I have 210 fry. I have got a batch of fry that came from my red platy, well 2 fry out of 30 (their almost grown now) 2 of them has what looks to me to be a sword growing out of the middle of there tail fin...it is about 1/2 longer than the tail fin. but out of the middle not the bottom like a sword. Has anyone seen a fish like this, and if so what is it called. It would be great to have raised a new strain of fish. thanks