The truth about “territory” and a tank at peace.

[Glenner’sreef]

So I rarely buy fish anymore as the group of aquatic tenants in my 180g know their place and who’s in charge. 90% of the drama (if not more) has to do with….uh? You’re on my lawn!
So for a brief moment and totally out of character, I thought I’d purchase four more fish and just toss em in. Well not exactly. I did purchase four small Yellowtail Blue Damsels. And then introduced them to the tank veterans. Neither party cared all that much and went on with their lives.

Days later I noticed that the four Damsels equally separated themselves one from another. In equal sections of the tank. One damsel occupying the first 17/18” of the tank. The next damsel occupying the second 17/18” of the tank. And of course damsel #3 and damsel #4 staking claim to the two final sections of the tank.

They sometimes crossover into the next damsel’s territory but are quickly escorted away.

My personal opinion: It’s a nice look. In my decades of reef keeping, I’ve never noticed this this kind of separating? It’s usually just “aggression” wherever in the tank they are? Maybe “damsels” are becoming civilized?

 

[MnFish1]

So I rarely buy fish anymore as the group of aquatic tenants in my 180g know their place and who’s in charge. 90% of the drama (if not more) has to do with….uh? You’re on my lawn!
So for a brief moment and totally out of character, I thought I’d purchase four more fish and just toss em in. Well not exactly. I did purchase four small Yellowtail Blue Damsels. And then introduced them to the tank veterans. Neither party cared all that much and went on with their lives.

Days later I noticed that the four Damsels equally separated themselves one from another. In equal sections of the tank. One damsel occupying the first 17/18” of the tank. The next damsel occupying the second 17/18” of the tank. And of course damsel #3 and damsel #4 staking claim to the two final sections of the tank.

They sometimes crossover into the next damsel’s territory but are quickly escorted away.

My personal opinion: It’s a nice look. In my decades of reef keeping, I’ve never noticed this this kind of separating? It’s usually just “aggression” wherever in the tank they are? Maybe “damsels” are becoming civilized?

I think it's pretty common - and you have a nice tank. I would carefully watch as your damsels age - to be sure that there is no injury to your existing fish - as they will protect their territory. That said - I think yellowtails may be slightly less territorial. I think you took a risk just 'tossing them in without quarantine - depending on the source' - Sorry not a criticism - just a public service announcement

 

[Glenner’sreef]

I think it's pretty common - and you have a nice tank. I would carefully watch as your damsels age - to be sure that there is no injury to your existing fish - as they will protect their territory. That said - I think yellowtails may be slightly less territorial. I think you took a risk just 'tossing them in without quarantine - depending on the source' - Sorry not a criticism - just a public service announcement

Definitely true with aging damsels. Had 4 blue chromis. Two years later I couldn’t wait to get rid of them!!! The store I purchased from does a decent job quarantining their livestock.