Pregnant?

Question
I have a pink White Skirt Tetra and a Black Skirt Tetra, the Black skirt tetra is very fat. Is it possible they bred together?

Answer
tetra lay eggs, the female will swell with eggs whether there is a male or not.

tetra eggs are hard to hatch and raise as most of the time if a male fertilizes the eggs after they have been laid, the adults will eat the eggs, also the aquarium light burns the egg, as the shell is extremely thin, you would have to be very experienced to raise them succesfully.