Animals kept in shape somehow (4)
I believe the answer is:
apes
'animals' is the definition.
(ape is a kind of animal)
'in shape somehow' is the wordplay.
'in' says the answer is hidden in the clue.
'APES' is hidden within 'shape somehow'.
'kept' is the link.
(Other definitions for apes that I've seen before include "Zoo animals" , "Imitates like primates" , "Mimics like primates" , "Large primates" , "Parrots" .)