Ecological notes on Actinostella flosculifera (Le Sueur, 1817) (Cnidaria: Actiniaria: Actiniidae) in the South-western Atlantic, Brazil

Sea anemones have developed various strategies for interspecific interaction with other organisms and their own ability to obtain food, due to their coevolutionary history, ranging from mutualistic (e.g. clownfish, crustaceans, etc.) and symbiotic associations (zooxanthellae or zoochlorellae) to depredation (e.g. sea slug). This study aims to record some observations on feeding habits and interspecific interactions of Actinostella flosculifera (Le Sueur, 1817) in the locality of Pedra da Sereia in Vila Velha, Espirito Santo, Brazil, and to describe the hunting strategy of the sea slug Spurilla braziliana MacFarland, 1909 and the escape strategy of A. flosculifera. We found that the habitat of A. flosculifera is characterized by shallow pools similar to 10 cm deep at low tides, and this functions as a trap for many organisms and some biowaste (e.g. bones or fish drifting in from nearby populations) that fall into the oral disc. This is the first report of S. braziliana predating on A. flosculifera. We also report interspecific relationships between A. flosculifera with four species of crustaceans: Omalacantha bicornuta (Latreille, 1825), Menippe cf. nodifrons Stimpson, 1859, Alpheus cf. angulosus McClure, 2002, and Alpheus cf. carlae Anker, 2012.

Automated summary

This study aims to observe feeding habits and interspecific interactions of Actinostella flosculifera and describe the hunting strategy of Spurilla braziliana and the escape strategy of A. flosculifera in Brazil. The habitat of A. flosculifera is characterized by shallow pools that act as traps for organisms and biowaste. This is the first report of S. braziliana predating on A. flosculifera, and interspecific relationships with four species of crustaceans were also observed.