pink spotted goby aggressive towards bicolor angel and foxface

[patricknco]

So I have my 30 gallon half moon. 3 fish as stated in the title. I feed them seaweed sheets and brine shrimp twice a day. Occasionally flake food.
The goby attacks and bites at the foxface and the bicolor angel. The new fish is the bicolor at 1 day. The goby has always been peaceful. Any ideas?

 

[zoidberg01]

Maybe it's territory