The other day I was browsing at my local Petco and I saw something unusual (at least to me). Inside the tank for the Serpae Tetras were a fish that looked exactly like a normal Serpae but missing the black spot located just behind the head. There were normal looking Serpae in there as well.
I asked one of the employees and he has a handful of guesses:
1) "They are females" - this didn't seem right to me. I recall reading that gender had something to do with the dorsal fin, but I wasn't sure.
2)"They are stressed"- again, didn't seem right. Other than the missing spot, their coloration was fine as was their behavior.
3)"They may have been breed that way" - I have no idea what can and can't be done with selective breeding, but why would somebody even want to remove something like that?
My own guess was that perhaps it was a different fish altogether.
Has anybody seen a fish like this before and have some insight? Again, they looked identical to a typical Serpae Tetra except they were missing the black, sorta diamond shaped, spot on the body.