dying zebra danio

[jiggerpolebill]

im currently in the process of putting down a zebra danio(freezer method). ive lost about 4 of my original 7 that i used to cycle my tank one year ago. all other fish in this tank are doing beautifully(including the remaining danios). the one thats dying now kept getting behind a powerhead and was unable to get back out. his fins were ripped to shreads and his tail almost completely gone. when i freed him from the powerhead, i noticed another danio nipping at him and then a neon rainbow started attacking him as well. he got away but was laying down on his side behind a plant, not moving much at all. he wouldnt eat and appears to be emaciated(sp?), so i decided he had suffered enough and removed him.

does anybody know the life expectancy of these fish and what are actual experiences with them? i have read before as much as 7 years, but im wondering what an actual average time is for them. thanks for any info/advice.

[kveeti]

I had long-finned zebra danios that lived between 4 & 4-1/2 years. I thought that was good, but not really, I guess, if the 7 years you quoted was right.

[yashinfan]

3 or 4 yrs for danios are their typical life span. I don't think that nipping by other danios is enough to shred tails but they do like to chase one another. Maybe the rainbow was enough to do this? I think you should look into what caused the fin-shredding to make sure it doesn't happen to the rest of your danios!

[KateA.]

For what ever reason, this danio was weakened and the other fish knew it and pestered him. What started it is anyone's guess. Just might want to double check your water params and make sure all is well there. Also, if you think there is excessive nipping going on, provide lots more hiding places with rocks and plants.