Zebra danio with wierd caudal fin?

[abrage22]

So I picked up 5 of these guys at my lfs the other day, all have normal tail fins, but theres one little guy whos got something like this: http://www.cuteandweird.com/wp-content/uploads/2010/08/zebrafish.jpg
It's actually quite a bit longer than that and he just looks so different compared to the rest. Is this something thats normal? He seems to be happy and healthy...

 

[absolutangel04]

He is probably a mix between a regular and a long fin zebra danio. Otherwise, fin deformities of various types are not uncommon in fish, but are not big deal if they do not impede swimming.

 

[abrage22]

Interesting, I thought it may be a mix of some type... And speaking of their fins, a serpae tetra of mine decided to just nip a big chunk of one of the danios fin off, great how am I supposed to prevent that from happening again.

 

[absolutangel04]

Well, the best way is to not own serpae tetras. They are notoriously nippy and not recommended as tankmates for anything with long-ish fins. Sometimes, people keep serpaes and they are good, peaceful community dwellers, but more often, they live up to their reputation of being fin nippers.
How many serpaes do you have? And what size tank? And what else is all in there?

 

[abrage22]

I have 5 in a 29 bowfront. I also have 1 molly, which they have NEVER bothered at all, 3 cories, which again have never been nipped at. But I've had 4 cardinals for a while, and just recently have had missing tail fin here and there, although I've never actually seen them get nipped at. And now my recent purchase of 3 scissor tails, and 5 of these danios haven't worked out well, 24 hours after I put them in, only the large scissor tail had a ton of torn fin. And just now tonight, I for the first time actually saw for myself them nip at a fish, that being a danio.

 

[absolutangel04]

Well, one option would be to up the serpae school to 6. Schoolers really do better in groups of 6 or 7 than in a group of 5. I know it doesn't seem like it would matter, but IME, it really does.
If it doesn't work to add 1 or 2, then I would recommend looking into rehoming the serpaes.
I think adding to the serpae school is a necessity if you want it to work.
Another option in addition to upping the schools is to turn off all the lights, wait, and then re-arrange all the decor and plants. That messes up the territories that the fish think they are protecting, so they all have to figure out how to love together and it can dispel aggression.