A novel epibiotic association in the benthic community: The sea anemone Verrillactis sp. (Actiniaria: Sagartiidae) on the necto-benthic fish, Inimicus japonicus

This is the first record of an epibiotic association between an acontiate sea anemone and a fish. We collected unidentified epibiotic sea anemones living on the necto-benthic fish Inimicus japonicus (Cuvier 1829) from the Seto Inland Sea, Japan. Molecular analyses revealed that the anemones were most closely related to Verrillactis paguri (Stimpson in Verrill 1869) sensu England (1971), which has a mutualistic relationship with hermit crabs. Therefore, we tentatively assigned the collected species as Verrillactis sp. (Actiniaria: Sagartiidae). This finding of sea anemones using fish as substrate is unprecedented. Future research into this relationship to determine if this is an incidental occurrence or facultative symbiosis is warranted. Our findings contribute to a wider understanding of symbiosis in sea anemones.