Fish whose heaviest species is the European conger (3)
I believe the answer is:
eel
(Other definitions for eel that I've seen before include "Sea creature like conger" , "Proverbially slippery fish" , "Apode" , "Slimy fish" , "Wriggly fish" .)
I believe the answer is:
eel
(Other definitions for eel that I've seen before include "Sea creature like conger" , "Proverbially slippery fish" , "Apode" , "Slimy fish" , "Wriggly fish" .)