Two bloodfins accidentally.

[Glenn407]

I recently picked up 8 embers and 6 glow lights to add the ones I already have. I quarantined them for two weeks in the only thing I have extra, a very large 'goldfish' bowl with a large plastic plant to make the embers happy. The problem is with the distortion on the bowl I didn't even notice till today when I introduced them to the tank that two of what were supposed to be either glow lights or Embers are actually bloodfins. Seems I was not paying close enough attention when she was netting them.

Question is will I have to get more of these now to prevent issues? They are in a 55 gal tank with primarily glow lights, embers and Harlequin Rasboras. They are sharp looking and would not mind if I had to add some but if not, that's fine too.

 

[Coryking]

If I was you I would get some more they probably won't attack or become aggressive to other fish but they may become aggressive to eachother

 

[Byron]

You have two options...return the two bloodfins, or acquire a group of 10 more (12 in total, though I might say 15 is minimum). This fish is prone to fin nip. All species in the genus Aphyocharax are feisty, some of them real killers in spite of their diminutive size. Increasing the shoal size is certainly needed if you want to keep them, or very soon you may seriously regret keeping them. There is scientific evidence that in groups less than 10, all shoaling species do show increased aggression, and a latency to feed--which is indicative of the importance of numbers to the fish.

Increasing the group will benefit the bloodfins. But now you have a species in the tank that will not generally tolerate sedate or long-fin fish, so it limits tankmates. You could not for example have gourami, cichlids, hatchetfish, etc in with these, that is like waving a red flag in front of a bull.

 

[Glenn407]

I guess they will have to go back. Don't have receipt so I guess I'll take the hit. So far the two keep their distance from each other and just swim around but it's only been a day.

 

[Byron]

I guess they will have to go back. Don't have receipt so I guess I'll take the hit. So far the two keep their distance from each other and just swim around but it's only been a day.

If you didn't ask for the bloodfins, and got two of them instead of two more Embers or Glowlights...they should give you the two Embers or Glowlights, take back the bloodfins, and call it square.

Fish that are programmed to be feisty/aggressive, may show the opposite in a new environment, but this will likely change and quickly. Overnight, meaning highly stressed fish.