Rodent biting skin of sportive monkey (8)
I believe the answer is:
marmoset
'monkey' is the definition.
(I know that marmoset is a type of New World monkey)
'rodent biting skin of sportive' is the wordplay.
'rodent' becomes 'marmot' (marmot is a kind of rodent).
'biting' is an insertion indicator (some letters bite or swallow others).
'skin of' says to hollow out the word (remove centre letters).
'sportive' with its centre taken out is 'se'.
'marmot' placed around 'se' is 'MARMOSET'.
(Other definitions for marmoset that I've seen before include "Small tropical American monkey" , "Turn morse mat over for the monkey" , "Monkey with claws" , "Primate" , "Somme rat? (anag)" .)