It is a fresh water shrimp. this is how I feed them to my sun coral. Turn off light and wait for it to open. Defrost mysis in a little bit of tank water. Rinse it to get ride of impurities, turn pumps off, use turkey baster( not your wifes, you'll need to get a new one
) then gently squeeze the mysis into the open polyps. If the fish come, gently tap them with baster, they won't hang around. Good luck