Trophic interactions and isotopic niche of octopuses and sea stars in North Patagonia

• Published in: Marine Biology
• Main Authors: Storero, Lorena Pia, Ocampo Reinaldo, Matías, Narvarte, Maite Andrea, Iribarne, Oscar Osvaldo, Botto, Florencia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer
• Subjects: Trophic interactions; isotopic niche; rocky shore; octopuses and sea stars; North Patagonia; https://purl.org/becyt/ford/1.6; https://purl.org/becyt/ford/1; Patagonia; Argentina; Ocampo; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/11336/113970

Coexistence of species is associated with differentiation of niches and partitioning of resources, which lessen niche overlap and the intensity of competition. Here, we used stable isotope analysis to evaluate and compare the trophic relationships and isotopic niche of two coexisting predators, the small octopus Octopus tehuelchus (d’Orbigny 1834) and the brooding sea star Anasterias antarctica (Lütken 1857), in the rocky intertidal community of northern Patagonia (Argentina). Our results show differences in the proportional contribution of sources between octopuses and sea stars. Octopuses consume mainly sessile filter-feeders, and sea stars show intra-specific diet differences, changing its preference with size and sex. Small and medium sea stars feed on sessile filter-feeders, such as small mussels, while large sea stars consume more frequently grazer gastropods and scavenger crustaceans. In the food web of the rocky north Patagonian ecosystem, differences in the isotopic niche space and the degree of dietary specialization between octopuses and sea stars indicate differential use of resources and trophic niche partitioning, possibly by limiting inter- and intra-specific competition. Fil: Storero, Lorena Pia. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina Fil: Ocampo Reinaldo, Matías. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación ...