Feline in vessel eating black cod initially (6)
I believe the answer is:
bobcat
'feline' is the definition.
(bobcat is a kind of feline)
'vessel eating black cod initially' is the wordplay.
'vessel' becomes 'boat' (boat is a kind of vessel).
'eating' is an insertion indicator.
'initially' says to take the initial letters.
The initial letters of 'black cod' is 'bc'.
'boat' enclosing 'bc' is 'BOBCAT'.
'in' is the link.
(Other definitions for bobcat that I've seen before include "Small N American lynx" , "Kind of lynx" , "Wild animal" , "North American feline" , "American native" .)