Those are some amaising eels especially when they go crossing the length of the tank.
About 17 yrs ago i use to sell corals and fish,and suppliers fill your order to its max,so i received a blue ribon eel.
Had it survived 2years in a 6ft tank amaising to view although it ate all the damsels in that tank and i fed it feeder gopies and feeder gold fish,and a couple frosen sardines a week.
Unfortunately the eel found its way over the tank and thats how it ennded up apox. 20 feet away from the tank
I don't recomend bying the eel as their survival rate is quite rare.I was one lucky dude.