LionFish says.......
This is often a common thing to see. Technically, you can name any eel you want a snowflake eel. There are some fresh/brackish water eels that are referred to as snowflakes but it is a rarity to find one in a store. Most likely this was a stupid mistake but I truly and firmly believe snowflakes should be kept in good-quality saltwater but some people put them in Brackish water. Usually the eel dies within months or even weeks. Pretty pathetic but it is seen every once in awhile. I have seen it once and sure enough, it was a snowflke in with Archers and Scats. But, the snowflake is best in a saltwater tank, and that is a fact.