HR: 1330h
AN: NB33Q-12    [Abstracts]
TI: Life History Variation in Invading Applesnails (Pomacea canaliculata) May Pose Ecological Threats to Wetlands
AU: * Marfurt, R K
EM: marfurtr@southwestern.edu
AF: Southwestern University, 1001 East University Avenue Department of Biology, Georgetown, TX 78626 United States
AU: Boland, B B
EM: bolandb@southwestern.edu
AF: Southwestern University, 1001 East University Avenue Department of Biology, Georgetown, TX 78626 United States
AU: Burks, R L
EM: burksr@southwestern.edu
AF: Southwestern University, 1001 East University Avenue Department of Biology, Georgetown, TX 78626 United States
AB: In native habitats, channeled applesnails (Pomacea canaliculata) graze periphyton. However, casual observations from introduced populations suggest these invaders show variation in feeding ecology, predator response and life history strategies. Attempts to predict this consumer influence on ecosystem function suffer from a lack of basic data. We tested how salinity affected snail mortality. Both adults and hatchlings tolerated salinity levels up to 8 ppt. Adult feeding on lettuce increased significantly at 8 ppt compared to 0 ppt (p = 0.002), while hatchling consumption of algae did not vary (p = 0.284). To see how these consumers responded to predators from the invaded ecosystem, we tested behavioural responses to predatory cues from fish, turtles, crayfish and adult applesnails. Results indicated that fish and crayfish prompted similar predator-avoidance behaviors in hatchlings (p's < 0.05) and that hatchling response changed over time. Consumption rates of juvenile redear sunfish did not vary (x2, p > 0.05) between native (ramshorn) and exotic applesnails, whereas adult fish consumed more applesnails (x2, p < 0.001). Our current efforts focus on examining if predator presence or macrophyte choice alters applesnail feeding rates. Research providing insight into the basic ecology of applesnails can foster management efforts at the ecosystem scale.
UR: http://www.southwestern.edu/~marfurtr
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly