Is it fishy in parts? (5)

I believe the answer is:

sprat

I'm a little stuck... Click here to teach me more about this clue!

'is it fishy' is the definition.
I can't judge whether this definition defines the answer.

'parts?' is the wordplay.
'parts' anagrams to 'SPRAT'.
But, I'm not sure how the anagram is indicated.

'in' is the link.

Can you help me to learn more?

(Other definitions for sprat that I've seen before include "Jack --, non-fat eater" , "Traps (anag.)" , "'Set a . . . . . to catch a whale'" , "Traps for small fish" , "Herring of the east North Atlantic" .)

I've seen this clue in the Evening Standard.

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