Damsel relentlessly attacking new goby?

[rennjidk]

20g system. Current stock:

2 ocellaris clowns
1 Caerulean damsel (maybe similar?)
1 Purple Firefish
1 Rainford's Goby

I added the firefish and goby today. The tank has had other inhabitants that aged out, including a long nose hawkfish.

I've never had an issue with adding peaceful fish, especially bottom dwellers over the years, but today when the small goby went in, the damsel immediately went on the attack. It's grabbing the goby by the lip and thrashing it. The poor 1 1/2" goby tries to hide, but is pursued mercilessly around the tank.

The damsel could care less about the firefish or other similar sized or larger fish. Is this a territorial display or is there some incompatiblility I missed?

And yeah, I know....damsels are jerks.

 

[Cthulukelele]

Damsels are absolutely relentless about bullying new additions if they can get away with it and don't have a boss fish keeping them in line ime

 

[dakoop]

Damsel=a$$hole

 

[Cthulukelele]

I think one of the reason damsels have the rep they do is their tenacity. If they decide to pick a fight, they fight morning, noon, and night until either it or the other fish are dead. It's really brutal to watch, and I think most people who've watched it happen are affected by it which leads to their reputation