Cuz jackasses were releasing the snakeheads into lakes, ponds, and etc. and the snakeheads began wreaking havoc on the ecosystem. They were eating all the native fish and such and snakeheads are HARDY fish so they were pretty much taking over. I think the deal with this mainly is that snakeheads are inexpensive for the most part. hell they are used as feeders A LOT OF THE TIMES, so its easy to get them and the Reds when to large, get released by people who cant care for them properly. Aimara on the other hand are very rare and whoever can afford to buy one is def. going to be able to care for it, and VERY MUCH LESS LIKELY TO RELEASE THE $2000 + fish....IMO