Reels in long form of sealife (3)
I believe the answer is:
eel
'long form of sealife' is the definition.
I can't tell whether this definition defines the answer.
'reels in' is the wordplay.
'in' indicates a hidden word.
'EEL' is hidden in the letters of 'reels'.
Can you help me to learn more?
(Other definitions for eel that I've seen before include "Elongated fish" , "Snaky fish" , "Long smooth fish" , "Electric swimmer, perhaps?" , "Slimy fish" .)