Fish both need also to be skinned (4)
I believe the answer is:
eels
'fish' is the definition.
(eel is a type of fish)
'both need also to be skinned' is the wordplay.
'both need' becomes 'ee' (I can't justify this - if you can you should give a lot more credence to this answer).
'to be skinned' means to look at the middle letters.
The middle letters of 'also' are 'ls'.
'ee'+'ls'='EELS'
Can you help me to learn more?
(Other definitions for eels that I've seen before include "Odd fish found in the lees" , "Fish (that may be jellied)" , "Lengthy fish" , "They have long bodies and very small fins" , "Slender fishes" .)