I actually have a 12-14 inch snowflake and chainlink right now. While they dont primarily eat fish, if the opportunity arises, it will without a doubt. Ive lost several green chromis and clownfish to those eels. I feed mine whole frozen shrimp 4-5 times a week, so it wasnt because they were starving. If a predator lives with potential prey, its only a matter of time until it makes a meal of them.