How do you tell a long fin eel with a short fin eel?

if the animal is alive and over about 20 cm it will tug and pull at it then do the death roll until its dead and then rips it apart and then swallows it. but if it is either dead or small enough to...

The ''Long fin eel pumps water over its gills to ''breathe. They take oxygen from the water before pumping out of its body. They can also breathe through their skin.''''

no they dont have fins i think

Because eels are like the snakes of the ocean, pure muscle that constricts and flexes to wiggle their bodies and propel them forward

snakes and other living things