They're all definately Pygos. Are all these fish the same kinds? The first pix looks like a baby Piraya, the 2nd looks also like Piraya with a red in the background, and the last.. uhm, if your inquiring about all of them, they are reds!!
i bought 3 new today and the guy at the LFS didnt know what specie, 2 yellow and one other. Before i had 5 natts in there bought them as red bellis but i dont know how much the guy at the LFS know about piranhas