99.4 Saturday, Jan. 7 Does predation by leeches inferred from chemical cues impose any appreciable costs on their snail prey? WETHINGTON, A R; Chowan University firstname.lastname@example.org
Physa acuta, a prominent member of freshwater ecosystems, is known to have morphological, life history, and behavioral responses to both fish and crayfish predators. However, less is known about physid response to leech predators that are commonly found in close proximity to P. acuta and their egg masses. Leeches wrap around a snail, invade the snail’s shell, and completely consume their prey, leaving the empty shell behind. Adult physids typically escape leech predation by violent shell swinging and sudden release of substrate to float away from danger. Physids can also crawl out of dangerous waters for short periods of time. Since juvenile physids are more vulnerable to leech predators than adults, effects that leech predation may have on a physid’s life history and reproductive behavior was studied. Generally, snails that were reared with predatory leech cue (fed conspecific snails) experienced a delay in reproduction. Snails also delayed their reproduction in the presence of crushed snail cue. Snails did not exhibit any size or shape difference over time when exposed to leech cue, although snail growth was depressed over time in the crushed snail treatment. All treatments experienced a similar number of crawl outs during mating trials. Both the cue from crushed snails and predatory leech fed snails caused a depression in the number of noticeable behaviors the snails displayed during mating behavior trials. Unlike the cue from crushed snails, the cue from predatory leech fed snails did not seem to affect mating outcomes when compared to a control.