Better line developed for fish (7)

I believe the answer is:

capelin

'for fish' is the definition.
(capelin is a kind of fish)

'better line developed' is the wordplay.
'better' becomes 'cap' (I've seen this before).
'developed' indicates an anagram.
'line' is an anagram of 'elin'.
'cap'+'elin'='CAPELIN'

(Another definition for capelin that I've seen is " fish".)

I've seen this clue in The Telegraph.

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