Crew devoured a little exotic sea creature (7)
I believe the answer is:
manatee
'sea creature' is the definition.
(I've seen this before)
'crew devoured a little exotic' is the wordplay.
'crew' becomes 'man' (both can mean to staff or operate something).
'devoured' becomes 'ate' (to devour is to eat).
'a little' indicates taking the first letters.
The initial letter of 'exotic' is 'e'.
'man'+'ate'+'e'='MANATEE'
(Other definitions for manatee that I've seen before include "Large swimmer" , "To find sea cow" , "Sirenian mammal" , "water animal" , "A neat me (anag) - large aquatic mammal" .)