Trophic relationship and diet composition of a Patagonian gastropod and its epibiotic anemone: combined stable isotopes and conventional dietary approach

ZABALA, S.; BIGATTI, G.; BOTTO, FLORENCIA; IRIBARNE, O.; D. GALVÁN

MARINE BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2013 vol. 160 p. 909 - 919

0025-3162

The carnivorous snail Adelomelon ancillausually carries, attached to its shell, the anemone Antholobaachates, which also lives attached to hard substrates inthe same area. Interaction between both species was studiedby stable isotopes analyses (SIA), direct observations,and analysis of gut contents. Results did not show evidencesof dietary overlap between anemones and snails.A. ancilla consumed mainly bivalves and secondarilygastropods. The diet of A. achates involved sea urchins andechiurids as main prey. The trophic niches of anemonesand snails did not overlap; the species had similar d15Nvalues but differences in their d13C values. Sessile andepibiotic anemones also showed differences in their d13Cmeans, revealing access to different resources. WhereasSIA provided information on trophic relationships andstructure, observation of feeding events provided details ofprey utilization patterns. Combining direct and indirectapproaches helps to overtake method weaknesses andgreatly improve dietary descriptions.