Predatory behavior and ecology of Agaronia propatula, a marine gastropod predator inhabiting dissipative sandy beaches on the Pacific side of Central America
Abstract
Agaronia propatula (Caenogastropoda: Olividae) is a small gastropod predator abundant in the eulittoral zones of certain dissipative sandy beaches throughout the Pacific side of Central America. Despite this abundance, relatively little has been written about this species in literature. We studied A. propatula in its native habitat in both El Salvador and Costa Rica to learn more about how A. propatula is able to select and capture its prey along with what potentially constitutes prey. We also examined if there was a ratio between the sizes of each A. propatula and successfully captured prey. In addition to looking at what constituted A. propatula's prey spectrum, we studied its sensory capabilities to determine its capabilities of detecting potential prey items by tactile and/or olfactory stimuli. Finally, we examined A. propatula's ability to autotomize a portion of its tail in the context of determining whether it was an evolutionary response to conspecific predation. We found that A. propatula's prey spectrum consisted of a lot more than just Olivella semistriata (Caenogastropoda: Olivellidae) as was documented prior (Metz, 1995, López et al., 1988). Agaronia propatula appears to be an opportunistic predator, and with few exceptions, it will attack any small animal it encounters along the beach, even some that are not typically found in its environment. Agaronia propatula will also attack smaller individuals of the same species. We found that A. propatula can readily detect its prey from both tactile and olfactory stimuli as long as a stimulus occurs proximal toward the anterior side of the animal, with tactile stimuli being much more effective at provoking a response. We also found evidence that the adaptation of autotomy is not likely a result of conspecific predation based on observations that captured individuals reached the point of suffocation without autotomy occurring.
Degree
M.S.
Advisors
Peters, Purdue University.
Subject Area
Biology|Ecology
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