I have seen some very big, healthy eels that have been in aquariums for 8 - 12 years....first time I hear of this statement. I know some are difficult to keep like the ribbon eels. But as far as eels in a reef.....Snowflakes, Zebra, Banded eels can be "fairly" safe in a reef.....they can eat smaller fish and inverts, but from questions I asked....answers I received...these are the ones that were recommended to me. Sorry, i have no pictures.