Other fish in the tank are yellow tang, naso tang, 2 clowns, 2 dart fish, lawnmower blenny, banded sand sifting goby, mandarin and 4 shrimp, as well as a number of various sized hermits (some pretty big). Haven't seen any aggression out of anyone except for a little from the yellow tang toward the mandarin when we added him last week and that was just a little fin flipping for the first 2-3 days.