Can new fish make other fish more aggressive?

[mnat]

In our 30G we had a pair or picasso clowns, an orchid dottyback, a mandarin, and a goby/pistol shrimp pair. They all got along just fine and the orchid was never ever ever ever aggressive. In fact he hid most of the time whenever we were around. We added a coral beauty angelfish to the mix and now our mandarin is dead. Reading around, it is pretty much stated that dwarf angels and mandarins SHOULD get along. However, what I feel happened is that the coral beauty was chasing the orchid out of his normal hiding spots in the back of the tank to the front. We have seen much more of the orchid than we usually have.

Now my questing comes down to if the coral beauty made the orchid more aggressive and attacked the mandarin or maybe the coral beauty did it on his own. All we know, we are pissed as the mandarin was our favorite fish. How do we know something attacked the mandarin and he just did not starve to death? We have pulled him out and examined him and the has chunks of fins missing and his dorsal fin that they stick up is all shredded. Also, he is not emaciated and was acting normal up until we saw him basically on his back. We have quarantined the orchid in a breeder thingy inside the 30g and we are contemplating selling him and getting another mandarin. We hate losing fish. :'( :'(

 

[qwik]

Sorry to hear that, I would sell the dotty and get another manderin like you said . Manderins are also one of my favorites After adding a pair of clowns to my tank my hippo tang now is acting like he has rabbies . He was perfect and peaceful and is now chasing everything and nipping at my sps and clam . Funny thing is he is not bothering the clowns ?? Hope you resolve your problem.

 

[Gecko]

How old was the mandarin and did it acclimate well? They can be difficult.

 

[Phyl]

I think that any time you add a fish you upset the balance and the selected hiding spots. That can most certainly cause fish to behave differently as the stresses on them have changed.

 

[mnat]

Well the dottyback will just have to be sold. We had the mandarin for over 5 months and we put more effort into making sure that fish did well due to their needs. At least we will be more prepared for the new one.

 

[Dave]

To your core question, I agree and have first hand experience of a new fish making other fish aggressive.

Regarding Mandarin. Did it eat food other then copepods? Were you supplementing copepods? I have heard 1 year in captivity for these fish before you can consider yourself successful.

30 G is generally considered too small for Mandarin, but this is assuming your fish is only eating copepods naturally generated within your tank.

 

[mnat]

The mandarin was on live copepods which we supplemented with live brine that we cultured. We also bought copepods to make sure we had enough in the tank. We also had him eating some of the rods reef food.

 

[Dave]

Sounds like the Mandarin was fat and happy on the food.

 

[JRWOHLER]

Yes for sure adding a fish can make others more Territorial/aggressive.

There is a solution that will make some LFS happy, upgrade your tank size.

I have a bi-color pseuodocromis...in a 24G nano he was a TERROR. In the 120 he is sort of shy and reserved.

The dottyback may have been responsible or could have even been the angel as they have similar behavior going around picking on rocks and such. I would be careful with the angel and the mandarin as they will end up competing for food sources.

 

[Baxreefs]

A short responce to the initial question .... YES! any new additions can make existing fish CRAZY!!!

But here's a story for you. My first tank was a 26 bow. I had a pair of o. clowns, with an RBTA, several clams, an orchid and a coral beauty ( a very small juvi) in it for over a year, nearly two. They were great tank mates. I still have the CB and one of the clowns over five years. The only extra fish I tried in that tank, resulted in death, I never tried again.

I think, if you want the Mandarin, and I don;t blame you for that desire, loose the OD & the CB for long term success. Your feeding regimen may just be your key to success. I am still not bold enough to try a mandarin even in my last 120 up for 3 years. I am in the camp of a well established, larger system for these for long term success.

Keep in mind the fin damage may have occurred post mortem ... yeah, ... right, ... and now I am a CSI!!!

 

[mnat]

When we found the mandarin he was laying on his back and we thought he was dead, but when we scooped him up he was still alive. Unfortunately he was beyond the point of no return and we just separated him until he passed away a little while later.

I put the orchid up for sale and I know he is going to a good home, as I have sold to the same guy several times. The coral beauty is a bigger one that kind of grew in the bag on the way home with my fiancee. It was going to be bound for the 20g but when we got it home we realized it was way to big and into the thirty it went.

The key now will be patience not to add too quickly. I was this close to adding a bluespot jawfish the other day, but we have no canopy over the 30 g and I was talked out of it at the LFS. We have now been scheming how to cover the tank.