Damselfish beating up my other damsel

[rappo]

So I'm setting up my first tank, I have plenty of live rock, levels are good, yadda ya. After a week with just the rock, I introduced two damsels. They're commonly called "yellow-tailed damsels" but I've found out they're actually half-yellow blue damsels, or Azure Damsels. (blue body, yellow tail, but small portions of the fin have yellow).

One of them started to shift the sand around to his liking and made a burrow under a rock. I had left for the weekend, but left someone else in charge of making sure everything was ok. Everything was fine until Sunday, when the damsel that made a home for him/herself started attacking the other. s/he chewed off the back tail completely and most of the left fin. As of this morning, the other guy couldn't even swim, he just kinda floated around in the current and pushed himself around with his good fin. Seeing as how this is my first and only tank, I couldn't contain him. I had placed two spotted damsels in the tank yesterday, after doing some reading online that damsels should not be in groups smaller than three. I'm fully expecting that injured fish to die from this whole fiasco. What do i do with this bully of a fish if he doesn't calm down? Is there something I'm doing wrong or something I could do to resolve this?

Please help :D

[Billybeau1]

Damsels are devils. They do not tolerate having another damsel of its kind. He will likely terrorize any fish his size or smaller. Mine did the same thing. Maybe your lfs will take him for trade.

[chopsuey]

Dont add any more fish. Complete your tank cycle with the damsels you have. More of them may die before your tank completes the cycle process. After yuor tank cycles then re-move all of the survivors and re-turn them to your LFS for credit toward new fish.

[Ocicat]

Get some Vita-Chem - it will help the injured fish regrow his fins.

[rappo]

Thanks for the advice so far. I just got home and my injured yellowtail is dead, as I expected. The mean one is still being mean to the other two, but they're much faster than him and he's not being nearly as mean this time around. (before he would bite off the tail and then spear the fish in the side until it gave up)

I'll keep these three and see how things go. If he keeps up being a jerk, I might see if I can trade him, it's not worth keeping him in my tank.

[Marinemom]

Damsels are terrible and it is likely that the damsels will kill anything else that you want to put in the tank. If I were you I would return the damsels, since it is not recommended that you cycle with fish anyways. Do you have live rock in the tank? If you do, then you can cycle the tank with that. After the cycle than wait a few weeks and always keep an eye on your water peremeters. Then add some inverts for the tank. It will probably be ready for them at that time. After a few weeks then you can think about what fish that you want to have in your reef. Just remember to please go very slooow in this. The rewards will be wonderful if you wait it out.

Hope this helps.

Marinemom

[kraze3]

Were these 4 damsels in a 12 g nano. I wouldnt put any damsels in a 12 g its too small and they are too aggressive. They will probably kill everything you put in the tank. I had 2 blue and yellow damsels in a 75 that were killing all new fish. Your better off taking them back now, letting your tank cycle, then focus on the fish you really want to keep.

[meco65]

Damsels are just mean fish and this is to be expected.

[saul]

i had damsels for a year after setting up my tank, but then all of a sudden they snapped and starting hurting themselves and other fish.... i ultimately had to catch them and take them back to lfs. you can avoid this by taking them out sooner.

[gigiba]

Damsels are evil fish and they are cheap. I would just take them back to lfs.