Rasbora Agression?

[Umberle]

I had 3 harlequin rasboras...and then I added 3 more to make a school of 6 since I know that they like to school. This morning one was missing and now the three original rasboras are staring down the two new ones who are hiding in a cornor behind a decoration. All five of them are being very still.

the new ones are smaller than the orgininals, is that why this is happening? What should I do? Would putting the newer ones in a breeder and feeding them up work?

 

[Pleco]

Sounds like there was a hierarchy among the old rasboras and when you added 3 more it kinda upset it. Unless you see fin nipping or acts of aggression it could just be that the fish are getting used to the tank.

-pleco

 

[Devilishturtles]

I agree. Likely will pass once they get used to each other. I hope anyways!

 

[Umberle]

Should I go ahead and replace the one that went missing now or wait until they get it worked out?

I've looked everywhere and while I can't find a body, I'm pretty sure he's not hiding somewhere either.

 

[Umberle]

...and then there were four. We mourn the passing of sally the rasbora who was found dead near the filter intake....

so yeah....I think they are getting bullied. :-(

 

[triazole]

when were the new ones added? did you QT them?
i've found rasboras to be slightly touchy fish, all of which won't survive the acclimation period even in an established tank. but the ones that do, are really hardy, and would survive through almost anything.

 

[Umberle]

they were added Sunday, they were not quarantined, mainly because I don't have another tank for it yet....long story there. I don't think it was something from the lfs as they were fine until Tuesday and it's definitely the bigger rasboras picking on the little ones. Water params all normal. The only thing going on is the big ones chase the small ones in a corner and 'guard' them. I caught some fin nipping this morning right before I left.

All the rest of the fish I got at the same time from the same place are doing really well.

 

[sudz]

I bought my girlfriend 3 of them... 2 of them died from bullying, the third died from an african dwarf frog, or was just so weakened that he died and the frog was caught eating him. :-S
As well, i find they are very prone to "missing" eyes. at the fish store. They're pretty, but i don't think i'll attempt them again.

 

[Umberle]

*nods* I actually had very good luck with them in my last tank. The major differences though are that in my last tank I bought them all at once and the tank was fairly heavily planted.

I'm trying to decide at this point whether to try again with bigger rasboras or more rasboras....I'm wondering if the new ones out number the old ones if less bullying will happen? Or if they are closer to being the same size? These guys were significantly smaller than the originals.

 

[sudz]

same size will definately help. I find even with angles, and gouramis... if the size varies too much, the bigger one will ALWAYS chase the little ones. When they're all even sized... its like they're all equal "threat" to them, so they don't tire out any one fish, but all the fish are chased equally

 

[triazole]

yup, numbers would definitely help spread the aggression, if that's the major reason. hmm, some more cover maybe? but i've really had no issues with aggression so far. i was thinking of adding more to my brood, now i'll have to think carefully...

 

[Umberle]

I really like the Rasboras so I'll try adding...let's see 5 that are closer to the same size....if it makes a significant difference than I'll definately let y'all know.