added a small shoal (10) of rummynose tetra's to my tank. all was good for about a week but one of them has decided to go and constantly attack my Pearl Gourami. I've sat and watched and it's the same fish all the time. the Pearl is fine aslong as it stays in the corner or doesn't move but any crossing of the tank results in this one rummynose going after if with what looks like nipping over and over until the Pearl backs into the corner again. never had any problem with rummynose aggression before, do you think i've just got a rogue psycho fish or are rummy's known for this?