Trophic ecology of the intertidal sea anemone Bunodosoma zamponii (Cnidaria, Actiniaria): diet composition, seasonal variation and trophic parameters

ERRALDE, STEFANÍA M.; ACUÑA, FABIÁN H.

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2020 vol. 92 p. 1 - 15

0001-3765

Sea anemones are important components of many benthic communities. Considered as polyphagous opportunistic predators, it is being suggested that their diet reflects the structure of the community they inhabit. The feeding ecology of intertidal species is an interesting topic to study due to their wide variety of food-obtaining strategies. In this sense, we studied the diet of Bunodosoma zamponii, the most abundant actiniarian in the rocky intertidal of Punta Cantera (Mar del Plata, Argentina). The objectives were to describe the diet of this species and analyze its possible variation between seasons and between daytime and nighttime high tides. We examined the gastric cavity content of 154 specimens collected in each season, at daytime and nighttime, identifying a total of 39 different prey items, some of which were first records for this species. The diet composition showed no variation between seasons nor between daytime and nighttime high tides, suggesting that the available food does not vary either. B. zamponii ingests mostly items with low average biomass, which contribute to the total biomass ingested in direct proportion to their frequency in the diet. The main prey was the bivalve Brachidontes rodriguezii, followed to a lesser extent by certain amphipods, other molluscs and algae.