Different parts of sea life (5)
I believe the answer is:
sprat
'sea life' is the definition.
(I know that sprat is a type of forage fish)
'different parts' is the wordplay.
'different' indicates an anagram (letters placed in a different order).
'parts' anagrammed gives 'SPRAT'.
'of' acts as a link.
(Other definitions for sprat that I've seen before include "'Set a . . . . . to catch a herring'" , "Small fish (used to catch mackerel?)" , "Strap up the small fish" , "Type of herring - small person or thing" , "little fish" .)