IBIOMAR - CENPAT   25620
INSTITUTO DE BIOLOGIA DE ORGANISMOS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Same old weapons against brand new enemies: A native anemone defensive mechanism can reduce predation from a novel invasive sea slug
Autor/es:
BATTINI NICOLÁS; SCHWINDT EVANGELINA; BORTOLUS ALEJANDRO; GIACHETTI CLARA
Lugar:
Buenos Aires
Reunión:
Congreso; Marine and Freshwater Invasive Species; 2016
Institución organizadora:
AEHMS and CONICET
Resumen:
The opisthobranch Pleurobranchaea maculata, native to New Zealand and SE Australia, was recently found in Argentina. These sea slugs are highly voracious and active predators that feed on a wide variety of invertebrates, especially sea anemones, which represent their main prey items. Natives Actinothoe lobata and Parabunodactis imperfecta are the dominant sea anemone species in the fouling and intertidal communities of shallow Patagonian waters, respectively. In order to determine if P. maculata preys on these two native sea anemone species, adults of these three species (predator and potential preys) were collected and transported to an experimental aquarium. Trials were performed in individual tanks, each one of them with three equal compartments associated to the following treatments: one prey alone, one predator with control food and one predator with one prey species. After a four day starvation period, 48 hrs feeding trials were performed and the percentage consumed was estimated for each prey. Although both sea anemone species were partially consumed, A. lobata showed a defensive behavior that tended to reduce the effect of predation. When initially attacked by sea slugs, A. lobata extruded their acontia, leading to withdrawal response by P. maculata. This behavioral reaction was not observed when P. imperfecta was attacked by P. maculata. This work presents the first evidence of a differential response shown by an introduced, voracious and invasive predator towards two native preys. The kind of defensive mechanism shown by A. lobata will surely not prevent P. maculata invasion success, but it may have important implications in the structure and dynamics of the benthic communities which it has invaded
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