I know this is an old post but I just was reading through and saw things about an eel that I have had for 13 years.
I have had the same Tesselata eel since 2004. I purchased it from someone that could not keep it anymore due to his tank size. I think he had a 180 tank. I owned a 180 tank for a number of years and this eel would not do well in a tank that size.
The main tank that the eel stays in is almost 300 gallons. So it has plenty of room to swim around if it needs too and plenty of coral to hide in. I have had this tank for about 18 years. It used to be a display tank in a Mall.
Feeding the eel can be the most difficult task, at least for me. Having it this many years you find it gets bored on what you are feeding it after awhile. And beings I do not live close to fresh fish markets I have to drive 2 hours south and pick up 20 to 30 lbs of fish and freeze them for future use.
Most of what I feed it are large fish meant for people consumption. And I usually feed it 2 times a month. When it was younger it ate much more than that but with age it seems to pass up food so rather than waste it I make sure it is hungry.
A new trick I have found was using a flash light that strobes a fast flashing bright light. It seems to perk up the eel and get it to be more aggressive and I actually have been able to get it to eat more.
This photo is of Daisy about 8 years ago.