I think some of you are getting mixed up with power that comes for size, the question was pound for pound. Think of the power that a salmon or sea trout needs to launch it’s self up a waterfall or rapids, and the stamina to sustained the effort needed to travel up a river in full flood
It's difficult to put eels and rainbow trout together.
I have caught a few half decent eels in my life and the last thing any of them has ever done is run off 50 yards of line and then jumped 4 feet in the air.
However an eel can swim backwards. And is capable of wrapping itself around the nearest snag in a very effective fashion.
In open water, an eel can be quite easy to land, even on fairly light gear.
I saw a huge eel of 7lbs landed on fairly light float tackle at a NASA fish in at Bluebell lakes some years ago.
i've had a double figure conger, in my opinion they are the hardest fighting fish followed by river carp and barbel.
trent carp fight like lunatics and ron i've had em run off over 100 yards of line on proper carp rods not floppy fly rods which don't have any stopping power.
i'm still not convinced that people say trout fight so hard because of the tackle that they catch them on, go catch a barbel on the same tackle then comment.
Tench fight hard but they also fight more intellegently than other fish and that for me makes them pound for pound the best fighting fish in UK freshwater.