitats. In this study, we hypothesized that apple snails had different food preference on different macrophyte species and produced different growth responses correspondingly. We conducted laboratory feeding experiment to study the growth responses of apple snails upon feeding on 3 common wetland macrophytes including Ipomoea aquatica, Acorus calamus, and Phragmites australis. Results from ANOVA and Tukey Test showed that I. aquatica supported the highest growth rate of snails in terms of shell length and biomass increment. Pomacea canaliculata demonstrated significantly lower feeding preference on A. calamus and P. australis. However, results from regression analysis indicated that snails feeding on A. calamus showed the lowest growth rates. We therefore suggested that A. calamus would have the potential importance in controlling the establishment of P. canaliculata to the constructed wetlands. Our future work will involve analysis of the chemical and physical properties of macrophyte leaves to assess the relationship between food quality and food preferences of the apple snails. Our results could therefore provide implications for macrophyte planting in constructed wetlands as biological control measure of the invasive snails based on the bottom-up biomanipulative approach instead of applying traditional methods such as using pesticides or labor-intensive physical removal.
Subjects
Apple snails | Biomanipulation | Constructed wetlands | Feeding preference | Macrophytes
Type
journal article