FWIW, I am fairly confident that that anemone is an E.quadricolor, AKA bubble tip, AKA BTA which is a naturasl host for maroon clowns. If you could get a pic of the underside of the oral disc, I could confirm. For feedings, there is a commercial food out there that when it first originated, the guy had anemones in mind. For the most part, it has small hunks of shrimp, scallop, oyster, clam , etc, but also has a lot of much smaller particles more like what is actually found in the gut of wild anemones.