DerpPH said:
I think its growth has been stunted. I have seen various stunted fish. Just like those. Well no helping him now. Best thing to do to be able to stop his suffering is to euthanize him.
This made me laugh...then I realised you weren't joking
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I've also seen many, many stunted and otherwise deformed fish and to me this looks just like a small genetic mutation, I've gotten a couple of fish like that when I've bred danios in the past, I currently have a leopard danio with a kink in its tail similar to this rasbora. Its deformity clearly gives it no grief.
Also, even if the fish WERE stunted - "It is actually an incurable disease." what the heck? I'm usually the one that's lecturing people on the dangers of stunting, especially of keeping cyprinids like goldfish, silver sharks, tinfoil barbs etc in too small aquaria - but that's just a strange and sweeping claim to make. Stunting can have many different physiological effects on the fish depending on the individual situation - some fish recover easily and grow fast, some are stunted permanently and some may have long-term internal damage as a result. However, in my experience, most stunted fish can live a very happy and long life with a caring new owner!
In addition, the OP just recently bought the fish from the LFS, its highly unlikely they have been there in the LFS tank long enough to be stunted! LFS fish have tendency to be sold or die before they can be in a display tank long enough to be stunted - especially a common cheap community fish like scissortails.
Give the poor scissortail a chance, it looks healthy enough to live a happy life and I guarantee you it will grow a lot!
Please don't euthanize..if you are really that picky about looks, find a new home for it or take it back to the LFS.
Edit to add: IMO a 20gal tank is too small for scissortail rasoboras anyway - these are very active and fast moving fish that should be kept in a proper shoal and get to 5" long chunky fish. I would return all 4 of them to the LFS to swap for a 6+ shoal of a smaller species, like 10 x harlequin rasboras. Otherwise YOU could possibly end up stunting the fish, and besides, its too small a tank to see the best of their behaviour.
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