Will damsels lose interest in new tank mates?

Kalinina · Mar 3, 2023

I have 3 fat blue devil damsels (one is a loner and two are paired) in an 84x30x24 tank with a bunch of tangs. Today I received and acclimated lyretail anthias,
Chromis and firefish. The damsels are relentlessly harassing the new additions.

Has anyone had experience with aggressive damsels accepting new tank mates eventually? I’m thinking I will need to catch the 3 of them and put them into an acclimation box until the other fish are settled in.

I admittedly wasn’t expecting this. They are 10x worse than my tangs at accepting new additions.

TnFishwater98 · Mar 3, 2023

They can be bullies. I swore I’d never get another damsel after my first blue damsel. I now have a springer damsel because I’ve heard they have less attitude. So far no issues with the springer. My first blue damsel harassed anything that moved in my old tank and good luck catching them! Had to tear my tank apart to catch the one. GL

Crustaceon · Mar 3, 2023

Like most aggressive fish, they'll harass new fish, sometimes to death because they have access to them. A lot of times, you can prevent this by putting the new fish in a "critter carrier" and set in on the bottom of the display for a week or two. The damsels will go nuts but tend to give up their bullying after a while and start acting like the new fish was just there all along and isn't a problem. This is when you actually add the fish to the display, but while the fish is in the carrier, it typically won't care too much. It seems like they know the bully can't get to them and they chill out in safety.

Sebastiancrab · Mar 3, 2023

Another suggestion is to put the damsels in a baby cage for "time out" or temporarily in your quarantine tank. You might rearrange your rockwork. I use tulle netting from Jo Anne's to section off parts of my tank if I need to catch fish. The rule of thumb for damsels is they need to be the last fish introduced to your tank.

Kalinina · Mar 3, 2023

Great suggestions! I do have a large critter carrier. I never thought about sinking it to the bottom and letting it rest there for a few weeks with the new fish! I’ll keep that in mind for future additions.

I like the tulle netting idea. That will be my go to if I need to catch them for a time out. I would be open to screening them off in their end of the tank for a few days as well. The tank is acrylic and has eurobracing on the top, so my old go to of egg crate partitions isn’t an option.

I forgot to mention I rearranged a rock structure and that didn’t help, but I can rearrange more pieces to hopefully make a bigger impact.

TnFishwater98 · Mar 3, 2023

Kalinina said:
Great suggestions! I do have a large critter carrier. I never thought about sinking it to the bottom and letting it rest there for a few weeks with the new fish! I’ll keep that in mind for future additions.

I like the tulle netting idea. That will be my go to if I need to catch them for a time out. I would be open to screening them off in their end of the tank for a few days as well. The tank is acrylic and has eurobracing on the top, so my old go to of egg crate partitions isn’t an option.

I forgot to mention I rearranged a rock structure and that didn’t help, but I can rearrange more pieces to hopefully make a bigger impact.

Sounds like the best option might be catching the paired damsels. Leave the loner. See if the loner becomes aggressive once the paired has been separated. Once separated do a little more rearranging. After a bit either release the paired damsels back into DT or sell at your LFS.

Kalinina · Mar 3, 2023

Yep! I think that will be the plan TnFishwater98. I will keep them. I’ll have to do my best to have them cohabitate.

I was just doing some reading and I’m an idiot!!!!?!!!?!?! When ordering the blue devils years ago, I ordered them specifically because they are in the Chrysiptera family. And because of that, i was under the impression they are a peaceful damsel. Now I’m reading *they* are the exception!!! LOL.