UCB Moorea Class: Biology and Geomorphology of Tropical Islands

Parasites are ecologically significant organisms and must be understood to properly appreciate nearly any community. Parasitism is one of the most common (if not the most common) lifestyles, and parasites can influence species throughout a community. One group of parasites, the Eulimidae, is a large family of marine gastropods. Unfortunately, eulimids have not been thoroughly studied and host use behaviors have not been well characterized at the specific, or even generic levels. Therefore, this study seeks to describe host preference, host detection and tracking, and dependence on host access for two eulimid species, both sharing the macrohabitat environment. A series of experiments and a field survey showed that Peasistilifer nitidula was host specific, actively located hosts by chemical cues, reattached to hosts quickly, and required frequent access to the host for survival. Conversely, Melanella acicula had a preferred host but parasitized others as well, did not actively pursue hosts by chemical or visual detection methods, reattached infrequently in the short-term, and could survive longer isolated from the host. Using these aspects of host use to compare these co-existing species showed significantly different life histories, and suggests possible niche differentiation between a generalist and specialist species.